Tuesday, February 2, 2010

Meaning: Wing tail
Time: Early Cretaceous
Size: 2 ft. 3 in.
Diet: Insects
Information: One of the small theropods that show distinctive bird features. It was very lightly built and had feathers on the wings and the tail. However, the wings were too small to allow it to fly. Here it is shown in the bottom, right of the picture.

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, or a bird, or both, and birds are either dinosaurs or they are not.

Because Caudipteryx has clear and unambiguously pennaceous feathers, like modern birds, and because several cladistic analyses have consistently recovered it as a nonavian, oviraptorid, dinosaur, it provided, at the time of its description, the clearest and most succinct evidence that birds evolved from dinosaurs. Lawrence Witmer stated: “The presence of unambiguous feathers in an unambiguously nonavian theropod has the rhetorical impact of an atomic bomb, rendering any doubt about the theropod relationships of birds ludicrous.”

However, not all scientists agreed that Caudipteryx was unambiguously non-avian, and some of them continued to doubt that general consensus. Paleornithologist Alan Feduccia sees Caudipteryx as a flightless bird evolving from earlier archosaurian dinosaurs rather than from late theropods. Jones et al. (2000) found that Caudipteryx was a bird based on a mathematical comparison of the body proportions of flightless birds and non-avian theropods. Dyke and Norell (2005) criticized this result for flaws in their mathematical methods, and produced results of their own which supported the opposite conclusion.

Other researchers not normally involved in the debate over bird origins, such as Zhou, acknowledged that the true affinities of Caudipteryx were debatable.


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