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古脊椎动物学报 ›› 1992, Vol. 30 ›› Issue (03): 169-184.

• 古脊椎动物学报 •    下一篇

记真盔甲鱼类两新属——兼论真盔甲鱼类系统发育关系

朱敏   

  • 出版日期:1992-09-15 发布日期:1992-09-15

Two NEW EUGALEASPIDS, WITH A DISCUSSION ON EUGALEASPID PHYLOGENY

Zhu Min   

  • Online:1992-09-15 Published:1992-09-15

摘要: 本文记述了早泥盆世真盔甲鱼类两新属:憨鱼属(Nochelaspis)和翼角鱼属(Pterogonaspis)。真盔甲鱼类是盔甲鱼类的一个单系类群,现有七属十二种,文中运用分支系统学原理对其系统发育关系进行了初步探讨。

Abstract: Two new Early Devonian eugaleaspids from Qujing, Yunnan in South China are described here. One is Nochelaspis maeandrine gen. et sp. nov., collected from the lower part of Xishancun Formation (early Early Devonian), the other Pterogonaspis yuhaii gen. et sp. nov. from Xujiachong Formation (late Early Devonian). Nochelaspis, the largest eugaleaspid so far described, is an element of the Early Vertebrate fauna in Xishancun Formation (Zhu, 1991), which includes polybranchiaspids, paleoniscoids, crossopterygian, arthrodire, antiarchs, petalichthyids (Zhu, dissertation; in preparation). Pterogonaspis, the huananaspid-like eugaleaspid, occurred in the same bed with Eugaleaspis xuiiachongensis, Sanchaspis magalarostra, yunnanolepids and plant remains. Both genera throw lights on the phylogeny of eugaleaspids and galeaspids. Eugaleaspids are assumed to be a monophyletic galeaspid group by (l) the eugaleaspid pattern lateral line system and (2) the longitudinal oval median dorsal opening (if the median dorsal opening of Nanpanaspis is due to the parallelism). By now, there have been 7 genera including 12 species of eugaleaspids described, ranging from Middle Silurian to Early Devonian (Fig. 3). The character analysis of eugaleaspids has been done in view of Cladistics. With the principle of parsimony, a new testable cladogram is established (Fig. 5).