Lewis Twiby's Past and Present

Paleo Profiles: Toxodon

In 1832 a young Charles Darwin on board the Beagle landed in Bahia Blanca in Argentina. There, he excavated some strange teeth, and when the expedition moved north to Uruguay some local farmers sold him a strange skull that the teeth belonged to. The extinct animal puzzled Darwin and when he returned to England he gave his notes and fossils to Richard Owen, the head of the zoology department at the British Museum who, in a few years time, would coin the word ‘dinosaur’. In 1837 Owen described the beast as Toxodon and Darwin would edit his notes to reflect the analysis:

Lastly, the Toxodon , perhaps one of the strangest animals ever discovered: in size it equalled an elephant or megatherium, but the structure of its teeth, as Mr. Owen states, proves indisputably that it was intimately related to the Gnawers, the order which, at the present day, includes most of the smallest quadrupeds: in many details it is allied to the Pachydermata: judging from the position of its eyes, ears, and nostrils, it was probably aquatic, like the Dugong and Manatee, to which it is also allied. How wonderfully are the different Orders, at the present time so well separated, blended together in different points of the structure of the Toxodon!

Darwin, Voyage of the Beagle, 87

Toxodon would be a puzzle to zoologists and palaeontologists for years to come, mainly as it belonged to a group of mammals that has gone extinct.

Discovery and Fossils

As we have just mentioned, the first fossils belonging to Toxodon were named by Richard Owen based off of the findings that Charles Darwin made on his trip on the Beagle. The first specimen to be described was given the scientific name Toxodon platensis meaning ‘Bowed tooth from La Plata’. The ‘bowed tooth’ came from the strange teeth that would puzzle Darwin and Owen, and ‘La Plata’ from Argentina. Due to how recently Toxodon platensis lived we have a lot of fossils belonging to this species, with some specimens that are nearly complete. Since then other species have been identified, but how many species there are has been debated. Up to 12 species are seen as valid by the Paleobiology Database, although some sources only classify six species as being valid. This post will largely be focusing on T. platensis, being the species we know most about, although do note that we are largely focusing on the largest Toxodon species.

Taxonomy and Evolution

A big reason why Toxodon was such a puzzle to palaeontologists was due to it belonging to a branch of mammals that has gone extinct. It was a member of the order Notungulata, or the ‘southern ungulates’. Ungulates are the hoofed mammals currently split between the ‘odd-toed’ ungulates like horses, rhinos, and tapirs and the ‘even-toed’ ungulates like deer, cows, boar, hippos, and even whales. Notungulata emerged as far back as 61 million years ago and evolved to become so unique due to where they evolved. Notungulata evolved in South America which had been isolated from the rest of the world for millions of years, only ending its isolation around 3 million years ago with the formation of the Isthmus of Panama. Notungulata would come to fill the void filled by other hoofed mammals and other herbivorous mammals in other continents with Toxodontids like Toxodon filling the role of rhinos, archaeohyracids filling the role of horses, and mesotheres taking the role of rodents. In 2015 DNA analysis finally answered the question of which mammals the Notungulata are most related to. They diverged from the odd-toed ungulates like rhinos and tapirs.

Biology

Toxodon were massive animals. They reached between 2.7 and 3 metres (8 to 10 feet) in length and weighed around 1,500 kilograms (3,300 pounds). This puts them at a similar body size to Indian rhinos, although white rhinos are much larger than Toxodon. A shoulder hump, which was the tallest part of the Toxodon, existed which would have limited movement of the neck. As a result, Toxodon would have been unable to lift its head too high so it would have kept its head low to the ground. The adults were so large that it would have been unlikely that they had many predators. For a long time it was believed that Toxodon lived like a hippo, mostly based on the nose, eyes, and ears being placed on top of the head like in hippos. The theory had it that Toxodon would have spent most of the day lounging and swimming in water, but this theory has fallen out of favour. Largely this is due to where Toxodon fossils being found which was not suitable for a hippo-like lifestyle. Isotope analysis also found that its bones contained isotopes more closer to that of terrestrial animals than amphibious or aquatic animals. Instead, Toxodon would have lived more like a rhino than a hippo.

Toxodon had a massive head, one almost comically large for its body. Equally unusual was its teeth which seemed to combine the teeth of both horses and rodents. The teeth were high-crowned like a horse with thick enamel and large molars. However, the top teeth and incisors were chisel-like, almost like a rodent, that seemed to constantly be growing. This is what really confused Owen and Darwin as this animal seemed to combine features from rodents and rhinos. It did also help Darwin to begin thinking about the nature of extinction and how animals were related to one another before he could arrive on the Galapagos Islands to study the unique finches and tortoises. These teeth evolved to let Toxodon eat as much vegetation as it could. The horse-like teeth were good for grinding with thick enamel allowing it to eat plants made of hard cellulose, as well as containing grit, without the teeth immediately being worn down. We do have evidence of teeth being worn from grinding. The rodent-like chisel teeth allowed them to snip off other species of plant. They were adaptable and from looking at isotopes in their molars we can find out what they ate. Toxodon were mostly grazers, but the type of plants they ate depended on where they lived. Those in southern Brazil and the Chaco ate more C4 plants, whereas those closer to the Amazon switched to browsing on C3 plants.

It is difficult to know about the behaviour of animals from just their bones. We do not know if they lived in herds, how aggressive they were, or when they were most active during the day. We can make a few assumptions – based on similar sized mammals they likely only had one calf at a time. While typically depicted with bent knees we now know that they walked with their legs straight, and we have evidence of strain on their legs in older specimens.

When and Where

Toxodon fossils first appear in the fossil record during the Pliocene, around 5.28 million years ago, and managed to survive until very recent times. The last Toxodon went extinct around 12,000 years ago at a time when humans were firmly starting to settle South America. They were found over a wide area in South America ranging from northern Argentina, Bolivia, and Uruguay in the south up as potentially as far north as Pernambuco in northern Brazil if a set of footprints turn out to belong to Toxodon. Toxodon and toxodontids managed to survive the ecosystem changes that came with the formation of the Isthmus of Panama. As northern mammals moved south many notoungulates went extinct, but the toxodontids continued to thrive with a relative of Toxodon called Mixotoxodon moving north to colonise Texas.

Habitat and Extinction

Toxodon were mainly found in grasslands and the edges of forests where they lived alongside a wide range of animals both familiar and bizarre. Some of the animals can be seen today like javelinas, jaguars, anteaters, and rhea, as well as truly unusual animals. These included the giant ground sloths, llama-like Macrauchenia, and giant armoured armadillos like Doedicurus. Smilodon would have potentially hunted Toxodon as their relatives in North America were hunting as equally large animals like bison. Around 12,000 years ago Toxodon began vanishing and eventually went extinct. The obvious answer is the arrival of humans, after all Toxodon bones have been found in a human habitation site at Tres Arroyos, Argentina. Human hunters would have introduced a new dynamic that resulted in Toxodon being unable to survive. However, this was not the only reason. As older and older archaeological sites are found in the Americas pushing back human habitation further the period of co-existence between humans and the now-extinct megafauna lengthens. Climate change associated with the end of the Ice Age impacted the entire planet, and this would have impacted Toxodon numbers. The mix of human hunting and climate change would have been enough to drive Toxodon to extinction.

Bibliography:

‘Toxodon Owen 1837 (notoungulate)’, PBDB Taxon, [Accessed 10/09/2026]
Michael Buckley, ‘Ancient collagen reveals evolutionary history of the endemic South American ‘ungulates’”, Proceedings of the Royal Society B, 282, (2015), 20142671
Donato Costamagna, Brenda S. Ferrero, Federico Giri, and Ana María Ribeiro, ‘Study of the shape and size in lower molars of Toxodon platensis (Mammalia: Toxodontidae) of the Late Pleistocene of South America’, Geobios, 88:89, (2025), 49-60
Ricardo da Costa Ribeiro, Angela Kinoshita, Hermínio Ismael de Araújo-Júnior, Ana Maria Graciano Figueiredo, Ismar de Souza Carvalho, and Oswaldo Baff, ‘ESR dating of Toxodon teeth from Baixa Grande, Bahia, Brazil’, Journal of South American Earth Sciences, 112, (2021), 103616
Darin Croft, Horned Armadillos and Rafting Monkeys: The Fascinating Fossil Mammals of South America, (Bloomington, IN: Indiana University Press, 2016)
Charles Darwin, The Voyage of the Beagle, (Santa Barbara, CA: The Narrative Press, 2000)
Renato P. Lopes, Ana Maria Ribeiro, Sérgio Rebello Dillenburg, and Cesar Leandro Schultz, ‘Late middle to late Pleistocene paleoecology and paleoenvironments in the coastal plain of Rio Grande do Sul State, Southern Brazil, from stable isotopes in fossils of Toxodon and Stegomastodon‘, Palaeogeography, Palaeoclimatology, Palaeoecology, 369, (2013), 385-394
Carlos A. Luna, Fernando H. De S. Barbosa, Romina Gonzalez, Ángel R. Miño-Boilini, Carolina Repetto, and Alfredo E. Zurita, ‘Bone diseases in a Pleistocene South American native ungulate species: the case of Toxodon platensis Owen, 1837 (Mammalia, Notoungulata, Toxodontidae)’, Journal of Quaternary Science, 39:8, (2024), 1206-1215
PBS Eons, ‘The Creature that Stumped Darwin’, YouTube.com, (01/09/2021), [Accessed 08/09/2026]
Gustavo G Politis, María A Gutiérrez, Daniel J Rafuse, and Adriana Blasi, ‘The Arrival of Homo sapiens into the Southern Cone at 14,000 Years Ago’, PLoS ONE, 11:9, (2016), e0162870
Donald Prothero, The Princeton Field Guide to Prehistoric Mammals, (Princeton, NJ: Princeton University Press, 2017)
Donald Prothero, Giants of the Lost World: Dinosaurs and Other Extinct Monsters of South America, (Washington, D.C.: Smithsonian Books, 2016)

Zoopedia: King Penguin

This week we’re looking at the second largest species of penguin, and one member of this species is a major general in the Royal Norwegian Guard. Quite fittingly, this is the king penguin, one of the most charismatic species of penguin and popular in aquaria all over the world.

Taxonomy and Evolution

King penguins have the scientific name Aptenodytes patagonicus which they share with one other species, the emperor penguin which we looked at here. A third species dating to the Pliocene, 5 to 3 million years ago, has been found in what is now Christchurch, Aotearoa which is currently the oldest known member of Aptenodytes. This was Ridgen’s penguin, named after the 11-year-old who found the bones. There is just one family of penguins alive today, and the order they belong to first appeared in the fossil record around 62 million years ago where they were already adapting to the water. By 40 million years ago they had evolved to be divers and some managed to get to large sizes, larger than the modern emperor and king penguins. There are some debates about whether king penguins have subspecies or not. CornellLab considers it to have no subspecies, but some sources will say that there are two: one in the south Atlantic and one in the south Indian ocean.

