A Carboniferous necrophagous myodocopid ostracod from Derbyshire, England

A monospecific population of cypridinid ostracods (Myodocopida) has been recovered from an ammonoid-bearing concretion of Namurian (Kindescoutian, R1a-b) age in the Bowland Shale Formation of Central England. These deposits represent sedimentation on the northern margin of a Carboniferous marine basin, the WNW-ESE orientated Widmerpool Gulf, where water depth probably exceeded 100 m. The ostracods occur in close association with the cranium of a shark (Orodus), on which they had most likely been scavenging. The sark carcass apparently formed a refuge to which the ostracods were restricted: they do not occur elsewhere within the concretion or surrounding strata. Adults and possibly as many as six moult stages are present so that the assemblage represents the original conspecific ostracod biocoenosis. The carapace morphology of this myodocopid ostracod. Eocypridina carsingtonensis sp. nov., is described and compared with related taxa. It is the oldest known myodocope to provide firm evidence of traces of an integumental circulatory system, present in positive relief on internal moulds as a series of anastomosing sinuses radiating away from the adductor muscle scar area, and comparable with modern cypridinids such as Vargula.

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