"Skull of lizard with Acrodont Dentition. One of those lizards which have the edge of the jaw, without bony aveoli on either the inner or the outer side."-Whitney, 1902

Acrodont

"Skull of lizard with Acrodont Dentition. One of those lizards which have the edge of the jaw, without…

"Skull of a member of the family Alligatoridæ, or some American member of the Crocodilidæ."-Whitney, 1902

Alligator Skull

"Skull of a member of the family Alligatoridæ, or some American member of the Crocodilidæ."-Whitney,…

The side view and base of the skull of an ape.

Ape Skull

The side view and base of the skull of an ape.

"Skull of Arciomys Monax." —The Encyclopedia Britannica, 1903

Arciomys Monax

"Skull of Arciomys Monax." —The Encyclopedia Britannica, 1903

"Skull of the Aye-aye (Chiromys madagascariensis)." —The Encyclopedia Britannica, 1910

Aye-Aye Skull

"Skull of the Aye-aye (Chiromys madagascariensis)." —The Encyclopedia Britannica, 1910

Skull of a baboon, showing the brain cavity.

Baboon skull

Skull of a baboon, showing the brain cavity.

"Skull and teeth of Bennett's Kangaroo (Macropus bennettii). i1, i2, i3, first second and third upper incisors; pm, second or posterior premolar (the first having been already shed); m1, m2, m3, m4, the four true molars. The last, not fully developed, is nearly concealed by the ascending ramus of the jaw." —The Encyclopedia Britannica, 1910

Bennett's Kangaroo

"Skull and teeth of Bennett's Kangaroo (Macropus bennettii). i1, i2, i3, first second and third upper…

A Brachycephalic cranium from above.

Brachycephalic Cranium

A Brachycephalic cranium from above.

A Brachycephalic cranium from the side.

Brachycephalic Cranium

A Brachycephalic cranium from the side.

Part of the central nervous system found in the skull.

Brain

Part of the central nervous system found in the skull.

A cross section of the brain from left to right. Labels: 1, thalamus; 2, skull; 3, cerebral membrane; 4, cerebral hemisphere; 5, lateral ventricle; 6, optic lobe; 7, septum lucidum; 8, longitudinal sinus; 9, great longitudinal fissure; 10, corpus callosum; 11, median cerebral cavity; 12, cerebral hemisphere; 13, gray matter; 14, white matter; 15, Corpora Albicantia.

Brain

A cross section of the brain from left to right. Labels: 1, thalamus; 2, skull; 3, cerebral membrane;…

The brain in relation to the skull and face, anterior view.

Brain in Relation to Skull and Face

The brain in relation to the skull and face, anterior view.

The brain in relation to the skull and face, lateral view.

Brain in Relation to Skull and Face

The brain in relation to the skull and face, lateral view.

The convolutionary projections of the precentral gyrus, and their relationship to motor areas.

Precentral Gyrus in the Brain

The convolutionary projections of the precentral gyrus, and their relationship to motor areas.

Showing the lines which indicate the position of the principal fissures of the brain.

Principle Fissures of the Brain

Showing the lines which indicate the position of the principal fissures of the brain.

"Side view of skull of Cape Jumping Hare. Pmx, premaxilla; Mx, maxilla; Ma, malar; Fr, frontal; L, lachrymal; Pa, parietal; Na, nasal; Sq, squamosal; Ty, tympanic; ExO, exoccipital; AS, alisphenoid; OS, orbito-sphenoid; Per, mastoid bulla." —The Encyclopedia Britannica, 1903

Cape Jumping Hare

"Side view of skull of Cape Jumping Hare. Pmx, premaxilla; Mx, maxilla; Ma, malar; Fr, frontal; L, lachrymal;…

"Vertical and Longitudinal section through skull of Castor Fiber, showing the cerebral cavity, the greatly-developed turbinal lamellae, the mode of implantation of the large over-growing chisel-edged incisor, and the curved rootless molars." —The Encyclopedia Britannica, 1903

Castor Fiber

"Vertical and Longitudinal section through skull of Castor Fiber, showing the cerebral cavity, the greatly-developed…

St. Jerome in his Cell is an engraving that was created by German artist Albrecht Dürer in 1514. It shows St. Jerome writing amongst a lion, dog and a skull. St. Jerome was a Roman Catholic priest who was known for translating the Bible into Latin during the 5th century.