Biology and Behaviour

As mentioned, the king penguin is the second largest species of penguin after the emperor penguin reaching between 90 and 100 cm (2.9 and 3.3 feet) in height. They have average weights of 11.8 kilograms although some penguins have been found to weigh as much as 17.3 kilograms. Males are just slightly larger than females and the main way to tell them apart is their calls. They look similar to emperor penguins but are slimmer with bright feather colouration. They have a white front, black or gray back with certain parts of the flippers having black spots, a black head, and orange spots around the ears and just below the head. King penguins have a long beak which the underside has an orange or reddish spot that can actually reflect UV light. Juvenile penguins are a duller version of the adults, but the chicks look wildly different. They are effectively brown lumps of feathers, something to keep them warm before they molt and get their waterproof feathers.

King penguins are very sociable birds forming colonies exceeding 100 pengunins! During the breeding season these colonies merge so tens of thousands of penguins congregate together. In one part of South Georgia a colony has been recorded as reaching 150,000 birds! They are vocal birds, with them and emperor penguins having an organ called the syrinx to make calls. This organ has two parts which the penguins can move independently to produce a variety of calls, something needed with the giant colonies they live in. This helps them find their chicks and mates in such a large colony. King penguins share a similar biology to other penguins as a way to live in an aquatic lifestyle. Highly evolved wings have turned into a flipper to help propel them through the water. Several layers of intersecting feathers help keep them warm as they swim. The top layers are made of waterproof feathers while the bottom layers are thick, insulating feathers which keeps the birds warm. King penguins need this as they can dive into the water 100 times a day hunting for food.

King penguins become sexually mature at three years of age, although many do not breed the first year they become mature. A large part of the reason why is because penguins have to compete for both space and partners with the older, larger penguins. They are monogamous, but do not mate for life with only a third of penguins going back to one another year after year. Mates are chosen by plumage and calls, and before reproduction happens the males will bulk up on food. This is because when the egg is laid he will not be able to eat for over a month. When the egg is laid between October and December the parents will take some time balancing the egg on their feet, and when the egg hatches the mother leaves for a month. Around half of eggs and chicks do not survive. During this period males lose a significant amount of their weight, around 30%, until the females return and they can share the chick rearing. The chicks will spend a lot of time in communal creches returning to their parents for feeding, a process that ends when they become independent at 14 to 16 months in age. The success of a breeding cycle depends on when in the year the egg is laid – earlier layings are more successful than those who lay in December. Pairs that have failed breeding cycles are more likely to lay their eggs earlier the following year. We do not have a concrete lifespan for wild penguins, but captive ones can live for 26 years.

Distribution and Habitat

King penguins are not truly Antarctic species as they live on islands just north of Antarctica. These islands are more rocky than ice covered with their breeding colonies being on the ice-free beaches of these islands. Some do make their way down to Antarctica, but this brings them into competition with the emperor penguin who is adapted to the ice shores. Some are found on southern Chile and Argentina, but the biggest colonies are on islands with fewer to no land predators like Las Malvinas, South Georgia, the Prince Edward Islands, and Ile aux Cochons to name a few. Of course, the waters around these islands are still cold, but not as cold as the Antarctic. However, climate change is allowing king penguins to move further south into territory once the home of the Antarctic penguins.

Diet and Predators

King penguins have a diet that overwhelmingly consists of fish. Heavy bones help the penguins dive into deeper water to go after fish that diving birds cannot get to. A section of their diet also consists of squid, again the ability to dive deeper thanks to heavy bones help them go after squid. Adult penguins are only hunted by two animals – leopard seals and orca. The chicks and eggs are attacked and hunted by large gulls, petrels, and skuas. Penguins can be accidentally killed by male elephant seals as these giant testosterone filled seals are known to crush smaller animals as they fight over mates.

Conservation and Threats

The IUCN Red List assessed king penguins in 2020 and gave them a rating of ‘Least Concern’, and stated they their numbers were increasing. Successful conservation efforts and protected zones have greatly helped prevent human encroachment into their breeding sites. Climate change warming the Antarctic has been a disaster for the planet, but king penguins have utilised it to expand their breeding colonies helping with the population increase. That does not mean that everything is bright for the future of king penguins. They very rarely deviate from what they eat, so climate change causing the shifting of ocean currents could dramatically change their access to fish and squid they rely on. Some colonies have actually shrunk thanks to this. The current growth in population could be temporary. However, they are very common in captivity. One of the most notable king penguins is in Edinburgh Zoo. King penguins are on the logo of the zoo and have housed the penguins for over a century, and since 1972 a penguin named Nils Olav has been the mascot for the Norwegian King’s Guard. As king penguins came from the Norwegian owned Bouvet Island this created a link, and Nils Olav and his successors has moved up the ranks. Nils Olav III in 2023 was promoted to the rank of major general, something insane for a penguin in a Scottish zoo.

Bibliography:

‘Major General Sir Nils Olav, Baron of the Bouvet Islands’, Edinburgh Zoo, (25/08/2026), [Accessed 04/09/2026]
BirdLife International, ‘King Penguin’, IUCN Red List, (08/09/2020), [Accessed 04/09/2026]
Émile Brisson-Curadeau, Kyle Elliott and Charles-André Bost, ‘Contrasting bottom-up effects of warming ocean on two king penguin populations’, Global Change Biology, 29, (2023), 998-1008
Keena Edwards, ‘Aptenodytes patagonicus (King Penguin)’, Animal Diversity Web, (13/02/2011), [Accessed 04/09/2026]
Manfred R. Enstipp, Charles-André Bost, Thomas Faulmann, Robin Laesser, Julien Courtecuisse, and Yves Handrich, ‘Penguin molt revisited: dive performance following the molt of adult king penguins (Aptenodytes patagonicus) and conflicting physiological demands at sea’, Journal of Experimental Biology, 228:18, (2025), e251141
Chris Habard and Guy Kirwan, ‘Penguins’, in Gill Pitts, (ed.), Bird, Second Edition, (New York, NY: DK, 2022), 136-142
Daniel T. Ksepka, Sara Bertelli, and Norberto P. Giannini, ‘The phylogeny of the living and fossil Sphenisciformes (penguins)’, Cladistics, 22:5, (2006), 412-441
Marcela M. Libertelli, Jose L. Ordeira and Facundo Alvarez, ‘The explorer king: southern report of the king penguin (Aptenodytes patagonicus) in the Antarctic Peninsula’, Antarctic Science, 36:3, (2024), 145-148
I. Martínez, F. Jutglar, and E. Garcia (2020). King Penguin (Aptenodytes patagonicus), version 1.0. In Birds of the World (J. del Hoyo, A. Elliott, J. Sargatal, D. A. Christie, and E. de Juana, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.kinpen1.01
Tony Williams, The Penguins, (Oxford: Oxford University Press, 1995)

Myths, Legends, Religion, and Faith: Tláloc

Among the Mexica, commonly referred to as the Aztecs, one of the most important of the gods, teotl, was Tláloc. The bringer of the rain, overseer of water, and the guardian of the land’s fertility Tláloc was one of the most important figures in the Mexica pantheon. This week we will look at Tláloc and the importance he held in Mexica society, and how this importance allowed him to survive the cultural apocalypse that was the Spanish Conquest.

Tláloc and Faith among the Mexica

As Camilla Townsend has argued, the belief system of the Mexica was greatly different to that of Europeans which has meant many scholars have fundamentally misunderstood Mexica religion. Often, they are described as polytheistic and their religion compared to the Greco-Roman pantheon of gods. A key concept of divinity was Ipalnemoani, ‘That by Which There is Life’, similar to the idea of monism that, instead of there being good or evil, there is just a oneness in all life. Pantheism is a more accurate description, where all things could hold divinity. The term use in the introduction, teotl, can mean ‘god’ or ‘deity’, but is more accurately described as a divinity that can be expressed through the natural world and religious processes. Names for divinity were fluid as different Nahuatl communities would exchange and change the names for teotl. The name was not important, it was a label for humans to understand and comprehend the divine which they hoped to evoke, worship, or appease. This is important to consider when we discuss Tláloc.

When the Spanish encountered Mexica belief systems they assumed Tláloc to be a rain god. In the Florentine Codex, written over two decades after the Conquest of the Aztec, Tláloc is described in this way:

This god named Tlaloc Tlamacazqui was the god of rain. They believed that he granted the rain to irrigate the earth, and that every grass and herb, tree, fruit, and grain grew because of this rain. They also believed that he sent down hail, thunder and lightning, and rain storms, and the dangers of the rivers and sea. The name Tlaloc Tlamacazqui means that he is the god who lives in the earthly paradise and gives men all the food necessary for their physical life.

Written through a Spanish-Catholic lens we see a dualism in Tláloc, but not the European good vs. evil dualism. Tláloc is the one that allows the communities to flourish by bringing the nourishing rains, but those rains can easily become destructive. Tláloc was also not confined to one singular person, and was instead manifested through the Tlaloque, the plural for Tláloc. Four Tláloc stood at each corner of the universe and Tlaloque were found in every mountain and spring. Various names for teotl were potentially Tlaloque, such as Napa Teuctli, ‘Lord of the Four Directions’, that made the reeds grow around the lakes and Atlacoya, ‘Drainer of Waters’, who prevented the droughts. Some cases saw Tláloc play with gender as one of the potential Tlaloque was Chalchiuhtlicue, the Jade Green Skirted Woman, who may have also been his sister and/or consort. Tláloc and the Tlaloque were the bringers of the rain, the protector of the crops, and the ones who could bring death through drought or flood.

Sites of Worship

Like with all divine figures there was a personal, local worship of Tláloc and an official state worship. Polly Schaafsma has identified a series of rock art in New Mexico which represents a northern, localised version of Tláloc with some of the later sites, dating to the 1400s, having vessel offerings found further south. Whether this was Tláloc or a local rain god is unsure, but it is not out of the question. The Mexica are believed to be from what is now northern Mexico and the southwest US, and trade with northern communities did happen with the Mexica. Through these cases Tláloc may have also been a northern deity. Shrines to Tláloc have also been found in caves around the Mexica heartland in what is now Mexico City and estado de Mexico – caves are places of potential security and are often waterlogged.

One of the oldest potential places of worship of Tláloc was the famous site of Teotihuacan, just north of Mexico City. Figures with large eyes dot the site, something which has led to the suggestion that the northern rock art could be Tláloc as they also display the same eyes. Teotihuacan was abandoned around 750, centuries before the rise of the Mexica, and often stands as a site that would come to influence many of the other Mesoamerican cultures to come. Chaan, the Mayan rain god, may have also had their origin through cultural diffusion through contacts with Teotihuacan. The main sites would come around during the Mexica cultural and political domination. Most notably Tláloc was prominent at Templo Mayor, the main pyramid and the focal point of Tenochtitlan which was the main city of the Mexica. The Templo Mayor was devoted to three teotl: Queztalcoatl, who had the central spine; Huītzilōpōchtli, the war teotl, which had the right side; and Tláloc, who had the left side. According to Mexica myth, Tenochtitlan was founded based on the sighting of an eagle resting on a cactus holding a snake which was promised by Tláloc. From there the Templo Mayor complex emerged. Until its destruction by the Spanish the Templo Mayor would hold many images of Tláloc and merlons depicting the teotl covered parts of the temple. We know these are Tláloc as they have large eyes and fangs, as well as certain animal and plants being shown alongside him. These are namely butterflies, conches, and water lillies.

