摘要
The constrictor internus dorsalis (CID) trigeminal muscles in vertebrates lie between the braincase and the palatoquadrate bar, and in reptiles they are believed to function in the relative movements between braincase and maxillary segment known as kinesis. In amniote taxa, the presence of a synovial basipterygoid articulation (BPA) correlates with presence of the CID. Previous descriptions of the CID in the tuatara Sphenodon (Rhynchocephalia) are inconsistent regarding presence, size and direction, particularly of the m. protractor pterygoidei. The Sphenodon skull is reported to be akinetic. The CID was investigated in Sphenodon by examination of sectioned embryonic and hatchling material, and by dissection of fixed specimens. Osteological correlates of CID muscles and morphology of the BPA were examined on disarticulated skulls and on CT scan images. The vectors of action of these muscles in relation to the BPA were projected onto CT images. Mm. levator bulbi and levator pterygoidei are found to be similar to most previous descriptions, but m. protractor pterygoidei was found in a different position, lying entirely medial to the palatoquadrate bar. The insertions of mm. levator pterygoidei and protractor pterygoidei are visible on the disarticulated pterygoid bone. The BPA is mobile only by rotation around the horizontal axis of the joints themselves; metakinesis is not possible in the Sphenodon skull. M. protractor pterygoidei appears to either resist or recognize lateral displacement of the BPA. M. levator ptergyoidei is placed to resist dorsal displacement of the braincase at the BPA, or torsion of the braincase around its longitudinal axis. The BPA appears to be a means to direct compressive stress via the base of the braincase and occipital condyle to the cervical spine in Sphenodon, and probably in its direct ancestors. Metakinesis may never have been a feature of the lepidosaur skull. J. Morphol., 2010. © 2009 Wiley-Liss, Inc.
摘要译文
大蟒internus足背（CID）三叉神经肌肉脊椎动物趴在脑壳和palatoquadrate杆之间，在爬行动物，他们被认为是在脑壳并称为室壁运动上颌部分之间的相对运动功能。在脊椎动物类群，滑液basipterygoid关节（BPA）的存在与该CID的存在下进行。在喙头蜥楔齿（爬行动物）的CID以前的描述是特别的米不一致就存在，大小和方向。量角器pterygoidei。该楔齿头骨据报道，运动不能。在CID，考察了楔齿通过检查切片胚胎和幼体的材料，并通过固定的标本解剖。CID肌肉和BPA形态的人体骨骼相关性进行了审查的脱节头骨和CT扫描图像。这些肌肉在相对于双酚A的动作的载体投射到CT图像。毫米。提痨和提pterygoidei被发现是类似于大多数先前的说明，但米。量角器pterygoidei被发现在不同的位置，完全躺在内侧到palatoquadrate吧。毫米的插入。提pterygoidei和量角器pterygoidei都在脱节翼骨可见。的双酚A是移动仅通过围绕关节本身的水平轴转动;中期分裂是不可能的，在楔齿头骨。 M.量角器pterygoidei出现要么抗拒或者承认BPA的横向位移。 M.提ptergyoidei放在抵御脑壳在BPA背侧移位，或绕其纵轴的脑壳扭转。BPA的似乎是经由脑壳的基极和枕骨髁颈椎在楔齿，而且很可能在它的直接祖先直接压缩应力的装置。中期分裂可能从来没有被lepidosaur头骨的功能。 J.吗啉，2010。
Peter Johnston[*]. The constrictor dorsalis musculature and basipterygoid articulation in Sphenodon[J]. Journal of Morphology, 2010,271(3): 280-292