Paleontologists have recovered a fossilized jaw fragment and three isolated bones from a relatively large (by Late Cretaceous standards) new species of Metatheria in the Williams Fork Formation of northwestern Colorado, USA. Found a tooth.
artist’s depiction Heleochora piceanus In a Late Cretaceous wetland. Image credit: Brian Engh / LivingRelicProductions.com / Utah Natural History Field House.
” Metatheria “[Marsupials and their closest fossil relatives]consist of about 330 extant species in seven orders, most of which live in the Southern Hemisphere,” said Jaylin Eberle, a professor at the University of Colorado Boulder. said.
“However, this clade appears to have originated in the Northern Hemisphere during the Early Cretaceous.”
“By the end of the Cretaceous period, Metatheria had dispersed across Europe, Asia, and North America, and were more diverse and numerous than their contemporaneous eutherians.”
“Most of the Late Cretaceous Metatheria species are represented almost exclusively by isolated teeth and jaws recovered from fossil localities in the interior western United States.”
The fossilized remains of a new species of Metatherian have been discovered. williams fork formation It is located in Douglas Creek Arch between the Uintah and Piance Creek basins in northwestern Colorado.
named Heleochora piceanusThis animal lived approximately 70 to 75 million years ago (late Cretaceous period), a time when a vast inland sea covered much of the American West.
Weighing about 1 kg (2 lb), it was larger than most Late Cretaceous mammals.
Based on the tooth, Heleochora piceanus They probably ate plants mixed with insects and other small animals.
It coexisted with creatures such as turtles, duck-billed dinosaurs, and giant crocodiles.
“This area could have been similar to Louisiana,” says Dr. Rebecca Hunt-Foster, a paleontologist at Dinosaur National Monument.
“We see a lot of animals like sharks, rays and guitarfish that are very happy in the water.”
“Colorado is a great place to find fossils, but mammals from this era tend to be quite rare,” Eberle says.
“So it’s really amazing to see this piece of time preserved in Colorado.”
“Compared to much larger dinosaurs that lived at the time, such as Tyrannosaurus and its horned ancestors, triceratopsColorado’s newest fossil addition may seem small and insignificant. However, it was surprisingly large for a mammal of its time. ”
This finding is reported in the following article: paper in a diary PLoS ONE.
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J. Hebert others. 2024. A new Late Cretaceous Metatherian discovered from the Williams Fork Formation in Colorado. PLoS ONE 19 (10): e0310948;doi: 10.1371/journal.pone.0310948
Source: www.sci.news
