Revisiting paravertebral muscles in European rabbits (Oryctolagus cuniculus) and European brown hares (Lepus europaeus) (Leporidae; Lagomorpha).

Domesticated European rabbits (Oryctolagus cuniculus) have long been chosen as laboratory model organisms. Despite this, there has been no definitive study of the vertebral musculature of wild rabbits. Relevant descriptions of well-studied veterinary model mammals (such as dogs) are generally applicable, but not appropriate for a species-specific topology. Our study aims to provide a consolidated list and description of the vertebral muscles in wild rabbits. Wild European brown hares (Lepus europaeus) are also included in this study as they have a similar bauplan, albeit different locomotive behaviors. We examined the gross anatomy of the paravertebral muscles in both species, describing 54 muscles that are compatible with the current anatomical terminology. Muscular topology was consistent between rabbits and hares, with subtle variation presented: the degree of muscular fusion (m. longissimus, m. splenius, mm. scaleni, and m. serratus dorsalis) and the relative muscle sizes (m. rectus capitis dorsalis major). Yet, the observed topology was noticeably different compared to the topology previously described in other mammals regularly used in veterinary anatomy. These differences are thoroughly discussed, and we suggest reinstating some leporid anatomical terms to better reflect the anatomy of this vertebrate group.