A study published in the Proceedings of the National Academy of Sciences introduced Eotephradactylus mcintireae, the earliest pterosaur yet found in North America and among the oldest recorded worldwide. The fossil came from an ash-rich bonebed in Petrified Forest National Park, Arizona, and volcanic minerals in the surrounding sediment dated it to 209.2 million years ago. The animal’s wingspan matched that of a small seagull.
The genus name, Eotephradactylus mcintireae, is drawn from Greek roots. It refers to the volcanic ash that entombed the site and the species’ place near the dawn of pterosaur evolution. The honorific mcintireae acknowledged Suzanne McIntire, a volunteer at the Smithsonian National Museum of Natural History’s FossiLab, who first noticed the lower jaw while cleaning a rock block sent from Arizona.
Researchers identified a three-centimeter lower jaw, a wing bone, and a single tooth. Pterosaur bones were hollow and rarely fossilized, so even small fragments offered valuable information about early flight among reptiles.
“It could’ve sat on your shoulder, like a small seagull,” said Ben Kligman, who led the research at the Smithsonian National Museum of Natural History, according to CBS News. The discovery pushed back the North American pterosaur record by roughly five million years.
The Arizona bonebed yielded nearly 1,500 fossils representing at least sixteen vertebrate groups. Large amphibians, crocodile relatives, freshwater sharks, and some of the oldest known frogs and turtles shared the habitat. “Turtles dispersed rapidly across Pangaea, which is surprising for an animal that was not very large and likely moved at a slow pace,” said Kligman, as reported by Newsweek.
Seasonal monsoonal floods swept ash and sediment into low-lying channels, burying fish, predators, and the ash-winged pterosaur together. Fang-like front teeth and multicusped rear teeth, scarred by wear, showed that Eotephradactylus hunted armored gar-like fish common in those streams.
“Because of the painstaking and time-consuming nature of preparing these fossils, the entire study would not have been possible without the thousands of hours of time FossiLab volunteers put into this study,” said Kligman in a Smithsonian statement. “What was exciting about uncovering this specimen was that the teeth were still in the bone, so I knew the animal would be much easier to identify,” said McIntire.
The species filled a gap just before the end-Triassic extinction 201.5 million years ago, when volcanic activity linked to Pangaea’s breakup eliminated about three-quarters of Earth’s species. “The only way to fully understand what happened during transformative events in Earth history like the end-Triassic extinction is to go out and find new fossil sites that fill critical gaps in the fossil record,” said Kligman, according to Popular Science.
The preparation of this article relied on a news-analysis system.