preserved appendages in a Silurian binodicope: implications for the evolutionary history of ostracod crustaceans

Derima paparme gen. et sp. nov. from the Herefordshire Silurian Lagerstätte is one of only a handful of exceptionally preserved ostracod crustaceans known from the Palaeozoic. A male specimen provides the first evidence of the soft-part morphology of Binodicopina, a major group of Palaeozoic ostracods comprising some 135 Ordovician to Permian genera. The appendage morphology of D. paparme, but not its shell, indicates that binodicopes belong to Podocopa. The discovery that the soft-part morphology of binodicopes allies them with podocopes affirms that using the shell alone is an unreliable basis for classifying certain fossil ostracods and that knowledge of soft-part morphology is critical for the task. Current assignment of many fossil ostracods to higher taxa may require reconsideration.

Methods
Colour images obtained through digital microscope photography and serial grinding of specimen OUMNH PAL-C.36094, at 20 micron intervals. The method is detailed in Sutton et al. (2014). Images have been registered, but not processed in any other way. There are two datasets, representing the part and counterpart.

3D Model is presented as a VAXML/STL model, manually prepared from the image data using the SPIERS software suite, following the method of Sutton et al. (2014).

Sutton, MD, Rahman, I, Garwood, RJ. 2014. Techniques for Virtual Palaeontology. Wiley, 218pp.