St. Jerome In His Cell

St. Jerome in his Cell is an engraving that was created by German artist Albrecht Dürer in 1514.…

"Palatal view of skull of Ceratodus." — Encyclopedia Britannica, 1893

Ceratodus

"Palatal view of skull of Ceratodus." — Encyclopedia Britannica, 1893

A ripe chick's head, 1.25 inches long.

Chick's Head

A ripe chick's head, 1.25 inches long.

"Ripe chick's skull, longitudinal section, vied inside, x 3 diameters; after Parker. px, premaxillary; aln, ali-nasal cartilage; en, septo-nasal; n, nasal bone; l, lacrymal; pe, perpendicular plate of ethmoid, ps, prespeenoidal region; as, alisphenoid; f, frontal; p, parietal; sq, squamosal; so, superoccipital; eo, exoccipital; oc, occipital condyle; st, the cross-like object, the stapes, whose foot fits fenestra ovalis; q, quadrate; pg, pterygoid; qj, quadrato-jugal; jugal; pa, palatine; mx, maxillary. In the mandible: d, dentary; su, surangular; a, angular; ar, atricular; iap, internal angular process; pap, posterior angular process. 2, optic foramen; 5, foramen ovale, for inferior divisions of the 5th nerve." Elliot Coues, 1884

Ripe Chick's Skull Profile

"Ripe chick's skull, longitudinal section, vied inside, x 3 diameters; after Parker. px, premaxillary;…

"Ripe chick's skull, longitudinal section, vied inside, x 3 diameters; after parker. In the mandible are seen: mk, remarks of meckelian rod; d, dentary bone; sp, splenial; a, angular; su, surangular; ar, articular; iap, internal articular process; pap, posterior articular process. In the skull: pn, the original prenasal cartilage, upon which is moulded the premaxillary, px, with its nasal process, npx, and dentary process, dpx; sn, septo-nasal cartilage, in which is seen nn, nasal nerve; ntb, nasal turbinal; the reference line crosses the cranio-facial suture, the face parts and cranial parts being nealry separated here by the nick seen in the original cartilaginous plate; eth, ethmoid; pe, perpendicular plate of ethmoid, which will spread nearly throughout the dotted cartilaginous tract in which it lies, to form nearly all the interorbital septum; transverse thickening (in some birds) below the reference line eth will form the pre-frontal, or orbito-nasal septum; iof, inter-orbital foramen; ps, pre sphenoidal region, just above which is the orbito-sphenoidal region; 2, optic foramen; as, alisphenoid, with 5 foramen for division of the 5th (trifacial) nerve; f, frontal; sq, squamosal; p, parietal; so, superoccipital; asc, anterior semicircular canal; sc, a sinus (venous canal); ep, epiotic; eo, exoccipital; op, opisthotic; po, prootic, with 7 meatus auditorius internus, for entrance of 7th nerve; 8, foramen nfor vagus nerve; bo, basioccipital; bt, basitemporal; ic, canal (in original pituitary space; ) by which carotid artery enters brain activity; ap; basipterygoid process; ap to rbs, rostrum ofhte skull, being the parasphenoid bone underflooring the basisphenoid and future perpendicular plate of ethmoid." Elliot Coues, 1884

Ripe Chick's Skull

"Ripe chick's skull, longitudinal section, vied inside, x 3 diameters; after parker. In the mandible…

The end view of the skull of a chicken three weeks old.

Chicken Skull

The end view of the skull of a chicken three weeks old.

