Tuesday, September 25, 2018

A New Pterosaur

Image result for pterosaur

Environmental & Science Education
Earth Science
Biological Evolution
Edward Hessler

A video on ABC news about the discovery of a very early pterosaur (aka pterodactyl)--roughly 200 million years bp (before present), led me to look for the press release announcing the find. The  Brigham Young University announcement includes the video used by ABC news.

The pterosaur has been named Caelestiventus (heavenly wind) hanseni (in honor of Bureau of land Management (BLM) geologist Robin L. Hansen). It was found by BYU's geological sciences professor Brooks Britt in a sandstone sample that he and his team collected at Saints and Sinners Quarry, on BLM land in Utah. The quarry is so fossil-rich (18,000 bones and counting) that researchers find it much more convenient to remove large blocks of the sandstone for later examination in the lab rather than chipping sandstone and bones apart in the field.

Britt was expecting to find early crocodiles--pterosaurs are rare, this one was new to paleontolgists and predates desert pterosaurs by 65 million years. Furthermore, it was in excellent condition. (bones preserved in sand cannot be compressed). The press release notes that these bones of Caelestiventus hanseni ... are uncrushed and three-dimensional because they are preserved in sand, which cannot be compressed. “Most Triassic specimens consist of just a single bone: for example, a little phalanx from a finger or one vertebra from the neck,” Britt said. “For this animal, we have the sides of the face and the complete roof of the skull, including the brain case, complete lower jaws and part of the wing.”

According to the press release C. hanseni is most closely related to a pteroaur known only from Lower Jurassic strata of Britain. This provides evidence that the family of pterosaurs originated in the latest Triassic and the lineage survived the Triassic-Jurassic mass extinction event.

If you are unfamiliar with geological terms, this rendition of the geological time scale should help.  BBC Nature provides information about the Triassic-Jurassic mass extinction. And if you'd like to know just what a pterosaur is, see this information from the American Museum of Natural History. Large, yes! Beautiful, yes!! If you wonder about the significance of this discovery, it is nicely summarized in a map at Everything Dinosaur (scroll down) which also makes further comments on the discovery. 

No comments:

Post a Comment