Puntanipterus

Puntanipterus globosus was named in 1975 by paleontologists José Bonaparte and Teresa Sánchez, based on a single incomplete specimen found in the Lower Cretaceous La Cruz Formation of San Luis Province, Argentina. The generic name translates to “Puntanos wing,” referencing a nickname for people from San Luis Province. The specific name translates to spherical, referencing the unique anatomy of the ankle. 

The only known specimen consists of a tibiotarsus, fibula, wing phalanx, foot phalanx, and one dorsal vertebra. The tibiotarsus is roughly 10.5 cm (4 inches) long and fibula is roughly 7 cm (2 3/4 inches) long. Bonaparte and Sánchez described the leg bones as being similar to those of Pterodaustro, known from slightly younger rocks in the same area, but with a very rounded, almost spherical ankle joint. 

When Bonaparte and Sánchez first named Puntanipterus, they didn’t assign it to any family, but in 1978, Bonaparte assigned Puntanipterus to the Pterodaustridae. In 1980, Peter Galton noted similarities between the Puntanipterus and dsungaripterids and assigned this genus to that family. 

In 1998, Luis Chiappe and colleagues reported finding several Puntanipterus-like tibiotarsi from the overlying Lagarcito Formation. Those leg bones are not articulated with any diagnostic skeletal material, but that formation is famous for hundreds of specimens of Pterodaustro and no other pterosaurs. Chiappe and colleagues considered it likely that Puntanipterus and Pterodaustro were actually the same animal, and that the supposed differences in ankle morphology were due to crushing in the majority of Pterodaustro specimens. This wasn’t universally accepted, as Lü and colleagues (2009) followed Galton in considering it a dsungaripterid. We’ve followed the interpretation of Galton and Lü and colleagues here at Pteros, although it could well be something similar to Pterodaustro instead. 

Puntanipterus lived in an ancient semi-arid valley with a large lake about 115 million years ago. Its diet is unknown, if it turns out to be a dsungaripterid it probably had stout teeth and focused on shellfish, and if it turns out to be a ctenochasmatid similar to Pterodaustro it was probably a suspension feeder with dozens of narrow teeth.