Just outside of Mexico City in Estado de Mexico there is another major shrine to Tláloc. On top of a mountain called Cerro Tláloc is a shrine with five stones depicting Tláloc and the four Tlaloque that stand at each corner of the universe. The Mexica and other cultures of Mesoamerica were experts at creating calendars and mapping out the movement of the sun and stars, and this is reflected in Cerro Tláloc. The height of the mountain created a divine landscape that could map the stars alongside a coordination with Templo Mayor further away. This sacred landscape further coalesced around the festival of Huey Tozoztli during April and May at a time when harvests would have produced enough food but before the thunderstorms made climbing Cerro Tláloc difficult. This festival surrounded the shrine on the mountain, a tall space to specifically reach out to the clouds to ask for rain.

Worship

As mentioned above, Tláloc was a central figure in the divine imaginary of the Mexica. The need to access regular rains meant that Tláloc was vital to society – too much rain could cause floods and kill crops, whereas too little would cause droughts. Priests could pray to him to ensure the rains came during times of drought, especially appealing to the need of the commoners. Camilla Townsend found evidence of one such prayer during the 1450s during a particularly bad few years:

Here are the common folk, the macehualtin, those who are the tail and
the wings [of society]. They are perishing. Their eyelids are swelling,
the mouths drying out. They become bony, bent, emaciated. Thin are
the commoners’ lips and blanched are their throats. With pallid eyes
live the babies, the children [of all ages] those who totter, those who
crawl, those who spend their time turning dirt and potsherds, those
who live sitting on the ground, those who lie on the boards, who fill the
cradles. All the people face torment, affliction. They witness that which
makes humans suffer. Already there are none who are passed over.

Townsend, Fifth Sun, 56

Due to the stratified nature of Mexica society, these prayers were to stress that the inability to serve Tláloc was not the fault of the commoners who were suffering the most. Instead, it was the elites who had failed and disappointed the teotl. While Tláloc would have been honoured all year round he had a specific festival devoted to him, the aforementioned Huey Tozoztli. This was a joint festival honouring Tláloc and the maize teotl, the god Cinteotl and the goddess Chicomecoatl. Catherine DiCesare has highlighted that sources dating to the pre-Conquest era emphasise the maiz teotl over Tláloc, with Tláloc’s connection to Huey Tozoztli potentially being found only in a few colonial era sources. However, she also highlights that Huey Tozoztli depicted in the Codex Borbonicus could represent to local and historical temporalities, ones that stressed maiz teotl over Tláloc, and vice versa, depending on these temporalities. Tláloc was therefore brought into Huey Tozoztli as a way to ensure good rains for the harvest.

Sacrifice was a key aspect of Mexica belief, although sacrifice was not always involving humans. Sacrificing crops and animals were done, including in the worship of Tláloc, and blood sacrifice where the priesthood or rulers cut their own bodies to provide blood happened. However, human sacrifice was indeed a feature of worship. Teotl had sacrificed themselves to make the sun and the moon, so to ensure the pleasure of the teotl and the continued cycles of the world sacrifice was needed. We do not have good estimates for how many people were sacrificed, but it was not a wholesale slaughter of populations. Instead, people were taken from certain segments of society – namely prisoners of war, slaves, and children of royal lineages. For Tláloc it was children who were to be sacrificed, both at the Templo Mayor and at Cerro Tláloc. What has been called ‘Offering 48’ at Templo Mayor saw a staggering 42 children sacrificed. Due to their importance the children were honoured and strewn with flowers to signify their importance enough to be sacrificed.

Tláloc after the Conquest

Following the destruction caused by the Spanish Conquest and the implementation of Christianity it would appear that Tláloc’s worship was stamped out. He and other teotl were seen as demons, especially thanks to child sacrifice as being part of his worship, which the Spanish wished to eradicate. However, Catholicism in the Americas saw a large amount of syncretism with local indigenous cultures, and Tláloc soon was brought into the Catholic Church. Smarter priests realised it was easier to bring Tláloc and other teotl into the Church and turn them into Christian parallels than to try and wipe them out. Tláloc’s demand for child sacrifice was soon equated to Abraham’s sacrificing of Isaac, and the usage of blood was equated to the Eucharist. His image was worked into churches, especially churches built in high places or in significant areas, to create a direct link between the old and new religions. Tlatelolco in Mexico City was demolished to make a church by the Spanish, and in that church Tláloc’s image was used. This allowed Tláloc to remain in the cultural imagery of New Spain and eventually Mexico, so much so that he is evoked as a local saint in some communities.

Bibliography:

Digital Florentine Codex, [Accessed 01/09/2026]
Catherine R. DiCesare, ‘Tlaloc Rites and the Huey Tozoztli Festival in the Mexican Codex Borbonicus’, Ethnohistory, 62:4, (2015), 683-706
Stanisław Iwaniszewski, ‘Archaeology and Archaeoastronomy of Mount Tlaloc, Mexico: A Reconsideration’, Latin American Antiquity, 5:2, (1994), 158-176
Miguel Leon-Portilla, Aztec Thought and Culture, Trans. by Jack Emory Davis, (Norman, OK: University of Oklahoma Press, 1963)
Guilhem Olivier, ‘Tlaloc, el antiguo dios de la lluvia y de la tierra en el Centro de Mexico’, Arquelogia Mexico, [Accessed 01/09/2026]
Polly Schaafsma, ‘Tlaloc and a Mesoamerican Cosmology in the American Southwest’, Journal of the Southwest, 64:3, (2022), 423-472
Camilla Townsend, The Aztec Myths, (London: Thames & Hudson, 2024)
Camilla Townsend, Fifth Sun: A New History of the Aztecs, (Oxford: Oxford University Press, 2019)
Shannon Winfield, ‘Containers of Power: The Tlaloc Vessels of the Templo Mayor as Embodiments of the Aztec Rain God’, Unpublished Masters Thesis, (2014), Tulane University

Florapedia: Potamogeton pondweed

Many different groups of freshwater aquatic plants have the name ‘pondweed’, and one notable group belong to the genus Potamogeton. Found on all continents except for Antartica, Potamogeton pondweed species are a widesparead group and are particularly diverse in the northern hemisphere. No matter where they are found they form an integral part of the local enviornment.

Taxonomy and Evolution

As mentioned, we are specifically looking at pondweed belonging to the genus Potamogeton, although not all plants that have the name ‘pondweed’ belong to this genus. In fact, there are five genera in the family Potamogetonaceae of which Potamogeton also belongs. This family belongs to a wider order called Alismatales which is a fairly unique order as many members of this order are actually aquatic, being found in both saltwater and freshwater. Not all members of Alismatales are aquatic with them also colonising the land; some notable members include taro and perhaps the largest flower in the world, the Titan arum. Potamogeton and similar water plants may also provide a clue to the evolution of flowering plants. Alismatales are monocots – any flowering plant with a ‘seed leaf’ that also includes orchids and grasses. There are theories that monocots, like pondweed, first evolved in water and moved onto land, although some like duckwood then evolved to return to the water. There are some debates on how many species of Potamogeton there are with there being between 60 and 95 species. The big debate revolves around how easily these plants hybridise, so we do not know which species are truly species or are hybrids.

Biology

Regardless of the species Potamogeton pondweed have a general body plan. They have a long, thin stem from which hair-like rhizomes, which act as the roots, and leaves grow from. While the stem and leaves are green or brown the rhizomes are generally a pink colour. These rhizomes not only help pondweed take nutrients from the soil, but also allow them to the stay grounded in water as well as reproduce. Plants can produce effective clones of themselves through producing a turion, and in pondweed a turion can grow on the rhizomes producing a new pondweed. With some species of Potamogeton the only way to differentiate them from other species is through the turions. Pondweed grow in conjunction with the confines of their environment. In deeper bodies of water they can grow to a staggering 6 metres (32.8 feet) in length! However, most individuals will not grow that long and will only grow to be a few centimetres in length.

Life in the water does offer challenges for pondweed. As Christopher David Preston has highlighted, competition for nutrients and carbon can be intense so pondweeds have had to be adaptable. By growing rhizomes into the sediment this allows them to take what little they can, even if some of it will be stolen by algae that may grown on the plant. As a plant they do need light which can be difficult while submurged. This is why Potamogeton pondweed grow two types of leaf. One is submerged that resembles grass, and the other rises to the surface and has a broad surface. Not only does this help pondweed have a wide surface area to best take in light, but it effectively blocks off competition. While this is not a problem in their natural habitat, but invasive species of pondweed – like the curly-leaf pondweed in North America – can really disrupt the local enviornment.

Water also creates other issues for aquatic plants, namely if a drought hits. Those species with developed rhizomes can wade this out, effectively being able to wait until water returns. Those that lack these rhizomes simply die. Plants typically use pollination to reproduce, that way they can keep genetic variability up, which is difficult, but not impossible, in water. They produce short, spiny flowers that will break the surface of the water which overcomes this issue. Not all do this though. P. berchtoldii have been spotted using bubbles to spread their pollen! When fertilised pondweed use various means to spread their seeds. The earlier mentioned turions can be broken off and regrow somewhere else, and likewise the seeds can simply fall into the water to be distributed. Another key way they spread is through birds. Birds will eat the seeds and spread them as their digestive system cannot break down the seeds fully.

Distribution and Habitat

Potamegeton are found across the world except for Antarctica, but they are most common in the nothern hemisphere. They do well in cooler, temperate climates, although this does not stop them from being naturally found in tropical climates. The curly-leaf pondweed is naturally found in Britain and northern Europe, as well as the tropical forests of Myanmar and Vietnam. They are normally found in slow moving or still bodies of freshwater, such as ponds and lakes, but some of the hardier species are at home in fast running rivers. Some species can survive in bodies of water that have experienced high levels of eutrophication. This is where a build-up of nutrients, mainly from human pollution, leads to the rapid growth of surface level plants and algae which block off light, killing those plants that are not close to the surface, and then results in the stripping of oxygen in the water killing animal life. Where pondweed is found they are an essential part of their environment by helping bring oxygen into the water, providing shelter for animals, and also food. Those species that live further north will be reduced to their turions during the winter, and will then regrow their stems and leaves when the temperature warms.

Conservation and Threats

Conservation for pondweed is difficult due to how hard it is to tell species apart, how easily they hybridise, and not knowing which species are hybrids or not. A 2018 paper found that a rare species, the Florida pondweed, was not actually a species but a hybrid. This does leave us in a strange place, especially as with pollution even the endangered species of pondweed could be endangered and we do not know about it.

Bibliography:

‘Curly-leaf Pondweed’, University of Minnesota Extension, [Accessed 29/08/2026]
‘Potamogeton‘, Kew Plants of the World, [Accessed 29/08/2026]
‘Potamogeton, Pondweeds’, BSBI.org, [Accessed 29/08/2026]
Thomas Horst Berthelier, Sébastien Christophe Cabanac, Caroline Callot, William Marande, Hélène San Clemente, Amélie Perez, Guillaume Marti1, Elisabeth Jamet, and Christophe Dunand, ‘Multi-Omics Unveils the Dual-Life of the Aquatic Plant Potamogeton nodosus‘, Physologia Plantarum, 178, (2026), e71037
Zdeněk Kaplan, Judith Fehrer, Veronika Bambasova, and C. Barre Hellquist, ‘The endangered Florida pondweed (Potamogeton floridanus) is a hybrid: Why we need to understand biodiversity thoroughly’, PLoS ONE, 13:4, (2018), e0195241
Gill Pitts, (ed.), The Natural History Book, Second Edition, (London: DK, 2021)
C.D. Preston, Pondweeds of Great Britain and Ireland, (London: Botanical Society of the British Isles, 1995)

The Rise of Humanity and Histories through Cities: Tell es-Sultan, Jericho, and the First Cities, 8,000-7,500 BCE

Throughout this series a particular archaeological site has been cropping up. Located in the West Bank, Palestine this site has the name Tell es-Sultan, but is better known by a biblical name – Jericho. We will be looking at Tell es-Sultan during the first half of the eighth-millennia BCE as this is roughly when archaeologists date its most iconic structure – the Tower of Jericho. With this post we will look at the origins of Jericho, what life was like there, and why they built the staggering walls and tower.

