724:) have the most advanced venom delivery method of any snake. Each maxilla is reduced to a nub supporting a single hollow fang tooth. The fangs, which can be as long as half the length of the head, are folded against the roof of the mouth, pointing posteriorly. The skull has a series of interacting elements that ensure that the fangs rotate into biting position when the jaws open. Solenoglyphous snakes open their mouths almost 180 degrees, and the fangs swing into a position to allow them to penetrate deep into the prey. While solenoglyph venom is typically less toxic than that of
1105:
374:
581:
650:
31:
695:
71:
534:
678:) have shortened maxillae bearing few teeth except for a substantially enlarged fang pointing downwards and completely folded around the venom channel, forming a hollow needle. Because the fangs are only a fraction of an inch long in even the largest species, these snakes must hang on, at least momentarily, as they inject their venom. Some
613:
called "rear-fanged". In order to envenomate prey, an opisthoglyphous snake must move the prey into the rear of its mouth and then penetrate it with its fangs, presenting difficulties with large prey although they can quickly move smaller prey into position. The opisthoglyphous dentition appears at
968:
A snake has from 175 to more than 400 vertebrae in its backbone. The means by which vertebrae are secured are twofold: either a ball and socket joint, or zygopophyses, which stick out from each vertebra to poke rear-pointing projections from the vertebrae ahead of it. This results in a spine
786:
I. Quadrate articulating with the cranium, supratemporal absent; mandible much shorter than the skull, with coronoid bone; maxillary small, on lower aspect of cranium; pterygoids not extending to quadrate; nasals forming long sutures with the premaxillary, prefrontals, and frontal:
803:
A. Mandible with coronoid bone; nasals in sutural contact with frontals and prefrontals; transverse bone short, not projecting much beyond cranium; maxillary not half as long as mandible, which is not longer than skull (to occiput):
1059:), may be expanded and plate-like above, and short or moderately long transverse processes to which the ribs are attached by a single facet. The centra of the anterior vertebrae emit more or less developed descending processes, or
562:) have no specialized teeth; each tooth is similar in shape and often size. When teeth vary in size, as in some bird eaters, they do not vary in shape. Most aglyphous snakes are non-venomous; some, like
361:, in which the skull is very compact and the maxillary much reduced. In the former this bone is loosely attached to the lower aspect of the cranium; in the latter, it borders the mouth and is
433:. It allows the maxilla to pivot in the plane of the photograph, and while it does not increase gape, it does facilitate the complex action by which the snake draws prey into its mouth.
241:, which may be very long, and the maxillary often emits a process towards the palatine, the latter bone being usually produced inwards and upwards towards the anterior extremity of the
758:
Common names for the various types of snake dentition originate largely from older literature, but still are encountered in informal publications. Aglyphous snakes are commonly called
510:. The latter form an "inner row" of teeth that can move separately from the rest of the jaws and are used to help "walk" the jaws over prey. Several snake lineages have evolved
885:
Quadrate longer than supratemporal; maxillary much longer than quadrate, nearly straight in front of prefrontal; a large vacuity between the frontal bones and the basisphenoid:
609:, which normally angle backward and are grooved to channel venom into the puncture. Since these fangs are not located at the front of the mouth, this arrangement is
1139:, attached to the lower branch of the first bifurcate transverse process of the lumbar vertebrae, bearing three short bones, the longest of which, regarded as the
265:
365:
joined to the premaxillary and the prefrontal. Both the transverse bone and the supratemporal are absent, but the coronoid element is present in the mandible.
985:
949:
230:
633:, respectively, after each underestimated the effects of the bite and failed to seek medical help. Opisthoglyphous snakes are found mostly in the families
916:
2. Maxillary much abbreviated and erectile; supratemporal not half as long as skull; mandible much longer than skull; basioccipital with a strong process.
189:
339:
238:
746:
is solenoglyphous but the fangs swing out sideways, allowing it to strike without opening its mouth, perhaps allowing it to hunt in small tunnels.
1060:
347:
234:
1065:
836:
242:
155:
887:
330:
1028:
878:
b. Maxillary not half as long as mandible, which is longer than skull; supratemporal not half as long as skull, projecting beyond cranium.
