Caradocian期三叶虫—新属Paratzuchiatocnemis，并讨论其分类位置问题

本文描述了采自湘西北奥陶纪 Caradocian 期的三叶虫新属——Paratzuchiatocnemis(gen.nov.)(副自家虫),并进一步讨论此新属的特征与自家虫属(Tzuchiatocnemis),瘤肋虫属(Hammatocnemis)、卵形头虫属(Ovalocephalus)的异同及它们的相互关系与归属问题,认为宜将 Ovalocephalus、Tzuchiatocnemis 与 Paratzuchiatocnemis 三属划归为新亚科——卵头虫亚科〔Ovalocephanae(subfam.nov.)〕.

A CARADOCIAN NEW TRILOBITE GENUS FROM CILI COUNTY,HUNAN PROVINCE

The present paper deals with the Caradocian trilobites collected from Cili County, Hunan Province in 1984 and 1985. A new genus Paratzuchiatocnemis(gen. nov.) is established and described. A new subfamily Ovalocephanae, including Ovalocephalus, Tzuchiatocnemis and Paratzuchiatocnemis (gen. nov.), is also established in this paper. The diagnoses of the new genus and the new subfamily are given as follows: Genus Paratzuchiatocnemis gen. nov. Type species: Paratzuchiatocnemis dialox gen. et. sp. nov. Diagnosis: Cephalon similar with Tzuchiatocnemis. The base of glabella in front of the occipital ring very narrow (tr.), but rapidly expanding anteriorly. There are two pairs of glabellar furrows near the base of glabella. The anterior pairs shorter. The occipital ring narrow (long.) at the dorsal furrows, expanding in width towards the middle, beecwing there twice as broad as at the sides. There is no preoccipital ring. Facial suture preparian. Locality and horizon: Pogoda (Baota) Formation in Cili County of NW Hunan, China; Caradocian. Subfamily Ovalocephanae nov. Diagnosis-Facial suture proparian. Cephalon middle sized. The base of glabella very narrow (tr.) but rapidly expanding anteriorly. There are two pairs glabellar furrows which are near the base of glabella. Occipital ring wider (sag.) in the middle than at the sides. Horizon and locality: Middle Ordovician, Caradocian; Soviet Union, China.