amphibian diversity III (Gymophiona and Caecilians)

morphology

wormlike body, limbless (no vestigial pectoral of pelvic girdles)

tail small or absent

no interior structure, unlike snakes

annuli present (rings of keratin)

skull heavily built, powerful jaws

body size range

98 mm (3.9 inches) to 152 cm (ab 60 inches)

all groups have at least how many annuli

one

these groups have primary/secondary/tertiary annuli

rhinatrematidae and icthyophiidae

ALL OTHER TAXA HAVE PRIMARY ONLY

these groups have primary/secondary annuli

chikilidae and indotyphlidae

ALL OTHER TAXA HAVE PRIMARY ONLY

this is the only group of amphibians that have

dermal scales in some species in pouches below annular grooves

gymonphiona skeleton features

has atlas

95-285 trunk vertebrae

no sacrum

all vertebrate (except atlas and last 3-6) have ribs

the three types of locomotion

internal concertina

whole body concertina

lateral undulation

internal concertina is when

contact points anchor the body, but the vertebral column is bent while the body is extended

(skin and vertebral column move independently)

whole body concertina is when

static contact points anchor the body while other parts are moved forward

lateral undulations is when

static push points propel the animal forward

eyes can be

covered by skin/bone

the tentacle functions how

opens to the surface of the head through an aperature in the skull located between the eyes and nostrils

this feature is a complex of muscles, glands, and ducts and may include both olfactory and visual receptors, depending on the family

scolecomorphidae is when

the eyes are on the tentacles

skull morphology of caecilians

the skulls are heavily ossified and akinetic (no cartilage, all bone)

caecilians misc facts

majority have sharp teeth

some caecilians do a death roll

venom glands present (recent)

all caecilians have what kind of fertilization

internal!!!

majority of this family has what kind of birth features

direct development and oviparity

aquatic larva transition into

fossorial adults