腕鉤基 的英文怎麼說
中文拼音 [wàngōujī]
腕鉤基
英文
crural base-
The feathers attached to the arms and the tail evidently possess the structures of " modern feathers ", which consisting of the central shafts ( rachis ) and parallel barbs. dromaeosaurids are unusual group of maniraptoran theropods. they share many similar or the same features with archaeopteryx or other primitive birds, such as : u - shaped furcula, uncinate process, laterally facing glenoid of shoulder girdle, comparatively long forelimb, large semilunate carple, retroverted pubis, ascending process of astragalus, and " modern feathers " with rachis and barbs etc. these facts indicate not only that dromaeosaurids had developed many bird - like characters in course of the advanced maniraptorans toward birds, but also that there seemed to be the co - evolutionary trend between the feathers and the skeletal bones
奔龍類是一類較為特殊的手盜龍類（ maniraptora ） ，它具有許多與始祖鳥archaeopteryx甚至其它早期鳥類相似或接近的特徵，主要表現在：叉骨u形與始祖鳥和孔子鳥類的相同，背肋鉤狀突在孔子鳥類和個別反鳥類中也存在，肩臼窩絕大部分指向側方類似於始祖鳥，肩胛骨與烏喙骨間的夾角非常接近90也和始祖鳥的相似，前肢從比例上講顯得較長，大的半月形腕骨使肘部能向側方折過來，恥骨伸向後下方，距骨上升突與原始鳥類中的為同源結構，羽毛已有顯著的分化且具備了現代羽毛的基本結構等等。
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