Devonian (Emsian-Eifelian) fish from the Lower Bokkeveld Group (Ceres Subgroup), South Africa

Four major groups of fish are represented by fragmentary remains from South Africa's Lower Bokkeveld Group of Early to Middle Devonian age: the Acanth odii, Chondrichthyes, Placodermi and Osteichthyes. These represent the olde st known occurrences of these groups in southern Africa, as well as an impo rtant addition to the very meagre record of earlier Devonian fish from the Malvinokaffric Province of southwestern Gondwana. Bokkeveld fish material c omes from the Gydo (Late Emsian) and Tra Tra (Middle Eifelian) Formations o f the Western Cape and Eastern Cape Provinces. The cosmopolitan marine acan thodian Machaeracanthus is represented only by isolated fin spines which ma y belong to two different species on the basis of their external ornamentat ion, cross-sectional outline and internal histology. The elasmobranchs are represented by four elements: (1) a flattened chondrocranium which bears af finity to the Late Devonian-Carboniferous symmoriid (protacrodont) 'clanodo nt' sharks. It is probably the earliest known (Emsian) shark chondrocranium ; (2) an isolated, primitive scapulocoracoid with a very short coracoidal r idge; (3) ankylosed and isolated radials, interpreted as parts of pterygial prates of a paired fin of an unknown chondrichthyan bearing affinity to th e Middle Devonian Zamponiopteron from Bolivia; and (4) isolated barlike str uctures, perhaps gill arch or a jaw elements, thought to be from the same t axon as (3). The placoderms are represented by an incomplete trunk armour a nd fragmentary, finely ornamented plates of a primitive antiarch. The Ostei chthyes are represented by a single large scale of an unidentified dipnoan from the Eifelian of the Cedarberg range, as well as a probable sarcopteryg ian dermal plate from the Emsian of the Prince Albert area. These are among the earliest sarcopterygian remains recorded from the Malvinokaffric Provi nce. (C) 1999 Elsevier Science Limited. All rights reserved.