Forelimb morphology as an adaptation for burrowing in kangaroo rat species (genus Dipodomys) that inhabit different soil substrates

Among burrowing rodents, forelimb morphology frequently shares an intricate relationship with soil substrates. Soils can vary widely in texture and density, leading to differences in friability, which often requires forelimb specializations in digging animals. Kangaroo rat species (genus Dipodomys) dig and occupy underground burrows, a trait which is essential to their survival. Some members of this genus are restricted to particular types of soil substrates that presumably require species-specific forelimb traits. Here we explored the forelimb morphology and soil substrates inhabited by four Dipodomys species, including two range-restricted species (D. compactus and D. elator) and two widely-ranging species (D. merriami and D. ordii) in an effort to explore the variation in soil usage, forelimb skeletal specializations, and the relationship between these traits. We assessed the size and shape traits of preserved specimen forelimb bones using traditional and geometric morphometric techn...