Are bears related to dogs

When cats and dogs were the same thing

When the dinosaurs, the gigantic rulers of the earth's land masses, took their last breath about 66 million years ago, the triumph of mammals began. At first they scurried through the huge primeval forests of the Paleocene as herbivores, but their enemies were already in the starting blocks: The first carnivorous mammals gradually appeared, the so-called "Carnivoraformes".

These "predatory animals" gradually developed in the subsequent geological age of the Eocene to what we know today under the term "predators" (in the scientific sense, unlike in everyday language, only carnivorous mammals are counted here). These "Carnivoraformes" are the ancestors of today's lions, tigers, bears, but also walruses, weasels, dogs and cats.

The family tree of the feline (Feliformia) and canine
(Caniformia) predators with their common ancestors.
Image: Charlène Letenneur (MNHN) / Pascale Golinvaux (RBINS)

Puzzle of teeth and knuckles

A team of scientists headed by Floréal Solé is now on the track of one of the earliest representatives of these prehistoric animals based on bone finds that are 55 million years old. With the help of 250 teeth and ankles from a site in Belgium, the researchers got the Dormaalcyon latouri reconstructed (picture above). The animal's primitively formed teeth made it clear to the scientists that the find was a very early specimen of the "Carnivoraformes" and suggests that this order could have its roots in Europe today. The construction of the ankles of Dormaalcyon latouri suggest that the animal lived “arboreally”, that is, it moved on trees.

The climate 55 million years ago was warm, humid and heavily forested; this short period of strong global warming is also known as the “Paleocene / Eocene temperature maximum”. These climatic conditions favored the evolution of many groups of mammals. During this time, the primal predators also moved from Europe to today's America, writes Solé in his study in the journal "Journal of Vertebrate Paleontology". At that time there was a continuous, evergreen forest belt in which the animals could move.

In the future, the researchers want to continue looking for the original form of all predatory species. "There are more fossils out there that need to be found in order to determine the origin of this group that is so popular today."