Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If You Use a Screen Reader

This content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.

Appendicular Skeleton in Amphisbaenians (Reptilia: Squamata)

Maureen Kearney
Copeia
Vol. 2002, No. 3 (Aug. 15, 2002), pp. 719-738
Stable URL: http://www.jstor.org/stable/1448153
Page Count: 20
  • Read Online (Free)
  • Download ($12.00)
  • Subscribe ($19.50)
  • Cite this Item
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Appendicular Skeleton in Amphisbaenians (Reptilia: Squamata)
Preview not available

Abstract

The appendicular skeletal elements in 32 species from all 23 extant genera of amphisbaenians were surveyed via the preparation and study of radiographs, dry skeletons, and cleared-and-stained specimens. Here I report on the presence or absence of those elements, describe their morphology, and make comparisons to several other limbless or limb-reduced squamate taxa that have previously been suggested as close relatives to amphisbaenians. Variability found here in the appendicular skeleton provides a new source of character data for ongoing phylogenetic studies of the group. Comparisons of these elements to those found in potential squamate sister groups indicate that some amphisbaenians share plesiomorphic similarities with limbed squamates such as gymnophthalmid lizards, whereas others share only absence or reduction features with other limbless or limb-reduced squamates, such as dibamid lizards and snakes. This pattern is considered potentially inconsistent with previously proposed hypotheses of amphisbaenian sister groups within squamates. For the pectoral girdle, every stage of reduction-including complete loss-occurs among lizards, amphisbaenians, and snakes. However, the pelvic girdle is never completely lost in lizards or amphisbaenians regardless of the degree of limb reduction or loss; all these taxa retain at least the ilium, and this is also true of most basal snakes. These pelvic girdle elements are variously modified among these taxa, a fact that, together with their widespread persistence, suggests both different patterns of reduction among higher taxa and possible new functional roles beyond the primitive one of supporting the hind limb.

Page Thumbnails

  • Thumbnail: Page 
[719]
    [719]
  • Thumbnail: Page 
720
    720
  • Thumbnail: Page 
721
    721
  • Thumbnail: Page 
722
    722
  • Thumbnail: Page 
723
    723
  • Thumbnail: Page 
724
    724
  • Thumbnail: Page 
725
    725
  • Thumbnail: Page 
726
    726
  • Thumbnail: Page 
727
    727
  • Thumbnail: Page 
728
    728
  • Thumbnail: Page 
729
    729
  • Thumbnail: Page 
730
    730
  • Thumbnail: Page 
731
    731
  • Thumbnail: Page 
732
    732
  • Thumbnail: Page 
733
    733
  • Thumbnail: Page 
734
    734
  • Thumbnail: Page 
735
    735
  • Thumbnail: Page 
736
    736
  • Thumbnail: Page 
737
    737
  • Thumbnail: Page 
738
    738