The bizarre skull of Xenotyphlops sheds light on synapomorphies of Typhlopoidea

Johann Chretien, Cynthia Y. Wang-Claypool, Frank Glaw, Mark D. Scherz*

*Corresponding author af dette arbejde

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

17 Citationer (Scopus)

Abstract

The emerging picture of non-monophyly of scolecophidian snakes is increasingly indicative that fossorial lifestyle, myrmecophagous diet, and miniaturisation are powerful drivers of morphological evolution in squamate skulls. We provide a detailed description of the skull of Xenotyphlops grandidieri, with reference to the skulls of other scolecophidian snakes. The skull, which shows dramatic ventral inflection of the snout complex, is remarkably bizarre, and the mouth opening is more ventrally oriented than in other typhlopoids. The eyes are strongly reduced, and the enlarged and rather flat anterior head shield is covered in numerous sensillae. We put forward several potential explanations for the evolution of these unusual modifications. On the other hand, Xenotyphlops shares numerous synapomorphies with other typhlopoid snakes, including the highly specialized jaw mechanism. We argue that the key differences between the jaw mechanisms of Leptotyphlopidae, Anomalepididae, and Typhlopoidea provide compelling evidence for a strong role of convergence in the evolution of the scolecophidian bauplan, and these clades therefore cannot be interpreted as representative of ancestral anatomy or ecology among snakes.

OriginalsprogEngelsk
TidsskriftJournal of Anatomy
Vol/bind234
Udgave nummer5
Sider (fra-til)637-655
Antal sider19
ISSN0021-8782
DOI
StatusUdgivet - 2019
Udgivet eksterntJa

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© 2019 Anatomical Society

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