title: Development of the skull of the pantropical spotted dolphin (Stenella attenuata).
abstract: We describe the bony and cartilaginous structures of five fetal skulls of Stenella attenuata (pantropical spotted dolphin) specimens. The specimens represent early fetal life as suggested by the presence of rostral tactile hairs and the beginnings of skin pigmentation. These specimens exhibit the developmental order of ossification of the intramembranous and endochondral elements of the cranium as well as the functional and morphological development of specific cetacean anatomical adaptations. Detailed observations are presented on telescoping, nasal anatomy, and middle ear anatomy. The development of the middle ear ossicles, ectotympanic bone, and median nasal cartilage is of interest because in the adult these structures are morphologically different from those in land mammals. We follow specific cetacean morphological characteristics through fetal development to provide insight into the form and function of the cetacean body plan. Combining these data with fossil evidence, it is possible to overlie ontogenetic patterns and discern evolutionary patterns of the cetacean skull.
authors: Department of Anatomy and Neurobiology, Northeastern Ohio Universities Colleges of Medicine and Pharmacy, Rootstown, 44272, USA. mmoran1@neoucom.edu
authors: Meghan M
authors: MM
authors: Moran
authors: Sirpa
authors: S
authors: Nummela
authors: J G M
authors: JG
authors: Thewissen
mesh_terms: D000818:Animals; D004429:Ear Ossicles / Q000033:anatomy & histology / Q000254:growth & development; D004432:Ear, Middle / Q000033:anatomy & histology / Q000254:growth & development; D012886:Skull / Q000033:anatomy & histology* / Q000254:growth & development*; D050706:Stenella / Q000033:anatomy & histology* / Q000254:growth & development*