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Ventral valve
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Eatonia bithynica
Phylum: Brachiopod
Genus: Eatonia Species: Eoatonia bithynica Location found: Baton River |
Eatonia bithynica seems to be uncommon in the Devonian rocks of the Baton River, and the specimen shown here is one of very few good specimens that I've found. Even this one, however, is vert distorted, presumably due to tectonic activity after the rocks had been consolidated and buried. Interestingly, the same is true of specimens illustrated by Shirley (1928) and it appears that either the fossils ared especially susceptible to distortion, or that the sediments they were laid down in were subject to particular conditions. Distortion suc h as this is a marked feature in the Devonian deposits, and one of the curiosities is the way the amount of ddistortion varies between different layers in the sediments, and between different specimens within a layer.
Detailed descriptions of the species are scarce in previous pubications, but a distinctive feature is the broad, rather flattened ribs that extend only part-way from the rim of the shell towards the beak. Typically, the shell seems to support 14-16 ribs. The deeply divided beak on the dorsal valve is also notable. |
Dorsal valve
Further reading: Shirley, J. 1938 The fauna of the Baton River beds (Devonian), New Zealand. Quarterly Journal of the Geological Society 94, 459-506. |