Field of Science

Neotype Proposal for Anchisaurus polyzelus

Galton, P.M. 2012. Case 3561 Anchisaurus Marsh, 1885 (Dinosauria, Sauropodomorpha): proposed conservation of usage by designation of a neotype for its type species Megadactylus polyzelus Hitchcock, 1865. Bulletin of Zoological Nomenclature 69 (1): 44-50.

Abstract - The purpose of this application, under Article 75.5 of the Code, is to conserve the usage of the name Anchisaurus Marsh, 1885 (Lower Jurassic, Connecticut Valley, northeastern U.S.A.) that is based on Megadactylus polyzelus Hitchcock, 1865. It is proposed to replace the fragmentary and non-diagnostic holotype of M. polyzelus with a diagnostic neotype, an almost complete skull and skeleton (YPM 1883, holotype of A. colurus Marsh, 1891). This specimen has formed the basis for the concept of Anchisaurus, the first basal sauropodomorph genus from the U.S.A. and still the best represented from there since it was illustrated by Marsh (1892, 1893), and of A. polyzelus since it was illustrated by Galton (1976). Anchisaurus is the basis for ANCHISAURIDAE Marsh, 1885, the first basal sauropodomorph family to be named, and for the Anchisauria Galton & Upchurch, 2004.


  1. Anyone else concerned with this? Sure Galton may not think the polyzelus holotype is diagnostic, but Yates (2010) does. Surely there should at least be consensus before taking such drastic action. I fear this and Galton's similar attempt to make stenops the type of Stegosaurus are indicative of a lazy and destabilizing new mindset where types are changed to the most complete specimens.

  2. Talk to Yates. If you can't reach him, submit a big-C Comment to the Bulletin of Zoological Nomenclature.

  3. spinosaurusancesterofmoderncrocodilianApril 16, 2012 at 10:09 PM

    name it after a crocodilian because dinosaurs are primtive crocodilian


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