A wolf-like dinosaur hunted primitive flying birds that had not yet mastered the art of fast take-offs, according to a study of new fossils.
Scientists have found fossil remains of three early birds in the belly of a Sinocalliopteryx unearthed in China.
All the meal victims were identified as Confuciusornis, a type of flying dinosaur with a crude version of a modern bird's skeleton and muscles.
The primitive birds were probably limited to slow take-offs and short flights, said the researchers.
Studies have found out more about the hunting habits of the Sinocalliopteryx
Two of them appear to have been eaten in quick succession, since both were in a similar state of partial digestion.
The discovery indicates that Sinocalliopteryx, which lived during the Lower Cretaceous period between 100 million and 145 million years ago, was a stealth hunter that stalked its prey.
Palaeontologist Scott Persons, who co-authored a study on the find published in the online journal Public Library of Science ONE, said that: "Sinocalliopteryx didn't have wings or the physical tools needed to be an adept tree climber.
"The fact that this Sinocalliopteryx had not one but three undigested birds in its stomach indicate it was a voracious eater and a very active hunter."
Artist Cheung Chungtat's interpretation of how the Sinocalliopteryx looked
Sinocalliopteryx was a small raptor-like dinosaur roughly the size of a modern wolf whose body was covered in rudimentary feathers, probably to provide insulation.
The fossil skeleton was found in China's Liaoning region along with a second Sinocalliopteryx which also bore evidence of a last meal.
The second dinosaur had eaten a Sinornithosaurus, a small feathered meat-eater about the size of a house cat that may have been able to fly or glide short distances.