Fossil teeth reveal how extinguished carnivorous mammals adapted to global warming 56 million years ago
During the thermal maximum of Paleocene-Eocene (PETM), a period of rapid warming and geological aridification about 56 million years ago, a Mammal Mesonychid Flesh Eat Dissacus forecast Responded in a surprising way – it started to eat more bones.
Dissacus forecast. Image credit: DIBGD / CC by 4.0.
“What happened during the PETM reflects a lot what’s going on today and what will happen in the future,” said Andrew Schwartz, a doctoral student at Rutgers, New Jersey-New Brunswick’s state University.
“We see the same patterns. Carbon dioxide levels increase, temperatures are higher and ecosystems are disturbed. ”
In their research, Schwartz and his colleagues used a technique called dental microwear texture analysis to study the tiny wells and scratches left on the fossilized teeth of Dissacus forecastA kind of mammal in the extinct family Mesonychidae.
Ranging from 12 to 20 kg, this former omnivore was the size of a jackal or a coyote.
The animal was quite common in the Cenozoic forests at the start and probably consumed a mixture of meat and other food sources such as fruits and insects.
“They looked superficially like wolves with oversized heads,” said Schwartz.
“Their teeth were a bit like hyenas. But they had small tiny hooves on each of their toes.”
“Before this period of temperature increase, Dissacus forecast had a diet similar to modern cheetahs, mainly eating hard flesh. »»
“But during and after this ancient period, his teeth showed harmful signs of materials, such as bones.”
“We have found that their micro-dentaires were more like that of lions and hyenas.”
“This suggests that they ate more brittle food, which were probably bones because their usual prey was smaller or less available.”
This food change has occurred in parallel with a modest reduction in body size, probably due to the food shortage.
“While the previous hypotheses blamed animals in narrowing only hot temperatures, the latter research suggests that limited food has played a more important role,” said Schwartz.
“This rapid global warming period lasted around 200,000 years, but the changes he triggered were rapid and dramatic.”
“Studies of the past and his can offer practical lessons for today and what comes next.”
“One of the best ways to know what will happen in the future is to come back to the past. How have animals changed? How did ecosystems react? ”
“The results also highlight the importance of food flexibility. Animals that can eat a variety of foods are more likely to survive environmental stress. ”
“In the short term, it’s great to be the best in what you do,” said Schwartz.
“But in the long term, it’s risky. Generalists, which means that animals that are good in many things, are more likely to survive when the environment changes. ”
Such a glimpse can be useful for modern conservation biologists, which allows them to identify the most vulnerable species today.
Animals with a narrow diet, such as pandas, can fight as their habitats shrink. But adaptable species, including jackals or raws, could get out of it.
“We already see that happening,” said Schwartz.
“In my previous research, jackals in Africa began to eat more bones and insects over time, probably because of the loss of habitat and climatic stress.”
The study has also shown that rapid warming of the climate as shown in the ancient past can cause major changes in ecosystems, including changes in available prey and changes in predators’ behavior.
This may suggest that modern climate change could also disrupt food networks and force animals to adapt or risk extinction.
“Even if Dissacus forecast was a successful and adaptable animal that lived for about 15 million years, it finally died, “said Schwartz.
“Scientists believe that this has happened due to changes in the environment and competition from other animals.”
The study was published in June 2025 in the journal Paleogeography, paleoclimatology, paleoecology.
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Andrew Schwartz and al. 2025. Food change through the thermal maximum of Paleocene-Eocene in the Mesonychid Dissacus forecast. Paleogeography, paleoclimatology, paleoecology 675: 113089; DOI: 10.1016/J.Palaeo .2025.113089
