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1
[MV] SKULL(스컬) _ I
[MV] SKULL(스컬) _ I'm getting married (결혼해요) (feat. Eugene(유진) of THE SEEYA)
::2014/07/17::
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2
Skull - Cry Die
Skull - Cry Die
::2012/08/14::
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3
skull bones
skull bones
::2008/10/25::
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4
Dr. Fabian Identifying Parts of the Skull Part 1 of 2
Dr. Fabian Identifying Parts of the Skull Part 1 of 2
::2008/10/16::
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5
Draw a Skull - Halloween Special
Draw a Skull - Halloween Special
::2013/10/31::
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6
Zomboy - Skull
Zomboy - Skull 'n' Bones
::2014/07/29::
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7
Trick Art, Drawing  Levitating 3D Apple Skull, Time Lapse
Trick Art, Drawing Levitating 3D Apple Skull, Time Lapse
::2013/11/01::
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8
[MV] SKULL(스컬) _ DEH PON TOP
[MV] SKULL(스컬) _ DEH PON TOP
::2014/07/17::
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9
[Teaser 2] SKULL(스컬) _ Who gives a sh*t?(연예인이고 지랄이고)
[Teaser 2] SKULL(스컬) _ Who gives a sh*t?(연예인이고 지랄이고)
::2014/07/10::
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10
King Kong - Skull Island Marking the Return of the Great Gorilla
King Kong - Skull Island Marking the Return of the Great Gorilla
::2014/07/27::
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11
Comic Con 2014 - Godzilla 2 and Skull Island aka King Kong from Legendary : Beyond The Trailer
Comic Con 2014 - Godzilla 2 and Skull Island aka King Kong from Legendary : Beyond The Trailer
::2014/07/26::
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12
스컬 (skull) / 하하 (haha) [REGGAErilla / Ragga Muffin] @SBS Inkigayo 인기가요 20130630
스컬 (skull) / 하하 (haha) [REGGAErilla / Ragga Muffin] @SBS Inkigayo 인기가요 20130630
::2013/07/01::
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13
Monster High Show | Skull Academy | 110 Exams
Monster High Show | Skull Academy | 110 Exams
::2014/07/28::
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14
SKULL - a Gate
SKULL - a Gate
::2007/11/09::
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15
3D Printing Large Terminator T-800 Skull w/ Ultimaker & colorFabb XT
3D Printing Large Terminator T-800 Skull w/ Ultimaker & colorFabb XT
::2014/07/31::
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16
Foramina of the Skull and Cranial Fossae - Anatomy Tutorial PART 1
Foramina of the Skull and Cranial Fossae - Anatomy Tutorial PART 1
::2011/09/21::
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17
Monster High Series | Skull Academy | 92 Tour
Monster High Series | Skull Academy | 92 Tour
::2014/01/30::
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18
DZ Deathrays - Reflective Skull
DZ Deathrays - Reflective Skull
::2014/05/27::
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19
Skull & Bones Society Built Atomic Bomb - Manhattan Project Secrets Revealed
Skull & Bones Society Built Atomic Bomb - Manhattan Project Secrets Revealed
::2014/07/28::
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20
Anatomy 3, The Skull
Anatomy 3, The Skull
::2013/07/15::
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21
Monster High Show | Skull Academy | 99 Fashion Show
Monster High Show | Skull Academy | 99 Fashion Show
::2014/04/05::
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22
Steve Austin
Steve Austin's Broken Skull Challenge : Sneak 1
::2014/07/02::
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23
Skull & HAHA (스컬 & 하하) _ Busan Vacance + Waikiki Brothers _ MV
Skull & HAHA (스컬 & 하하) _ Busan Vacance + Waikiki Brothers _ MV
::2012/07/29::
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24
Crystal skull; a work of the aliens?
Crystal skull; a work of the aliens?
::2011/12/28::
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25
Monster High Show | Skull Academy |106 More Studying
Monster High Show | Skull Academy |106 More Studying
::2014/06/21::
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26
Monster High Series | Skull Academy | 104 Happy Faces
Monster High Series | Skull Academy | 104 Happy Faces
