A new late Permian ray-finned (actinopterygian) fish from the Beaufort Group, South Africa
Date
2002
Authors
Bender, Patrick
Journal Title
Journal ISSN
Volume Title
Publisher
Bernard Price Institute for Palaeontological Research
Abstract
A new genus and species of actinopterygian (ray-finned) fish, Kompasia delaharpei, is described
from Late Permian (Tatarian) fluvio-lacustrine, siltstone dominated deposits within the lower Beaufort
Group of South Africa. It is currently known from two localities on adjoining farms, Wilgerbosch and
Ganora, both in the New Bethesda district of the Eastern Cape Karoo region. The fossils were
recovered from an uncertain formation, possibly closely equivalent to the Balfour Formation, within the
Dicynodon Assemblage Zone. Kompasia delaharpei differs from previously described early
actinopterygians, including the recently described new lower Beaufort Group taxon Bethesdaichthys
kitchingi, on the basis of a combination of skull and post cranial characters. The genus is characterised
by: a uniquely shaped subrectangular posterior blade of the maxilla, a shortened dorsal limb of the
preopercular, and a dermopterotic and dermosphenotic contacting the nasal; furthermore, the
subopercular is equal to or longer than the opercular, the dorsal fin is situated in the posterior third of
the body, slightly behind the position of the anal fin, and the anterior midflank scales exhibit a smooth
dermal pattern or surface, with a number of faint ganoine ridges present parallel to the posterior and
ventral scale margins. Kompasia appears to exhibit a relatively conservative morphology similar to that
in the lower Beaufort Group taxon Bethesdaichthys kitchingi. As such, Kompasia is derived relative
to stem-actinopterans such as Howqualepis, Mimia and Moythomasia, and also derived relative to
earlier southern African Palaeozoic actinopterygians such as Mentzichthys jubbi and Namaichthys
schroederi, but basal to stem-neopterygians such as Australosomus and Saurichthys.
Description
Main article
Keywords
Ray finned; fish; Beaufort; South Africa
Citation
None