Modern methods of analysis allow paleontologists not only to find out what an ancient creature looked like, but also to learn a lot about its way of life. The discovery of the remains of a giant sloth of the Eremotherium laurillardi species, which lived in Belize more than 27 thousand years ago, is a striking example of this.
By studying the fossilized tooth of an extinct creature, researchers were able to learn a lot about the last year of its life and put forward new hypotheses about the life and state of the environment of the megafauna, which scientists know little about. Let us clarify that by megafauna, experts mean a set of animal species whose body weight exceeds 40 kilograms.
Belize, located between the Caribbean Sea and the east coast of Central America, is a small country with many rainforests and tremendous biodiversity. For example, Belize is home to the second largest barrier reef in the world.
Nevertheless, during the life of a giant sloth (reaching four meters in height), the territory of Belize looked completely different: there was no dense jungle, one had to be content with only barren and dry terrain.
The sloth found the last glacial maximum. The level of the World Ocean at that time was significantly lower than today due to the fact that water accumulated in the form of ice in the ice sheets was withdrawn from the hydrosphere.
At that time, the animal and its contemporaries did not have enough water. Most likely, it was thirst that led E. laurillardi to a huge hole, from which he never managed to get out alive.
His remains - a humerus and femur, as well as part of a tooth - were discovered by divers 27,000 years later.
The researchers analyzed the sloth's tooth tissues. The indentations show the locations where samples were taken for analysis.
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Stanley Ambrose and colleagues at the University of Illinois at Urbana-Champaign studied the tooth of an ancient creature (the tooth was almost 10 centimeters long).
However, scientists faced a number of problems. Unlike other huge animals such as mammoths, giant sloths did not have tooth enamel, a hard layer that “records” information about what the creature ate.
Most of the original tissue has also been replaced with minerals over time (this happens during the petrification process).
Nevertheless, cathodoluminescence microscopy allowed Ambrose's group to separate the "surviving" tissues from the minerals. As a result, scientists received 20 samples of orthodentin - the tissue from which the teeth are built.
Experts found that the sloth faced a nine-month dry season, and only three months of rains made his life somewhat easier. From what he ate, the sloth lived in the savannah, not in the forest.
The ancient sloth of the Eremotherium laurillardi species grew up to four meters in height. (illustration by Julie McMahon).
In addition, scientists found that sloths could adapt to a wide variety of environmental conditions.
The fact that giant sloths have adapted to different conditions explains why they were so widespread and survived for so long. Climate change is one of the factors that some scientists associate with their extinction (this happened 12-13 thousand years ago).
Meanwhile, new data suggests that these individuals could survive such "whims of nature." Therefore, another hypothesis of their extinction - the hunt for them by ancient people - now sounds more plausible.
A scientific article on the results of the work is presented in the publication Science Advances.