On the identity of Monsieur Dussumier's Dutch tortoise and the lectotype of Testudo dussumieri Gray, 1831

Although it was forgotten for over a century, the binomen Testudo dussumieri Gray, 1831, is an available name, and the specimen RMNH 3231 deposited in the natural history museum of Leiden - evidently one of the two original syntypes of T. dussumieri - has been designated as the lectotype of this taxon. Recently several authors have actively promoted this as the name-bearing type for the Aldabra tortoise, escalating debates in which this chelonian has been immersed for nearly two decades. This lectotype designation is highly significant to nomenclatural and taxonomic disputes regarding tortoises (Testudinidae), living and extinct, from the western Indian Ocean; and an attempt has been made in this paper to compile all information relevant to the lectotype as well as to better understand the history of the binomen applied to it. Several critical aspects of the history are uncertain and open to speculation. The provenance of RMNH 3231 is unknown and unlikely to be Aldabra Atoll; the specimen was most likely collected in the granitic Seychelles, between 1823 and 1829. The combination of estimated date and locality of collection raises the possibility that the lectotype is not an Aldabra tortoise, but rather an extinct taxon from the granitic Seychelles. It is concluded that RMNH 3231 is not a suitable name-bearing type for the Aldabra tortoise, and the continued use of the name T. dussumieri will cause persistent nomenclatural and taxonomic confusion and unending debate. Copyright © 2010 © Magnolia Press.