Neutrons help track down mammalian ancestors

An animal species that has been extinct for 220 million years has been identified by a team of researchers from Germany and Argentina. Insights into the evolution of mammals are provided by findings on the new species.

A long snout, a massive jaw and sharp teeth are some of the features of the new species. It is part of the group of Cynodontia, which is a subgroup of mammals.

In the west of Argentina, there is a desert-like Talampaya National Park. It wasn't possible to remove the rock without damaging the bones. He was involved in the project with Dr. Gaetano from CONICET.

Thanks to neutrons, there are clear images.

The X-ray images were used to see the bones. The high iron content of the petrified soil made it hard for the bones to be seen in the X-ray images. Iron is not a problem for Neutrons. The Comisin Nacional de Energa Atmica in Argentina is where the research was done.

There were promising images but with low resolution. The researchers continued their analysis at ANTARES. Cold neutrons give us better contrast than a longer wavelength. Higher spatial resolution is offered by ANTARES.

There's a big jaw and whiskers.

Thanks to ANTARES, the paleontologists were able to determine that the bones were from a previously unknown species. It was a big surprise for us. Cynodonts are very rare during that period of the Norian. The new species was named after a scientist from Argentina.

Features that weren't found in other findings were found in the study. The specimen had different numbers of teeth in the upper and lower jaws. There is a space in the lower jaw that is outside of the tooth row in this specimen. There was a canal in the upper jaw of the new specimen. Nerves ran through this canal when the animal was dead. The characteristics of this canal suggest that it was used by a mammal.

One step closer to understanding the origin of mammals.

New information is added to the evolutionary tree of cynodonts. By reconstructing evolutionary steps like the development of whiskers in the evolutionary tree, researchers can understand the evolution of mammals. There is a theory that mammals originated in the south of Brazil. Researchers are one step closer to figuring out the origins of mammals.

More information: L. C. Gaetano et al, A new cynodont from the Upper Triassic Los Colorados Formation (Argentina, South America) reveals a novel paleobiogeographic context for mammalian ancestors, Scientific Reports (2022). DOI: 10.1038/s41598-022-10486-4 Journal information: Scientific Reports