::2014/05/31::
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27
Mr. Plinkett
Mr. Plinkett's Indiana Jones and the Kingdom of the Crystal Skull Review
::2014/03/21::
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28
Skull Fist - Hour to Live (2014)
Skull Fist - Hour to Live (2014)
::2013/12/23::
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29
Deadpool Test Footage Leaked! Legendary wants Joe Cornish for Skull Island! - Beyond The Trailer
Deadpool Test Footage Leaked! Legendary wants Joe Cornish for Skull Island! - Beyond The Trailer
::2014/07/29::
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30
Majora
Majora's Mask Live Action: The Skull Kid
::2013/12/23::
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31
Monster High Series | Skull Academy  | 101 Invitations
Monster High Series | Skull Academy | 101 Invitations
::2014/04/25::
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32
Misfits- Skulls
Misfits- Skulls
::2007/07/10::
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February 2014 Starchild Skull Updates
February 2014 Starchild Skull Updates
::2014/02/12::
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34
Monster High Show | Skull Academy | 108 Kissing
Monster High Show | Skull Academy | 108 Kissing
::2014/07/13::
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35
Steve Austin
Steve Austin's Broken Skull Challenge : Ep 102 : Sneak
::2014/07/09::
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36
Everything Wrong With Indiana Jones & The Kingdom Of The Crystal Skull
Everything Wrong With Indiana Jones & The Kingdom Of The Crystal Skull
::2014/03/06::
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37
Monster High Show | Skull Academy | 105 Studying
Monster High Show | Skull Academy | 105 Studying
::2014/06/07::
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38
How-To Make a Tie Dye Skull Shirt
How-To Make a Tie Dye Skull Shirt
::2013/08/13::
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39
Human skull - exploded skull with bones labelled, based on CT scanning
Human skull - exploded skull with bones labelled, based on CT scanning
::2011/08/10::
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40
Watch a woman get a 3D-printed skull
Watch a woman get a 3D-printed skull
::2014/03/26::
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41
Photoshop Tutorial - Skull Face
Photoshop Tutorial - Skull Face
::2013/10/26::
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42
RED SKULL VACILÃO #11 - GOL DA ALEMANHAAAA!!!!!
RED SKULL VACILÃO #11 - GOL DA ALEMANHAAAA!!!!!
::2014/07/10::
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43
Crush the Skull 2
Crush the Skull 2
::2013/10/31::
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44
Drenge - Face Like A Skull (Official Video)
Drenge - Face Like A Skull (Official Video)
::2013/08/07::
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45
LazerHawk - Skull and Shark [Full Album]
LazerHawk - Skull and Shark [Full Album]
::2013/11/17::
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46
Skull And Bones, Un Secta en la Élite
Skull And Bones, Un Secta en la Élite
::2014/06/04::
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47
Monster High Series | Skull Academy | 97 Punch
Monster High Series | Skull Academy | 97 Punch
::2014/03/22::
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48
Monster High Show | Skull Academy | 109 Schedule
Monster High Show | Skull Academy | 109 Schedule
::2014/07/20::
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49
Monster High Show | Skull Academy | 95 Venecia
Monster High Show | Skull Academy | 95 Venecia
::2014/02/28::
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50
Sugar Skull Makeup Tutorial (800 RHINESTONES! ORIGINAL MADEULOOK!)
Sugar Skull Makeup Tutorial (800 RHINESTONES! ORIGINAL MADEULOOK!)
::2013/09/09::
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From Wikipedia, the free encyclopedia
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This article is about the skulls of all animals including humans. For information specific to the human skull, see Human skull.
"cranium" and "crania" redirect here. For other uses, see cranium (disambiguation).

