Rocha-Barbosa O, Loguercio M F C, Velloso A L R, Bonates A C C
Departamento de Zoologia, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil.
Braz J Biol. 2008 Aug;68(3):649-55. doi: 10.1590/s1519-69842008000300024.
Bipedalism has evolved on numerous occasions in phylogenetically diverse lizard families. In this paper we describe, for the first time, bipedal locomotion on South American lizards, the sand-dweller Liolaemus lutzae and the generalist Tropidurus torquatus. The lizards were videotaped running on a racetrack and the sequences were analyzed frame by frame. The body posture, as a whole, diverged a lot during bipedal locomotion between the two species, even though there was no difference regarding their sprint performance. The locomotor behavior of L. lutzae is, in general, more similar to the one observed on other sand-dweller lizards. Certain particularities are common, such as the digitigrade posture at footfall and throughout stance, trunk angles; and tail posture. In contrast, T. torquatus exhibited high trunk angles and dragged its tail, in a posture compared to basilisks. This body posture could be related to certain characteristics and obstacles of a microhabitat such as the one around lakes and streams (basilisks) and the one with compact shrubby vegetation (T. torquatus).
双足行走在系统发育上不同的蜥蜴科中已经多次进化。在本文中，我们首次描述了南美蜥蜴的双足运动，即沙地栖息的卢氏鬃狮蜥和广食性的饰纹角蜥。这些蜥蜴在跑道上奔跑时被录像，并对序列进行逐帧分析。尽管两种蜥蜴的短跑表现没有差异，但在双足运动过程中，它们的整体身体姿势差异很大。一般来说，卢氏鬃狮蜥的运动行为与在其他沙地栖息蜥蜴身上观察到的更为相似。某些特点是共有的，比如着地和整个站立阶段的趾行姿势、躯干角度以及尾巴姿势。相比之下，饰纹角蜥表现出较高的躯干角度并拖着尾巴，其姿势与蛇怪蜥蜴相似。这种身体姿势可能与微生境的某些特征和障碍物有关，比如湖泊和溪流周围的微生境（蛇怪蜥蜴）以及有紧凑灌木植被的微生境（饰纹角蜥）。
