Whole Lizard Discovered Inside 120 Million-year-old Dinosaur's Stomach

A new species of lizard has been discovered inside the stomach of a 120 million-year-old dinosaur. Researchers in China found the near-complete specimen inside a Microraptor zhaoianus—a small predatory dinosaur that lived during the Early Cretaceous in what is now northeastern China.

Microraptors were a genus of four-winged dinosaurs that are believed to have been capable of flight. They were among the smallest dinosaurs to live, measuring just a few feet in length. It is thought they were opportunistic predators, feeding on mammals, birds, fish and lizards.

Previously, four other microraptor fossils have been discovered with other species preserved inside their stomach. In a study published in Current Biology, researchers at the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences and the Shandong Tianyu Museum of Nature, identified another example of this—but after examining the lizard realized it was an entirely new species.

Artist impression of a microraptor eating a lizard whole. DOYLE TRANKINA

The lizard was found to be "largely complete" and had been swallowed head first. It had unusual, widely spaced teeth unlike anything else found in this part of China. It appears to have been related to Liushusaurus—an extinct species of lizard that lived in the same region, also during the Early Cretaceous.

The species has been named Indrasaurus wangi. This was after Chinese paleontologist Wang Yuan and Indra, a Vedic god. In the legend, Indra was swallowed by the dragon Vritra during a battle.

Discovering a lizard swallowed whole inside the microraptor's stomach confirms previous suggestions that the dinosaur was an opportunistic feeder that would swallow prey whole, similar to reptiles and carnivorous birds living today.

From the microraptor and lizard remains, the researchers were able to create a food web of the ecosystem in this part of China at the time.

Professor Mike Benton, from the U.K.'s University of Bristol, who was not involved in the study, told Newsweek: "A key job for paleontologists is to understand the life of the past, and this includes ancient food webs. Just what did dinosaurs eat? The new find gives clear evidence that on one day in the Cretaceous, a particular Microraptor ate a lizard. Not only that, this little tree-dwelling and gliding dinosaur swallowed the lizard whole and head-first. No chomping or dismemberment.

"These kinds of fossils are fantastic for the light they shed on the 'other worlds' that existed on earth hundreds of millions of years ago. The quality of preservation, and the hundreds of specimens found so far, provide cast-iron proof of these ancient feeding interactions."

The lizard was found in the stomach of the microraptor fossil. Jingmai O'Connor