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Photo courtesy of BYU Photo, Michael Skrepnick, Nate Edwards
Recent pterosaur finding is a big deal
By ELLEN GOLDBAUM
Published August 20, 2018 This content is archived.
Jack Tseng
The rare pterosaur fossil announced last week by scientists at Brigham Young University is the most complete early pterosaur ever found. Pterosaurs were extremely unique creatures, believed to be the first vertebrates capable of powered flight. They are described as having fang-like teeth, some with pouches near their mouths like pelicans; others would evolve to become the size of small airplanes.
Jack Tseng, an evolutionary biologist and assistant professor of pathology and anatomical science in the Jacobs School of Medicine and Biomedical Sciences at UB, talks to UBNow about why this finding is so significant.
Let’s get the most obvious question out of the way first: Does this have any impact or meaning for human or mammalian evolution?
JT: The time period in question is way before humans — and even mammals — and pterosaurs were an evolutionary dead end, so this discovery doesn’t really pertain to anything human or mammal.
Pterosaurs are believed to be the first vertebrates capable of powered flight. They have been described as having fang-like teeth, some with pouches near their mouths like pelicans. Image courtesy of BYU
Why is this such an important discovery?
JT: The find itself is unusual for the type of habitat in which pterosaurs are typically found. Rather than from marine or lakeshore paleoenvironments like most other pterosaur fossils around the world, the new fossil from Utah was preserved in sand dune deposits. Indeed, a rare find for that type of rock! It’s like finding a needle in a haystack, and that needle is broken into a dozen pieces.
Why is the fossil’s age so important?
JT: What is really neat about this find is that the new pterosaur is a whopping 65 million years older geologically than the next-oldest desert-preserved pterosaur. This suggests that pterosaurs were living in or traveling through diverse habitats like desert, lake and coastal environments a lot earlier in their evolutionary history than scientists previously thought. This revolutionizes the way we think about pterosaur evolution and adaptation as a whole.
How might the discovery be relevant to animals that exist today?
JT: The discovery could stimulate some discussion about how other flying vertebrate animals; for example birds, which evolved from the dinosaur lineage independent of pterosaurs, may or may not have lived in the past. Absence of evidence is not evidence of absence, so there is ample opportunity to fill in gaps of the overall evolutionary record, and what fossils such as those in the study can tell us about the “secret lives” of extinct animals. Fortune awaits the lucky — and persistent — field paleontologist. The exceptional preservation of the new fossils in that particular time and space shows us just how rare such fossil records can be for flying animals.
The pterosaur skull unearthed by Brigham Young University scientists. The skull is uncrushed and three-dimensional because it was preserved in sand, which cannot be compressed. Photo courtesy of BYU Photo, Michael Skrepnick, Nate Edwards
What was interesting about the way they analyzed the fossils?
An especially cool approach used in the study of the new pterosaur specimens is describing and presenting the fossilized bone fragments using CT scanning and 3D reconstruction.
Rather than a full extraction of the delicate and thin fossil fragments from the hard sandstone, and in the process risking damage to those specimens, the researchers first exposed the surface of each bone fragment by mechanical means. Then they used CT scanning to get the shape of the whole bones using 3D reconstruction and documented the anatomy of the bones from 3D models.
In this way, the delicate specimens are preserved and critical anatomical information is obtained to definitively diagnose the fossils to a new species, Caelestiventus hanseni. Old specimen meeting new technology equals an amazing discovery!