Tell es-Sultan: Setting the Scene

Jericho has been excavated for a very long time with some of the earliest people to look at the site being the early Christian community in Palestine who formed a small community on the Jericho Oasis. The first of what we might consider ‘modern’ excavations took place in 1868 when British army officer and amateur early archaeologist Charles Warren got a commission to excavate in Palestine. He did not initial find anything at the site, writing it off as being of ‘little interest’, and left for Jerusalem. He had a strange career and would later served as commissioner for the Metropolitan Police where he tried, and failed, to catch Jack the Ripper. The next major excavation would be undertaken in the 1950s when Palestine was under Jordanian rule. Heading the excavation was a pioneer in archaeology called Kathleen Kenyon who was an Oxford graduate and had already participated in a monumental archaeological excavation. In the 1920s she joined an all-women team to Zimbabwe, then called Rhodesia, excavating Great Zimbabwe and categorically proved what local Africans had been saying for years, that the site was made by Africans. For more information on Great Zimbabwe please read our other post here. Kenyon focused on stratigraphy as a way to properly capture the changes to Tell es-Sultan over the millennia, and was keen to hire local displaced Palestinians in the excavation. Tell es-Sultan is located close to the Ein es-Sultan refugee camp which had been formed in 1948 thanks to Israel’s ethnic cleansing of Palestinians. From 1952 to 1957 the excavation provided an economic lifeline for a displaced community. Israel’s invasion of the West Bank in 1967 and Apartheid policies meant no major excavation took place until the Italian-Palestinian Expedition of 1997 to 2017. This joint Italian-Palestinian team gave new insights into the site, and was a key driving force behind UNESCO declaring it a World Heritage Site in 2023.

Tell es-Sultan was in use for over 9,000 years from around 10,000 BCE to around 900 BCE, although it was not consistently occupied for this entire period. Tell es-Sultan is one of the sites often highlighted as having the title of ‘oldest city’ in history, but it was far from the only place where we see the construction of permanent settlements. In this series we have already looked at some of those sites – there were Tell Qaramel and Abu Hureyra in Syria and Göbekli Tepe in Turkey. The occupation of Tell es-Sultan, at least in part, coincided with the occupation of these sites with the same culture that occupied Abu Hureyra and Tell Qaramel, the Natufians, also being behind Tell es-Sultan. From 10,000 BCE we see aross west Asia a series of cultures who begin remaining in a single area, ‘sedentarism’, and began the domestication of grains and hoofed animals. This was the early origins of agriculture in west Asia, what pioneering archaeologist Vere Gordon Childe called the ‘Agricultural Revolution’. This came even before the widespread development of pottery – archaeologists refer to this period as the Pre-Pottery Neolithic (c.9,600-6,500 BCE). Why this began is still at hotly debated topic, but it seems the changing climate put pressure on communities who found that by ensuring the cultivation of wheat, barley, and einkorn they could have an ample supply of food.

Tell es-Sultan: A Proto-City

Tell es-Sultan has been described as a proto-city which is a settlement that does not show clear signs of an organised form of urban planning. However, Tell es-Sultan does begin to enter the ‘city’ definition based on the evidence of the walls and tower. We will discuss these later and will instead look at what the settlement was like during the Pre-Pottery Neolithic (PPN). Class distinctions were not noticeable during this period. Kenyon and successive archaeologists have found evidence of emerging societal hierarchies around the third millennia BCE, but in the PPN these signs are lacking. None of the preserved settlements show signs of being larger, having more goods, or being differently decorated as we see later on, however this does not mean that no hierarchies existed. Hierarchies may have existed through personal relations and social standing, rather than access to goods. Even the construction of the walls and tower may not have been done through the coercion of labour, but could have been done from a sense of communal understanding. The move from hunter-gathering to sedentary agriculture has never been a clean one, and up to the present it is common to see communities use both hunter-gathering and cultivation. The number of gazelle bones indicate that people were still regularly hunting them, but there were scythes preserved in large numbers. Attached to the Tower was a silo that stored grain, and silos existed in homes implying a need for individuals to have their own food supply. During the PPNA, (9,600-7,500 BCE), stone silos for storing water, food, and domestic waste were a common feature of homes.

Tell es-Sultan was well positioned to become a large settlement. The nearby oasis, which still provides water to Palestinian villages today, provided fertile land for growing grains. This provided enough resources so Tell es-Sultan could start growing in size so by the 8000s BCE there were certainly hundreds to perhaps thousands of people living in the settlement. Homes were roughly loaf-shaped, made of mudbrick and were built with no sense of an organised city planning. Some were built to purposefully have courtyards so different dwellings could come together and socialise, whereas others stood alone. As people moved on or died new people would move in, or perhaps tear down old dwellings to build on top of it. This is how, over millennia, the tell, an artificial mound, developed.

Tower and Walls

Around 8,000 BCE the people of Tell es-Sultan constructed what easily would have been the largest structures at that time. Along the west side of the settlement, conspicuously not along the east, was a large wall. It stood 3.6 metres (11.8 feet) high and 1.8 metres (5.9 feet) wide at the base. Inside the wall was a tower that was the tallest manmade structure in history to that time, and it would not be exceeded in height for another four-thousand years. At its base the Tower had a diameter of 9 metres (29.5 feet) and stood 8 metres (26.2 feet) high, and was made of 1,000 tons of stone. From base to summit there were 22 steps made of stone. The Tower was an icon, one that would have inspired awe in anyone who saw it. Again, we do not know how they built the walls and tower; not as in what tools and materials, but as to what social forces were used to build them. As mentioned, we do not know if hierarchies existed to enact some form of social coercion to build the wall and tower, or if the people of Jericho felt a desire to construct it.

Originally, it was believed that the wall and Tower was for defensive measures. We normally build walls to defend things, and the Tower was certainly tall enough to give the defenders an ability to rain down projectiles. Sites in Sudan and Kenya do show that prehistoric warfare was not unheard of and could be brutal, so a defensive origin seems obvious. However, since the 1980s this theory has been debated, and Omar Bar-Yosef highlighted that we do not actually have evidence of warfare among the Natufians. There are no other foritified settlements during the PPN; we have no large amounts of weapons used for offensive means and not simply hunting found; the Tower was inside the wall making it more difficult to defend a wall; and we do not know who could have possibly be the attackers. Bar-Yosef suggested that the wall’s defensive nature was not against other communities, but it was defensive against nature itself. At the end of the Younger Dryas the climate was becoming wetter, and west Asia was seeing more rain. Floods and mudslides posed a threat to the community, so a wall served as a way to protect the community from a natural disaster. That does not mean that the Tower and walls were never used to defend Tell es-Sultan. It was supposed to inspire awe. Ran Barkai and Roy Liran expanded on this theory, arguing that the Tower aligned with the stars and local geographical features making it a spiritually symbolic structure.

History Rhyming – Walls and Roman Frontiers

Walls like those at Jericho can hold multiple functions and meanings. If a state or community wanted to create a visually impressive structure to show its boundary or power a large wall is a significant way to show exactly this. One example of this which springs to mind is Hadrian’s Wall. During the reign of Hadrian the emperor decided that the empire had grown too large which made it ungovernable and vulnerable to attack. He decreed that a wall was to be made demarcating the border between the Roman Empire and the lands of the ‘barbarians’ beyond it. In some areas natural borders like the Atlas Mountains or the Rhine created a border, in others a wall had to be built. You can find traces of the wall all across Northern Africa, west Asia, and Europe, but the most noticeable one lies in northern England as it was primarily made of stone. Obstensibly, Hadrian’s Wall was defensive. Regular checkpoints were positioned along it, and soldiers guarded the wall from all across the empire. However, that was not its main function. It was to control trade. People who wanted to trade were forced into specific gates where they could be taxed, something they could not do before. Like at Jericho this wall was to show how powerful Rome was. Large, impassable, and extending as far as the eye could see the wall was to show whoever came near just how powerful Rome was.

Life and Death in Jericho

People lived in Jericho for millennia. The regular building on top of houses to build new ones ended up meaning that the walls and Tower were abandoned by around 7,800 BCE. Why, we do not know, but it seems that the building of new buildings had made the structures no longer needed. New layers effectively forced Jericho above flood lines rendering the walls not as needed. As the PPNA gave way to the PPNB shortly after the abandoning of the Tower changes came to Jericho. Houses became more cigar-shaped causing buildings to slowly become more and more rectangular. What remained the same with these houses was actually what was under them. In Tell es-Sultan people lived with their dead. Relatives were buried under the house with little goods deposited with them, left for a bit, and then had their heads removed which was reburied somewhere else in the community. Kenyon’s excavation found around 276 burials in people’s homes, and this continued through to the PPNB.

Throughout both the PPNA and PPNB it seemed that only the skulls of adults were removed, with the exception of one area which had five infant skulls. Kenyon believed that this was a specific altar. Of the bodies found in Jericho around 40% were children and infants but it was only those five infants which had been decapitated. For PPNB bodies the living began putting plaster over the skulls and would often place cowrie shells over where the eyes would be in life. It has been theorised that this was an ancestor cult, which would also explain why it was only adults who had this done and not the children. This seems to have been a common feature as plastered skulls, or even the action of severing the heads of the deceased, as part of preparing the dead was common in the region. This even extended far outside of Palestine – to the north in Turkey the site of Çatalhöyük, which was founded at the end of Jericho’s PPNB, also had deceased relatives decapitated. The specific reason for this we do not know, but it shows some fascination with the head as the essence of the being. We see a communal aspect of Jericho’s society with the burial. While the body was buried with the family it was the skull, the body part that it most identifiable, that was buried in a more communal area. Without distinction, everyone was part of this system.

Other Events:

Other events happened in the first half of the eigthth millennium. Here are some of them:

Around 7560 BCE the Rotoma Caldera, part of the Taupō Volcanic Zone in Aotearoa erupted. It was one of four massive eruptions within a period of 400 years.
Around this period near Lake Titicaca some of the first potato plants will be domesticated.
At Howick in Northumberland and Mount Sandel in Ireland some of the oldest evidence of human habitation of Britain and Ireland happens in this part of the millennium.
At around 7,500 BCE we have the earliest date for the settling of Çatalhöyük in Turkey, a site we will discuss next time.

