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A sagittal crest is a ridge of bone running lengthwise along the midline of the top of the skull
Skull

The skull is a bone structure found in the head of many animals. The skull supports the structures of the face and protects the head against injury....
 (at the sagittal suture
Sagittal suture

The sagittal suture is a dense, fibrous connective tissue joint between the two parietal bones of the skull. At birth, the bones of the skull do not meet....
) of many mammal
Mammal

Mammals are a class of vertebrate animals whose name is derived from their distinctive feature, mammary glands, with which they feed their young....
ian 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, which is one of the main chewing muscles. Development of the sagittal crest is thought to be connected to the development of this muscle.






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A sagittal crest is a ridge of bone running lengthwise along the midline of the top of the skull
Skull

The skull is a bone structure found in the head of many animals. The skull supports the structures of the face and protects the head against injury....
 (at the sagittal suture
Sagittal suture

The sagittal suture is a dense, fibrous connective tissue joint between the two parietal bones of the skull. At birth, the bones of the skull do not meet....
) of many mammal
Mammal

Mammals are a class of vertebrate animals whose name is derived from their distinctive feature, mammary glands, with which they feed their young....
ian 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, which is one of the main chewing muscles. Development of the sagittal crest is thought to be connected to the development of this muscle. A sagittal crest usually develops during the childhood of an animal in conjunction with the growth of the temporalis muscle, as a result of convergence and gradual heightening of the temporal lines. A sagittal crest tends to be present on the skulls of adult animals that rely on powerful biting and clenching of their teeth, usually as a part of their hunting strategy. Skulls of some dinosaur species, including tyrannosaurs, possessed well developed sagittal crests. Among mammals, dogs, cats, lions, and many other carnivores have sagittal crests, as do some leaf eaters, including tapirs and some apes. Sagittal crests are found in robust great apes, and some early hominins (Paranthropus
Paranthropus

The robust australopithecines, members of the extinct hominin genus Paranthropus , were bipedal hominins that probably descended from the gracile australopithecine hominins ....
). Prominent sagittal crests are found among male gorillas and orangutans, and, with the notable exception of the prominent crests of the particularly robust Bili Ape
Bili Ape

Bili Ape, also Bondo Mystery Ape, is the name given to a large primate that is said to inhabit Bili Forest in the Democratic Republic of the Congo....
, do occur but only rarely in male chimpanzee
Chimpanzee

Chimpanzee, sometimes colloquially known as a chimp, is the common name for the two Extant taxon species of ape in the genus Pan where the Congo River forms the boundary between the native habitat of the two species:...
s.

The largest sagittal crest ever discovered in the human lineage belongs to the 'Black Skull', Paranthropus aethiopicus
Paranthropus aethiopicus

Paranthropus aethiopicus is an extinct species of hominid. The finding discovered in 1985 in West Lake Turkana, Kenya, KNM WT 17000 , is one of the earliest examples of robust australopithecines....
 field number KNM WT 17000, the earliest known robust hominid ancestor and the oldest robust australopithecine discovered to date. The prominence of the crest appears to have been an adaptation for the aethiopicus's heavy chewing, and the Black Skull's cheek teeth are correspondingly large. Smaller sagittal crests are also present on the skulls of other Paranthropines, including Paranthropus boisei and Paranthropus robustus.

See also


  • Mountain Gorilla
    Mountain Gorilla

    The Mountain Gorilla is one of the two subspecies of the Eastern Gorilla. There are two groups. One is found in the Virunga Mountains of Central Africa, within 4 national parks: Mgahinga Gorilla National Park, in south-west Uganda; Volcanoes National Park, in north-west Rwanda; and Virunga National Park and Kahuzi-Bi?ga National Park, in t...
  • Paranthropus aethiopicus
    Paranthropus aethiopicus

    Paranthropus aethiopicus is an extinct species of hominid. The finding discovered in 1985 in West Lake Turkana, Kenya, KNM WT 17000 , is one of the earliest examples of robust australopithecines....
     (The Black Skull)
  • Phrenology
    Phrenology

    Phrenology is a defunct field of study, once considered a science, in which the personality traits of a person were determined by "reading" bumps and fissures in the skull....
  • Sagittal Keel
    Sagittal Keel

    The Sagittal Keel is a thickening of bone on part or all of the midline of the frontal bone, or parietal bones where they meet along the sagittal suture, or on both bones....


External links

  • - 'Black Skull' (Australopithecus aethiopicus, specimen KNM-WT 17000)