New species of ancient Synodont 220 million years old

Virginia Tech College Ledge Science Ph.D. Bone fragments of rat-like animal remains found in Arizona’s Petrified Forest National Park last year. The candidate is in fact a newly discovered 220-million-year-old species of synodont or stem-mammal, a precursor to modern-day mammals.

The discovery of this new species, Cataigidon venetus, has been published in the journal Today Biology Letters By Ben Kligman, lead author, doctoral student in the Department of Geosciences.

“This discovery will shed light on geography and the environment during the early development of mammals,” Kligman said, adding that evidence suggests that humid climates played an important role in the early evolution of mammals and their close relatives. Cataigidon lived with dinosaurmorphs and possibly early early dinosaurs – a small bipedal predator – and Cataigidon was probably one of these early predators. Crocodilomorphs related to dinosaurs and other predators such as crocodiles, quadrupedal predators such as small coyotes. “

Kligman added that finding a fossil as part of Synodontia, which includes mammals such as Assig Tigidon as well as true mammals from the Triassic rocks, is an extremely rare phenomenon in North America. Prior to Kligman’s discovery, the only other unrelated cyanodont relic of the late North American Triassic was the discovery of the brain of Adelobacillius cromptoni in 1990 in Texas. Note that 220 million years ago, modern-day Arizona and Texas were located near the continents, close to the epic of Penguin. Cataigidon would live in a nice tropical forest ecosystem.

Kligman made the discovery in 2019 while working as a seasonal paleontologist at Petrified Forest National Park. Two fossilized jaws of cataigidon were found in the formation of the Upper Triassic Chinle. Because only the lower jaws have been discovered and they are very small – half an inch, the size of a medium grain of rice – just how the animal looks like in Kligman, about inches in total body size. inches inch, is the latter half of the tail.

Along with the remains of the jaws, Kligman found teeth of modern-day mammals, such as incisors, canines, and complex-postcanine teeth. Kligman added that given the negative shape of his teeth and the small size of his body, he feeds into the diet of potential insects. (Why are jaw remains commonly found even among smaller specimens? According to Kligman, the fossil record is “biased” toward preserving only the largest and strongest skeletal bones. Other smaller or more fragile bones – ribs, arms, and legs – Invisible.)

Kligman studied and outlined field work, sample preparation, CT scanning, concept and manuscript. He added that after reviewing the jaw CT scan dataset and comparing other related species with it, he and his colleagues only discovered a new fossil species.

“It probably would have felt like a little mouse or a mouse.” If you saw it face to face you would think it was a mammal. “Is it fur? To identify and name the animal that Kligman and the researchers worked with, who don’t really know.” There was fur, so scientists believe that the Triassic people did too. “

The name Cataigidon Venetus is derived from the Greek words for hurricanes, “Cataigidos,” and teeth, “Oden,” and the Latin word blue, “Venetus,” all referring to the discovery of Thunderstem Ridge, and the blue color rocks at this site. Kligman did not name the animal, though. That work fell on Hans Dieter-Suz, co-director and curator of vertebrate paleontology at the Smithsonian National Museum.

Additional collaborators include Adam Pale Marsh, a park paleontologist at Petrified Forest National Park, and Christian Sidor, an associate professor at the University of Washington’s Department of Biology, a park paleontologist and Christian Sidor at Petified Forest National Park. The research was funded by the Petrified Forest Museum Association, Friends Pet F Petrified Forest National Park and the Virginia Tech Department of Geosciences.

“This study represents an example of what we collect determines what we can say,” said Michelle Stoker, an assistant professor of geology and Kligman’s doctoral adviser. “Our hypotheses and interpretations of past life on Earth are based on the actual fossil material we have, and if our search images for fossils focus only on large-bodied animals, we will miss the important small specimens that are key to understanding diversity.” There are many groups. “

Since Cataigidon is the only other obscure cyanodont fossil from the late Triassic found in western North America, why wait to find more new species?

Kligman probably said said. He added, “We have preliminary evidence that more species of sonodonts are present at the same site as ketigidon, but we hope to find better fossils of them.”