904:
362:
135:
423:. It is highly mobile in most directions, allowing a wider gape (i.e., the snake can open its mouth wider) and greater jaw flexibility.
1088:
In the caudal region, elongate transverse processes take the place of ribs, and the haemapophyses are paired, one on each side of the
796:
II. Quadrate suspended from the supratemporal; mandible at least as long as the skull; pterygoids extending to quadrate or mandible.
1051:
in addition to the cup-and-ball on the centrum, and interlock by parts reciprocally receiving and entering one another, like the
1281:
614:
least two times in the history of snakes. The venom of some opisthoglyphous snakes is strong enough to harm humans; notably,
525:
Most snakes can be placed into one of four groups, based on their teeth, which correlate strongly with venom and lineage.
248:
The quadrate is usually large and elongate, and attached to the cranium through the supratemporal (often regarded as the
353:
The deviation from the normal type is much greater still when we consider the degraded wormlike members of the families
1256:
894:
Quadrate not longer than supratemporal; maxillary little longer than quadrate, strongly curved in front of prefrontal:
902:
Quadrate longer than supratemporal; maxillary little longer than quadrate, nearly straight in front of prefrontal:
293:
852:
Supratemporal not half as long as skull, projecting but slightly beyond cranium; mandible much longer than skull:
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have modified fang tips allowing them to spray venom at an attacker's eyes. This form of dentition is unique to
1047:, just below the base of the neural spine. Thus the vertebrae of snakes articulate with each other by eight
728:, this system allows them to deeply inject large quantities of venom. This form of dentition is unique to
350:
in front of the frontals; the dentary may be freely movable, and detached from the articular posteriorly.
843:
Supratemporal not half as long as skull, projecting far beyond cranium; mandible much longer than skull:
338:; the pterygoids may taper and converge posteriorly, without any connection with the quadrate, as in the
988:, all of which, except the first or first three, bear long, movable, curved ribs with a small posterior
861:
Supratemporal not half as long as skull, not projecting beyond cranium; mandible not longer than skull:
272:
required by the passage of prey, often much exceeding the size of the mouth. For the same reason, the
834:
Supratemporal half as long as skull, projecting far beyond cranium; mandible much longer than skull:
1055:
joints. The precaudal vertebrae have a more or less high neural spine which, as a rare exception (
605:("rearward grooves") snakes possess venom injected by a pair of enlarged teeth at the back of the
1190:
507:
311:
is reduced to a pair of cartilaginous filaments situated below the trachea, and united in front.
225:
are long and parallel to the axis of the skull, the latter diverging behind and extending to the
17:
1316:
618:
115:
1039:, broad, flattened, and overlapping, and of a pair of anterior wedge-shaped processes called
1020:
1213:
Animales venenosos. Vertebrados terrestres venenosos peligrosos para el ser humano en España
1195:
997:
410:
8:
750:(blind burrowing snakes) typically have few teeth, often only in the upper or lower jaw.
342:; the supratemporal may be much reduced, and wedged in between the adjacent bones of the
143:
1321:
663:
76:
1242:
Rose, Walter; The reptiles and amphibians of southern Africa; Pub: Maskew Miller, 1950
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is provided with additional articular surfaces in the form of pre- and post-
1251:
Engelmann, Wolf-Eberhard. Snakes (No. 05352). Publisher
Bookthrift 1982.
1158:
1136:
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at the base, the last of these ribs sometimes forked; two to ten so-called
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334:); the maxillary may be much abbreviated and movable vertically, as in the
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467:: the joint between the supratemporal and parietal. Immobile, except for
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770:; and both Proteroglyphous and Solenoglyphous snakes are referred to as
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is single and small and as a rule, connected with the maxillary only by
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of the mandible; the pterygoid is connected with the maxillary by the
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the seven or eight last vertebrae are enlarged and fused into one.
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The vertebrae number 130 to 500 - in the
European forms 147 (
487:
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96:
to allow the snake to swallow prey far larger than its head.
93:
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47:
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169:
is situated, on each side, between the frontal bone and the
1303:
External and
Internal snake anatomy with postmortem images.
