During the Cretaceous, a period of time spanning 145 to 66 million years ago, a little feathered dinosaur swooped down to the ground to gobble up an unsuspecting lizard, swallowing it whole. Now, a team of palaeontologists has unearthed the fossil of this mini dino, complete with the reptilian snack trapped in its belly.
In Current Biology, the scientists describe the fossil of Microraptor zhaoianus, which was uncovered in northeastern China and lived about 120 million years ago during the Lower Cretaceous. Microraptor literally means "small thief" and this marks the fourth time these sneaky little hunters have been caught with fossilized critters preserved in their stomachs. The previous three specimens contained birds, mammals, and fish.
Often described as having four wings, members of the Microraptor genus sported feathers on both their arms and legs. Whether they could fly is a topic of debate, but they likely used their feathered appendages to glide about the forest canopy, traveling from tree to tree instead of flapping their wings like the birds of today.
But while finding another Microraptor specimen is certainly exciting, the contents of its stomach are perhaps more so. The unlucky lizard actually turns out to be a new species, unlike any other previously found from the Cretaceous. Named Indrasaurus wangi, the former part of its moniker refers to Indra, a god who was swallowed by a dragon during a battle in Vedic legend. The latter part is a nod to Professor Wang Yuan, director of the Paleozoological Museum of China and scientist at the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP).
“The position of the body suggests that the lizard was swallowed head first, consistent with feeding behavior in extant carnivorous lizards and birds,” the authors write in their paper.
The new lizard had teeth unlike any other in the Jehol Biota – a vast fossil deposit containing creatures that lived in northwestern China between 133 and 120 million years ago. This, the researchers note, could mean that I. wangi had a unique diet. Fossilized critters and their stomach contents have given scientists intriguing insights into predator-prey interactions in the Jehol Biota, with a total of 20 such specimens having been found.
Using this evidence, the researchers of the new study created the first ever food web of the Jehol Biota, concluding that fish were the most crucial form of food for larger hungry beasties like aquatic reptiles, lizards, dinosaurs, and early birds.