Search results
Results from the WOW.Com Content Network
The quadrate bone is a skull bone in most tetrapods, including amphibians, sauropsids (reptiles, birds), and early synapsids. In most tetrapods, the quadrate bone connects to the quadratojugal and squamosal bones in the skull, and forms upper part of the jaw joint. The lower jaw articulates at the articular bone, located at the rear end of the ...
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]
In most modern reptiles and amphibians, the quadratojugal is a prominent, straplike bone in the skull and provides structural integrity in the postorbital region of the skull. [6] In many reptiles, the inner face of the quadratojugal also connects to the quadrate bone which forms the cranium's contribution to the jaw joint.
The larger bone is the cleithrum. The cleithrum (pl.: cleithra) is a membrane bone which first appears as part of the skeleton in primitive bony fish, where it runs vertically along the scapula. [1] Its name is derived from Greek κλειθρον = "key (lock)", by analogy with "clavicle" from Latin clavicula = "little key".
These two terms, used in anatomy and embryology, describe something at the back (dorsal) or front/belly (ventral) of an organism. [2] The dorsal (from Latin dorsum 'back') surface of an organism refers to the back, or upper side, of an organism. If talking about the skull, the dorsal side is the top. [38]
The critter’s robust skull had additional bones and elements that have likely disappeared with evolution, and its elongated snout paired with a short region of the skull behind the eyes was ...
In medical disciplines, all references to a location on or in the body are made based upon the standard anatomical position. A straight position is assumed when describing a proximo-distal axis (towards or away from a point of attachment). This helps avoid confusion in terminology when referring to the same organism in different postures.
Temporal fenestrae in relation to the other skull openings in the dinosaur Massospondylus, a type of diapsid. The supratemporal fenestra, also called the upper temporal fenestra, is positioned above the other fenestra and is exposed primarily in dorsal (top) view. In some reptiles, particularly dinosaurs, the parts of the skull roof lying ...