reptiles

history of crocs

heavily calcified eggs

eggs vary from 10-60

fertilisation is internal

egg laying takes place weeks after mating

sex of baby crocs

30C or less only female

31C gives both

32 and 33C gives males

above 33C male in some species other female

osteoderms

integumentary sense organs

on jaws of all crocodilians and on body scales of Crocodylidae and gavialida

ISO

integumentary sense organs

ISO functions

detection of water movements

indicating when to bite

feel things in mouth

alligatoridae

alligators and caiman

broad long jaws

Alligatoridae species

2 alligator

3 genera and 7 species of caiman

Alligatoridae habitats

water pools at sand dunes

marshes

swamps

large lakes and rivers

crocodylidae

2.5m to 7m

long broad jaws

4th madibukar tooth externa’

lingual salt gland

crocodylidae species

3 gerera and 14 species

salt water croc

largest croc

tidal and freshwater rivers and swamps

gavialidae species

2 genera 1 species

gavialidae

long narrow jaw

teeth outside closed mouth

most aquatic cros

males develop boss (soft tissue) on tip of snout

alligator vs crocodile

alligator croc

shovel shaped head

4th tooth hidden 4th tooth outside

lizards

>5000 species from 3cm to 3m

80% weigh less than 20g

most large are herbivores (not monitors)

agamidae

dragon lizards

small to large

tail is long doesnt fall off

terrestrial and semiarid

diurnal

canrnivorous

acrsont teeth and soft tongue

oviparous

agamidae species

54 genera

421 species

chamaeleonidae

chameleons

strongly laterally compressed bodies

prehensile tail (5th limb)

head casques covering their necks

zygodactyls feet - 3 grouped and 2 grouped digits

soft tongue

independently movable eyes

acrodont teeth

both oviparous and vivparous

chamaeleonidae species

6 genera

171 species

iguanidae species

671+ species

corytophanidae - 9

igaunine - 29

polychronitae - >320

iguanidae

corytophaninae - arboreal, casque headed, slender body, long tails, slow colour change

iguaninar - large 1-2m, herbivores, stout build, long whip like tails

polychrotinae - arboreal, flap beneath throat, laying 1 egg at a time

chameleon colour change

use chromatophores for colour

melanophores are dark

dewlap

flap of skin under neck

anoles

example of adaptive radiation

species in different habitats different

gekkonidae species

79 genera

800+ species

Gekkonidae

most are nocturnal

unique among lizards in vocalisations

large eyes covered with a transparent scale

most insectivorous

all oviparous

adhesive toe pads

made of hair like bristles called setae

lacertidae species

31 genera

220 species

lacertidae

wall and rock lizards

mainly terrestrial

elongate whiptail

insectivorous

oviparous

lizard in ireland

zootoca

coastal

vivparous - live young

scincidae species

133 genera

1200+ species

¼ of all lizards

scinidae

skinks

trop rain forests, savannnahs, arid deserts, forests

cylindrical body and tail conical head short limbs

tail droppers

varanoidea species

1 genus

63 species

varanoidae

monitor lizards

parietal eye - photosensory organ (third eye - cant see only light used to tell time)

small head, long necks, long and robust bodies, long muscular tail

120mm to 3.1m

forked tongue

most terrestrial to semi arboreal

buccal pumping

snakes species

2900+ species

snakes overview

all continents except antarctica

all carnivores

pectoral girdle and forelimbs absent

use body and mouth for capture and manipulation of prey

dont unhinge jaw

left lung reduces

eye covered by transparent scale

use smell and touch

flicking fork tongue

ability to sense infrared thermal radiation - pit organs

jacobsons organ

in snakes

small organ on the roof of oral cavity for taste

snake venom delivery systems

elapidae and viperidae and venomous

<20% of snakes are venomous

aglypha - no groves in fang

opisthoglypha - rear grove in fang

proteroglypha - front fang no hinge

solenoglypha - front hinged

colubridae species

1660 species

60% of snakes

colubridae

contains grass and smooth snake of uk

paraphyletic group

reared fangs

most are not venomus

elapidae species

160 genera

295 species

elapidae

reletively immovable venom conducting fangs at front of mouth

viperidae

venomous snakes long fangs folded against palate

robust bodies and triangular heads

crotalines- mainly nocternal, use sensory apparatus, terrestrial, long lived and viviparous

viperines - >2m terrestrial and diurnal, no sensory apparatus

boidae species

7 genera

47 species

boidae

no venen use constriction

aglyphous teeth

heat sensory organ

tuatara

only surviving member of sphenodontia

single species - sphenodon punctatus

single row of lower teeth fit between to rows of upper teeth

uk and irish reptiles

leatherback turtles

vivparous lizard

slow worm

grass snake

smooth snake

adder

wall lizard

sand lizard