"The skull of a cod. b, branchiostegal rays born on c.h., the ceratohyal bone; d, dentary portion of the mandible; f, frontal; h.m., hyomandibular; i.o., interoperculum; l, lachrymal; m, maxilla; n, nasal; o, operculum; p.m., premaxilla; p.o., preoperculum; p.s., parasphenoid; q, quadrate; s.o., sub-operculum; s.oc., supra-occipital." — Galloway

Cod Skull

"The skull of a cod. b, branchiostegal rays born on c.h., the ceratohyal bone; d, dentary portion of…

The bones of the top of the head are fastened together by what are called sutures which are locked together by little teeth of bone that shoot by each other, as shown in the figure. <em>b</em> is the suture at the top of the head between the two parietal bones; <em>a a</em> is that between the two parietal bones and the frontal bone in front; and <em>c c </em> is that between the parietal bones and the bone at the back part of the cranium. These bones are not completely formed in the newborn infant.

Cranial Sutures

The bones of the top of the head are fastened together by what are called sutures which are locked together…

A human skull viewed from the top.

Cranium

A human skull viewed from the top.

The skull of a crocodile with visible teeth.

Crocodile Skull

The skull of a crocodile with visible teeth.

"Membranous cartilage skull of <em>Cyclostoma</em>."&mdash;Finley, 1917

Skull of Cyclostoma

"Membranous cartilage skull of Cyclostoma."—Finley, 1917

"Under Side of Skull of Cynomys Ludovicianus." &mdash;The Encyclopedia Britannica, 1903

Cynomys Ludovicianus

"Under Side of Skull of Cynomys Ludovicianus." —The Encyclopedia Britannica, 1903

The Arms of Death is an engraving that was created by German artist Albrecht D&uuml;rer in 1503. It shows a woman standing behind a helmet that is topped with eagle wings and a large skull on the bottom.

The Arms of Death

The Arms of Death is an engraving that was created by German artist Albrecht Dürer in 1503. It…

Skull of a deer, showing the brain cavity.

Deer skull

Skull of a deer, showing the brain cavity.

"Skull and Dentition of Dendrohyrax Dorsalis." &mdash;The Encyclopedia Britannica, 1903

Dendrohyrax Dorsalis

"Skull and Dentition of Dendrohyrax Dorsalis." —The Encyclopedia Britannica, 1903

"Skull of Dinotherium Giganteum." &mdash;The Encyclopedia Britannica, 1903

Dinotherium Giganteum

"Skull of Dinotherium Giganteum." —The Encyclopedia Britannica, 1903

"Longitudinal and Vertical section of the skull of a dog, with mandible and hyoid arch. an, anterior narial aperture; MT, maxillo-turbinal bone; ET, the ethmo-turbinal; Fr, frontal; Pa, pariental; IP, interparietal; SO, supra-occipital; ExO, sphenoid; OS, orbito-sphenoid; PS, presphenoid; Pl, palatine; Vo, vomer; Mx, maxilla; PMx, premaxilla; sh, stylo-hyal; eh, epi-hyal; ch, cerato-hyal; bh, basihyal; th, thyro-hyal; s, symphysis of mandible; cp, coronoid process; cd, condyle; a, angle; id, inferior dental canal. The mandible is displaced downwards, to show its entire form; the * indicated the part of the cranium to which the condyle is articulated." &mdash;The Encyclopedia Britannica, 1903

Dog Skull

"Longitudinal and Vertical section of the skull of a dog, with mandible and hyoid arch. an, anterior…

A Dolichocephalic cranium from above.

Dolichocephalic Cranium

A Dolichocephalic cranium from above.

A Dolichocephalic cranium from the side.

Dolichocephalic Cranium

A Dolichocephalic cranium from the side.

Ethmoid bone from above.

Ethmoid Bone from Above

Ethmoid bone from above.

Ethmoid bone from behind.

Ethmoid Bone from Behind

Ethmoid bone from behind.

Ethmoid bone, posterior surface. The ethmoid bone is an exceedingly light, spongy bone, placed between the two orbits and at the root of the nose, contributing to form a part of each of these cavities. Label: 2, cribriform, or perforated plate.

Ethmoid Bone of the Human Skull

Ethmoid bone, posterior surface. The ethmoid bone is an exceedingly light, spongy bone, placed between…

The outer surface of the ethmoid bone.

Outer Surface of Ethmoid Bone

The outer surface of the ethmoid bone.

