Cundall David, Shardo Judith
Behavioral and evolutionary Biosciences, Lehigh University, Bethlehem, Pennsylvania 18015-3007.
Department of Biology, University of Massachusetts, Amherst, Massachusetts 01003-0027.
J Morphol. 1995 Jul;225(1):31-50. doi: 10.1002/jmor.1052250104.
Radiographic and cinegraphic behavioral data, combined with anatomical evidence, indicate that the snout in Nerodia and Thamnophis consists of four movable elements (1, premaxilla; 2, paired nasals; 3, right septomaxilla and vomer; and 4, left septomaxilla and vomer), a condition we refer to as rhinokinetic. In thamnophiine snakes, movements of the snout bones allow the teeth of the right and left sides to separate further and increase the effective stroke distance of each palatomaxillary cycle during swallowing. Histological and microdissectional analyses suggest that snout movement is keyed to the placement of the cartilaginous nasal septum and associated nasal capsules relative to the surrounding bones. The nasal septum separates the paired septomaxillae and is surrounded by loose connective tissues that extend ventrally between the vomers. The nasal capsules separate the nasal bones from the underlying septomaxillae, and also surround the anterior ends of the septomaxillae, providing a cartilaginous cushion between these bones and the premaxilla. The extraordinary rotations of the snout tip seen during swallowing in thamnophiine snakes are thus due to motion at the prokinetic joint between snout and braincase, and at all rhinokinetic joints connecting the four functional elements of the snout. © 1995 Wiley-Liss, Inc.
射线照相和动态影像行为数据，结合解剖学证据，表明颈槽蛇属（Nerodia）和束带蛇属（Thamnophis）的吻部由四个可移动部分组成（1. 前颌骨；2. 成对的鼻骨；3. 右侧隔颌骨和犁骨；4. 左侧隔颌骨和犁骨），这种情况我们称之为鼻动性。在束带蛇亚科的蛇类中，吻部骨骼的运动使得左右两侧的牙齿能够进一步分开，并在吞咽过程中增加每个腭颌周期的有效行程距离。组织学和显微解剖分析表明，吻部运动与软骨鼻中隔及相关鼻囊相对于周围骨骼的位置有关。鼻中隔将成对的隔颌骨分开，并被在犁骨之间腹侧延伸的疏松结缔组织所包围。鼻囊将鼻骨与下方的隔颌骨分开，并且还包围隔颌骨的前端，在这些骨骼和前颌骨之间提供一个软骨垫。因此，束带蛇亚科的蛇类在吞咽过程中看到的吻尖的非凡旋转是由于吻部与脑壳之间的前动关节以及连接吻部四个功能元件的所有鼻动关节处的运动所致。© 1995威利 - 利斯公司。
