Representative locomotion types in lizards include terrestrial, arboreal, grass swimmer, sand swimmer and bipedal. Few studies explain the locomotion habit of extinct lizards, and even less asses those of bipedal ones. Here, we use quantitative methods to infer the type of locomotion of two Albian Mexican lizards (Lower Cretaceous) and three Cretaceous lizards from Brazil, North America and Spain, assessing the similarities of the hindlimb-forelimb length ratio amongst extinct and extant species. Additionally, an ancestral character state reconstruction analysis was performed, to evaluate the evolution of lizard locomotion habits. The species Huehuecuetzpalli mixtecus was bipedal while Tijubina pontei was facultative bipedal, Hoyalacerta sanzi, Tepexisaurus tepexii and Polyglyphanodon sternbergi cannot be differentiated amongst terrestrial or arboreal with the approach used in this work. The ancestral character state reconstruction analysis showed a terrestrial ancestral locomotion type, with a basal character state of hindlimbs longer than forelimbs. Equal length between hind and forelimbs appear to be a derivate state that evolved multiple times in lizard evolutionary history.

蜥蜴的代表性运动类型包括陆地，树栖，草游泳者，沙游泳者和两足动物。很少有研究能够解释灭绝蜥蜴的运动习惯，甚至没有两足动物能够评估它们的运动习惯。在这里，我们使用定量方法来推断来自巴西，北美和西班牙的两只Albian墨西哥蜥蜴（下白垩纪）和三只白垩纪蜥蜴的运动类型，评估了已灭绝和现存物种的后肢与前肢长度比的相似性。另外，进行了祖先特征状态重建分析，以评估蜥蜴运动习惯的演变。物种Huehuecuetzpalli mixtecus是两足动物，而Tijubina pontei是兼性两足动物，Hoyalacerta sanzi，用这项工作所采用的方法，不能将特氏猿和特氏豚鼠区别于陆地或树栖动物。祖先特征状态重建分析显示出陆生祖先运动类型，后肢的基础特征状态比前肢长。后肢和前肢之间的等长长度似乎是蜥蜴进化史上多次进化的一种衍生状态。