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Sail (anatomy)
The term sail or dorsal sail has been used to refer to sail-like structures on the back of various animals. Such animals can also be referred to as sail-backed or fin-backed. Such structures include the following: * Neural spine sail – formed by the neural spines of the vertebrae *Dorsal fin A dorsal fin is a fin on the back of most marine and freshwater vertebrates. Dorsal fins have evolved independently several times through convergent evolution adapting to marine environments, so the fins are not all homologous. They are found ... – in some aquatic species with tall fins on their back. * Crest (anatomy) – a feature which has been referred to as a "sail" when occurring on the back of some animals {{SIA ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neural Spine Sail
A neural spine sail is a large, flattish protrusion from the back of an animal formed of a sequence of extended Vertebra#Processes, vertebral spinous processes and associated tissues. Such structures are comparatively rare in modern animals, but have been identified in many extinction, extinct species of amphibians and amniotes. Paleontologists have proposed a number of ways in which the sail could have functioned in life. Function Varying suggestions have been made for the function of the sail. Thermoregulation The structure may have been used for thermoregulation. The base of the spines have a channel which may have contained a blood vessel supplying abundant blood to the sail. The animal could have used the sail's large surface area to absorb heat from the sun in the morning. As ectotherms they required heat from an external source before their muscles would start to function properly. A predator would thus have an advantage over its slower moving prey. The sail could be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neural Spines
Each vertebra (: vertebrae) is an irregular bone with a complex structure composed of bone and some hyaline cartilage, that make up the vertebral column or spine, of vertebrates. The proportions of the vertebrae differ according to their spinal segment and the particular species. The basic configuration of a vertebra varies; the vertebral body (also ''centrum'') is of bone and bears the load of the vertebral column. The upper and lower surfaces of the vertebra body give attachment to the intervertebral discs. The posterior part of a vertebra forms a vertebral arch, in eleven parts, consisting of two pedicles (pedicle of vertebral arch), two laminae, and seven process (anatomy), processes. The laminae give attachment to the ligamenta flava (ligaments of the spine). There are vertebral notches formed from the shape of the pedicles, which form the intervertebral foramina when the vertebrae articulation (anatomy), articulate. These foramina are the entry and exit conduits for the spi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dorsal Fin
A dorsal fin is a fin on the back of most marine and freshwater vertebrates. Dorsal fins have evolved independently several times through convergent evolution adapting to marine environments, so the fins are not all homologous. They are found in most fish, in mammals such as whales, and in extinct ancient marine reptiles such as ichthyosaurs. Most have only one dorsal fin, but some have two or three. Wildlife biologists often use the distinctive nicks and wear patterns which develop on the dorsal fins of whales to identify individuals in the field. The bones or cartilages that support the dorsal fin in fish are called pterygiophores. Functions The main purpose of the dorsal fin is usually to stabilize the animal against rolling and to assist in sudden turns. Some species have further adapted their dorsal fins to other uses. The sunfish uses the dorsal fin (and the anal fin Fins are moving appendages protruding from the body of fish that interact with water to ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
