Gluteus (genus)

Gluteus minimus is an extinct species of animal from the Late Devonian (Frasnian-Famennian) of Iowa that is the only species within the genus Gluteus. It was first collected in 1902, but only described in 1975 and the holotype is SUI 34978-91. Each animal appears as a bi-lobed lens up to 11 mm × 8 mm (0.43 in × 0.31 in), and almost all specimens share the same slight asymmetry. The species is of uncertain affinities, having been variously thought of as either fish teeth, some sort of fish scales, brachiopods, or otoliths.