A remarkable young Scolecomorphus vittatus (Amphibia: Gymnophiona: Scolecomorphidae) from the North Pare Mountains, Tanzania

Authors

  • Simon P. Loader,

    Corresponding author
    1. Department of Zoology, The Natural History Museum, London SW7 5BD, U.K.
    2. Institute of Biomedical and Life Sciences, Division of Molecular Genetics, University of Glasgow, Pontecorvo Building, 56 Dumbarton Road, Glasgow G11 6NU, U.K.
    3. Frontier, 50–52 Rivington Street, London EC2A 3QP, U.K.
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  • Mark Wilkinson,

    1. Department of Zoology, The Natural History Museum, London SW7 5BD, U.K.
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  • David J. Gower,

    1. Department of Zoology, The Natural History Museum, London SW7 5BD, U.K.
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  • Charles A. Msuya

    1. Department of Zoology and Marine Biology, P.O. Box 35064, University of Dar es Salaam, Dar es Salaam, Tanzania
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*Simon Loader, Department of Zoology, The Natural History Museum, Cromwell Road, London SW7 5BD, U.K. E-mail: simonloader@hotmail.com

Abstract

A description is given of the external morphology of a single young caecilian (gymnophionan) amphibian from the North Pare Mountains, Tanzania, referable to Scolecomorphus vittatus (Boulenger, 1895). This is the smallest known free-living Scolecomorphus, and it is characterized by many remarkable features previously unrecorded for any life-history stage of any caecilian. The cheeks have conspicuous, posteroventrally divergent paraoral processes that border a concavity on the ventral surface of the snout. The mandibles are very flexible about their articulation with the cranium, and they have a broader curvature than the upper jaw. The dentition is heterogeneous, with adult-like monocusped teeth in single rows, but also some supernumerary teeth, some of which are bicornute. The posterior parts of the paraoral processes bear a small number of monocuspid teeth that lie outside, and project away from, the mouth. The nuchal region of the body bears a distinctive concavity on the underside of the throat, bordered by longitudinal ridges that terminate in fleshy nipples. All of these features are unknown in adult Scolecomorphus, and many are unique for caecilians, and they suggest a highly distinctive life-history stage. The discovery and description of this specimen adds substantially to the currently meagre information on the life history of scolecomorphids and of the diversity of caecilian reproductive biology. Two modes of viviparity in caecilians are identified, with S. vittatus resembling the caeciliid Geotrypetes in giving birth to small altricial young that seem to require extended post-parturition parental care.

Ancillary