Data from: Appraisal of the fossil record of Homarus (nephropid lobster), with description of a new species from the upper Oligocene of Hungary and remarks on the status of Hoploparia

The fossil record of the clawed lobster genus, Homarus, is appraised. The taxonomic history of Homarus and Hoploparia is 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 of Homarus, 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. Homarus is now known by two extant species (H. americanus and H. gammarus) and six fossil taxa, one of Early Cretaceous (Albian; H. benedeni) and five of Cenozoic age (H. hungaricus n. sp., H. klebsi, H. lehmanni, H. morrisi, and H. percyi). The new fossil Homarus differs 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 are Homarus and all are from Western Europe. Homarus makes 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.本文对螯龙虾属（Homarus）的化石记录进行系统评述。总结了螯龙虾属（Homarus）与似螯龙虾属（Hoploparia）的分类学历史，并分别列出二者所确认的物种名录。通过对海螯虾科（Nephropidae）全部化石物种的列表统计，可推演该类群随地质时间的物种多样性变化。本次研究记述了产自匈牙利北部曼伊（Mány）地区渐新统上部（恰特阶，Chattian）曼伊组（Mány Formation）的螯龙虾属新种：匈牙利螯龙虾（H. hungaricus）。该新种仅基于一件标本，标本包含部分头胸甲、不含尾节的腹部以及部分螯足。目前螯龙虾属共计确认2个现生种（美洲螯龙虾H. americanus与欧洲螯龙虾H. gammarus）以及6个化石分类单元：1个早白垩世（阿尔必阶，Albian；H. benedeni）类群与5个新生代类群（本研究发表的匈牙利螯龙虾H. hungaricus n. sp.，以及H. klebsi、H. lehmanni、H. morrisi与H. percyi）。该化石螯龙虾新种与现生同属物种的区别主要在于头胸甲及腹部的纹饰特征，尤其是切螯的形态。本次发现为渐新世海螯虾科物种的第4笔化石记录，所有渐新世海螯虾科物种均隶属于螯龙虾属，且全部产自西欧地区。螯龙虾属的化石记录最早出现于早白垩世（阿尔必阶），此后直至古近纪均无可靠化石记录；尽管海螯虾类群在晚白垩世的化石记录已较为丰富。海螯虾科物种的化石记录以白垩纪时期最为丰富，远多于新生代类群。无论是基于原始物种数量还是针对陆表海覆盖面积进行校正（标准化）后的物种数量，均显示栖息于陆架环境的海螯虾类群在晚白垩世达到物种多样性峰值。