This article incorporates text from a public domain edition of Gray's Anatomy.

The skull is a bony structure in the head of most vertebrates (in particular, craniates) that supports the structures of the face and forms a protective cavity for the brain. The skull is composed of two parts: the cranium and the mandible. The skull forms the anterior most portion of the skeleton and is a product of encephalization, housing the brain, many sensory structures (eyes, ears, nasal cavity), and the feeding system.

Functions of the skull include protection of the brain, fixing the distance between the eyes to allow stereoscopic vision, and fixing the position of the ears to help the brain use auditory cues to judge direction and distance of sounds. In some animals, the skull also has a defensive function (e.g. horned ungulates); the frontal bone is where horns are mounted.

The English word "skull" is probably derived from Old Norse "skalli" meaning bald, while the Latin word cranium comes from the Greek root κρανίον (kranion).

The skull is made of a number of fused flat bones.

Fish skull[edit]

Fish head parts, 1889, Fauna of British India, Sir Francis Day

The skull of fishes is formed from a series of only loosely connected bones. Lampreys and sharks only possess a cartilaginous endocranium, with both the upper and lower jaws being separate elements. Bony fishes have additional dermal bone, forming a more or less coherent skull roof in lungfish and holost fish. The lower jaw defines a chin.

The simpler structure is found in jawless fish, in which the cranium is normally represented by a trough-like basket of cartilaginous elements only partially enclosing the brain, and associated with the capsules for the inner ears and the single nostril. Distinctively, these fish have no jaws.[1]

Cartilaginous fish, such as sharks and rays, have also simple, and presumably primitive, skull structures. The cranium is a single structure forming a case around the brain, enclosing the lower surface and the sides, but always at least partially open at the top as a large fontanelle. The most anterior part of the cranium includes a forward plate of cartilage, the rostrum, and capsules to enclose the olfactory organs. Behind these are the orbits, and then an additional pair of capsules enclosing the structure of the inner ear. Finally, the skull tapers towards the rear, where the foramen magnum lies immediately above a single condyle, articulating with the first vertebra. There are, in addition, at various points throughout the cranium, smaller foramina for the cranial nerves. The jaws consist of separate hoops of cartilage, almost always distinct from the cranium proper.[1]

Skull of an Atlantic wolffish

In ray-finned fishes, there has also been considerable modification from the primitive pattern. The roof of the skull is generally well formed, and although the exact relationship of its bones to those of tetrapods is unclear, they are usually given similar names for convenience. Other elements of the skull, however, may be reduced; there is little cheek region behind the enlarged orbits, and little, if any bone in between them. The upper jaw is often formed largely from the premaxilla, with the maxilla itself located further back, and an additional bone, the symplectic, linking the jaw to the rest of the cranium.[2]

Although the skulls of fossil lobe-finned fish resemble those of the early tetrapods, the same cannot be said of those of the living lungfishes. The skull roof is not fully formed, and consists of multiple, somewhat irregularly shaped bones with no direct relationship to those of tetrapods. The upper jaw is formed from the pterygoids and vomers alone, all of which bear teeth. Much of the skull is formed from cartilage, and its overall structure is reduced.[2]

Tetrapod skull[edit]

Skull of Tiktaalik, an extinct genus transitional between the lobe-finned fish and the early tetrapods. From the Late Devonian.

The skulls of the earliest tetrapods closely resembled those of their ancestors amongst the lobe-finned fishes. The skull roof is formed of a series of plate-like bones, including the maxilla, frontals, parietals, and lacrimals, among others. It is overlaying the endocranium, corresponding to the cartilaginous skull in sharks and rays. The various separate bones that compose the temporal bone of humans are also part of the skull roof series. A further plate composed of four pairs of bones forms the roof of the mouth; these include the vomer and palatine bones. The base of the cranium is formed from a ring of bones surrounding the foramen magnum and a median bone lying further forward; these are homologous with the occipital bone and parts of the sphenoid in mammals. Finally, the lower jaw is composed of multiple bones, only the most anterior of which (the dentary) is homologous with the mammalian mandible.[2]

In living tetrapods, a great many of the original bones have either disappeared, or fused into one another in various arrangements.

Fenestrae[edit]

Amphibians skulls, Hans Gadow, 1909 Amphibia and Reptiles
Scheme of Spinosaurus skull
A Centrosaurus skull

Living amphibians typically have greatly reduced skulls, with many of the bones either absent or wholly or partly replaced by cartilage.[2] In mammals and birds, in particular, modifications of the skull occurred to allow for the expansion of the brain. The fusion between the various bones is especially notable in birds, in which the individual structures may be difficult to identify.

