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Stegosaurus type species petition before ICZN

From: Ben Creisler

I don't recall seeing mention of this item on the DML. Peter Galton has
filed a formal petition with the ICZN to make Stegosaurus stenops the type
species of Stegosaurus. The topic of poor type material for Stegosaurus has
come up a number of times on the DML.[He published a paper last year about
the type species problem: Galton, Peter M. 2010. Species of plated dinosaur
Stegosaurus (Morrison Formation, Late Jurassic) of western USA: new type
species designation needed. Swiss Journal of Geosciences 103: 187-198.]

Galton, P.M. (2011)
Case 3536 Stegosaurus Marsh, 1877 (Dinosauria, Ornithischia): proposed
replacement of the type species with Stegosaurus stenops Marsh, 1887.
Bulletin of Zoological Nomenclature 68(2): 127-133

The purpose of this application, under Article 81.1 of the Code, is to
preserve stability in the taxonomy of stegosaurian dinosaurs by replacing
Stegosaurus armatus Marsh, 1877, the unidentifiable type species of the
ornithischian dinosaur genus Stegosaurus Marsh, 1877, with the very well
represented nominal species Stegosaurus stenops Marsh, 1887, also from the
Upper Jurassic Morrison Formation, U.S.A. This genus is the basis for
Stegosauria Marsh, 1877, STEGOSAUROIDEA Marsh, 1880, STEGOSAURIDAE Marsh,
1880 and STEGOSAURINAE Marsh, 1880. Maidment et al. (2008) listed seven
putative autapomorphic characters for Stegosaurus and five for the species
Stegosaurus armatus in its current usage. However, the holotype of S.
armatus, which consists of an articulated series of 18 incomplete vertebrae
from the proximal half of the tail and a very large but incomplete dermal
plate, shows none of these diagnostic characters and so S. armatus must be
considered a nomen dubium. However, the holotype of S. stenops Marsh, 1887
shares all 12 autapomorphies with S. armatus in its current usage, being
based on an almost complete skeleton (USNM 4934), most of it still in the
rock preserving almost natural articulation, which would make S. stenops by
far the best available species to replace S. armatus as type species of
Stegosaurus Marsh, 1877.

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