Robin Whatley and Research Team Discover North America’s Oldest Known Pterosaur
ºÚÁÏÍø students and instructor Robin Whatley at the Petrified Forest National Park where the fossils were found. Left to right: Meme Thermpangpun ’17, Sarah Matthews ’17, Sierra Romesburg ’20, Abbigail Ladwig ’17, Jake Hughes ’16, Dane Wheaton ’18, and Robin Whatley
Kay Behrensmeyer (left), curator of vertebrate paleontology at the Smithsonian’s National Museum of Natural History, with Robin Whatley (right) in Petrified Forest National Park digging for fossils in a quarry in 2023. Photo credit: Ben Kligman, Smithsonian Institution
Paleontology Field Observation and Methods Honors class looks out on the Painted Desert while learning about the history and geology of the Petrified Forest National Park. Left to right: Abbigail Ladwig, Jake Hughes, Robin Whatley, Meme Thermpangpun, Sarah Matthews (obscured), Dane Wheaton. Photo credit: Sierra Romesburg
An artist’s reconstruction of the fossilized landscape. The pterosaurs and some of the earliest turtles were found preserved in a remote bonebed in the Petrified Forest National Park in Arizona. Illustration by Brian Engh
Jay Meyers films fossil preparator Bill Amaral (Harvard University, Emeritus) at work in the Petrified Forest National Park. Photo Credit: Robin Whatley
Artist’s depiction of the paleocommunity and the channel setting where bonebed components including mud clasts, coprolites (fossilized poop), and disarticulated vertebrate bones and teeth will soon be buried by a flash flood caused by the distant rainstorm. Credit: PNAS/Alex Boersma (illustrator)Robin Whatley, PhD, faculty member in ºÚÁÏÍø’s School of Design, helped rewrite prehistoric history as part of a Smithsonian and ºÚÁÏÍø-led team that uncovered North America’s oldest known pterosaur, a winged reptile that lived during the time of early dinosaurs, and was the first vertebrate group to develop powered flight. The team’s discovery—published in “ (PNAS)”—challenges long-held assumptions about where these ancient flying reptiles once roamed and fills a 12-million-year gap in the fossil record.
Unearthed in Arizona’s Petrified Forest National Park, the fossilized remains offer new insights into pterosaur evolution and how these creatures coexisted with turtles, frogs, and other vertebrates before the end-Triassic extinction 201.5 million years ago. The finding also redefines what is known about the global distribution of early pterosaurs—showing they lived far beyond Europe in non-marine environments.
“I initiated and designed the research project in the Petrified Forest National Park with my colleague Anna (Kay) Behrensmeyer, PhD, who I’d worked with as a postdoctoral fellow at the Smithsonian Institution before joining ºÚÁÏÍø,” Whatley says. Their work began in 2009, when they discovered the first fossils from the Owl Rock Member in the park’s remote northern Wilderness Area. A return visit in 2011 led to the fossil bone bed site—where the newly named pterosaur, Eotephradactylus mcintireae, was uncovered.
“It’s not common for paleontology field research to be led by women,” she adds, “though there is a precedent in the Petrified Forest where some of the earliest vertebrate fossils were found and collected by in the 1920s.”
Pushing the Boundaries of Paleontological Research
The fossil was discovered under a microscope in a block of sediment too delicate for traditional screen-washing methods. “We quickly determined this to be too damaging to preserve fragile fossils like Eotephradactylus,” Whatley explains. “The method we used, carefully extracting and preparing blocks of sediment to find and preserve delicate bones and teeth, provides another important avenue for discovery of microfossils that would not otherwise be preserved.”
Unlike many early pterosaur fossils found in shallow marine environments, Eotephradactylus was preserved in river deposits alongside terrestrial and freshwater species. Its teeth show wear patterns consistent with a diet of hard-scaled fish, and scans of its jaw and tooth structure mark a first in pterosaur research. “We hope our analysis will provide features for future comparisons and help resolve questions about the relationships between pterosaurs and their early dinosaur relatives,” Whatley says.
ºÚÁÏÍø supported the research with Faculty Development Grants in 2010 and 2012. ºÚÁÏÍø students also joined the expeditions and contributed directly to the findings. Jay Meyers ’11, a Film and Television major, documented the fieldwork in his film “,” a Weisman Award-winning documentary that premiered at Chicago’s Landmark Century Centre Cinema.
Art History alum Jenna Domeischel ’11 analyzed fossil bivalves collected during the 2010 trip and later joined the 2012 expedition, helping collect fossils at the site that yielded the new pterosaur.
A Landmark Discovery in Prehistoric Science
For Whatley, identifying the fossil as a pterosaur was one of the most satisfying parts of the process. “It’s always exciting to make any fossil discovery. But the process of identifying the fossil as an early pterosaur, which required comparing and ruling out other similar but different kinds of animals that were living at the same time, was really interesting and rewarding,” she says. She added that drawing and describing the features of the Eotephradactylus jaw was a big part of that identification.
Whatley also proposed the new genus name, Eotephradactylus, meaning ‘ash-winged dawn goddess’ referencing the animal’s early evolutionary position, the site’s volcanic ash, and the fourth finger that makes up the pterosaur wing. “It was fun coming up with a name that my colleagues agreed fit its importance as the earliest known member of its group with an associated radioisotopic date.” The species name references its discoverer, volunteer Suzanne McIntire, who found the fossil while preparing the quarry block in the Smithsonian’s FossiLab.
In addition to Eotephradactylus, the site preserved fossils from at least 15 other species, including fish, freshwater sharks, large amphibians, carnivorous reptiles, early jumping frogs, turtles, and lizard-like sphenodontians. “This is the first evidence that modern vertebrate groups that are commonly found living later in the Jurassic and Cretaceous Periods began forming ecological communities as early as 209.2 million years ago,” Whatley says. “It’s the oldest association of frogs, turtles, sphenodontians, and pterosaurs—some 26 million years earlier than previously reported.”
Read the full study in PNAS: