This study tests whether three species of fossorial, scratch-digging mammals – Dasypus novemcinctus , Ictidomys tridecemlineatus , and Taxidea taxus – show commonality in pelvic anatomies inferred to be adaptive for this behavior and, correspondingly, divergence in these anatomies from nonfossorial species. The fossorial and nonfossorial species are in the same superorder or family; the comparative sets of species are D. novemcinctus with Bradypus variegatus and Choloepus hoffmanni , I. tridecemlineatus with Sciurus carolinensis , and Ta. taxus with Gulo gulo , Martes americana , and Neovison vison . Fossorial species are hypothesized to show higher prevalence of fusion of sacroiliac and sacroischial (if present) joints, reduction in size or loss of pelvic symphysis, greater number of sacral vertebrae, greater number of vertebrae in articulation with ilium and ischium, and longer ischium. Only males were used in the study; total sample size was 318 adults and 135 subadults. Results show commonality among fossorial species in greater number of sacral vertebrae and rigidity of the pelvis. One inconsistency with expectations is that the pelvic symphysis in fossorial species is as sturdy as in nonfossorial species, based on prevalence of symphyseal fusion and relative length and breadth of pelvic symphysis. Greater number of sacral vertebrae may be due to assimilation of a lumbar vertebra(−e) with the sacrum in fossorial species associated with their slow running speed. A rigid pelvis, due to fusion of pelvic joints and relatively longer or broader pelvic symphysis, effectively transfers forces between vertebral column and hind limb.

中文翻译：

---

三种化石、抓挠、哺乳动物的盆腔解剖学共性

这项研究测试了三种化石、抓挠式哺乳动物——Dasypus novemcinctus、Ictidomys tridecemlineatus 和 Taxidea taxus——是否在推断适合这种行为的盆腔解剖结构中表现出共性，以及相应地，这些解剖结构与非化石物种的差异。化石和非化石物种属于同一超目或科；比较组的物种是 D. novemcinctus 与 Bradypus variegatus 和 Choloepus hoffmanni，I. tridecemlineatus 与 Sciurus carolinensis，以及 Ta。红豆杉与 Gulo gulo、Martes americana 和 Neovison vison。假设化石物种表现出较高的骶髂关节和骶坐骨（如果存在）融合的发生率，骨盆联合的尺寸减小或丧失，更多的骶椎骨，与髂骨和坐骨连接的椎骨数量更多，坐骨更长。研究中仅使用男性；总样本量为 318 名成人和 135 名亚成人。结果显示，在更多的骶椎骨和骨盆僵硬方面，化石物种之间存在共性。与预期不一致的是，基于骨盆融合的普遍性和骨盆联合的相对长度和宽度，骨盆物种的骨盆联合与非骨盆物种一样坚固。更多的骶椎可能是由于腰椎（-e）与骶骨同化，与它们缓慢的跑步速度相关。由于骨盆关节和相对较长或较宽的骨盆联合融合，刚性骨盆可有效地在脊柱和后肢之间传递力。