Atractosteus 'strausi' Nomen Dubium

[piranha]

There are a couple of important nomenclatural updates for fossil gars to report. The iconic example (A. strausi) from the Messel Shale has been sunk and formally named Atractosteus messelensis by Lance Grande. Additionally, the classic Green River 'Lepisosteus' simplex is now reclassified in the genus Atractosteus. Although the old names will continue to persist around the internet, it's useful to update the labels and records for these fossils in many important institutional and private collections around the world.

"Discussion -- In a redescription of the species of Atractosteus from Messel, Gaudant (2005) correctly noted that the name A. strausi (Kinkelin), 1884, based on an isolated ganoid scale "devoid of any diagnostic character" found in Miocene deposits of Frankfurt-Niederrad, cannot be applied to either of the Messel gar species because the name is inapplicable and a nomen dubium (he used nomen vanum but the International Code does not recognize this sometimes ambiguously defined term, so I follow Chorn and Whetstone (1978) and others in using nomen dubium). Gaudant (2005) offered a replacement name for A. strausi (A. kinkelini) but unfortunately, he did not clearly designate a validly diagnosable holotype for the new name. He instead chose a skull fragment (SMF P. 1676, consisting of several lacrimomaxillae and a partial dentary) to serve as a "Lectotype" (p. 131) for A. strausi, and holotype (caption for fig. 2, p. 112) for A. kinkelini. He stated that the "[reduced number of infraorbitals]" is the diagnostic feature of this specimen, but the specimen is missing its anterior end making a complete count of lacrimomaxillary bones (his "infraorbitals") impossible. The count of lacrimomaxillary bones in the Messel Atractosteus also falls completely within the ranges of A. spatula, A. tristoechus and A. simplex (Table 181). Therefore, this species is not differentiated with an applicable diagnosis. Also, the fragmentary type, like the Kinkelin scale, is "devoid of any diagnostic character." Therefore a new name is erected here for the Messel Atractosteus (Atractosteus messelensis sp. nov.) with a unique combination of characters to diagnose it and a nearly complete specimen as holotype."

Grande, L. (2010)

An empirical synthetic pattern study of gars (Lepisosteiformes) and closely related species, based mostly on skeletal anatomy. The resurrection of Holostei.

American Society of Ichthyologists and Herpetologists, Copeia, Special Publication 6, Supplementary Issue, 10(2A):1-871

Edited March 23, 2014 by piranha

[piranha]

Just in case anyone is curious to see the holotype for Atractosteus messelensis, it's a spectacular specimen prepared in dorsolateral and ventrolateral aspects from both sides of the fish!

Grande, L. (2010)

An empirical synthetic pattern study of gars (Lepisosteiformes) and closely related species, based mostly on skeletal anatomy. The resurrection of Holostei.

American Society of Ichthyologists and Herpetologists, Copeia, Special Publication 6, Supplementary Issue, 10(2A):1-871