Data from: A method for deducing neck mobility in plesiosaurs, using the exceptionally preserved Nichollssaura borealis

The elongate-necked aquatic plesiosaurs existed for 135 million years during the Mesozoic. The function of this elongate neck is a point of debate. Using computed tomography (CT) and 3-dimensional (3D) modelling, the range of motion (ROM) of the plesiosaur *Nichollssaura borealis* neck was assessed. To quantify the ROM, the intervertebral mobility was measured along the cervical vertebral column. This was done by manipulating the 3D models in the lateral and dorso-ventral directions during two trials. The first assessed the mean intervertebral ROM between pairs of cervical vertebrae along the entire column, and the second assessed ROM with reduced intervertebral spaces. The results suggest that there may be preference for lateral neck movements in *N. borealis*, which could correspond to an ecological function related to prey capture. This study demonstrates that 3D modelling is an effective tool for assessing function morphology for structures where no good modern analogue exists.

长颈水生蛇颈龙类在中生代存续了1.35亿年。这类长颈结构的功能至今仍存在学术争议。本研究借助计算机断层扫描（computed tomography, CT）与三维（3-dimensional, 3D）建模技术，对北方尼可尔斯蛇颈龙（Nichollssaura borealis）颈部的运动幅度（range of motion, ROM）进行了评估。为量化该运动幅度，研究人员沿颈椎柱测量了椎体间活动度。研究通过两次试验，在侧方与背腹方向上对三维模型进行操作以完成该测量：首次试验评估了整条颈椎柱各相邻颈椎间的平均椎体间运动幅度，第二次试验则在缩小椎体间隙的条件下评估运动幅度。研究结果显示，北方尼可尔斯蛇颈龙可能更倾向于进行颈部侧方运动，这一特征可能对应其与捕食相关的生态功能。本研究证明，对于缺乏合适现代类比物的结构，三维建模是评估其功能形态学的有效工具。