Just out | Evolution of postcranial skeleton in worm lizards inferred from its status in the Cretaceous stem-amphisbaenian Slavoia darevskii @ Acta Palaeontologica Polonica


Just out @ Acta Palaeontologica Polonica


Title: 

Evolution of postcranial skeleton in worm lizards inferred from its status in the Cretaceous stem-amphisbaenian Slavoia darevskii


Author(s):

Mateusz Tałanda


Abstract:

Amphisbaenians are one of the most derived fossorial groups among Squamata. Studies of their evolution were hampered by their specialized limbless morphology and unrecognized early fossil record. This study presents a detailed description of the postcranial anatomy of the oldest known stem-amphisbaenian Slavoia darevskii. The skeleton shows an incipient adaptation to the fossorial mode of life, expressed in the early stages of limb reduction and elongation of the trunk, typical aspects of modern worm lizards. The forelimbs show a hyperphalangy of the first digit. They were probably strengthened this way to support the head in burrowing. Such an anatomy of the most ancient amphisbaenians implies that the forelimbs were lost multiple times in the amphisbaenians to be retained only in the Bipedidae. The hindlimb reduction was initiated early (before the split into modern families) but may have been completed independently. Despite these changes, S. darevskii still had the plesiomorphic 26 presacral vertebrae but the neck region was shorter, as shown by the ribs morphology and position.


READ IT HERE:

http://app.pan.pl/article/item/app002942016.html

Lurdes Fonseca

Assistant Professor and Researcher at University of Lisbon
Sociologist (PhD), Paleontologist (Researcher in Micropaleontology), Majors in Sociology and Biology, Minor in Geology. Main interests in Paleontology: Microfossils, Molecular fossils, Paleobiology and Paleoecology. (read more about me)
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