April 24, 2014
International Research Team Names Most Primitive Species Of Flying Reptile
Lawrence LeBlond for redOrbit.com - Your Universe Online
Pterosaurs, an order of winged reptiles that were the earliest reptiles to evolve powered flight and had gone on to become the largest known flying creatures to have ever existed, are at the center of a new fossil study from a team of international researchers.
Researchers from the University of South Florida, George Washington University and Chinese Academy of Sciences say they have found the most primitive pterodactyloid known, establishing that the winged reptiles flew high above the Earth some 163 million years ago.
The study is based on a fossil discovered in northwest China in 2001 by Chris Sloan, formerly of National Geographic and now president of Science Visualization. The fossil was found in a mudstone of the Shishugou Formation 35 meters below an ash bed in the well-known “dinosaur death pits.” The fossil came from the same area that had also produced one of the oldest tyrannosaurs: Guanlong.
Not only have the team described this new species, they also named it: Kryptodrakon progenitor.
Through extensive analysis the team established that this was the first pterosaur to bear the characteristics of the Pterodactyloidea, which would become the dominant winged creatures of the prehistoric era. The findings of the study are published in the journal Current Biology.
"This finding represents the earliest and most primitive pterodactyloid pterosaur, a flying reptile in a highly specialized group that includes the largest flying organisms," said Chris Liu, program director in the National Science Foundation's Division of Earth Sciences. "The research has extended the fossil record of pterodactyloids by at least five million years to the Middle-Upper Jurassic boundary about 163 million years ago."
K. progenitor lived around the time of the Middle-Upper Jurassic boundary and through studies of other fossil fragments, researchers have determined that pterodactyloids originated, lived, and evolved in terrestrial environments, rather than marine environments where other specimens have been found.
The new discovery has been described as belonging to a small pterodactyloid with a wingspan of about 54 inches. Pterodactyloids of a later period had become giant creatures, some as big as small planes. However, these winged reptiles had become extinct along with the dinosaurs about 65 million years ago. The pterosaurs were considered close relatives of dinosaurs, but were not dinosaurs themselves.
Paleontologist Brian Andres, lead researcher from USF, said this discovery provides novel information on the evolution of pterodactyloids. The area where the fossil was found was likely a flood plain during the time this creature existed, he added.
As pterosaurs evolved, their wings changed from being narrow – a sign of living in marine habitats – to being broader, which helped them navigate terrestrial environments more easily.
“He (Kryptodrakon progenitor) fills in a very important gap in the history of pterosaurs," Dr. Andres said in a statement. "With him, they could walk and fly in whole new ways."
The specimen is now housed at the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing, China. Its genus name comes from Krypto (hidden) and drakon (serpent), referring to “Crouching Tiger, Hidden Dragon,” which was filmed near where the species was discovered. Its species name (progenitor) means ancestral or first-born, referring to its status as the earliest known pterodactyloid, explained Andres.
"Kryptodrakon is the second pterosaur species we've discovered in the Shishugou Formation and deepens our understanding of this unusually diverse Jurassic ecosystem," said Dr. Clark, GW's Ronald B. Weintraub Professor of Biology. "It is rare for small, delicate fossils to be preserved in Jurassic terrestrial deposits, and the Shishugou fauna is giving us a glimpse of what was living alongside the behemoths like Mamenchisaurus."
Pterosaurs were a diverse group of Mesozoic flying reptiles that underwent a body plan reorganization, adaptive radiation, and replacement of earlier forms midway through their long history, resulting in the origin of Pterodactyloidea.
The new research also provides some unique viewpoints on the significant correlation seen in the wing shape and environment in pterosaurs and that of modern flying vertebrates. However, pterosaurs are not the ancestors of modern birds and scientists believe that pterosaurs did not evolve into early birds or any other flying animals that are known.