Data from: Postcrania of juvenile Pinacosaurus grangeri (Ornithischia: Ankylosauria) from the Upper Cretaceous Alagteeg Formation, Alag Teeg, Mongolia: implications for ontogenetic allometry in ankylosaurs

The ankylosaurine Pinacosaurus is one of the best known ankylosaur to date in terms of the number and preservational quality of specimens. Juvenile to sub-adult postcrania collected by the Soviet-Mongolian Paleontological Expedition from the Upper Cretaceous Alagteeg Formation at Alag Teeg, Mongolia can be assigned to Pinacosaurus grangeri based on discrete cranial characters. One individual is significantly larger than the others and demonstrates delayed fusion of postcranial elements with the earliest occurring between dorsal ribs and vertebrae. The robustness of forelimb elements is positively allometric with respect to their length, indicating weight-bearing relationship. Such length-dependent correlations are not seen in the hind limbs. Finally, incipient cervical half rings suggest a developmental pathway of outgrowths from the underlying band combined with fusion of overlying osteoderms.

甲龙亚科绘龙属（Pinacosaurus）是目前已知标本数量与保存质量均属上乘的最具知名度的甲龙类群之一。由苏蒙古生物考察队（Soviet-Mongolian Paleontological Expedition）在蒙古国阿拉特格（Alag Teeg）的晚白垩世阿拉特格组（Alagteeg Formation）中采集的幼体至亚成体颅后骨骼标本，可依据其专属头骨鉴别特征归入格氏绘龙（Pinacosaurus grangeri）。其中一件个体体型显著大于其余标本，其颅后骨骼元素的愈合存在延迟现象，最早的愈合事件发生于背肋与椎骨之间。前肢骨骼的粗壮度与其长度呈正异速生长关系，表明其前肢具备负重功能；而后肢骨骼中未观察到此类与长度相关的生长相关性。最后，初期发育的颈侧半环提示，该类群颈甲的发育路径为：源自下方颈骨带的突起形成，叠加覆盖在其上的皮内成骨（osteoderms）发生愈合。