Clevosaurus hadropondon: Tiny Tusked Dinosaur Discovered in Brazil

Thursday, August 15, 2019

Randall L. Nydam, Ph.D., Midwestern University

Researchers have recently discovered a gecko sized reptile species from the Triassic period, named clevosaurus hadropondon.

The Clevosaurus hadropondon is a newly discovered reptile species from the Triassic Period that was found in the Brazilian state of Rio Grande do Sul.

Researchers have found the remains of a jaw and other skull belonging to the new species. The remains were found in Triassic rock dating back to around 237M years ago.

The clevosaurus hadropondon is the oldest discovered fossil to of it’s kind from Gondwana, the continent which now makes up Africa, Antarctica, Australia, India and South America.

This gecko sized Triassic reptile possessed small blade like teeth with “a large, blunt, tusk-like tooth in the first tooth position of the both premaxilla (upper jaw) and of dentary (lower jaw). This feature is typically observed only in later sphenodontian lineages” according to Annie Schmaltz Hsiou,  Associate Professor at the University of São Paulo. Annie Schmaltz Hsiou is also the head of the study which analysed the remains. By sphenodontian she means a lizards like reptile also known as a Rhynchocephalia.

Co-author of the study Randall Nydam is Professor at Midwestern University (US). Nydam is a vertebrate paleontologist studying the evolutionary history of lizards and snakes. “Clevosaurus hadroprodon is an important discovery because it combines a relatively primitive sphenodontian-type tooth row with the presence of massive tusk-like teeth that were possibly not for feeding, but rather used for mate competition or defense. If correct, this means that non-feeding dental specialisations predated changes in the sphenodontian dentition related to feeding strategies. This is a very exciting discovery.”

Nydam is currently working on the early evolution and distribution of snakes based on specimens from both the north and southern hemispheres including the oldest known snake fossils.

The new discovery will help with the understanding of small reptilian evolution.