Bibliography:

‘Ancient Jericho/Tell es-Sultan’, UNESCO, (2023), [Accessed 25/08/2026]
‘Jericho: An Ancient City Revealed’, Oriental Museum Durham University, [Accessed 19/08/2026]
Ran Barkai and Roy Liran, ‘Midsummer Sunset at Neolithic Jericho’, Time and Mind, 1:3, (2013), 273-283
O. Bar-Yosef, ‘The Walls of Jericho: An Alternative Interpretation’, Current Anthropology, 27:2, (1986), DOI: https://doi.org/10.1086/203413
Kathleen Kenyon, Digging up Jericho, (London: Ernest Benn, 1957)
Steve Mithen, After the Ice: A Global Human History, 20,000–5000 BC, (London: Orion Books, 2003)
Lorenzo Nigro, ‘Tell es-Sultan 2015: A Pilot Project for Archaeology in Palestine’, Near Eastern Archaeology, 79:1, (2016), 4-17
Rachael Thyrza Sparks, Bill Finlayson, Bart Wagemakers and Josef Mario Briffa, (eds.), Digging up Jericho: Past, Present and Future, (Oxford: Archaeopress Publishing, 2020)
Hamdan Taha, ‘Tell es-Sultan, Ancient Jericho’, This Week in Palestine, (2021), 48-51
A. Douglas Tushingham, ‘The Joint Excavations at Tell es-Sulṭân (Jericho)’, Bulletin of the American Schools of Oriental Research, 127, (1952), 5-16
Trevor Watkins, ‘From Mobile Foragers to Complex Societies in Southwest Asia’, Chris Scarre, (ed.), The Human Past: World Prehistory and the Development of Human Societies, Fourth Edition, (London: Thames & Hudson, 2018), 198-229

Zoopedia: Chaco Golden Knee Tarantula

Continuing this month’s theme of looking at wildlife from the Chaco we are focusing on the Chaco golden knee tarantula. These large spiders play a key role in regulating the populations of smaller invertebrates in the Chaco, but a lot more research is needed to see how endagered these tarantulas are.

Taxonomy and Evolution

The Chaco golden knee has the scientific name Grammostola pulchripes with it sharing its genus with twenty other species. The most famous member of the genus Grammostola is the Chilean rose tarantula which is incredibly popular in the pet trade for their docile nature. Chaco golden knees are also known for sharing this nature which makes them popular as well, just not as popular as Chilean rose tarantulas. They are true tarantulas, official scientific name being Theraphosidae, which are generally the largest spiders, at least by weight. Some non-tarantula spiders are larger based on how long their legs are, but are not as heavy as the largest tarantulas. Tarantulas first appear in the fossil record during the Cretaceous with some frozen in amber being found in Myanmar.

Biology and Behaviour

Being a tarantula the Chaco golden knee is a large species of spider. They reach between 17.8 and 20.3 cm (7 to 8 inches) in length and reach weights of 56.7 grams, or 2 ounces. Females are larger than males, something which is the norm among spiders. Chaco golden knees are black with golden patches on their legs and the abdomen, something that gives them their name. Another point that Chaco golden knees share with other tarantulas is how hairy they are. These hairs cover the entire body, and there are seven types of hair which the tarantulas use for different purposes. Despite having eight eyes their sense of sight is actually quite small, so they use the hairs, mainly on their legs, as a way to properly detect the world. The hairs are highly sensitive which allows the spiders to detect when other animals are approaching, and even changes in the climate. A different set of hairs on the legs are used for defense. When threatened they can flick these hairs, which are irritating, at predators to scare them off.

Chaco golden knees are ambush predators, waiting in the undergrowth for prey to come near. Those hairs alert the spider to prey passing by, and another set of hairs serve as an adhesive which helps the spider keep hold of the prey. Like other spiders, Chaco golden knees inject their prey which a venom that dissolves them from the inside so the tarantula can effectively drink up the insides of the prey. During the day they may stay in burrows which the tarantulas move into when abandoned by rodents and lizards. These burrows are also essential for reproduction. Male tarantulas will deposit sperm on a special web which he then places in packet on his fangs. When a female is receptive he will effectively bite her to deposit his sperm, but this can be dangerous. She is much larger than he is, and if she gets mad he can be a meal. If fertilised she will create an egg sac in which she lays over 100 eggs. From there her spiderlings can safely hatch, although many will not survive to adulthood. Spiders will molt and develop a new skin to grow, but when molting they are most vulnerable. Males live for five to ten years whereas the larger females can live for over 20 years!

Distribution and Habitat

As their name says, the Chaco golden knee tarantula is found in the Chaco region, specifically being found in the Paraguayan and Argentinian Chaco. While there are humid parts of the Chaco, where the golden knee is found is the dry Chaco. This region is generally warm and dry with seasonal rains. To survive during some of the hottest and driest summers that South America faces the tarantula largely comes out from its burrow or the undergrowth at night.

Diet and Predators

Like all spiders the golden knee is a carnivore. Their diet mostly consists of invertebrates ranging from cockroaches to crickets to even smaller spiders. Some of the larger tarantulas can eat fellow tarantulas, baby rodents, and baby lizards. Spiderlings are more likely to be eaten compared to the adults, although all spiders are at risk as they molt. Tegus, birds, maned wolves, peccaries, and hawks can all eat the spiders with spiderlings being at risk from a wider range of animals. Furthermore, tarantula wasps do target adults for their babies – let’s just say tarantula wasps reproduce the same way as the alien in Alien…

Conservation and Threats

The IUCN Red List, CITES, and other conservation organisations have not evaluated the Chaco golden knee so we do not know how endangered they are. The only member of Grammostola to be evaluated by the IUCN was G. vachoni in 2012 which was assessed as being ‘Vulnerable’. As the Chaco is at risk from climate change and human expansion this could potentially endanger the tarantula. Due to their docile nature they are increasingly common in the pet trade, something that could lead to the capture of wild spiders to sustain demand.

Bibliography:

‘Chaco Golden Knee Tarantula’, Oakland Zoo, [Accessed 20/08/2026]
N.E. Ferretti and G. Pompozzi, ‘Grammostola vachoni‘, IUCN Red List, (16/05/2012), [Accessed 24/08/2026]
Nelson Ferretti, Gabriel Pompozzi, Alda González and Fernando Pérez-Miles, ‘The genus Grammostola Simon 1892 (Araneae: Theraphosidae): a new species from western Argentina, new synonymy and distributional data’, Journal of Natural History, 47:47-48, (2013), 2961-2977
Norman Platnick, (ed.), Spiders of the World, (Princeton, NJ: Princeton University Press, 2020)
Tarantula Collective, ‘Chaco Golden Knee Tarantula: Life of the Grammostola pulchripes’, YouTube.com, (19/04/2022), [Accessed 24/08/2026]

The Making of Today: The Māori Encounter Captain Cook, October-December 1769

On Saturday 7 October 1769 the British sailor James Cook wrote in his journal that ‘At 2 p.m. saw land from the Masthead bearing West by North‘. After he had witnessed the transit of Venus in Tahiti earlier in the year, Cook had received a second set of instructions. As a way to compete with the French and Spanish in the Pacific Cook was to find Terra australis incognita, the Southern Unknown Land. If the land was found Cook was instructed ‘with the Consent of the Natives to take possession of Convenient Situations in the Country in the Name of the King‘. This meant that if Cook found Terra australis he was to ensure it became a British possession. A few days later Cook’s crew on the Endeavour made landfall on the spotted land. This land was Aotearoa, the North Island of New Zealand.

Aotearoa before Cook

Like elsewhere in the Pacific, Aotearoa had long been discovered before Europeans arrived. For the purpose of centring indigenous voices for this post I will be referring to New Zealand by its Māori name, Aotearoa. The Māori of the eighteenth-century would refer to North Island as Aotearoa, and today’s post we will mainly be focusing on North Island. Māori is sort of an anachronism. The term ‘Māori ‘ means ‘normal’ or ‘ordinary’ as a way to distinguish themselves from the spirits, but the arrival of Europeans meant that ‘Māori’ came to refer to the indigenous people of Aotearoa to contrast with the Pākehā, the European settlers. Identity was instead based around the iwi, community, which through oral history could sometimes be traced to a specific canoe. Sometime between the 1250s and 1350s Polynesian families began settling and spreading out over Aotearoa. With the exception of those who settled at the very south of South Island many of these communities abandoned sailing, other than for fishing and trade in the local area, becoming settled farmers. Especially on North Island communities called pā emerged which were hillforts designed to show the strength of the iwi.

The Māori iwi becoming farmers that substituted their economy with hunting local wildlife and gathering plants meant that the ocean-based navigation that characterised Polynesian cultures became less important. The remoteness of Aotearoa meant that Māori iwi became increasingly isolated from other Polynesians, but not so much that Māori ideology, religion, and language became too diverged. Like the Tahitians, Māori used the concept of mana in their worldview. This is a spiritual or almost supernatural force that permeates everything where people and objects that acquire mana allows them to exert influence and power. The Māori would adapt mana into mana tangata, mana derived from lineage and connection to the land, and mana huaanga, a mana derived from gift giving and the exertion of power to give gifts. Finally, there were many iwi in Aotearoa wo would trade, marry, and go to war with one another. Warfare was hand-to-hand and guided by a principle called utu – often translated as ‘revenge’ Michael King argued that it is more accurate to describe it as ‘balanced exchange’. This meant warfare could be done to re-establish broken connections between communities, although, in some cases, enslavement and even ritualised cannibalism. However, war was not waged to eradicate another community with many such wars ending in a marriage as to rebuild ties.

Europeans in the Pacific

As we have seen in several recent posts as part of The Making of Today, the French and British, in particular were interested in exploring the Pacific. France’s defeat in the Seven Years’ War wiped out their continental American empire, and they saw the Pacific as a potential way to rebuild their imperial prestige. The British, meanwhile, hoped to beat the French to it. Science and colonialism overlapped. The Pacific voyages, including that of Cook, were ostensibly scientific expeditions, but the understanding of the natural world was done to see how it could be exploited. Helen Tilley’s Africa as Living Laboratory provides a useful framework to understand this. In colonial Africa European administrators used Africa as a laboratory where a belief emerged that if the colonisers understood Africa’s people, geography, climate, and natural world then they could better rule and exploit its resources. In Tilley’s words:

Maintaining the British Empire and comprehending its different elements was, these men realized, far more difficult than extending its reach had been. Whether they cared more about Africa or about empire, they agreed that the production and dissemination of knowledge held the key to effective governance. Early in 1929, several of these individuals began to circulate plans for another think tank, based in Oxford and connected with the Rhodes Trust, of which Philip Kerr was now secretary. The proposed “Institute of Government” would undertake a “systematic and scientific study” of the British Empire, “the most interesting experiment in government in the history of the world.” In their view, the empire provided a “unique laboratory” in which to examine problems relating to “democratic states and their international association,” in conjunction with “the good government of the coloured peoples and the harmony of their relations with the white peoples.”

Tilley, Africa as Living Laboratory, 87

Effectively, this meant that African colonial officials looked to Africa as a place to explore new ideas and ‘develop’ the continent to their benefit. This colonial ideology was also present in the Pacific, except this time it was to show the prestige of Empire. The eighteenth-century captains were also following on old ground. A century before Spanish and Dutch sailors, using the Philippines and Indonesia respectively as a jumping off point, had made moves into the south Pacific. In fact, Cook’s party were not the first Europeans that Māori met. In December 1642 Dutch sailor Abel Tasman landed in Aotearoa, and much like Cook just over a century later, got into conflict with the local iwi causing the death of four Dutch sailors and one Māori. The Dutch would leave no lasting impression on the Māori, but Tasman’s navigations would give Europe some idea that there was land in the southern Pacific which the Dutch gave the name ‘New Zeelandia’.

