herpetology chapter 4 pt 2 (exam 1)

what is the only remaining member of the rhynchocephalia and where is it found

sphenodontidae (spheonodon punctatus)

\
tuatara

\
new zealand

anatomical differences between rhychocephalians and modern squamates (9)

1. akinetic skull (vs kinetic)
2. lower temporal bar (lizards don’t have)
3. no streptostylic quadrate
4. teeth are large, acrodont (attached to top of jaw), heterodonty (teeth different shapes)
5. teeth on palatine bones
6. bony down growths of premaxilla
7. ucinate processes on ribs
8. gastralia (abdominal ribs)
9. pineal eye (associated with gland in brain)

relationship among the major clades

1. gekkota
2. scincomorpha
3. lacertoidea
4. amphisbaenia
5. amguimorpha
6. iguania (2)

2 groups of the inguania

1. acrodonta
2. pleurodonta

defining features of dibamidae (4)

blind skinks (basal family)

\

1. burrowers with vestigial eyes covered by scales
2. lack external ear openings
3. both ends of body are blunt
4. males have small, flaplike hindlimbs and females are limbless

defining features of pygopodidae (3)

flap-footed lizards (gekkota)

\

1. snakelike without forelimbs and hindlimbs reduced to scaly flaps
2. eyes covered by immovable spectacle
3. long, autotomic tail

defining features of gekkonidae (2)

spectacled geckos (gekkota)

\

1. second largest lizard family
2. about 10% of them lay eggs in communal nest

defining features of scincidae (5)

skinks (scincomorpha)

\

1. largest and most morphologically diverse family of lizards (1,600 species)
2. viviparity
3. limb reduction has evolved among skinks more often than in any other lizard family
4. smooth, shiny cycloid scales underlain by osteoderms
5. osteoderms made of multiple bones

defining features of lacertidae (3)

wall lizards and relatives (lacertoidea)

\

1. diurnal active terrestrial and rock dwelling species
2. one species (zootoca vivipara)
3. lives farther north than any other reptile

defining features of helodermatidae (2)

gila monster and mexican beaded lizard (anguimorpha)

\

1. short, blunt tails used for fat storage
2. heloderma venomous, venom glands are non-muscularized, located in the tissue alongside the mandible

defining features of varanidae (4)

monitors and goannas (anguimorpha)

\

1. greatest body size range of any lizard family
2. active lifestyle
3. lungs of varanids are large and more complex
4. use throat muscles to help ventilate lungs

defining features of chamaeleonidae (6)

chameleons (acrodonta)

\

1. devlopment of casques, horns, and crests on heads
2. laterally compressed body
3. can change colors
4. zygodactylous feet
5. prehensile tail (in aboreal species)
6. projectile tongue and independently moving eyes

defining features of agamidae (3)

dragons and relatives (acrodonta)

\

1. extensive crests, frills, or spines
2. draco: only extant lizard species capable of true gliding flight
3. many species live in dense colonies (well developed social hierarchy and territories)

defining features of dactyloidae (3)

anoles (pleurodonta)

\

1. extraordinarily diverse
2. subdigital lamellae bearing setae
3. brightly colored dewlaps (throat patch)

which family has the widest range of body sizes

varinidae

traits of the axillary skeleton (4_

1. cervical vertebrae (ribs)
2. atlas and axis (1st two cervical vertebrae)
3. thoracic and lumbar vertebrae generally have paired ribs on either side
4. coccygeal vertebrae possess ventral haemal arches

single occipital condyle

how the skull articulates with the atlas cervical vertebra

3 types of cranial kinesis

parts of the skull are mobile

\

1. metakinesis
2. mesokinesis
3. streptostyly

metakinesis

mesokinesis

streptostyly

rotate so lower jaw can move laterally

modified diapsid skull

no lower temporal bar

2 types of tooth attachment

1. acrodont
2. pleurodont

acrodont (2)

1. agamidae
2. chamaeleonidae

pleurodont

most lizards

vomeronasal organ

jacobson’s organ

\
tongue extension captures odor particles from air

\
tongue retraction where odor particles mix with fluids in mouth and are taken to ducts to go to vomeronasal organ

which families have various kinds of ornaments (3)

1. agamidae (frills)
2. corytophanidae (casque/helmet)
3. dactyloidae (dewlap)

what is intravertebral tail autonomy

vertebrae that have fracture planes

\
break in between vertebrae

\
do not grow back

how do gecko toe pads work

stick like magnets to surface (not wet)

what is zygodactyly in chameleons

unequal distribution of digits

\
forelimbs: 2 toes out, 3 toes in

\
hindlimbs: 3 toes out, 2 toes in

limb reduction in lizards

common

details about amphisbaenia (10)

1. mostly limbless lizards
2. lack pectoral girdle elements but have vestige of pectoral girdle
3. right lung reduced
4. body annulated
5. two body annuli per vertebra
6. elongate
7. all species burrow (body adaptations)
8. brain entirely surrounded by frontal bones
9. head shape varies (shovel, spade shaped, rounded, keeled)
10. skin can move independently of underlying trunk

which lizard families produce venom (2)

1. gila monsters
2. monitor lizards

what are hemipenes

2 peni

\
inside vent

\
grooves (spermatica) in sulcus

are lizards mostly oviparous or viviparous

oviparous

what types of sex determination are found in lizards (2)

1. genetic (ZW, XY)
2. temperature dependent