摘要
自从19世纪中叶,欧文氏(Owen)提出同源这个名词以来,在比较解剖学的研究方面,特别对脊椎动物四肢骨骼的演化,即如何从鱼的鳍演变成四足动物的肢体,一直是一个争论的问题。而对於前肢两骨(桡骨与尺骨)究竟那一块骨应该和Sauripterus或Eusthenopteron胸鳍的背侧一辐鳍(radial)同源,更不能得到一个统一的结论。
From a study of the developmental history of the fore-limb of the opossum,Didelphys,and of the external morphological changes of the fore-limb of some tetrapods,the authorbelieves that the dorsal one of the two radials of the crossopterygian pectoral fin ishomologous to the radius rather than the ventral one.During the development of thefore-limb,there is always a twist(pronation-like)present at the elbow region.By thistwist the palm of the hand is made possible to face the ground,and the radius turns asthe antero-lateral element of the forearm.This embryonic story suggests that in thephylogenetic history,i.e.from a fish fin to the tetrapod fore-limb,a pronation-like twistis present instead of a simple Hexion as is suggested by some investigators.
作者
郑思竞
CHENG CZE-CHING(Department of Anatomy,The First Medical College of Shanghai)
出处
《解剖学报》
CAS
1954年第2期185-190,共6页
Acta Anatomica Sinica
