Nomenclatural and morphological notes on the rare agamid lizard Pseudocophotis sumatrana (Hubrecht, 1879) (Squamata: Agamidae: Draconinae)

The earless, nose-horned agamid lizard Pseudocophotis sumatrana is only represented by a few specimens in collections worldwide. We discovered a historical publication from 1855 by van der Hoeven where the species was described as Calotes nasicornis before the currently accepted original description by Hubrecht in 1879. In order to uphold nomenclatural stability, we provide proof that Calotes nasicornis is a nomen oblitum and that Pseudocophotis sumatrana is to be treated as a nomen protectum. Our investigations into historical records put the type locality on Sumatra in question and we conclude that P. sumatrana is most probably restricted to Java. Through examination of all  known specimens, including the synonymised Calotes aberrans, we discuss taxonomic characters and add further details to the species diagnosis with respect to external and internal morphology. In
particular by means of μ-computer-tomography we show that only the distal part of the tail is prehensile and for the first time we examine the cranial skeleton and dentition of P. sumatrana.