Search results
Results from the WOW.Com Content Network
The function of some dermal bone is conserved throughout vertebrates, although there is variation in shape and in the number of bones in the skull roof and postcranial structures. In bony fish, dermal bone is found in the fin rays and scales. A special example of dermal bone is the clavicle. Some of the dermal bone functions regard ...
The dermatocranium is the portion of the cranium that is composed of dermal bone, as opposed to the endocranium and splanchnocranium, which are composed of endochondral bone. The dermatocranium comprises the skull roof, the facial skeleton (usually excluding the dentary), and—in fishes—the opercular bones. [1]
A more or less full shield of fused dermal bones was common in early bony fishes of the Devonian, and particularly well developed in shallow water species. [3] Cartilaginous fish, such as sharks, have a skeleton which is entirely formed from cartilage. They lack a continuous dermal armour and thus have no proper skull roof.
Machine translation, like DeepL or Google Translate, is a useful starting point for translations, but translators must revise errors as necessary and confirm that the translation is accurate, rather than simply copy-pasting machine-translated text into the English Wikipedia.
The dermal base may contain bone and produce dermal armour. Scutes with a bony base are properly called osteoderms . Dermal scutes are also found in the feet of birds and tails of some mammals , and are believed to be the primitive form of dermal armour in reptiles.
Cancellous bone or spongy bone, [12] [11] also known as trabecular bone, is the internal tissue of the skeletal bone and is an open cell porous network that follows the material properties of biofoams. [13] [14] Cancellous bone has a higher surface-area-to-volume ratio than cortical bone and it is less dense. This makes it weaker and more flexible.
The squamosal is a skull bone found in most reptiles, amphibians, and birds. In fishes, it is also called the pterotic bone. [1] In most tetrapods, the squamosal and quadratojugal bones form the cheek series of the skull. [2] The bone forms an ancestral component of the dermal roof and is typically thin compared to other skull bones. [3]
Osteoderms are dermal bone structures that support the upper layer of skin and serve as protection against the elements in a large variety of extinct and extant organisms, especially reptiles. [1] This structure is commonly called "dermal armor" and serves to protect the organism, while also helping with temperature regulation.