Appraisal of the fossil record ofHomarus(nephropid lobster), with description of a new species from the upper Oligocene of Hungary and remarks on the status ofHoploparia

Abstract

AbstractThe fossil record of the clawed lobster genus,Homarus, is appraised. The taxonomic history ofHomarusandHoplopariais summarized, and a list of species recognized for each is provided. A tabulation of all fossil species of the family Nephropidae permits assessment of nephropid species diversity through time. A new species ofHomarus,H.hungaricus, is recorded from the upper Oligocene (Chattian) Mány Formation at Mány, northern Hungary. The species is known by a single specimen consisting of a partial cephalothorax, a pleon minus telson, and partial chelipeds.Homarusis now known by two extant species (H.americanusandH.gammarus) and six fossil taxa, one of Early Cretaceous (Albian;H.benedeni) and five of Cenozoic age (H.hungaricusn. sp.,H.klebsi,H.lehmanni,H.morrisi, andH.percyi). The new fossilHomarusdiffers from modern congeners in aspects of carapace and pleon ornamentation and, especially, cutter claw shape. This is the fourth Oligocene occurrence of a nephropid species; all areHomarusand all are from Western Europe.Homarusmakes its appearance in the fossil record in the Early Cretaceous (Albian) and then is not known again until the Paleogene, despite the fact that nephropid lobsters in general are well known from the Late Cretaceous. Nephropid lobsters are better known from the Cretaceous than from the Cenozoic. Both raw species numbers and numbers corrected (normalized) for epicontinental sea coverage show that shelf-dwelling nephropid lobsters were most diverse during the Late Cretaceous.