Functional morphology and ontogeny of Keichousaurus hui (Reptilia, Sauropterygia)
By: Kebang Lin --, Olivier Rieppel --.
Contributors: Rieppel, Olivier.; Field Museum of Natural History.
Series: Fieldiana -- new ser., no. 39; Publication -- 1491; Publication (Field Museum of Natural History) -- 1491.
Publisher: Field Museum of Natural History
Published: 1998
Place of publication: Chicago. Ill
Subjects: Keichousaurus hui -- Morphology.; Keichousaurus hui -- Development; Sauropyerygia -- Morphology.; Sauropterygia -- Development.; Paleontology -- Triassic.
Other titles: Functional morphology of Keichousaurus
Description: Keichousaurus hui Young, 1958, from the Middle Triassic of Guizhou, China, is a small sauropterygian reptile. It has a short snout and elongated temporal openings, resembling the European pachypleurosaurid Dactylosaurus. Unlike all other stem-group eosauropterygians, the parietal foramen is displaced anteriorly. The neck is long and flexible. The body is rigid and the bones pachyostotic. There are two or three sacral vertebrae. There is distinct sexual dimorphism, as in Alpine pachypleurosaurids. The broad ulna is autapomorphic for Keichousaurus. The growth of the humerus is highly positively allometric, reflecting the principal role of the forelimb in locomotion. The overall horizontal orientation of the pectoral girdle indicates that Keichousaurus was not a subaquatic flyer. Instead, a drag-based regime was used in locomotion.