Re-evaluation of batoid pectoral morphology reveals novel patterns of diversity among major lineages.

摘要: Batoids (Chondrichthyes: Batoidea) are a diverse group of cartilaginous fishes which comprise monophyletic sister lineage to all neoselachians or modern sharks. All species in this possess anteroposteriorly expanded-pectoral fins, giving them unique disc-like body form. Reliance on pectoral fins for propulsion ranges from minimal (sawfish) almost complete dependence (skates and rays). A recent study the diversity planform fin shape batoids compared overall patterns morphological variation within group. However, inconsistent homology prevented accurately representing relationships among major batoid taxa. With previous work mind, we undertook an independent investigation form evaluated implications locomotion lifestyle, particularly skates (Rajoidei) rays (Myliobatoidei). We used geometric morphometrics with sliding semilandmarks analyze outlines also calculate aspect ratios (AR), functional trait linked locomotion. In agreement work, our results indicated that much evolution has occurred along axis is closely related AR. For where kinematic data were available, both AR associated swimming mode. This further revealed novel batoids, including strong bimodality rays, intermediate location skate morphospace between benthic/demersal pelagic approximately parallel trajectories skates. Finally, manipulation landmarks verified need consistent accurate definition outcome efficacy analyses function batoids.