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About 120 million years ago, a crow-sized bird of prey devoured a mammal for its last meal. Scientists came across the last meal of Microraptora bird-like carnivorous dinosaur with four wings, while examining its fossilized remains at a secret museum in China, a new study shows.
The well-preserved fossil of Microraptor zhaoianus included the 0.39-inch-long (1 centimeter) foot of a small mammal, likely a rodent, resting inside the small theropod’s thorax, according to a statement (opens in new tab).
The discovery marks the earliest known case of a dinosaur eating a mammal, the researchers wrote in the study published Dec. 20 in Journal of Vertebrate Paleontology (opens in new tab).
“At first I couldn’t believe it,” the study’s co-author Hans Larsson (opens in 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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Prior to this find, there were only 20 known cases of fossilized remains containing the last meal of a carnivorous dinosaur, according to the statement. It included the skeleton of Daurlong wangi, a species of raptor also found in China, whose gut contained “a large, bluish layer in the abdomen.” Among the 20 cases, the researchers have only four published examples (excluding this one) of stomach contents from Microraptor one.
The new discovery is also only the second direct evidence that theropods – a group of bipedal, mostly carnivorous dinosaurs that include Tyrannosaurus Rex – devoured mammals, the researchers wrote in the study.
This Microraptor, whose name means “little raider”, was found in Liaoning Province in northeast 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 new tab) was found.
“We already know Microraptor specimens preserved with parts of fish, a bird and a Lizard in the stomach,” Larsson said. “This new finding adds a small mammal to their diet, suggesting these dinosaurs be opportunistic and not picky eaters.”
He added, “Knowing that they didn’t specialize in any particular food is a big deal,” because this could be the first evidence of a generalist carnivore that was part of the Cretaceous ecosystem. It could have acted as a “stabilizer in the ecosystem” much like today’s foxes and crows, according to the statement.
“Know that Microraptor was a generalist carnivore 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.”
