Sobolevskiĭ E I
Arkh Anat Gistol Embriol. 1978 Nov;75(11):74-80.
Skeletotopically, cervical thickening of the spinal cord in semiwater mammals (Callorhinus ursinus, Eumetopias jubatus, Phoca larga, Phoca kurilensis, Enhydra lutris) corresponds to 4--5, and in terrestrial mammals (Ursus arctos, Vulpes vulpes)--to 3--6 cervical vertebrae. Lumbar thickening in terrestrial spicies and in Enhydra lutris is situated more caudally from the thoracic portion than in Phocidae. In a typically water animal (Phocaenoides dalli) the cervical thickening is expressed feebly, the lumbar one is absent, the epidural space is developed better than in terrestrial and semiwater animals. In Phocidae, comparing terrestrial species, bringing together of the nerve fasciculi taking their origin from the spinal cord is observed, a powerful development of a "horse tail", elongation of nerve bands, going from the spinal cord to spinal ganglia. The relative length of the spinal cord in semiwater and water animals is less than in terrestrial ones. It is stated that differences in spinal cord construction and topography of the animals in question are closely connected with their environmental conditions, functional loading and locomotor peculiarities.
从骨骼定位来看，半水生哺乳动物（海狗、北海狗、北海狮、千岛海豹、海獭）脊髓的颈部增粗对应于第4至5颈椎，而陆生哺乳动物（棕熊、赤狐）的脊髓颈部增粗对应于第3至6颈椎。陆生物种和海獭的腰部增粗部位比海豹科动物更靠后，位于胸部下方。在典型的水生动物（白腰鼠海豚）中，颈部增粗不明显，没有腰部增粗，硬膜外腔比陆生和半水生动物发育得更好。在海豹科动物中，与陆生物种相比，可以观察到起源于脊髓的神经束聚集在一起，“马尾”发育强大，从脊髓延伸到脊神经节的神经带延长。半水生和水生动物的脊髓相对长度比陆生动物短。据称，所讨论动物的脊髓结构和地形差异与它们的环境条件、功能负荷和运动特点密切相关。
