A comparative study of degeneration of the posterior limbs and girdles of some scelotes species.

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Date

1981

Journal Title

Journal ISSN

Volume Title

Publisher

University of the Western Cape

Abstract

The genus Scelotes was instituted by Fitzinger in 1826 and is represented by nineteen species and subspecies in Southern Africa (Fitzsimons, 1943) . Valuable contributions have been made to our knowledge of the Lacertilia by pioneers such as Gadow (1881) , Cope (1892) , El-Toubi (1938) , King (1964) and Tiedeman et al . (1975) who investigated the osteology and myology. Essex (1927) , Stokely (1947) , Lande (1978) and Leonard (1979) dealt with the evolution of limb loss and pelvic girdle degeneration in the lizards , and especially in the skinks. van der Klaauw (1948), Snyder (1952; 1954) and Gans (1962; 1966; 1973) studied the ecology and behaviour of limbless tetrapods, while De Witte and Laurent (1943) and Greer (1970) contributed to our knowledge on the systematics of the skinks. Partial or complete loss of limbs and degeneration in the pelvic arch have possibly evolved independently in a variety of tetrapods. The genus Scelotes exhibits a full range of degeneration - from fully pentadactyle tetrapodous forms to limbless species. The question arises : Can a general pattern of devolution be observed in this genus? Al though many of the Scelotes species have already been described, it will here for the first time be attempted to compare the different stages of degeneration as exhibited in this genus. A major objective of this work will , therefore be to analyze the pattern of degeneration in Scelotes. Firstly, the osteology of the pelvic girdle and hindlimbs of the Scelotes species will be described and, secondly, these structures will be compared. Thirdly, an attempt will be made to graphically reflect the major trends associated with limb regression by employing morphometric data obtained from the limited number of specimens available

Description

Masters of Science

Keywords

Pelvic girdle degeneration, Limb loss, Tendency for joints, Loss of hindlimbs, Scelotes species

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