Endeavour and Aotearoa

James Cook started life as the son of a Yorkshire farmer and rose through the ranks of the British navy, rising high thanks to the Seven Years’ War. Of course he was not the only one on the Endeavour, and it was the surgeon’s boy Nicholas Young who would spot Aotearoa. The point where they landed would be named ‘Young Nick’s Head’ in his honour. There was another significant person on board who has largely been overlooked in narratives about European arrival on Aotearoa, one that blurs the line between Māori and Pākehā. This person was Tupaia, sometimes spelt Tupia, who was an arioi, a religious figure similar to a priest, on Ra’iatea in what is now the Society Islands. Tupaia seemed to strike up a friendship with the Endeavour’s botanist Joseph Banks and requested to join the British, hoping to take his young servent Taiata with him. Cook’s attitude to Pacific Islanders has often been portrayed one of mutual trust by older historians, including some pioneering ones of indigenous history like Michael King. It is more complicated and we will get to it later, but Cook’s attitude towards Tupaia was telling. Cook did not want to bring Tupaia on board in case he was accused of enslaving the man and only allowed him to join the Endeavour if it was Banks who would ‘take’ him. This effectively meant in Cook’s eyes Tupaia was a ward despite the fact he was a knowledgeable navigator and advisor. Cook even admitted he was a ‘very intelligent person’. Banks wrote about Tupaia in this way:

This morn Tupia came on board, he had renewed his resolves of going with us to England, a circumstance which gives me much satisfaction. He is certainly a most proper man, well born, cheif Tahowa or preist of this Island, consequently skilld in the mysteries of their religion; but what makes him more than any thing else desireable is his experience in the navigation of these people and knowledge of the Islands in these seas; he has told us the names of above 70, the most of which he has himself been at. The Captn refuses to take him on his own account, in my opinion sensibly enough, the government will never in all human probability take any notice of him; I therefore have resolvd to take him. Thank heaven I have a sufficiency and I do not know why I may not keep him as a curiosity, as well as some of my neighbours do lions and tygers at a larger expence than he will probably ever put me to; the amusement I shall have in his future conversation and the benefit he will be to this ship, as well as what he may be if another should be sent to these seas, will I think fully repay me.

Banks quoted in Smith, ‘Banks, Tupaia, and Mai’, 139

Again, we see the dehumanisation of Tupaia based on him being Polynesian – I doubt Banks would have described a Dutch priest they had picked up as a ‘curiosity’ like a big cat. Why Tupaia wanted to go with the British is not known. He was a well-learned and inquisitve man from accounts, so he may have simply wanted to see what England was like. After all, in our earlier post on Europeans in Tahitians a young man who was the son of a local leader called Ahutoru wanted to go with a French ship as he wanted to see France. Jean-Stephane Massiani has suggested this and a way to escape political ramifications for backing the wrong side of a civil conflict may have influenced Tupaia’s decision. Tupaia became essential for Cook’s navigation from Tahiti. A navigator himself and part of a culture that relied heavily on the sea he knew how to navigate even the giant Endeavour through the shallow waters surrounding islands. Reefs could easily cut through the hull of a ship like scissors through paper, and Tupaia’s knowledge ensured the Endeavour avoided the reef. Vanessa Smith and David Turnbull have suggested that this might have caused Cook to feel envious of Tupaia. In Cook’s journal he suggested there was some intellectual rivalry between Banks and Tupaia, but Banks’s journal goes from describing Tupaia as a curiosity to being in awe of him. Smith suggests that as Tupaia was middle-aged like Cook and was a skilled navigator, making excellent maps to help the sailors, Cook got jealous while the much younger Banks came to see Tupaia as a fellow scientist who, if anything, legitimised Banks’s position on board.

Joseph Jenner Merrett’s nineteenth-century depiction of a haka

Cook and his animosity to Tupaia could have been the reason why he asked Tupaia not to join the expedition onto Aotearoa. On Monday 9 October 1769 Cook led a party landing near where modern Gisborne is. The fertile soil and good access to fishing thanks to the sea and nearby river meant four separate iwi were established in the area – the Ngāti Porou, Rongowhakaata, Ngāi Tāmanuhiri and Te Aitanga-a-Māhaki. Members of the iwi, meanwhile saw a floating island while others claimed it was a giant bird with great white wings – this was the Endeavour. Unfortunately, a deadly precedence began on that day. Māori of the Ngāti Oneone iwi came to see the crew and did something they would do with any other stranger – they performed a haka. This ceremonial dance can precede a battle, but it portrays your own mana and size the power projection of each other. The British panicked and fired, killing a leader, Te Maro. The next day Cook changed tactic – he brought Tupaia with him. This next encounter did not immediately descend into violence thanks to Tupaia – Māori and Tahitian not being too different which allowed them to communicate. The exchange of gifts, mana huaanga, started and Cook was even greeted with a hongi. Again, a misunderstanding escalated with Cook alleging that the Māori tried to steal the weapons. The British again shot the largely unprepared Māori and chief Te Rakau of the Rongowhakaata was killed. The crew fled back to the Endeavour and the next day when Cook spotted two fishing canoes. Again, Tupaia’s calls were ignored as the crew undertook Cook’s standard policy to begin negotiations – by kidnapping people. Musket fire rained down on the canoes killing three, wounding one, and leading three to jump overboard. The British took captive three young boys, aged between 10 and 20, to act as hostages. On 12 October another negotiation led by Tupaia returned the boys and a ‘parley’ was opened to facilitate trade.

History Rhyming – Tisquantum and Mediators

Local mediators between colonisers and indigenous people have been present throughout the history of colonialism. Notably, Hernan Cortes used an enslaved woman called Malintzin, whom he also sexually abused, to translate and negotiate with local Mesoamerican polities to facilitate the Spanish conquest of the Aztecs. However, one example similar to Tupaia and Cook is that of Tisquantum. Called Squanto by English settlers in the early-1600s he had been kidnapped and enslaved by the English, taken to Europe, and managed to escape back to his Patuxet community in what is now Massachusetts. In 1620 the pilgrim ship the Mayflower landed and the settlers almost were wiped out through war, disease, and famine. This is where Tisquantum stepped in. His knowledge of English allowed him to broker peace between the settlers and local indigenous nation, and then proceeded to show them how to plant local foods and trade. This would ensure the pilgrims survived their first few winters, but Tisquantum sadly did not. He caught some form of disease from either the settlers or the vectors that wiped out his community. In November 1622 Tisquantum died of a fever.

Cook, Tupaia, and Māori

Tupaia’s drawing of Joseph Banks and a Māori bartering over a lobster

After the initial disastrous encounters with the Endeavour the local iwi were cautious about the ship. Each time they had encountered the Endeavour’s crew people had died, and now three people had been kidnapped. The presence of Tupaia was the only thing reassuring them – here was someone who was a stranger and different, but one they could communicate with and understand them. Nicholas Thomas has described this as a new discovery for the Māori, one where they rediscovered Polynesians. It was Joseph Banks, not Cook, who suggested they put Tupaia at the forefront of the party. This meeting would not descend into violence, and this encounter would dramatically shape the history of Aotearoa. In successive European arrivals in the region they would find that Māori villages were growing potatoes, a crop introduced by Cook. Māori had been farming yams for centuries so it was not a large leap to go from farming yams to farming potatoes.

Oral history, and later journals by Cook, also reveal who captured the thoughts of the local iwi. When they spotted Cook’s ship during his Second Voyage a few years later the name the local Māori shouted was ‘Tupaia’. For them, the true head of the ship was Tupaia, not Cook. After all, it was Tupaia who talked between the two groups, was aware of mana, and was a religious figure. It was only natural that Tupaia was seen as the head of the ship and not the man who allowed his men to kill people almost immediately. Sadly, Tupaia died just over a year after he arrived in Aotearoa. When the Endeavour docked in Batavia, modern Jakarta, he and his ward Taiata got ill. Taiata died of the illness and a distraught Tupaia died not too long after on 20 December 1770. Cook’s crew would never shoot on another Māori, but if he had followed Tupaia’s lead then his life may not have ended being stabbed on a beach in Hawai’i.

Noble Savagery and Cook

James Cook can be a puzzling figure to understand in regards his relations with Pacific Islanders. He clearly had some form of respect for Tupaia, he regularly wrote that Tupaia was incredibly intelligent and an expert navigator. Yet, he was reluctant to use Tupaia as a negotiator until his own method of kidnapping was not helping open negotiations with the iwi. In his later voyages he would show respect to Polynesian political leaders, on his Third Voyage he would invite Māori chiefs to dine with him in his cabin, but he would then proceed to try and kidnap a Hawai’ian monarch to get some equipment back. Explaining this is simple – the ‘noble savage’ myth. Originally applied to indigenous Americans it soon was placed onto Pacific Islanders, so much so that Cook referred to Polynesians as ‘Indians’. This idea positioned that indigenous peoples were in a state of savagery – originally for not knowing Christianity, by the time of Cook concepts of private property fed into this – but their connection to the natural world or intelligence made them ‘noble’. Tupaia, for Cook, was a ‘noble savage’. He was an intelligent scholar and navigator, but he came from a culture that had no knowledge of Christ and private property. Tahiti, Aotearoa, Hawai’i, all were presented as Gardens of Eden inhabited by noble ‘savages’ living in bliss. It was this view that encouraged Cook to use kidnapping people to open negotiations – one that you cannot imagine him doing to the French or the Dutch. It was only because Polynesians were cast as the noble savage could he justify this action.

Other Events:

Other events happened in the last quarter of 1769. Here are some of them:

October 23, French inventor Nicolas-Joseph Cugnot would demonstrate a steam-powered tractor which effectively makes him an early pioneer of automobiles.
November 1, a contingent of Spanish conquistadors arrived in what is now known as San Francisco Bay becoming the first Europeans in the area.
On November 3, Diane Adélaïde de Mailly-Nesle, the former mistress of Louis XV of France, would die aged 57.
On November 12 the newly united Nepalese army conquers the last settlements of the Malla dynasty paving the way for the Gorkha dynasty to rule until 2008.
On December 22 the Chinese and Burmese Konbaung dynasty would sign a peace treaty. Several years earlier China intervened in Burma’s invasion of the Ayutthaya in Thailand, which you can read about here.