The fenestrae in the skull of the dinosaur Massospondylus.

The fenestrae (from Latin, meaning windows) are openings in the skull.

Ceratopsian dinosaurs may have fenestrae in their frills.

Temporal fenestrae[edit]

The temporal fenestrae are anatomical features of the skulls of several types of amniotes, characterised by bilaterally symmetrical holes (fenestrae) in the temporal bone. Depending on the lineage of a given animal, two, one, or no pairs of temporal fenestrae may be present, above or below the postorbital and squamosal bones. The upper temporal fenestrae are also known as the supratemporal fenestrae, and the lower temporal fenestrae are also known as the infratemporal fenestrae. The presence and morphology of the temporal fenestra are critical for taxonomic classification of the synapsids, of which mammals are part.

Physiological speculation associates it with a rise in metabolic rates and an increase in jaw musculature. The earlier amniotes of the Carboniferous did not have temporal fenestrae but two more advanced lines did: the Synapsids (mammal-like reptiles) and the Diapsids (most reptiles and later birds). As time progressed, diapsids' and synapsids' temporal fenestrae became more modified and larger to make stronger bites and more jaw muscles. Dinosaurs, which are sauropsids, have large advanced openings, and their descendants, the birds, have temporal fenestrae which have been modified. Mammals, which are synapsids, possess no fenestral openings in the skull, as the trait has been modified. They do, though, still have the temporal orbit (which resembles an opening) and the temporal muscles. It is a hole in the head and is situated to the rear of the orbit behind the eye.

Classification[edit]

Chimpanzee skull

There are four types of amniote skull, classified by the number and location of their fenestra. These are:

  • Anapsida – no openings
  • Synapsida – one low opening (beneath the postorbital and squamosal bones)
  • Euryapsida – one high opening (above the postorbital and squamosal bones); euryapsids actually evolved from a diapsid configuration, losing their lower temporal fenestra.
  • Diapsida – two openings

Evolutionarily, they are related as follows:

Human skull[edit]

Model of a male human skull in the collections of the Museum of Osteology
For details and the constituent bones, see human skull, neurocranium and viscerocranium.

In humans, as in other mammals, the aforementioned division of the skull into the cranium and mandible is not usually followed. Instead, for the purposes of describing their anatomy and enumerating their bones, mammalian and human skulls are divided differently: They are deemed to consist of two categorical parts, the neurocranium and the viscerocranium. The neurocranium (or braincase) is a protective vault surrounding the brain. The viscerocranium (also splanchnocranium or facial skeleton) is formed by the bones supporting the face. Both parts have different embryological origins.

Except for the mandible, all of the bones of the skull are joined together by sutures, rigid articulations permitting very little movement.[3]

Bones[edit]

The jugal is a skull bone found in most reptiles, amphibians, and birds. In mammals, the jugal is often called the malar or zygomatic.

The prefrontal bone is a bone separating the lacrimal and frontal bones in many tetrapod skulls.

Terminology[edit]

Gallery[edit]

Paracyclotosaurus davidi skull, a prehistoric amphibian species 
Tyrannosaurus rex skull, a dinosaur species 
Alligator skull, a reptile species 
An elephant skull, a mammal species 
A lion's skull 
A hippopotamus' skull 
Killer whale (Orcinus orca) skull 
A bulldog skull 
A Grizzly bear skull 
A coypu skull 
A gerbil skull 
A Four-horned antelope skull drawing 
Skull of a multi horned Jacob sheep 
A Vulture skull 

References[edit]

  1. ^ a b Romer, Alfred Sherwood; Parsons, Thomas S. (1977). The Vertebrate Body. Philadelphia, PA: Holt-Saunders International. pp. 173–177. ISBN 0-03-910284-X. 
  2. ^ a b c d Romer, Alfred Sherwood; Parsons, Thomas S. (1977). The Vertebrate Body. Philadelphia, PA: Holt-Saunders International. pp. 216–247. ISBN 0-03-910284-X. 
  3. ^ The hyoid bone and the ossicles are joined together with synarthroses, but despite their location, they are not normally considered skull bones.

External links[edit]

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