Range of movement in ray I of manus and pes and the prehensility of the autopodia in the Early Permian to Late Cretaceous non-anomodont Synapsida.

ABSTRACT: The mobility of ray I was analysed in seventy-eight Early Permian to Late Cretaceous specimens of non-mammalian Synapsida and one extant mammal. In all non-mammaliamorph Synapsida investigated, ray I formed a digital arcade. The first phalanx was maximally extendable to the zero position in the metapodiophalangeal joint I. Metapodiale I was the functional equivalent to a basal phalanx of digits II-V. In contrast, there was no digital arcade in ray I in Mesozoic Mammaliamorpha. Phalanx 1 I was dorsally extendable and metapodiale I was functionally part of the metapodium. During the propulsion phase, autopodial rotation occurred in the majority of Synapsida with abducted limb posture. Regarding ray I, the reduction of autopodial rotation can be estimated, e.g., from the decrease of lateral r

SUBMITTER: Kummell SB 

PROVIDER: S-EPMC4269487 | biostudies-literature | 2014

REPOSITORIES: biostudies-literature