Perpendicular plate of ethmoid, shown by removing the right lateral mass.

Perpendicular Plate of Ethmoid

Perpendicular plate of ethmoid, shown by removing the right lateral mass.

"Skull of Eupleres goudoti." &mdash;The Encyclopedia Britannica, 1903

Eupleres Goudoti

"Skull of Eupleres goudoti." —The Encyclopedia Britannica, 1903

"Skull of Fiber zibethica." &mdash;The Encyclopedia Britannica, 1903

Fiber Zibethica

"Skull of Fiber zibethica." —The Encyclopedia Britannica, 1903

Skull of <em>salamandra maculosa</em>, the fire salamander.

Skull of fire salamander

Skull of salamandra maculosa, the fire salamander.

The upper view of the skull of an old fowl.

Fowl Skull

The upper view of the skull of an old fowl.

The skull of an adult fowl.

Fowl Skull

The skull of an adult fowl.

The skull of an adult fowl. Here the temporal fossa is bridged over by the junction of the post-frontal and squamosal processes.

Fowl Skull

The skull of an adult fowl. Here the temporal fossa is bridged over by the junction of the post-frontal…

"Fig. 62 Skull of common fowl, enlarged. from nature by Dr. R.W. Shufeldt, U.S.A. The names of bones and some other parts are printed, requiring no explanation; but observe the following points: The distinction of none of the bones composing the brain-case (the upper back expanded part) can be found in a mature skull. The brain is contained between the occipital, sphenoidals, squamosals, parietals and part of frontal; the ethmoidals belong to the same group of cranial bones proper. All other bones, excepting the three otic ear-bones, are bones of the face and jaws. The lower jaw, of five bones, is drawn detached; it articulates by the black surface marked articular with the prominence just above- the quadratic bone. Observe that from this quadrate a series of bones quadrato-jugal, jugal, maxillary-makes a slender rod running to the premaxillary; this is the zygoma, or jugal bar. Observe from the quadrate also another series, composed of pterygoid and palatine bones, to the premaxillary; this is the pterygo-palatine bar; it slides along a median fixed axis of the skull, the rostrum, which bears the loose vomer at its end. The under mandible, quadrate, pterygoid, and vomer are the only movable bones of this skull. But when the quadrate rocks back and forth, as it does by its upper joint, its lower end pulls and pushes upon the upper mandible, by means of the jugal and pterygo-palatine bars, setting the whole scaffolding of the upper jaw in motion. This motion hinges upon the elasticity of the bones of the forehead, at the thin place just where the reference-lines from the words "lacrymal" and "mesethmoid" cross each other. The dark oval space behind the quadrate is the external orifice of the ear; the parts in it to which the three reference-lines go are diagrammatic, not actual representations; thus, the quadrate articulates with a large pro-otic as well as with the squamosal. The great excavation at the middle of the figure, containing the cirlet of the unshaded bones, is the left orbital cavity, orbit, or socket of the eye. The mesethmoid includes most of the background of this cavity, shaded diagonally. The upper one of the two processes of bone extending into it from behind is post-frontal or sphenotic process; the under one (just over the quadrate) is the squamosal process. A bone not shown, the presphenoid, lies just in front of the oval black space over the end of basisphenoid. This black oval is the optic foramen, through which the nerve of sight passes from the brain-cavity to the eye. The black dot a little behind the optic foramen is the orifice of exit of a part of the trifacial nerve. The black mark under the letters "on" of the word "frontal" is the olfactory foramen, where the nerve of smell emerges from the brain-box to go to the nose. The nasal cavity is the black space behind nasal and covered by that bone, and in the oval blank before it. The parts of the beak covered by horn are only premaxillary, nasal, and dentary. The condyle articulates with the first cervical vertebra; just above it, not shown, is the foramen magnum, or great hole through which the spinal medulla, or main nervous cord, passes from the spinal column. The basioccipital is hidden, excepting its condyle; so is much of the basisphenoid. The prolongation forward of the basisphenoid, marked "rostrum," and bearing the vomer at its end, is the parasphenoid, as far as its thickened under border is concerned. Between the fore end of the pterygoid and the basisphenoidal rostrum, is the site of the basipterygoid process, by which the bones concerned articulate by smooth facets; further forward, the palatines ride freely upon the parasphenoidal rostrum. In any passerine bird , the vomer would be thick in front, and forked behind, riding like the palatine upon the rostrum. The palatine seems to run into the maxillary in this view; but it continues on to premaxillary. The maxillo-palatine is an important bone which cannot be seen in the figure because it extends horizontally into the paper from the maxillary about where the reference life "maxillary" goes to that bone. The general line from the condyle to the end of the vomer is the cranial axis, basis cranii, or base of the cranium. This skull is widest across the post-frontal; next most so across the bulge of the jugal bar." Elliot Coues, 1884

