扬子鳄附肢关节的初步研究

A PRELIMINARY STUDY ON THE LIMB JOINTS OF ALLIGATOR SINENSIS

观察了6例扬子鳄附肢骨骼的连结情况,并对前、后肢各主要关节的结构和功能进行了比较.发现肩带仅以上喙软骨与胸廓相连,腰带形成完整的骨环;肩臼鞍状,髋臼大而浅;肩关节和髋关节结构相似,囊的前下方均有滑膜襞,但后者关节囊较厚,且囊内有韧带;肘关节和膝关节结构亦相似,膝关节内尚有半月板和交叉韧带;足关节较复杂;掌指、跖趾和指、趾间关节均为屈戌关节;指、趾短伸、屈肌肌腱分别止于爪的基部背、腹侧.

We observed the limb joints of 6 individuals of Alligator Sinensis and made a comparison ofthe structure and function between major joints of fore-and hind-limbs. The findings were as follows: Epicoracoid cartilage joined pectoral girdles only to throax, and pelvic girdles formed into awhole bone ring. The glenoid fossae were in saddle shap and acetabula were big but shallow.Articulatio humeri were similar to articulatio coxae in structure, with plica synovicalis in thearticular capsule anterio and underly, but the latter had a thick articular capsule in which therewere ligaments. The structure of cubital and patellar articulationes were also alike, and there weremeniscus and cross-ligaments in patellar articulatio. Pes articulationes were complex.The articulationes metacarpophalangeae and articulationes interphalangeae were all ginglymus. Thethree inside fingers (or toes) had a claw at the end of them, and the tendons of digitalbrevi- extensor and digital brevi-flexor came to end respectively at the dorsal and ventral sides ofthe base of each claw.