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.

长颈部水生蛇颈龙类在中生代时期存续了1.35亿年。这类长颈部的功能一直是学界争论的焦点。本研究借助计算机断层扫描（CT）与三维（3D）建模技术，对北方尼科尔森蛇颈龙（*Nichollssaura borealis*）颈部的活动度（ROM）进行了评估。为量化该活动度，研究人员沿颈椎柱测量了椎间活动度，具体通过两次试验实现：分别在侧向与背腹向方向对三维模型进行调整以完成测量。第一次试验评估了整条颈椎柱各颈椎椎体对之间的平均椎间活动度，第二次试验则评估了椎间隙缩窄情况下的活动度。研究结果显示，北方尼科尔森蛇颈龙可能更倾向于进行颈部侧向运动，这一特征或对应其与猎物捕获相关的生态功能。本研究表明，对于缺乏理想现代类比类群的结构而言，三维建模是评估其功能形态学的有效工具。