Chapter 15 - Lepidosaurs - Tuatara, Lizards & Snakes

Lepidosaurians

characterized of having a transverse cloacal slit, skin shed in one piece, characteristics of bone growth, skull, pelvis, and feet

True

True or False: Molecular data and the discovery of diapsid stem turtles now places them

as a more derived Diapsid group closer to Archosaurs, rather than a previously considered Anapsid

paraphyletic

Since they cannot be distinguished phylogenetically, are lizards and snakes monophyletic, paraphyletic, or polyphyletic?

three

How many suborders do 95% of all living reptiles belong in?

hemipenes

two-part reproductive organ

determinate growth

growth stops at genetically determined point; reaches a finite size

nocturnal

these type of reptiles have a problem because they have a body temperature of 6-16°C, and they need to bask during the day to reach 28°C or higher for digestion

ectothermic

adjust their body temperature by moving from one microclimate to another to bask or cool down

limblessness/legglessness

this specific characteristic has evolved >60x times among lizards and one large group (the

Amphisbaenians) exclusively have this characteristic

annuli

rings that encircle the body

zygodactylous feet

their toes are fused together, which allows them to grip branches firmly, and they have a prehensile tail

horned lizards

which animal squirts blood from their eyes?

eastern fence lizard

Which lizard is known as an arboreal lizard?

active predators

Monitor lizards display complex hunting behavior and will adjust their strategies depending on the behavior of their prey. These lizards are known as what?

10 cm to 10 m

What is the minimum and maximum length for snakes?

Infraorder Scoleocophidia

more than 300 species of small burrowing (fossorial) snakes

Infraorder Alethinophidia

about 160 species that include the boas, pythons and a variety of boa-like snakes

Superfamily Colubroidea

more than 2400 species including the Colubridae, Elapidae and Viperidae.

reduced eyes

surface dwelling snakes likely re-developed eyes after long period of fossorial existance

Solenoglyphous

they have long fangs that rest horizontally when the mouth is closed

Copperhead, Cottonmouth, Eastern Diamondback Rattlesnake, Timber Rattlesnake, and Pigmy Rattlesnake

Which snakes are considered venomous in Georgia?

Proteroglyphous

they have short, venomous fangs

Opisthoglyphous

they are rear-fanged snakes

viviparous

Are old world constrictors ovoviviparous or viviparous?

ovoviviparous

Are new world constrictors ovoviviparous or viviparous?

rectilinear motion

belly scales are alternately lifted slightly from the ground and pulled forward, and then pulled downward and backward (slow movement)

lateral undulation

body curves push against substrates - waves of lateral bending are propagated along the body from head to tail

concertina locomotion

involves alternately pulling up the body into bends and then straightening out the body forward from the bends

sidewinding

loops of the body are lifted off the ground and placed on ground with at two contact points

vomeronasal organ

forked tongue samples the air and picks up molecules that are delivered to this organ when the tongue is withdrawn

Duvernoy’s gland

produces toxic secretion that immobilizes prey (analogous to venom glands of vipers/elapids)

neurotoxic

this type of venom interferes with nervous system or muscle function (includes respiratory/diaphragm) and immobilized/kills prey (mostly elapsids)

cytotoxic

this type of venom breaks down and digests tissue primarily at site of envenomation and begins internal digestion (viperids)

hemotoxic

this type of venom affects blood or circulation, e.g., by preventing clotting (anticoagulant), causing blood to congeal, or lowering blood pressure; they also immobilize prey (slower acting) and may aid in digestion (viperids, colubrids)

aposematic

bright advertising coloration by venomous snakes and mimicry by non-venomous snakes

squamata

which reptile group is known for having all modes of reproduction (viviparous, ovoviviparous, and oviparous)

parthenogenesis

a form of asexual reproduction where an embryo develops from an unfertilized egg

True

True or False: sex determination can be both X/XY and ZZ/ZW or temperature (or environmental)-dependent sex determination

hemipenes

usually held inverted within their bodies, everted for reproduction via erectile tissue like that in the human penis