appendicular skeleton The part of the vertebrate endoskeleton that is composed of paired fin or limb bones, and the pelvis. Fins of vertebrate fish have a basic morphology composed of three elements: a small number of fan-like basal elements support a greater number of cylindrical radials, which in turn support a large number of fin rays. These may be soft and flexible (soft rays) or hard and inflexible (fin spines), supporting the fin web. The limbs of tetrapods articulate with a pectoral (scapula) or pelvic (pelvis) girdle and consist of five segments: the propodium (humerus or femur); epipodium (ulna/radius or fibula/tibula); mesopodium (carpus or tarsus); metapodium (metacarpus or metatarsus); and phalanges. Although pectoral and pelvic fin and limb appendages have an apparently homologous structure, they are derived serially from different body segments. Compare AXIAL SKELETON. See also PENTADACTYL.
More From encyclopedia.com
Fin , fin / fin/ • n. a flattened appendage on various parts of the body of many aquatic vertebrates and some invertebrates, including fish and cetaceans,… Actinopterygians , Holostei Group of marine and fresh water bony fish including many fossil species, e.g. Lepidotes (Triassic—Cretaceous), and Dapedius (Jurassic). Holo… Rib , rib / rib/ • n. 1. each of a series of slender curved bones articulated in pairs to the spine (twelve pairs in humans), protecting the thoracic cavit… Heterocercal Tail , Skip to main content heterocercal tail heterocercal tail In fish, a tail in which the tip of the vertebral column turns upward, extending into the do… trestle , trestle •hassle, Kassel, passel, tassel, vassal •axel, axle •cancel, hansel, Hänsel, Mansell •transaxle •castle, metatarsal, parcel, tarsal •chancel… Ray , ray1 / rā/ • n. 1. each of the lines in which light (and heat) may seem to stream from the sun or any luminous body, or pass through a small opening:…
About this article
All Sources -
Updated About encyclopedia.com content Print Topic
You Might Also Like