恐龍的兩腿之間的巨大骨頭對應什麼器官？

01-08

昨天了參觀了牛津大學自然科學博物館，看到了霸王龍骨架中兩腿之間的巨大骨頭，但在其他恐龍的骨架中似乎並不存在，十分好奇它是對應什麼器官，起到什麼作用的？

盆骨

All known dinosaurs are divided into two large groups:Saurischia ("lizard-hipped") and Ornithischia ("bird-hipped"). Most saurischians had forward-jutting pubic hip bones, while in ornithischians each pubic bone slanted back, parallel to the ischium.

There were two major saurischian subgroup: the carnivorous, bipedal theropods and the plant-eating, mostly quadrupedal sauropodomorphs.

Ornithischians (all plant-eaters) were divided into three main groups: birdlike ornithopods, armored thyreophorans, and horned or thick-skulled marginocephalians.

信息來源： http://teachersnetwork.org/everywhere/Vaillancourt/Classification.html

蜥臀目恐龍的恥骨

那突出的一根是恥骨，並不是對應某個器官，而是提供腹部肌肉的附著部位，以便肌肉能圍成腹腔，完成保護腹腔以及增加腹壓、身體前屈等動作

比較容易混淆的是：鳥類屬於蜥臀類恐龍，而非鳥臀類恐龍。鳥類和鳥臀類恐龍盆骨的類似是由於趨同進化。

感覺是你的小JJ

恥骨