Caudipteryx

*Caudipteryx zoui*

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***Caudipteryx*** (which means "tail feather") is a genus of peacock-sized theropod dinosaurs that lived in the Aptian age of the early Cretaceous Period (about 124.6 million years ago). They were feathered and remarkably birdlike in their overall appearance.

The hands of *Caudipteryx* supported symmetrical, pennaceous feathers that had vanes and barbs, and that measured between 15–20 centimeters long (6–8 inches). These primary feathers were arranged in a wing-like fan along the second finger.No fossil of *Caudipteryx* preserves any secondary feathers attached to the forearms, as found in *Archaeopteryx* and modern birds.Either these arm feathers are not preserved, or they were not present on *Caudipteryx* in life. An additional fan of feathers existed on its short tail. The shortness and symmetry of the feathers, and the shortness of the arms relative to the body size, indicate that *Caudipteryx* could not fly.The body was covered in a coat of short, simple, down-like feathers.It is thought to have been an omnivore.

The discovery of *Caudipteryx* led to many intensive studies on and debate over the relationship of birds and dinosaurs. The possible positions in the debate can be summarized as follows: *Caudipteryx* is either a member of the Oviraptorosauria, a bird, or both.

## Description

*Caudipteryx*, like many other maniraptorans, has an interesting mix of reptile- and bird-like anatomical features.

*Caudipteryx* had a short, boxy skull with a beak-like snout that retained only a few tapered teeth in the front of the upper jaw. It had a stout trunk, long legs and was probably a swift runner.

*Caudipteryx* has a short tail stiffened toward the tip, with few vertebrae, like in birds and other oviraptorosaurs. It has a primitive pelvis and shoulder, and primitive skull details in the quadratojugal, squamosal, quadrate, jugal, and mandibular fenestra (in the cheek, jaw, and jaw joint). It has a hand skeleton with a reduced third finger, like that of primitive birds and the oviraptorid Ingenia.

### Feathers

The hands of *Caudipteryx* supported symmetrical, pennaceous feathers that had vanes and barbs, and that measured between 15–20 centimeters long (6–8 inches). These primary feathers were arranged in a wing-like fan along the second finger, just like primary feathers of birds and other maniraptorans. No fossil of *Caudipteryx zoui* preserves any secondary feathers attached to the forearms, as found in dromaeosaurids, *Archaeopteryx* and modern birds.[3] Either these arm feathers are not preserved, or they were not present on *Caudipteryx* in life. An additional fan of feathers existed on its short tail. The shortness and symmetry of the feathers, and the shortness of the arms relative to the body size, indicate that *Caudipteryx* could not fly.

The body was covered in a coat of short, simple, down-like feathers.

*Caudipteryx* had uncinate processes on the ribs, birdlike teeth, a first toe which may or may not be partially reversed and overall body proportions that are comparable to those of modern flightless birds.

## Paleobiology

### Diet

*Caudipteryx* is thought to have been an omnivore. In at least two specimens of *Caudipteryx* (NGMC 97 4 A and NGMC 97 9 A), gastroliths are preserved. As in some herbivorous dinosaurs, the avialan *Sapeornis*, and modern birds, these gastroliths remain in the position where the animals’ gizzards would have been.

## Classification

The consensus view, based on several cladistic analyses, is that Caudipteryx is a basal (primitive) member of the Oviraptorosauria, and the oviraptorosaurians are non-avian theropod dinosaurs. Incisivosaurus is the only oviraptorosaur that is more primitive.
Halszka Osmólska et al. (2004) ran a cladistic analysis that came to a different conclusion. They found that the most birdlike features of oviraptorids actually place the whole clade within Aves itself, meaning that Caudipteryx is both an oviraptorid and a bird. In their analysis, birds evolved from more primitive theropods, and one lineage of birds became flightless, re-evolved some primitive features, and gave rise to the oviraptorids. This analysis was persuasive enough to be included in paleontological textbooks like Benton's Vertebrate Paleontology (2005). The view that Caudipteryx was secondarily flightless is also preferred by Gregory S. Paul, Lü et al., and Maryańska et al.
Others, such as Stephen Czerkas and Larry Martin have concluded that Caudipteryx is not a theropod dinosaur at all. They believe that Caudipteryx, like all maniraptorans, is a flightless bird, and that birds evolved from non-dinosaurian archosaurs.

## JPInstitute.com Description

Caudipteryx is one of several types of feathered dinosaurs recently discovered in China. These new finds have caused one of the greatest controversies in modern paleontology. They have many of the characteristics that were expected in a "missing link" between dinosaurs and birds, but they lived millions of years after Archaeopteryx, the first known bird ancestor.

Caudipteryx was a turkey-sized dinosaur that had feathers, but was unable to fly. It had short forelimbs, large eyes and long, sharp, spiked teeth. Quick and agile, it had long slender legs. The most prominent feature of Caudipteryx had to be its tail, which was covered with 6-inch-long tail feathers. The feather fossils show bands of dark and light that may have been color, giving us an idea of how Caudipteryx looked.

Some of the evolutionary advantages feathers may have provided to a flightless animal may include the ability to control body heat, some lived in a wetland area, it is easy to imagine it wading into shallow water on its long legs to spear small fish and amphibians with its long sharp teeth. All known remains of Caudipteryx have been found with gastroliths, or "gizzard stones" about an inch in size. This indicates Caudipteryx did not chew its food, probably swallowing small prey whole.

Did Archaeopteryx and Caudipteryx descend from a common ancestor? Or was Caudipteryx a dinosaur sharing a convergent evolution with birds. This will be a long and lively debate.

## Dinosaur Field Guide Description

Caudipteryx ("'tail feathers") was one of the most amazing dinosaur discoveries of the 20th century. It showed a dinosaur that was not a bird but had true feathers on its arms and tail. Some scientists thought Caudipteryx was no more than some kind of primitive flightless bird, but when the skeleton of this little creature was studied in detail, it turned out to be an oviraptorosaur. Oviraptorosaurs were a type of meat-eating dinosaur common in the Late Cretaceous of Asia and North America. Caudipteryx was the oldest of the oviraptorosaurs and one of the most primitive. The arms of Caudipteryx were very short, so it certainly could not fly. Then why did it have feathers? Paleontologists suggest a number of possibilities. It might be that they were used for signaling other Caudipteryx, as a peacock does. They might have been used to cover Caudipteryx's eggs while it brooded its nest. Or possibly the ancestors of Caudipteryx really did fly but later become grounded (as happened with
ostriches, kiwis, and chickens). We may never know for sure.

### Fun Facts

Some Caudipteryx fossils have been found with stomach stones, which would have helped grind up thair food,

### Trivia

One of the newest dinosaur museums in the world is being built in China next to the site where Caudipteryx and other feathered dinosaur fossils were found.

## Links

http://web.archive.org/web/20030803053007fw\_/http://www.jpinstitute.com/dinopedia/dinocards/dc\_caudi.html