Rosenberg Herbert I, Russell Anthony P, Cavey Michael J
Vertebrate Morphology Research Group, Department of Biological Sciences, The University of Calgary, Calgary, Alberta, Canada T2N 1N4.
J Morphol. 1992 Mar;211(3):243-258. doi: 10.1002/jmor.1052110302.
Subdigital adhesive pads play an important role in the locomotion of many species of gekkonid lizards. These pads consist of integrated components derived from the epidermis, dermis, vascular system, subcuticular tendons, and phalanges. These components become intimately associated with each other during the developmental differentiation of the digits and the sequence of this integration is outlined herein in Ptyodactylus guttatus. The pads initially appear as paired swellings at the distal tips of the digits. Subsequently, a fan-like array of naked scansors develops on the ventral surface of each digit, at about the same time that scales differentiate over the surface of the foot as a whole. At the time of appearance of the naked scansors, the vascular sinus system of the pad also differentiates, along with subcuticular connective tissue specializations. At this stage the digits, along with the rest of the body, are clad in an embryonic periderm. Only after hatching and as the periderm is shed, do the epidermal setae and spines appear. The developmental sequence described here is consistent with predictions previously advanced about the evolutionary origin and elaboration of subdigital pads in gekkonid lizards. The paucity of available staged embryonic material leaves many questions unresolved.
指下黏附垫在许多壁虎科蜥蜴的运动中起着重要作用。这些垫子由源自表皮、真皮、血管系统、皮下肌腱和指骨的整合成分组成。在指的发育分化过程中，这些成分彼此紧密相连，本文概述了斑点沙虎指的这种整合顺序。垫子最初表现为指远端尖端的成对肿胀。随后，在每个指的腹面出现扇形排列的裸露扫描器，与此同时，整个足部表面的鳞片开始分化。在裸露扫描器出现时，垫子的血管窦系统以及皮下结缔组织特化也开始分化。在这个阶段，指以及身体的其他部分都覆盖着胚胎周皮。只有在孵化后，随着周皮脱落，表皮刚毛和棘才会出现。这里描述的发育顺序与之前关于壁虎科蜥蜴指下垫的进化起源和演化的预测一致。可用的分期胚胎材料稀少，留下了许多未解决的问题。