Skull of a Common Fowl

"Fig. 62 Skull of common fowl, enlarged. from nature by Dr. R.W. Shufeldt, U.S.A. The names of bones…

"Typical Skull of Common Fowl (Galliformes). A, side view: sa, surangular bone of mandible; ar, articular of mandible; d, dentary; f, frontal; j, jugal; l, lacrymal; me, mesethmoid; mx, maxillary; p, parietal; pf, postfrontal process; pt, pterygoid; px, premaxillary; q, quadrate; qj, quadratojugal; sq, squamosal; v, vomer." -Whitney, 1911

Skull of Common Fowl

"Typical Skull of Common Fowl (Galliformes). A, side view: sa, surangular bone of mandible; ar, articular…

"Typical Skull of Common Fowl (Galliformes). B, vertical longitudinal section: sa, surangular bone of mandible; ar, articular of mandible; d, dentary; f, frontal; me, mesethmoid; p, parietal; pf, postfrontal process; px, premaxillary; sq, squamosal; v, vomer; as, alisphenoid; bo, basioccipital; so, supraoccipital; os, orbitosphenoid; p', prootic; pf, pituitary fossa; sp, splenial bone." -Whitney, 1911

Skull of Common Fowl

"Typical Skull of Common Fowl (Galliformes). B, vertical longitudinal section: sa, surangular bone of…

A front view of the frontal bone; a,a, frontal sinuses; b, the temporal arch, beneath which lies the temporal muscle, which closes the lower jaw; d, the supra-orbitary hole for a passage of a branch of the fifth pair of nerves.

Frontal Bone

A front view of the frontal bone; a,a, frontal sinuses; b, the temporal arch, beneath which lies the…

The frontal bone, seen from in front.

Frontal Bone

The frontal bone, seen from in front.

The frontal bone at birth. Developed from two lateral halves.

Frontal Bone at Birth

The frontal bone at birth. Developed from two lateral halves.

The frontal bone from behind.

Frontal Bone from Behind

The frontal bone from behind.

Frontal bone of the human skull, outer surface. The frontal bone forms the forehead, roof of the orbital cavities, and the nasal cavity. Labels: 1, frontal eminence; 7, roof of orbital cavitiy; 10, orbital arch.

Frontal Bone of the Human Skull

Frontal bone of the human skull, outer surface. The frontal bone forms the forehead, roof of the orbital…

The frontal bone viewed from below.

Frontal Bone Viewed From Below

The frontal bone viewed from below.

Anterior view of the frontal bone.

Anterior View of Frontal Bone

Anterior view of the frontal bone.

"Skull and teeth of Gray's Rat Kangaroo (Bellongia grayii). c, upper canine tooth. i1, i2, i3, first, second, and third upper incisors; pm, second or posterior premolar (the first having been already shed); m1, m2, m3, m4, the four true molars." &mdash;The Encyclopedia Britannica, 1910

Gray's Rat Kangaroo

"Skull and teeth of Gray's Rat Kangaroo (Bellongia grayii). c, upper canine tooth. i1, i2, i3, first,…

Skull of a Greek tortoise, showing the brain cavity.

Skull of Greek tortoise

Skull of a Greek tortoise, showing the brain cavity.

The skull of a nestling sparrowhawk, palatal view.

Sparrowhawk Skull

The skull of a nestling sparrowhawk, palatal view.