About 120 million years ago, a crow-sized bird of prey devoured a mammal for its last meal. Scientists came across the last supper Microraptora bird-like carnivorous dinosaur with four wings, while examining its fossilized remains at an undisclosed museum in China, a new study shows.
The well-preserved fossil of Microraptor zhaoianus including the 0.39-inch-long (1 centimeter) foot of a small mammal, probably a rodent, resting inside the small theropod’s ribcage, according to a statement (opens in a new tab).
The discovery marks the earliest known case of a dinosaur devouring a mammal, the researchers wrote in the study, published Dec. 20 in Journal of Vertebrate Paleontology (opens in a new tab).
“At first I couldn’t believe it,” study co-author Hans Larsson (opens in a new tab), director of the Redpath Museum and a vertebrate paleontologist at McGill University in Montreal, said in the statement. “These findings are the only solid evidence we have about the food consumption of these long-extinct animals – and they are exceptionally rare.”
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Before this discovery, there were only 20 known cases of fossilized remains containing a carnivorous dinosaur’s last meal, according to the statement. It included the skeleton of Daurlong wangi, a species of bird of prey also found in China, whose gut contained “a large, bluish layer in the abdomen.” Among the 20 cases, researchers have only four published examples (not including this one) of stomach contents from Microraptor itself.
The new discovery is also only the second direct evidence that theropods – a group of two-legged, mostly meat-eating dinosaurs that include Tyrannosaurus Rex – swallowed mammals, the researchers wrote in the study.
This Microraptor, whose name means “little plunderer”, was found in Liaoning Province in northeastern China’s Jiufotang Formation. Although the exact dates of Jiufotang are unknown, it contains fossils from early times Cretaceous period (145 million to 100.5 million years ago), a 2000 study that originally described the fossil in the journal Nature (opens in a new tab) found.
“We already know about Microraptor specimens preserved with parts of fish, a bird and a lizard in their stomachs,” Larsson said. “This new finding adds a small mammal to their diet, suggesting these dinosaurs were opportunistic and not picky eaters.”
He added, “knowing that they weren’t specialized for any particular food is a big deal”, as this may be the first evidence of a generalist predator that was part of the Cretaceous ecosystem. It could have acted as a “stabilizer in the ecosystem” much like modern foxes and crows, according to the statement.
“Know it Microraptor was a generalist predator puts a new perspective on how ancient ecosystems may have functioned,” Larsson said, “and a possible insight into the success of these small, feathered dinosaurs.”