Confuciusornis, from the early Cretaceous of China, is the oldest known beaked bird, and one of the oldest known birds -- only Archaeopteryx, from the late Jurassic of Germany, is older. Confuciusornis is a member of the Confuciusornithidae, the sister-group to the clade composed of Enantiornithes + Ornithurae (includes modern birds).

This specimen is preserved in lithographic stone. This is the case for most fossil birds, because their very delicate bones, many of which are hollow, can only survive the fossilization process in environments producing particularly fine-grained stone. Unfortunately, preservation in slabs such as this obscures the entire ventral side of the specimen. However, CT scanning enables us to digitally erase the lithographic stone, revealing the underside of these specimens with unprecedented detail. Examples are shown below.

This specimen was collected from Lower Cretaceous sediments of the Liao Ning Province in northeastern China. It was made available to the University of Texas High-Resolution X-ray CT Facility for scanning by Dr. Jian Guan of the Beijing Natural History Museum and Dr. Oscar Alcober of the Museo de Ciencias Naturales, San Juan, Argentina. Scanning was funded by Dr. Timothy Rowe of The University of Texas at Austin.

The specimen was scanned by Richard Ketcham and Timothy Rowe on 16-17 July 1998 along the long axis of the slab encasing it for a total of 618 slices, each slice 0.5 mm thick, with an interslice spacing of 0.45 mm (for a slice overlap of 0.05 mm).

Literature

Chiappe, L. M., J. Shu-an, J. Qiang, and M. A. Norell. 1999. Anatomy and systematics of the Confuciusornithidae (Theropoda: Aves) from the late Mesozoic of northeastern China. Bulletin of the American Museum of Natural History 242:3-89.

Hou, L.-H., Z. Zhou, L. D. Martin, and A. Feduccia. 1995. A beaked bird from the Jurassic of China. Nature 337:616-618.