Bibliography:

Early meetings between peoples, URL: https://nzhistory.govt.nz/page/early-meetings-between-peoples, (Manatū Taonga — Ministry for Culture and Heritage), updated 20-Aug-2026
James Cook, Endeavour: Captain Cook’s Journal During His First Voyage Round the World, Edited by Alan Frost, (Anboco: 2016)
John Gascoigne, Encountering the Pacific in the Age of the Enlightenment, (Port Melbourne, VIC: Cambridge University Press, 2014)
Michael King, The Penguin History of New Zealand, (Auckland: Penguin: 2006)
Jean-Stéphane Massiani, ‘Tupaia, an Indigenous Collaborator on Board Captain Cook’s Endeavour‘, Études Anglaises, 72:4, (2019), 387-399
Toon van Meijl, ‘Maori Socio-Political Organization in Pre- and Proto-History: On the Evolution of Post-Colonial Constructs’, Oceania, 65:4, (1995), 304-322
Anne Salmond, ‘Their Body is Different, Our Body is Different: European and Tahitian Navigators in the 18th Century’, History and Anthropology, 16:2, (2005), 167-186
Vanessa Smith, ‘Banks, Tupaia, and Mai: Cross-cultural exchanges and friendship in the Pacific’, Parergon, 26:2, (2009), 139-160
Alice Te Punga Somerville, ‘Two Hundred and Fifty Ways to Start an Essay about Captain Cook’, New Zealand Journal of History, 53:1, (2019), 3-49
Nicholas Thomas, Islanders: The Pacific in the Age of Empire, (New Haven, CT: Yale University Press, 2010)
Helen Tilley, Africa as a Living Laboratory: Empire, Development, and the Problem of Scientific Knowledge, 1870-1950, (Chicago, IL: University of Chicago Press, 2011)
David Turnbull, ‘(En)-Countering Knowledge Traditions: The Story of Cook and Tupaia’, in Tony Ballantyne, (ed.), Science, Empire and the European Exploration of the Pacific, (Oxon: Routledge, 2004), 225-246
Stephen Turner, ‘A History Lesson: Captain Cook Finds Himself in the State of Nature’, in Alex Cadder, Jonathan Lamb, and Bridget Orr, (eds.), Voyages and Beaches: Pacific Encounters, 1769-1840, (Honolulu, HI: University of Hawai’i Press, 1999), 89-99

Florapedia: Quebracho Blanco

Keeping with this month’s theme we are heading back down to the Chaco to look at one of the region’s unique trees. Known as the quebracho blanco, white quebracho, this is one of the many trees that have evolved to survive in the dry environments of the Chaco. For centuries the local indigenous people of the Chaco used the quebracho blanco for medicinal purposes – in this tree a wide range of medicines could be extracted.

Taxonomy and Evolution

Quebracho blanco has the scientific name Aspidosperma quebracho-blanco making it one of over sixty species belonging to its genus. Some of the species are large enough to be trees while others are smaller and are more accurately shrubs. ‘Quebracho’ is not a formal taxonomic grouping, but an informal one for typically South American trees with incredibly hard wood. The term ‘quebracho’ is derived from the Spanish ‘quebrar hacha‘ meaning ‘axe-breaker’. Quebracho blanco belongs to an order of plants called Gentianeles whose members also include milkweed and coffee.

Biology

Quebracho blanco are tall trees being able to reach 25 metres (82 feet) in height, although this is only the case in wetter environments. Those in drier habitats reach between 8 and 12 metres, a good half of the height of those in humid environments. They have straight trunks which are a light brown-yellow which is, strangely enough, gives them their name. While not actually ‘white’ the trunk is far lighter than another tree in the area, the quebracho colorado or ‘red quebracho’. The trunk is not particularly thick having a diameter between 0.8 and 1 metres, but the sheer hardiness of the tree means that it can have a narrow trunk without it collapsing. It also means that for its size it is surprisingly heavy. Quebracho blanco trees can also produce a new stem from their roots – this is fairly common with plants which allows the same individual to create several trees, effectively cloning themselves.

Quebracho blanco are flowering plants, so every year they will produce flowers in order to reproduce. These flowers are funnel-shaped and yellow which is an evolutionary feature for two purposes. The funnel helps stop self-pollination, (when a plant accidentally pollinates itself using its own pollen), as the cone prevents pollen from easily being blown by the wind. Self-pollination can happen, but the cone helps reduce this occuring. The yellow colouration is another evolutionary tool. While yellow might seem common or even drab to us, for moths and butterflies it stands out. Moths, in particular, will drink nectar from the flower and in doing so will shake pollen onto its body. It will then fly to another quebracho blanco and spread the pollen. The tree will then produce green fruits 7 to 12 cm long, 4 to 6 cm wide, and 2 to 2.25 cm thick. Inside the fruit are the seeds which are eventually dispersed when the fruit bursts, or if eaten. In the past this job would have been done by giant ground sloths! In the Arid Chaco the seeds often need a ‘nurse plant’ to help keep the saplings covered from the dryness of the environment as they grow.

Quebracho blanco are described as sclerophyllous. This means that their foliage has evolved to be resilient to long periods of heat and dryness. They are evergreen, keeping their leaves throughout the year. The leaves are thin and narrow to reduce water loss during the heat of the day, and the hardiness of the trunk is a response to the heat. That hardiness makes it difficult for animals to break into the trunk to access the water inside. Furthermore, the roots spread out so when it does rain they can cover a wider area to absorb water, something which also allows them to grow new stems.

Distribution and Habitat

Quebracho blanco are only found in South America and predominantly in the Gran Chaco – the dry forests and savannah that covers south Bolivia, north Paraguay, north Argentina, and southwest Brazil. Pockets of these trees are also found in Uruguay and the Argentinian espinal. Most of this region is dry, sometimes not seeing rain for extended periods, which made these trees become so-well adapted to their environment. Parts of the Chaco receive far more rainfall, the Humid Chaco, which is where you will find the larger trees which congregate together forming forests. In the drier savannahs and plains these trees will be in smaller groups surrounded by shrubs.

Conservation and Threats

The IUCN Red List last evaluated the quebracho blanco in 2020 giving them a rating of ‘Least Concern’. This means they are not at immediate risk of becoming endangered. For centuries indigenous peoples had used these trees for a wide range of purposes, with many parts of the tree having medicinal properties. The bark contains alkaloids which are good for treating infections, especially malaria. Some of the alkaloids have been synthesised to produce anti-malaria treatements. These chemicals are also found in the leaves, fruits, and roots which has allowed people to produce remedies for malaria, fever, heart disease, swellings, and asthma. They have also been used to produce contraceptives, abortives, and aphrodisiacs. Despite the hardness of the wood it is malleable making it good for construction and even artisanal purposes. However, as climate change becomes worse and farms expand into the Chaco to fit consumption demands of the Global North, the quebracho blanco could become endangered soon.

Bibliography:

‘Aspidosperma quebracho-blanco Schltdl.’, Kew Plants of the World, [Accessed 13/08/2026]
Noelia E.A. Almiron, Gisela M. Via do Pico, Andrea Cosacov, Esteban N. Paredes, German A. Robledo Dobladez, and Viviana G. Solís Neffa, ‘The geography of Aspidosperma quebracho-blanco vulnerability, an emblematic species of the South American Gran Chaco’, Forest Ecology and Management, 523, (2022), e120503
Alicia H. Barchuk and Marı́a del Pilar Dı́az, ‘Regeneration and structure of Aspidosperma quebracho-blanco Schl. in the Arid Chaco (Córdoba, Argentina)’, Forest Ecology and Management, 118:1-3, (1999), 31-36
Alicia H. Barchuk, Maria del Rosario Iglesias and Marta N. Boetto, ‘Spatial association of Aspidosperma quebracho-blanco juveniles with shrubs and conspecific adults in the Arid Chaco, Argentina’, Austral Ecology, 33:6, (2008), 775-783
H. Rotton, ‘White Quebracho, Aspidosperma quebracho-blanco‘, IUCN Red List, (16/10/2020), [Accessed 13/08/2026]
Diego A. Sampietro, M. del Huerto Sánchez Matías, Marta A. Vattuone, and César A. N. Catalán, ‘Aspidosperma quebracho-blanco Schltdl.’, in Ákos Máthé and Arnaldo Bandoni, (eds.), Medicinal and Aromatic Plants of South America Vol. 2: Argentina, Chile and Uruguay, (Cham: Springer, 2022), 75-83

Paleo Profiles: Mamenchisaurus

This week we are looking at a giant among sauropods, a considerable feet considering just how big sauropods are. This was Mamenchisaurus, a sauropod which had several species in the genus that are in the running for the longest species of sauropod. Often described as a ‘wastebasket taxon’ there are debates about how many species actually belong to the genus. However, the species which are confirmed are some of the largest to ever live!

Discovery and Fossils

Like with many fossil discoveries, the first fossils belonging to Mamenchisaurus were found by accident in a construction site. Construction on the Yitang highway in Sichuan Province in southwest China revealed a fossil site that palaeontologist Yang Zhongjian, who published under the name C.C. Young, analysed. In 1954 he published a paper officially describing the fossil as a large sauropod which he named Mamenchisaurus constructus – ‘Construction Mamenxi Lizard’. A few years several specimens were found further north in Gansu which Yang also placed in M. constructus, but he did not realise that some belonged to a new species. Just north of Chongqing in 1957 locals brought to the attention of authorities of fossils they had found during the Chinese Revolution a decade prior. Despite being weathered the fossils were well preserved with only the forelimbs and skull missing. In 1972 Yang and another palaeontologist called Zhao Xijin realised this was a new species which they named Mamenchisaurus hochuanensis. Since then more and more specimens have been found, however the fragmentary nature of many of them has meant identifying if they are Mamenchisaurus or not very difficult.

Taxonomy and Evolution

As mentioned, the fragmentary nature of many Mamenchisaurus specimens has meant that it is difficult to know whether fossils are individuals of an already known species, individuals in a new species, or individuals of an entirely new genus. Six species of Mamenchisaurus have been declared either a new genus or being invalid leaving us with five valid species and two dubious species. The valid species are M. constructus, M. hochuanensis, M. jinyanensis, the utterly massive M. sinocanadorum, and M. sanjiangensis which was just described in 2025. There are then the two dubious species, M. anyuensis and M. youngi, although the authors of the 2025 paper describing M. sanjiangensis have highlighted that the fragmentary nature of Mamenchisaurus research means that M. sanjiangensis could belong to a different taxa. As mentioned, Mamenchisaurus was a sauropod beloning to a family named after itself – Mamenchosauridae. This family was distinct to a taxa called Neosauropoda which would comprise many of the massive sauropods that we know of, so gigantic sauropods evolved independently several times.

Biology

Mamenchisaurus was a giant dinosaur, one so much that even the smallest species were still titans. One of the smallest species was the first discovered, M. constructus, which reaches around 15 metres (50 feet) in length, effectively one and a half buses in length. Meanwhile, M. jingyanensis could exceed 25 metres (85 feet) in length and M. sinocanadorum could potentially reach a staggering 35 metres (115 feet)! The neck alone for M. sinocanadorum was incredibly long with the upper limits reaching 12 metres – while this is unlikely, if it was this length then the neck of M. sinocanadorum was almost the same length of M. constructus. If accurate, M. sinocanadorum would be one of the longest species of dinosaurs. Regardless of species, one common factor for Mamenchisaurus was the insane length of their necks which may have been the same length as the rest of the body. This has led to other questions, mainly, how did it keep such a long neck held high? For M. youngi one specimen had a neck the same length as 41% of the rest of the body, so mechanically lifting that neck would have been difficult. Mamenchisaurus had lots of cervical ribs which provided the structure to support such a long neck, and a paper published in 2013 found Mamenchisaurus had quite a stiff neck compared to other really long-necked sauropods, like Diplodocus. Sauropods also had air sacs in their bones to help with respiration which actually made them lighter for their size, so these air sacs would have also made their necks easier to lift.

