Literaturdatenbank
Literaturdatenbank |
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Zug, G. R. (1971). Buoyancy, locomotion, morphology of the pelvic girdle and hindlimb, and systematics of cryptodiran turtles. Miscellaneous Publications Museum of Zoology University of Michigan, 142, 98 pp.
Added by: Admin (06 Jan 2014 18:25:33 UTC) |
| Resource type: Journal Article BibTeX citation key: anon1971b View all bibliographic details  |
Categories: General Keywords: Schildkröten - turtles + tortoises, Verhalten - ethology Creators: Zug Collection: Miscellaneous Publications Museum of Zoology University of Michigan |
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| Abstract |
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Cryptodires cannot be taxonoinically subdivided by the present method of gait analysis. On land, turtles proceed at a very slow or slow walk and generally with a lateral sequence gait. In water, they move at speeds ranging from a fast walk to a moderate run with a diagonal sequence gait. Only in aquatic locomotion are two distinct patterns evident, i.e., bottom-walking and swimming. The former is characterized by vertical limb movements, the latter by horizontal limb movements. Most aquatic testudinids and all trionychids are swimmers. Chelydrids, kinosternids, and some aquatic testudinids are bottom-walkers. It is suggested that bottomwalking has had two different origins, the kinosternid mode from a swimming ancestor, the chelydrid-testudinid mode from a terrestrial or semiaquatic ancestor. Tlle dermatemydid-kinosternid and the chelydrid-testudinid lineages appear to form two natural, monophyletic groups. Further evidence is presented to show that the trionychids are related to the dermatemydid-kinosternid lineage. It is suggested that the chelydrids and platysternines are closely related, thereby providing an additional tie between the chelydrids and testudinids.
Added by: Admin |