Anatomy of the very tiny:
FIRST DESCRIPTION OF THE HEAD SKELETON oF THE RARE
SOUTH AMERICAN CatFISH Sarcoglanis simplex
(SILURIFORMES: TRICHOMYCTERIDAE)

Kerin M. Claeson, James W. Hagadorn, Kyle Luckenbill, and John G. Lundberg

ABSTRACT

The osteology of Sarcoglanis simplex, a rare, miniature South American catfish, is described for the first time based on a single, 17 mm adult specimen that was both cleared and Alizarin-stained, and visualized with microfocus computed tomography (MicroCT). Previously, the internal skeletal features of this species could be predicted based only on conditions observed in its closest relatives within the subfamily Sarcoglanidinae of the Trichomycteridae. The relatively new MicroCT technique successfully revealed fine details of the skeletal morphology of this tiny fish. As predicted, Sarcoglanis shares with Stauroglanis, Stenolicmus, Malacoglanis, Microcambeva, and Ammoglanis an anterior ossification of the palatine and a large posteriorly directed dorsal process on the quadrate. Contrary to predictions, however, the mesethmoid of Sarcoglanis does not have the distal ends of the cornua distinctly wider than at their bases, and the anterior margin of the mesethmoid is not convex.

Kerin M. Claeson. The Department of Geological Sciences, The Jackson School of Geosciences, The University of Texas at Austin, Austin, Texas USA
James W. Hagadorn. Department of Geology, Amherst College, Amherst, Massachusetts USA
Kyle Luckenbill. Department of Ichthyology, Academy of Natural Sciences, Philadelphia, Pennsylvania USA
John G. Lundberg. Department of Ichthyology, Academy of Natural Sciences, Philadelphia, Pennsylvania USA

KEY WORDS: miniature, osteology, Sarcoglanidinae, Microcambeva, Stauroglanis

PE Article Number: 11.2.6A
Copyright: Society of Vertebrate Paleontology July 2008
Submission: 8 January 2007. Acceptance: 30 November 2007