Weight estimates for an animal that we only know from fossils, but palaeontologists have made some estimates. With some of the smaller species estimates of 5 to 7 tonnes, or the same as a large elephant, but the larger species reach around 25 tonnes. If M. sinocanadorum could reach the giant 35 metres in length then these giant Mamenchisaurus could have reached over 70 tonnes! This would have made these large Mamenchisaurus some of the largest land animals ever reaching sizes only reached by the titanosaurs. Alongside their large weight and long necks the Mamenchisaurus had a noticeably long tail. While not nearly as long as the neck, the tail partially acted as a counterbalance to the neck to avoid it being too out of balance. Like with many sauropods these tails were become increasingly thinner and taper out becoming a bit like a whip. Like the neck the tail had ‘ribs’ to give it structure, and notable vertebrae helped strengthen this. The end of the tail in at least one species, M. hochuanensis, seems to have ended in a small tail club. This is not unusual for sauropods as many have evolved a similar structure, but why Mamenchisaurus developed this ‘club’ is not entirely known. The paper which described this club argued that it would not have been used as a weapon, but was instead full of neural canals allowing Mamenchisaurus better detect the world. The length of the dinosaur would make it harder to sense the world far from it, so these ‘clubs’ helped Mamenchisaurus sense the world.

From bones, especially fragmented ones, it can be difficult to know the behaviour of these dinosaurs. Some specimens have been found together so we know that they formed at least small herds, but we do not know how these herds were structured. A young Mamenchisaurus has been found in Mongolia that seemed to stand 1.5 metres at the shoulder and reached 8 metres in length. This dinosaur had signs it was still growing, hence why we know it was a juvenile. Comparing Mamenchisaurus to other sauropods then we know that they reach their large sizes quite quickly – from hatchling to behemoth takes about 20 years.

When and Where

Mamenchisaurus comes from China with most of the fossils coming from Sichuan and Yunnan provinces in southwestern China. They are not exclusively found in these areas with the Junggar Basin in northern Xinjiang being a noted fossil site that specimens of Mamenchisaurus have come from. One specimen has been found in Mongolia, although, as always with this genus, we are not sure if it is for certain a Mamenchisaurus. There are also two specimens, one in Thailand and one in Japan, which have been theorised as belonging to Mamenchisaurus but we are currently not sure. For many years we thought that Mamenchisaurus was a dinosaur found in the middle and late Jurassic, however more recent analysis has found that their fossil sites were younger than previously thought. Mamenchisaurus was found in the Late Jurassic, around 161 million years ago, but survived until the Early Cretaceous, around 114 million years ago! As the 2019 paper said, this new evidence meant that Mamenchisaurus was around 30 million years longer than previously thought.

Habitat

Mamenchisaurus lived in forests, although the larger species probably lived along forest edges simply due to how large they were. They did live alongside other sauropod species, so their neck helped them carve out a niche and reduce competition with these sauropods. Palaeontologists found that Mamenchisaurus could not raise its head particularly high, but it was good at sweeping its head quite low. This means it was a specialist in eating lower growing vegetation instead of high growing plants meaning it did not need to compete with the other sauropods. Adult Mamenchisaurus would have had no predators, but juveniles and hatchlings would have been predated on by carnivores like Sinraptor, Monolophosaurus, and Guanlong. These carnivores would have been crushed by an angry adult Mamenchisaurus, and most likely a large juvenile would have scared them off.

Bibliography:

Andreas Christian, Guangzhao Peng, Toru Sekiya, Yong Ye, Marco G Wulf, and Thorsten Steuer, ‘Biomechanical Reconstructions and Selective Advantages of Neck Poses and Feeding Strategies of Sauropods with the Example of Mamenchisaurus youngi‘, PLoS ONE, 8:10, (2013), e71172
Hui Dai, Xu-Feng Hu, Chao Tan, Xin-Xin Ren, Qing-Yu Ma, Guang-Biao Wei and Hai-Lu You, ‘A new mamenchisaurid sauropod dinosaur from the Upper Jurassic of Southwest China reveals new evolutionary evidence from East Asian eusauropods’, Nature Scientific Reports, 15:43308, (2025)
Benjamin Gutierrez, ‘Mamenchisaurus‘, Prehistoric-wildlife.com, (13/02/2015), [Accessed 09/08/2026]
Mark Hallett and Mathew Wedel, The Sauropod Dinosaurs: Life in the Age of Giants, (Baltimore, MA: John Hopkins Press, 2016)
Rubén Molina-Pérez and Asier Larramendi, Dinosaur Facts and Figures: The Sauropods and Sauropodomorphs, Trans. by Joan Donaghey, (Princeton, NJ: Princeton University Press, 2020)
Andrew J. Moore, Paul M. Barrett, Paul Upchurch, Chun-Chi Liao, Yong Ye, Baoqiao Hao and Xing Xu, ‘Re-assessment of the Late Jurassic eusauropod Mamenchisaurus sinocanadorum Russell and Zheng, 1993, and the evolution of exceptionally long necks in mamenchisaurids’, Journal of Systematic Palaeontology, 21:1, (2023), e2171818
Gregory S. Paul, The Princeton Field Guide to Dinosaurs, Second Edition, (Princeton, NJ: Princeton University Press, 2016)
Jun Wang, Mark A. Norell, Rui Pei, Yong Ye, and Su-Chin Chang, ‘Surprisingly young age for the mamenchisaurid sauropods in South China’, Cretaceous Research, 104, (2019), e104176
Lida Xing, Martin G. Lockley, Anthony Romilio, Hendrik Klein, Guangzhao Peng, W. Scott Persons IV, Yong Ye, Shan Jiang and Miaoyan Wang, ‘An historic theropod-dominated track assemblage from the Upper Jurassic of Sichuan, China’, Historical Biology, 33:11, (2021), 2822-2828
Lida Xing, Yong Ye, Chunkang Shu, Guangzhou Peng and Hailu You, ‘Structure, Orientation and Finite Element Analysis of the Tail Club of Mamenchisaurus hochuanensis‘, Acta Geologica Sinica, 83:6, (2009), 1031-1040

Zoopedia: Greater Rhea

This week we are looking at the largest species of terrestrial bird in the Americas, the greater rhea. Called the ñandú by Guarani it is also referred to as an ‘ostrich’ due to how much they resemble ostriches. Despite their similarities to ostriches, rheas like the greater rhea belong to an entirely different order of birds and is a case of ‘convergent evolution’.

Taxonomy and Evolution

There are two species of rhea alive today – the greater and Darwin’s rhea. We are only looking at the greater rhea in today’s post with them having the scientific name Rhea americana. The ancestors of rheas first appear in the fossil record around 40 million years ago from what is now Brazil. We do not have specific dates about when the ratites – the large flightless birds – diverged into the different orders, but DNA analysis has put rheas as being consistently close to ostriches out of all the ratites. The greater rhea is made of five subspecies which are distinguished solely by geography, and it is nearly impossible to identify the subspecies without knowing where they are from.

Biology and Behaviour

Greater rheas, as mentioned in the introduction, are the largest terrestrial birds in the Americas, but they are dwarfed by ostriches. They are still large birds reaching weights between 20 and 40 kilograms (44 to 88 pounds), reach lengths of 1.2 to 1.4 metres (4 to 4.5 feet), and stand between 0.9 and 1.5 metres (3 to 5 feet) tall. They do resemble ostriches having their long necks, long feathers, and long legs, but this is down to convergent evolution. This is when two organisms that are not directly related but live in similar environments so evolve to look like one another. Unlike ostriches, greater rhea are not particularly sexually dimorphic with males only being slightly larger than the females. Rheas are grey-brown in colour, and during the breeding season males develop a black collar which they use to show off. Despite being flightless they have long wings which are used as rudders to help them turn while running. Like the other large grasslands ratites the rhea is a good runner and this serves as their main form of defence.

Greater rhea are quite sociable birds with them often forming large flocks that will claim an area around 2.6 square kilometres in size. These flocks will break apart during the breeding season into male, female, and a mixed flock of yearlings. They spend most of the day pecking at the earth looking for food. Rheas are not particularly vocal, although a 2021 paper found that at night rheas in semi-captivity would make low vocal booms. Whether this is also the case for fully wild rhea is currently unknown. Rhea will run to avoid predators, but their powerful legs ending in three toes means a kick can easily scare off a predator.

In early spring the flocks of rhea break apart and the males begin developing their black collars. Here the males become vocal making loud booms to impress mates and deter rivals. Using vocal booms and elaborate displays with their wings the males hope to attract around seven females. He will mate with them and they will move on to mate with another male. Like with ostriches the male rhea will make a nest which several females will lay their eggs in. Sometimes males will share a nest to look after the clutch which can exceed 30 eggs. The males will take care of as many of the chicks as he can, after all he will not know which hatchlings are his and which are not. As the chicks get older the male gets less attentive until they reach six months when they begin leaving the nest for good. They will stay close to dad for another year when the next clutch will replace them. In captivity they have been recorded as living for 13 years.

Distribution and Habitat

Greater rhea are South American birds living in grasslands and around the edges of forests in Paraguay, Argentina, Uruguay, Bolivia, and Brazil. These habitats include the savannahs of Brazil and Uruguay, the Brazilian cerrado, and the great Chaco ecoregion that covers parts of Paraguay, Bolivia, and Argentina. These birds are adapted for open plains where they can use their heights to look over long grasses, and use their long legs to traverse long distances quickly. Several escape rhea have now formed a permanent population in northern Germany!

Diet and Predators

Greater rhea are omnivorous, but a significant part of their diet is vegetation. In particular, they eat seeds, fruits, and flowers with them largely avoiding grasses. One thing that farmers have found is that greater rhea are fond of avocados. Other farmers can be quite thanful for rheas as they often eat insects which can damage crops, especially flies, grasshoppers, and beetles. They will sometimes also eat very small reptiles. Needing more protein to grow means that juveniles eat more animal matter compared to the adults. Greater rhea do not have many predators with the main predators being cougars, jaguars, humans, and caiman. Eggs and chicks can sometimes be killed by hawks, eagles, tegu, and even armadillos.

Conservation and Threats

The last time that the IUCN Red List evaluated the greater rhea was in 2022 when they gave it the rating of ‘Near Threatened’, and they raised the warning that greater rhea numbers are decreasing. The main reason for this has been human expansion into their environment. Large plantations of soy, avocados, and chard have reduced or biseccted their habitat placing greater pressure on their numbers.

Bibliography:

‘Greater Rhea’, Datazone by Birdlife, [Accessed 08/08/2026]
‘Greater Rhea’, Smithsonian National Zoo, [Accessed 08/08/2026]
BirdLife International, ‘Rhea americana, Greater rhea’, IUCN Red List, (12/08/2022), [Accessed 08/08/2026]
Kelly Hodges, ‘Rhea americana, Greater rhea’, Animal Diversity Web, (16/09/2016), [Accessed 08/08/2026]
Guy Kirwan, ‘Rheas’, in Gill Pitts, (ed.), Bird, Second Edition, (New York, NY: DK, 2022), 103
Cristian Pérez-Granados and Karl-L. Schuchmann, ‘Vocalisations of the Greater Rhea (Rhea americana): an allegedly silent ratite’, Bioacoustics, 30:5, (2021), 564-574