- publication
- 01-09-2001
The anatomy of the osteoglossomorph Palaeonotopterus greenwoodi Forey is redescribed on the basis of more complete material than used in the original description. This new material shows large rounded and attached parasphenoid tooth plates with a Plethodus -like histology. We are therefore able to associate some species ofPlethodus with a skull. Not all species of Plethodus may belong to the same kind of fish: specifically,Plethodus oblongus Dixon, which is known from articulated skull material, appears to be a very different kind of fish.Palaeonotopterus shows a mixture of notopterid and mormyroid characters. With notopterids Palaeonotopterus shares an elongate foramen for V+VII straddling the suture between prootic and pterosphenoid in the orbital wall, an auditory fenestra between the prootic and basioccipital (homoplastic with Hiodon), a sagitta with a prominent anterior process (inferred in Palaeonotopterus from the shape of the labyrinth cavity). With primitive mormyroids Palaeonotopterus shares a similar and distinctively shaped supraoccipital crest and a suture between the paraÍsphenoid and autosphenotic. A supraorbital branch of the otic sensory canal, formerly thought to be a character of notopterids, is present in mormyroids and therefore is interpreted as a character of notopterids+mormyroids.
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