Abdominal Contents from Two Large Early Cretaceous Compsognathids (Dinosauria: Theropoda) Demonstrate Feeding on Confuciusornithids and Dromaeosaurids

Abdominal Contents from Two Large Early Cretaceous Compsognathids (Dinosauria: Theropoda) Demonstrate Feeding on Confuciusornithids and Dromaeosaurids

1. Lida Xing (a)

2. Phil R. Bell (b,*)

3. W. Scott Persons IV (a)

4. Shuan Ji (c)

5. Tetsuto Miyashita (a)

6. Michael E. Burns (a)

7. Qiang Ji (c)

8. Philip J. Currie (a)

a. Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada

b. Pipestone Creek Dinosaur Initiative, Clairmont, Alberta, Canada

c. Institute of Geology, Chinese Academy of Geological Sciences, Beijing, China

*. Author to be contacted: philbyb@gmail.com

Abstract:

Two skeletons of the large compsognathid Sinocalliopteryx gigas include intact abdominal contents. Both specimens come from the Jianshangou Beds of the lower Yixian Formation (Neocomian), Liaoning, China. The holotype of S. gigas preserves a partial dromaeosaurid leg in the abdominal cavity, here attributed to Sinornithosaurus. A second, newly-discovered specimen preserves the remains of at least two individuals of the primitive avialan, Confuciusornis sanctus, in addition to acid-etched bones from a possible ornithischian. Although it cannot be stated whether such prey items were scavenged or actively hunted, the presence of two Confuciusornis in a grossly similar state of digestion suggests they were consumed in rapid succession. Given the lack of clear arboreal adaptations in Sinocalliopteryx, we suggest it may have been an adept stealth hunter.

Paper link.

Sinocalliopteryx Ate 3 Confuciusornis!

University of Alberta researchers found evidence that a feathered, but flightless dinosaur was able to snag and consume small flying dinosaurs.

The U of A paleontology team found the fossilized remains of three flying dinosaurs in the belly of a raptor-like predator called Sinocalliopteryx. Sinocalliopteryx was about two meters in length and roughly the size of a modern-day wolf.

Sinocalliopteryx's flying meals were three Confuciusornis. Confuciusornis was one of the earliest birds and had a crude version of a modern bird's skeleton and muscles. The researchers say such primitive birds were probably limited to slow take-offs and short flights.

According to the researchers, this is the first time a predator has been linked to the killing of multiple flying dinosaurs.

Scott Persons, a U of A paleontology student and research coauthor, says Sinocalliopteryx may have used stealth to stock the flyers. "Sinocalliopteryx didn't have wings or the physical tools needed to be an adept tree climber," said Persons.

Persons explains Sinocalliopteryx had feathers or hair-like fuzz covering its body creating a level of insulation that helped maintain a warm body temperature and high metabolism that required a lot of food to fuel.

"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," said Persons.

This find was made in China's Liaoning province, and U of A researchers analyzed stomach contents of a second Sinocalliopteryx fossil discovery from that area. The researchers identified this Sinocalliopteryx's last meal as 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.

Link. Looking for the paper.