摘要
本文讨论了假海乐菊石群在湖南分布的特点。文中记述了这个头足类动物群中的2个新属和5个新种;并认为假海乐菊石群的时代属早二叠世茅口期早期,少数分子延续到茅口期中期。
A large number of Pseudohalorites have been discovered at many localities in central Hunan.Geographically,they are generally distributed in a east-west direction along the Baimashan-Lungshan structural belt.The Pseudohalorites-fauna is regarded as belonging to early to middle Maokouian of early Permian in age.In this paper,Yinoceratinae is translated into a family rank,2 new genera(Linonautilus and Shaoyangoceras)and 5 new species(L.communis.L.nanus,S.jiangjiachongense,Lanceoloboceras hunanense and Waagenina xiangtanensis)are also described.Nautiloidea Agassiz,1847 Pleuronautilidae Hyatt,1900 Linonautilus(gen.nov.)Type species:Linonautilus communis(gen.et sp.nov.)Diagnosis:Shell nautiloid,subevolute,perforate with a moderate umbilicus.Whorls transverse trapezoid in section,the rate between width and height about 1.8:1.Surface smooth,inner suture-line with a funnel-like annular lobe.The present new genus differs from other genera of Pleuronautilidae in the smooth surface.Ammonoidea Zittel,1884 Yinoceratidae Ruzhencev,1960;trans.Zhou,1977 Diagnosis:Involute,lenticular to subglobular ammonites with transverse ribs.Suture-line subammonitic,ventral lobe apparently bifurcate,lateral lobe with numerous lanceolate denticulations,external saddle high and narrow.Siphuncle dorsocentral in position.Shaoyangoceras(gen.nov.)Type species:Shaoyangoceras jiangjiachongense(gen.et sp.nov.)Diagnosis:Shell involute,subglobular in shape.Whorls rather low.Surface ornamented with numerous bifurcate ribs.Suture-line subammonitic,with a long bifurcate ventral lobe;external saddle high and narrow;lateral lobe wide,bearing peculiar denticulations.Siphuncle distinct,dorso-central in position.This new genus differs from Yinoceras in the subglobular shape and the longer ventral lobe.
作者
周祖仁
Zhou Zu-ren(Regional Geological Surveying Team of Hunan)
出处
《古生物学报》
1979年第4期383-394,428-429,共14页
Acta Palaeontologica Sinica
