Snakes

-ventral scales (gastrolia)

-large, rectangular

-fx: traction for land locomotion

-dorsal scales

-overlapping

-fx: protection, camouflage, reduced friction

-keeled scales

-raised ridge in middle of scale

-fx: friction & grip (terrestrial snakes)

-smooth scales

-glossy, flat surface

-drag reduction in arboreal or aquatic snake

-rostral/labial scales

-enlarged scale on snout/lips

-fx: burrowing, prey handling

-subcaudal scales

-paired or single

-under tail

-ID

which spp do not have a parietal organ? 

-snakes, birds, mammals

teeth: 

Aglyphous

-non-venomous

-teeth are all similar

-no specialized fangs

-ex: pythons, boas, colubrids

aglyphous

-opisthoglyphous

-nnlarged grooved fangs at the rear of the maxilla

venom along grooves, not thru a canal.

-some colubrids (e.g. Boomslang).

-Proteroglyphous

-short, hollow fangs at the front of the maxilla

-fixed in position

-venom injected through internal canal

-ex: Elapids — cobras, taipans, brown snakes, coral snakes

-solenoglyphous

-long, hollow fangs on a rotating maxilla — fold back when mouth is closed

-maxilla can swing forward to strike.

-ex: vipers, pit vipers

A - VO (Jacobson’s organ)

B - connects external nostrils to the internal part of the mouth (nasal cavity)

C - opening of larynx (glottis)

D - sheath covering forked tongue

snake kidneys

kidney