Meeting Abstract
In addition to having unique extra articulations on its vertebrae, the hero shrew (Scutisorex) is unusual in having almost twice as many lumbar vertebrae as other shrews of its size. Other than being noted in descriptive literature, this increase in vertebral number has received little attention; there has been no investigation of how it might reflect the elusive function of the highly modified Scutisorex spine. Comparisons of individual vertebrae and whole-column characteristics between Scutisorex and other large shrews are also lacking, despite the fact that such studies could give insight into i) function of particular vertebral regions in shrews with and without external vertebral modifications, and ii) developmental patterns driving regional proportions. We collected µCT scans and linear measurements of cervical, thoracic, and lumbar vertebrae in two species of Scutisorex and three other species of large shrews. We compared a variety of linear vertebra measurements, and trabecular bone characteristics of each centrum, across species. Further, using this combined suite of measurements, we executed principal coordinates analysis and segmented regression to detect unique vertebral regions in each taxon. Our results show that relative to other large shrews, Scutisorex has a shorter thoracic region and longer lumbar region, and, despite having more dorsal vertebrae than other species, does not have a proportionally longer body length. Regionalization signals vary within and across the five species, but generally suggest that functional regions may not correspond exactly with traditionally recognized anatomical regions of the column, and that the extended lumbar region in Scutisorex may afford it an additional functional region.
