AVIS-IBIS

Birds of Indian Subcontinent

A Late Jurassic salamander (Amphibia: Caudata) from the Morrison Formation of North America

Publication Type:Journal Article
Year of Publication:2005
Authors:EVANS, SE, LALLY, C, CHURE, DC, ELDER, A, MAISANO, JA
Journal:Zoological Journal of the Linnean Society
Volume:143
Issue:4
Date Published:2005
ISBN Number:1096-3642
Keywords:Asia, biogeography, computed tomography, Corvidae, Corvus, Corvus corone, Eastern Asia, Evolution, Lissamphibia, phylogeny, Portugal, skeleton, United Kingdom, Urodela
Abstract:Despite some remarkable recent discoveries, the Mesozoic fossil record of salamanders remains limited, particularly for the Jurassic. Here we describe the first articulated salamander skeleton from the Jurassic of Euramerica, recovered from Upper Jurassic deposits of the Morrison Formation, Dinosaur National Monument, USA. The specimen was studied using both conventional methods and high-resolution computed tomography. It shows a combination of primitive and derived character states that distinguish it from all known Mesozoic salamanders and which permit the erection of a new genus and species, Iridotriton hechti. The derived states (including the presence of spinal nerve foramina in the tail) suggest a position on the stem of the Salamandroidea. Together with microvertebrate material from Britain, Portugal, and North America, this specimen confirms the presence of both stem- and crown-group salamanders in Euramerica from the Middle Jurassic (Bathonian) onwards, paralleling their evolution in Central and eastern Asia. This, in turn, provides qualified support for the current vicariance model of salamander evolution whereby basal caudates on an undivided Laurasian plate became separated into two populations by the incursion of the Turgai Sea in the Middle Jurassic, yielding Cryptobranchoidea in Asia and Salamandroidea in Euramerica. © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society, 2005, 143, 599−616.
URL:http://dx.doi.org/10.1111/j.1096-3642.2005.00159.x
Short Title:Zoological Journal of the Linnean Society
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