Whitephippus tamesis was a highly distinctive lampriform fish from the London Clay, known from a three-dimensional skull. Modern study has shown that it belongs with the lineage that includes oarfishes, opahs and ribbonfishes rather than the scombrid groups to which some early Eocene fishes were historically compared. The head is laterally compressed and strongly keeled, with a small toothless mouth.

Lampriforms are predominantly pelagic fishes, and the cranial form of Whitephippus is consistent with life in the water column. Its exact diet cannot be recovered directly, but the small edentulous mouth suggests feeding on relatively small prey rather than biting large animals. The species is important evidence that lampriforms independently evolved specialised pelagic cranial designs early in the Cenozoic.