Pseudotherium argentinus: Triassic-Era Mammal Relative Had Saber Teeth

Wednesday, August 28, 2019

An artist’s impression of Pseudotherium argentinus. Image credit: Agencia CTyS-UNLaM.

A new species of cynodont has been identified from a fossilized skull found in the San Juan province, Argentina.

The extinct mammal relative, named Pseudotherium argentinus, lived during the Triassic Period, about 231 million years ago.

Pseudotherium argentinus lived in an environment warmer than today, with abundant flora mostly made up of ferns and conifers, since there were no flowering plants during its time,” said Dr. Ricardo Martínez, a paleontologist with the Institute and Museum of Natural Sciences at the University of San Juan.

The ancient animal was about 10 inches (25 cm) long and had very long fangs.

“The species had a very long, flat, and shallow snout, and its very long fangs located almost at the tip of the snout, so the resemblance to Scrat, the renowned squirrel-like character with saber teeth in the Ice Age movies, is tremendous,” Dr. Martínez said.

“His long fangs could have served him on one hand, to nail and trap insects or prey, but another option is that this animal has been a male and we are in the presence of sexual dimorphism, that is, that the males of this species had developed these great fangs as a way to attract females.”

“But, at this point, you can’t know much, because we only have one specimen.”

Pseudotherium argentinus, incomplete right stapes of Pseudotherium. (A) Anteromedial view of stapes, (B) medial view of footplate of stapes, and (C) semitransparent isosurface render of stapes in situ and skull in oblique-ventral view.

The well-preserved skull of Pseudotherium argentinus was found at the Valle Pintado locality of the Ischigualasto Formation.

Dr. Martínez and colleagues used high-resolution CT scans of the specimen to study its internal structure.

“With these images, we could observe the developed inner ear, the loss of the post-orbital bar, as well as the presence of the turbinals that are like partitions that allowed this animal to heat the air entering its respiratory system, which would indicate that he had hot blood,” Dr. Martínez said.

paper on the discovery was published in the journal PLoS ONE.


R.V.S. Wallace et al. 2019. First record of a basal mammaliamorph from the early Late Triassic Ischigualasto Formation of Argentina. PLoS ONE 14 (8): e0218791; doi: 10.1371/journal.pone.0218791