云南昭通早泥盆世肉鳍鱼类—新属(英文)

记述了产于云南昭通早泥盆世布拉格期基干肺鱼形动物一新属、新种——多孔弓鱼(Arquatichthys porosus gen.et sp.nov.)。新材料包括一件较为完整的下颌和鳞片若干。与基干肺鱼形动物相近的特征有:第四下齿骨水平凹线呈"L"形;下颌表面可见许多不规则排列的感觉管开孔;具三块冠状骨;冠状骨侧部为宽阔的小齿带;侧联合齿骨附着区较小;颌收肌窝大;菱形鳞片具明显的前腹突。鉴别特征包括下颌背缘明显隆起,以及后缘具加长的被覆压区。多孔弓鱼的发现为探讨肉鳍鱼类的早期分化提供了新的资料,在早期肉鳍鱼类的系统发育关系框架下讨论了鳞片的特征演化序列。

AN EARLY DEVONIAN (PRAGIAN) SARCOPTERYGIAN FROM ZHAOTONG,YUNNAN,CHINA

A new basal dipnomorph sarcopterygian, Arquatichthys porosus gen.et sp. nov., from the Lower Devonian (Pragian) of northeastern Yunnan, China,is described on the basis of a nearly com- plete mandible and several isolated scales.It closely resembles basal dipnomorphs in following charac- ters: short and L-shaped pit-line of infradentary 4(uniquely shared with dipnomorphs),small parasym- physial dental plate attachment,three coronoids, broad"tooth pavement"on the lateral portion of coro- noids, large adductor fossa,irregularly scattered pores of mandibular sensory canal on the lateral sur- face of mandible,and distinct anteroventral process of rhomboid scale.Arquatichthys has a unique man- dible morphology characterized by a strongly arched upper margin,and an elongated overlapped area by quadratojugal and maxillary.As the second dipnomorph from the Pragian of China,Arquatichthys adds evidences to understanding the early diversification of sarcopterygians.The character transitions of scales are discussed within the framework of the interrelationships of early sarcopterygians.