Tuesday, January 17, 2017

Trinidad & Tobago Polychrus distinct from the Guyana-Amazonian species

Audubon's Multicolored Lizard, Polychrus audubonii (Hallowell, 1845)
For the past century the Trinidad and Tobago herpetofauna has been considered to composed of mostly widespread Amazonian and Guianan species. In fact this is not correct and the evidence is mounting that the T&T herpetofauna is composed of more endemics and  near endemics that the islands share with the Venezuelan coastal ranges.

The most recent evidence is a paper by Murphy et al. (2017) that demonstrates the widespread multicolored lizard Polychrus marmoratus (Linnaeus, 1758) is a species complex. The Trinidad and Tobago populations and in the Venezuelan Coastal Range populations are distinct from the Guyana endemic Polychrus marmoratus. The new species actually has an old name.

Edward Hallowell (1845) described Leiolepis auduboni based on a specimen collected by Samuel Ashmead at a location within 200 miles of Caracas, Venezuela. Hallowell’s specimen was identified as Polychrus marmoratus by Roze (1958) and placed in the synonymy of the Linnean species. However its status as a junior synonym of Polychrus marmoratus has been overlooked in more recent works.

Polychrus auduboni  is distinct from P. marmoratus, in having the loreal usually fragmented into two scales (usually three or more in marmoratus); nasal does not usually contact first upper labial (in marmoratus is usually does not contact the first upper labial); total femoral pores 17–28 (8-19 in marmoratus); multicarinate scales in paravertebral rows few or none (many in marmoratus); paravertebrals much larger than laterals (about the same size in marmoratus). The two species are also genetically different.

The authors also suggest there is at least one undescribed species in Para, Brazil and that the names   Polychrus virescens Schniz and Polychrus neovidanus Wagler are valid names for species currently not recognized in Brazil's Atlantic Forest.

Murphy JC, Lehtinen RM, Charles SP, Wasserman D, Anton T, Brennan PJ. 2017. Cryptic multicolored lizards in the Polychrus marmoratus Group (Squamata: Sauria: Polychrotidae) and the status of Leiolepis auduboni Hallowell. Amphibian & Reptile Conservation 11(1): 1–16 (e132).

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