słonie: Hagfish

Evidence: 100 • authority: 72

Hagfish, of the class Myxini (also known as Hyperotreti) and order Myxiniformes , are eel-shaped jawless fish (occasionally called slime eels). Hagfish are the only known living animals that have a skull but no vertebral column; however, they do have rudimentary vertebrae. Hagfish are marine predators and scavengers that can defend themselves against other larger predators by releasing copious amounts of slime from mucous glands in their skin. Although their exact relationship to the only other living group of jawless fish, the lampreys, was initially the subject of controversy, genetic evidence suggests that hagfish and lampreys are more closely related to each other than to jawed vertebra…

Evidence: 61 • authority: 72

Vertebrates (), also called craniates, are animals with a vertebral column and a cranium. The vertebral column surrounds and protects the spinal cord, while the cranium protects the brain. The vertebrates make up the subphylum Vertebrata ( VUR-tə-BRAY-tə) with some 65,000 species, by far the largest ranked grouping in the phylum Chordata. The vertebrates include mammals, birds, amphibians, and various classes of fishes and reptiles. The two major living vertebrate subgroups are the jawless Cyclostomi (including hagfish and lampreys), and the jawed Gnathostomata. The jawed fish include both the cartilaginous fish and the bony fish. Bony fish include the lobe-finned fish, which gave rise to t…

Evidence: 54 • authority: 72

Fish anatomy is the study of the form or morphology of fish. It can be contrasted with fish physiology, which is the study of how the component parts of fish function together in the living fish. In practice, fish anatomy and fish physiology complement each other, the former dealing with the structure of a fish, its organs or component parts and how they are put together, as might be observed on a dissecting table or under a microscope, and the latter dealing with how those components function together in living fish. The anatomy of fish is often shaped by the physical characteristics of water, the medium in which fish live. Water is much denser than air, holds a relatively small amount of…

Evidence: 47 • authority: 72

A chordate ( KOR-dayt) is a bilaterian animal belonging to the phylum Chordata ( kor-DAY-tə). All chordates possess, at some point during their larval or adult stages, five distinctive physical characteristics (synapomorphies) that distinguish them from other taxa: a notochord, a hollow dorsal nerve cord, an endostyle or thyroid, pharyngeal slits, and a post-anal tail. In addition to the morphological characteristics used to define chordates, analysis of genome sequences has identified two conserved signature indels (CSIs) in their proteins: cyclophilin-like protein and inner mitochondrial membrane protease ATP23, which are exclusively shared by all vertebrates, tunicates, and cephalochorda…

Evidence: 39 • authority: 80

The Transoral-Transmaxillary Access Route to the Anterior Vertebral Column and Skull Base

Evidence: 39 • authority: 80

The Transoral-Transmaxillary Access Route to the Anterior Vertebral Column and Skull Base

Evidence: 39 • authority: 80

Embryology of the Skull Base and Vertebral Column

Evidence: 39 • authority: 80

Chapter-11 Embryology: Skull and Vertebral Column

Evidence: 39 • authority: 92

Modularity and integration of the neural arch and vertebral centrum in primates.. The vertebral column consists of multiple homologous elements that have specialized within and between taxa and serve important functions in positional support and as protection for the central nervous system. The study of modularity and integration provides new insights into the evolution of complex structures such as the vertebral column. Patterns of modularity and integration may reflect underlying genetic-developmental patterns and facilitate evolution. Previous studies have identified mixed modularity patterns within and between elements across mammals generally, within primates and carnivorans. Here, we…