Giant turtle discovered that lived in the Amazon – 03/13/2024 – Science

The first humans to arrive in the Amazon may have encountered a portentous inhabitant in the region’s large rivers: a turtle whose carapace averages around 1.80 m. Everything indicates that the Peltocephalus maturinwhose discovery was just announced this Wednesday (13) by an international team of scientists, was the last of the giant Amazonian tortoises, having disappeared at the end of the Pleistocene (the Ice Age).

The possibility of the animal coexisting with the Homo sapiens is still a subject of discussion. What can be said with a reasonable degree of certainty is that the super turtle lived less than 40 thousand years ago, taking into account the age of the sediments from which the fossil comes, in a gold mining area on the Madeira River, in Rondônia.

As the remains of the animal (for now, just a dentary, or piece of the jaw) were found by the miners themselves, there is no certainty about where they were in the sediment layers and, therefore, about their age.

Remains of charred wood in the lowest part of the mining layers are dated between 46,000 and 21,000 years before the present. Dating from the bone itself produced ages between 14,000 and 9,000 years ago.

This second age range coincides with the arrival of ancestors of current indigenous peoples in the Amazon territory, but the state of preservation of the fossil and the surrounding environmental conditions could be influencing the result, “rejuvenating” the sample in a misleading way.

In any case, the species presented in an article in the specialized journal Biology Letters is an impressive addition to the Brazilian fauna of the Ice Age. The size of the animal was estimated based on its teeth, which itself measures almost 30 cm. Anatomical details of the bone structure allow classifying the animal as a member of the genus Peltocephalus, the same as a species that still exists today in rivers in the North region. This is the Amazon big-headed turtle, also popularly known as the “loggerhead”.

The research team, whose first author is Gabriel Ferreira, from the University of Tübingen, and also includes Max Langer, from USP Ribeirão Preto, Mario Cozzuol, from UFMG, and other scientists, decided to pay homage to fictional characters by naming the animal. Maturin is the name of a cosmic turtle in the work of American writer Stephen King and, in turn, owes its name to the character Stephen Maturin, a doctor and naturalist who meets the giant tortoises of the Galápagos Islands in the naval adventure novels by British writer Patrick O’Brian.

In the current Amazon basin, the record holder for size is Podocnemis expanda, or Amazon turtle, whose shell does not exceed 1.1 m in length. A P. maturinwhich reached close to 2 m, has a dentary that suggests an omnivorous diet, unlike its current cousins ​​in the Amazon region, which are predominantly herbivorous.

In more remote times, the group of turtles had even larger representatives in the area. The most stupendous, as the scientific name suggests, was the Stupendemys geographicapresent in Acre, Venezuela and Colombia, whose carapace was approximately 3 m long and disappeared around 5 million years ago.

In the study, researchers speculate about a possible relationship between the end of P. maturin and the arrival of human beings in the Amazon. This is because extinctions of large turtles have occurred several times during the millennia of expansion of our species across the planet. For now, however, there is no direct evidence that the ancestors of the indigenous people and the supercagado lived together, or that people at some point devoured the animal.