Paleontologists from the University of Texas at Austin have identified a new species of ancient beaver from the fossilized remains found at several sites in the Texas Coastal Plain.
A partial skull fossil from the ancient beaver Anchitheriomys buceei (right) alongside a skull reconstruction. Image credit: Matthew Brown / Jackson School Museum of Earth History, the University of Texas at Austin.
The newly-discovered species lived in what is now Texas, the United States, about 15 million years ago (Miocene epoch).
Named Anchitheriomys buceei, it was a relatively large beaver, similar to a previously known species, Anchitheriomys fluminis, in size.
It co-existed with ancient elephants; proto-horses Merychippus and Cormohipparion; rhinos Aphelops, Peraceras, and Teleoceras; and the carnivores Paratomarctus, Tomarctus, and Edaphocyon.
“To the casual observer, Anchitheriomys buceei probably wouldn’t have looked much different from beavers living in Texas today,” said Dr. Matthew Brown, the director of the vertebrate paleontology collections of the Jackson School Museum of Earth History at the University of Texas at Austin.
“However, one key difference is size. Anchitheriomys buceei was bigger — about 30% larger than modern beavers — though still much smaller than the bear-size beavers that lived in North America during the Last Ice Age.”
The fossils of Anchitheriomys buceei were found at six paleontological sites in the Texas Coastal Plain in the 1800s through the 1930s.
But most of what Dr. Brown and his colleague, Dr. Steven May, found about the new species comes from a unique partial skull from Burkeville, Texas.
The fossil is a fusion of bone and brain cast that was created when sediment naturally seeped into the beaver’s brain cavity eons ago, creating a rock replica of the brain as the specimen fossilized.
High-resolution X-ray images of the skull brought small anatomical details of the skull into clear view.
“New discoveries in the field capture lots of attention, but equally as valuable are the discoveries made in existing museum collections,” Dr. Brown said.
“We know that these opportunities are littered throughout the drawers in these cabinets.”
The team’s paper was published online in the journal Palaeontologia Electronica.
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Steven R. May & Matthew A. Brown. 2023. Anchitheriomys buceei (Rodentia, Castoridae) from the Miocene of Texas and a review of the Miocene beavers from the Texas Coastal Plain, USA. Palaeontologia Electronica 26.1.a7; doi: 10.26879/1236
Source : Breaking Science News