515:
448:
154:. The basioccipital may bear a curved ventral process or
1023:, with the nearly hemispherical or transversely elliptic
981:
514:
which is typically delivered by specialized teeth called
55:
173:, and may or may not be in contact with the nasal bone.
1165:, and rudimentary femur, the ischium forming a ventral
777:
568:, are considered mildly venomous. The feature is not a
1199:, 2nd edition. London: Methuen & Co., Ltd., 1913.
1147:
which usually appears externally on each side of the
451:
to upturn slightly, increasing gape and assisting in
300:
and a few other small families, are connected at the
1043:, fitting into a pair of corresponding concavities,
146:, or a simple knob formed by the basioccipital; the
782:Modifications of the skull in the European genera:
1063:, which are sometimes continued throughout, as in
753:
740:A few snakes do not conform to these categories.
126:region. The nose is less ossified, and the paired
969:well-adapted to the snake's method of movement.
314:There are various modifications according to the
1308:
820:1. Maxillary elongate, not movable vertically.
381:, with visible kinetic joints labeled. Red =
1268:Campbell, Sheldon; Shaw, Charles E. (1974).
1267:
368:
118:, which is large and extends forward into a
130:are often attached only at their base. The
92:is a very complex structure, with numerous
318:. A large hole may be present between the
268:are more or less movable to allow for the
1116:No living snake shows any remains of the
419:: the joint between the quadrate and the
1103:
693:
648:
579:
532:
372:
69:
29:
1112:showing the bones inside the anal spurs
1008:with simple transverse processes. When
429:: the joint between the prefrontal and
304:by a very extensible elastic ligament.
14:
1309:
827:a. Maxillary half as long as mandible.
184:behind, rarely also above, and in the
99:The typical snake skull has a solidly
963:
813:B. No coronoid bone; nasals isolated.
1236:
980:(composed of two vertebrae) without
778:Taxonomic key of skull modifications
196:between it and the prefrontal bone.
276:of the lower jaw, which consist of
24:
1099:
477:
25:
1333:
1294:
1261:
996:without ribs, but with bifurcate
725:
292:elements, with the addition of a
1000:(lymphapophyses) enclosing the
754:Informal or popular terminology
644:
575:
413:to the joint in mammalian jaws.
377:Lateral view of the skull of a
264:The quadrate and maxillary and
180:, usually present, borders the
1245:
1225:
1205:
689:
13:
1:
1184:
1180:: a single bone on each side.
735:
1143:, terminates in a claw-like
7:
1270:Snakes of The American West
10:
1338:
1004:; and a number of ribless
114:extending downward to the
46:consists primarily of the
1211:Bruna Azara, C. (1995). "
762:; opisthoglyphous snakes
528:
369:Joints of the snake skull
439:: the joint between the
65:
1232:LD50 for various snakes
1191:George Albert Boulenger
932:Maxillary bone hollow:
508:lateral pterygoid plate
62:remnants of the limbs.
1113:
1031:vertebrae), while the
923:Maxillary bone solid:
714:
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552:
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322:and the basisphenoid (
266:palatopterygoid arches
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1021:ball and socket joint
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150:is excluded from the
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1196:The Snakes Of Europe
998:transverse processes
409:and quadrate. It is
106:, with the separate
986:precaudal vertebrae
950:Coluber leopardinus
490:are located on the
231:articular extremity
27:Skeleton of a snake
1114:
964:Vertebrae and ribs
715:
669:
664:Ophiophagus hannah
600:
553:
395:
138:and formed by the
82:
77:Python reticulatus
35:
1283:978-0-394-48882-0
1053:mortise and tenon
1002:lymphatic vessels
625:were killed by a
595:Heterodon nasicus
548:Python bivittatus
201:premaxillary bone
190:supraorbital bone
132:occipital condyle
122:extending to the
16:(Redirected from
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1155:Leptotyphlopidae
1006:caudal vertebrae
994:lumbar vertebrae
974:vertebral column
447:. It allows the
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680:spitting cobras
676:forward grooved
672:Proteroglyphous
655:proteroglyphous
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603:Opisthoglyphous
586:opisthoglyphous
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560:lacking grooves
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518:located on the
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478:Snake dentition
387:slightly mobile
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340:Amblycephalidae
309:hyoid apparatus
239:transverse bone
167:prefrontal bone
110:and the united
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1108:Skeleton of a
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1094:rattlesnakes
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1066:Tropidonotus
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1037:zygapophyses
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645:Proteroglyph
639:Homalopsidae
619:Karl Schmidt
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576:Opisthoglyph
570:synapomorphy
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243:basisphenoid
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116:basisphenoid
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58:, with only
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36:
1178:Typhlopidae
1145:pelvic spur
1078:Ancistrodon
1033:neural arch
984:; numerous
935:Ancistrodon
888:Coelopeltis
768:back-fanged
764:rear-fanged
743:Atractaspis
704:rattlesnake
690:Solenoglyph
355:Typhlopidae
331:Coelopeltis
214:is narrow.
