Smallest fossil reptile - Neuticosaurus species

Science News, Feb 20, 1988

Smallest fossil reptile

Paleontologist Martin Sander has found what may be the smallest known skeleton of an extinct reptile species, he reports in the Feb. 12 SCHIENCE. Measuring 51 millimeters long, or slightly more than 2 inches, this 230-million-year-old member of the Neusticosaurus species reached only 22 percent of the average adult length. Neusticosaurus was an aquatic reptile that frequented warm coastal waters.

The skeleton is curled up and displays many undeveloped features. This indicates that the animal was an embryo, which makes it an extremely rare fossil find, says Sander, a paleontologist at Zurich University in Switzerland. The embryo fossil will help detail the growth patterns of Neusticosaurus. In addition, scientists can use the fossil to discern evolutionary relationships between Neusticosaurus and other reptiles.

The embryo may fuel the debate over the possibility that some ancient reptile, including some dinosaurs, gave birth, to live young. It is believed that most extinct reptiles laid eggs, a process confined to land. But paleontologists have found one species, a fully aquatic propoise-like creature, that gave birth to live young in the water. Sander suggests that Neusticosaurus may also have borne live young because the fossil embryo was found in sediments that were miles offshore, and it is not clear how an egg could be carried that far from land.