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A sagittal crest is a ridge of bone running lengthwise along the midline of the top of the skull (at the sagittal suture) of many mammalian and reptilian skulls, among others. The presence of this ridge of bone indicates that there are exceptionally strong jaw muscles. The sagittal crest serves primarily for attachment of the temporalis muscle ...
Sagittal keels differ from sagittal crests, which are found in some earlier hominins (notably the genus Paranthropus) and in a range of other mammals. While a proper crest functions in anchoring the muscles of mastication to the cranium, the keel is lower and rounded in cross-section, and the jaw muscles do not attach to it.
A crest is any of various anatomical features appearing as a raised point or ridge, most prominently those on the head or back of an animal. A part of a bone: Sagittal crest; Cnemial crest; Iliac crest; Frontal crest; Infratemporal crest; Anterior lacrimal crest; Posterior lacrimal crest; Buccinator crest; A feature on various animals: Crest ...
KNM-ER 406, the skull of a Paranthropus, brain volume estimated to 410 cm 3 with a visible sagittal crest and mild or intermediate post-orbital constriction but KNM-ER 37333, the skull of a Homo erectus, brain volume of 850 cm 3 with no visual sagittal crest and an almost not present or reduced post-orbital constriction. [4]
The large supratemporal fossae and tall sagittal crest on the frontals provide an expanded attachment area for large jaw-closing muscles. The rostral region of the ventral surface is covered by an elongated and wide fossa that is defined towards the rostrum by the prefrontal suture, towards the middle by the interfrontal suture, towards the ...
The true purpose of the occipital bun has not yet been defined. [3] However, some studies have found possible evolutionary purposes. In a study published in Proceedings of the Royal Society B , the occipital bun has been attributed to the enlargement of the visual cortex ; this is hypothesized to be an adaptation to lower light levels found in ...
deltopectoral crest The deltopectoral crest is a forward directed bony flange on the upper part of the humerus. An especially long and prominent deltopectoral crest is a dinosaurian synapomorphy, i.e., a feature differentiating the group from other groups. In dinosaurs, the crest measures 30–40% of the length of the humerus.
The brow ridge is a nodule or crest of bone situated on the frontal bone of the skull. It forms the separation between the forehead portion itself (the squama frontalis) and the roof of the eye sockets (the pars orbitalis). Normally, in humans, the ridges arch over each eye, offering mechanical protection.