210:The paired
128:nasal bones
1311:Categories
1185:References
1057:Xenopholis
1041:zygosphene
1029:procoelous
947:) to 330 (
736:Exceptions
659:king cobra
635:Colubridae
631:twig snake
565:Thamnophis
470:Dasypeltis
453:swallowing
445:nasal bone
385:, green =
325:Psammophis
270:distension
229:or to the
134:is either
1322:Skeletons
1173:Aniliidae
1167:symphysis
1157:: ilium,
1135:: a long
1092:. In the
1045:zygantrum
905:Tarbophis
864:Coronella
702:snake. A
657:snake. A
627:boomslang
588:snake. A
556:Aglyphous
541:snake. A
539:aglyphous
496:lower jaw
411:analogous
389:, blue =
363:suturally
336:Viperidae
302:symphysis
290:articular
250:squamosal
223:pterygoid
136:trilobate
124:ethmoidal
104:braincase
60:vestigial
52:vertebrae
1222:: 32-40.
1217:Bol. SEA
1085:genera.
1083:European
1081:, among
990:tubercle
790:Typhlops
760:fangless
720:snakes (
709:Crotalus
674:snakes (
607:maxillae
558:snakes (
506:and the
482:In most
407:mandible
391:immobile
294:coronoid
282:splenial
227:quadrate
205:ligament
142:and the
101:ossified
43:skeleton
1163:ischium
1133:Pythons
1025:condyle
855:Coluber
846:Zamenis
706:skull (
684:elapids
661:skull (
592:skull (
545:skull (
520:maxilla
500:maxilla
494:of the
492:dentary
459:Green B
437:Green A
431:maxilla
344:cranium
296:in the
286:angular
278:dentary
258:Polemon
186:pythons
171:maxilla
158:in the
120:rostrum
18:Aglypha
1280:
1255:
1161:, and
1149:cloaca
1122:pelvis
1075:, and
1072:Vipera
1049:joints
1017:centra
926:Vipera
868:Contia
730:vipers
629:and a
529:Aglyph
502:, the
498:, the
484:snakes
401:: the
316:genera
288:, and
160:vipers
94:joints
54:, and
1159:pubis
1141:femur
1137:ilium
1010:bifid
978:atlas
516:fangs
512:venom
488:teeth
427:Red C
417:Red B
403:joint
399:Red A
212:vomer
182:orbit
90:snake
88:of a
86:skull
66:Skull
48:skull
40:snake
1278:ISBN
1253:ISBN
1131:and
1129:Boas
1015:The
982:ribs
972:The
807:Eryx
637:and
621:and
465:Blue
449:nose
443:and
357:and
307:The
298:boas
274:rami
221:and
217:The
199:The
176:The
165:The
84:The
56:ribs
1215:".
1193:.
766:or
711:sp.
584:An
537:An
252:).
237:or
192:is
1313::
1276:.
1220:11
1069:,
953:).
866:,
774:.
732:.
698:A
686:.
653:A
641:.
522:.
486:,
328:,
284:,
280:,
245:.
207:.
188:a
162:.
50:,
37:A
1286:.
1169:.
1151:.
938:.
929:.
891:.
871:.
858:.
849:.
840:.
810:.
793:.
713:)
667:)
598:)
572:.
551:)
473:.
455:.
393:.
80:.
20:)
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