Scientists find mammal foot inside dinosaur, first fossil

Paleontologists are taking a second look at a small, four-winged species dinosaurs have found a fossilized mammal foot in the predator’s stomach.

It’s the first concrete evidence that dinosaurs ate mammals, researchers say. dinosaur specimens, Microraptor zhaoinushave been discovered which contains ancient birds, fish and lizards, so the mammal find is only the last known source of protein for it. worthy hunter. The team that re-examined the Microraptor fossil published their findings today in the Journal of Vertebrate Paleontology.

“It really demonstrates the generalist diet in this little feathered dinosaur,” Hans Larsson, a paleontologist at McGill University and lead author of the study, said in an email to Gizmodo. “Adding mammals to the menu shows how unspecialized this dinosaur was.”

The house of trees Microraptor lived during the early Cretaceous, and specimens have been found in what is now northeastern China. The fossil-rich region is called the Jehol Biota, and its well preserved treasures they are a great resource for understanding the nuances of dinosaur anatomy, as well as details about the ecological niches of different animals.

Microraptor it is believed that it lived in the trees, gliding through Cretaceous forests looking for morsels both on branches and on the ground. The recently studied specimen is the holotype, meaning it was the first of its kind to be found and named. It has recently been revised after its discovery in 2000. The new analysis revealed the mammalian foot, something apparently unprecedented to find.

The researchers were unable to identify the particular mammal species, but of the foot preservation within Microraptor allowed them to understand their ecological niche and, obviously, their predators.

“Gut contents are incredible snapshots of the diet of fossil animals, but they are so rare that it can be difficult to figure out whether the preserved ‘last meal’ represents the animal’s normal diet or a rare, one-off event that got lucky. fossilized,” Stephanie Drumheller-Horton, a paleontologist at the University of Tennessee, Knoxville, who was not affiliated with the recent paper, said in an email to Gizmodo.

“Microraptor is shaping up to be a very interesting exception to this rule, with multiple beautifully fossilized specimens that preserve different ‘last meals,'” added Drumheller-Horton. “Together, the authors make a convincing case that this small theropod was not a particularly picky eater, eating all manner of small-bodied animals in its environment.”

The mammal foot apparently it did not belong to a distant one human ancestor; the team he said it had similarities to the morphologies of Sinodelphys, Yanoconodoni Eomaiaall ancient species of early mammals that roughly resembled opossums or rodents.

The foot belonged to an animal the size of a mouse. The team’s analysis found the critis he would not have been a good climber, an indicator that Microraptor may have occasionally descended to the forest floor to feed.

“The foot appears completely intact and was therefore swallowed whole. It is unknown what part of the mammal was swallowed,” Larsson said. “However, there were several unidentified bones around the foot in the ribcage, so I suspect more of this mammal was consumed.”

Investigators could not determine if the animal was hunted and killed or if the feathered dinosaur had your trash body.

Given the luck paleontologists have had so far with the Jehol Biota, it may only be a matter of time before another food-laden specimen offers more insight into the Cretaceous food scene.

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