74 terms

Vert Zoo Test 2 Ch 10

Rib Modifications
A tetrapoda synapomorphies
Cervical ribs are short
Thoracic ribs are elongated the connected to a sternum
Lumbar ribs are short or absent
Sacral ribs are connected to pelvic girdle and are immobile
Two Skeletal modifications that allow for greater mobility of the skull
Atlas: first cervical vertebra is modified on its anterior surface to form atlantal cotyles which are two cup-shaped structures that form joints with occipital condyles
-Development of 2 occipital condyles on the posterior end of the skull
Tetrapoda Synapomorphies
Pentadactly, possession of 5 digits
Modified Pectoral and Pelvic girdle
Two Skeletal Modifications
Rib modifications
Dermal body armor is greatly ruduced or absent
Muscular tongue
Middle ear components
Anuran Characteristics
-Specializations of the body for jumping
-Tail loss in adult
-Eyes large and placed well forward on the head.
-Variation of of body form based on locomotion type and habitat
- Arboreal species have pads with discs that secrete viscous (sticky) solutions
-Toothless dentary
-Most anurans have catapult-like mechanism to project the tongue which has a sticky substance to trap prey
-Keratinous beaks and denticles on larval mouthparts
Gymnophiona Reproduction
Internal fertilization accomplished by the male copulatory organ

25% of species are oviparous and females coil around eggs

75% of species are viviparous and matrotrophic

Yolk is absorbed first
Fetuses scrape the oviduct for "uterine" milk. Other species the offspring are born and they scrape the mother's outer layer of skin for nutrients

Some fetuses have gills
Terrestrial - branched gills
Aquatic - saclike gills
Amphibia Synapomorphies
Papilla amphibiorum
Green rods
Levator bulbi muscle structure
All amphibians have mucous glands and poison
Pedicellate teeth
Three-chambered heart
Urodela Reproduction
Male salamanders perform variety of courtship displays for females

During courtship, pheromones play an important role in attrracting mates and stimulating the endocrine activity
Stimulate pheromone release by salamanders by direct contact

Internal fertilization is performed by a spermatophore

Spermatophore - sperm packet with a sperm cap and gelationous base

Most salamanders are _oviparous_, but a few species are _vivaparous_. Some species lay only a few _eggs_ , while other species lay _masses_ of eggs.
Ichthyostega Synapomorphies
Ribs at base of tail for swimming
Robust paddle like hindlimbs
Ear specializations for hearing under water
Distinct thoracic and lumbar regions of the spine
Robust overlapping ribs
Bendable weight supporting elbow
Tiktaalik Synapomorphies
Well developed gills
Poorly ossified vertebrae
Very long body
Fish like characteristics
Large overlapping ribs
Pectoral fin could bend
- Suggests they could bear some weight out of the water
intermediate between fish and tetrapods
What has the head of a crocodile and the gills of a fish?
...early tetrapod that was mostly aquatic in nature
short ribs, wrists, and ankles making it incapable to bear weight on land
...early tetrapod with modifications for living in both an aquatic and terrestrial life
ribs at base of tail for swimming
robust paddle like hindlimbs
ear specializations for hearing under water
distinct thoracic and lumbar regions of the spine
robust overlapping ribs
bendable weight supporting elbow
Modified Pectoral and Pelvic girdle
allows for the weight of the body to be transferred to the limbs
-supracleitherum is absent causing the connection to the skull to be lost
-scapula is enlarged for attachment of limbs
-pelvic girdle is greatly enlarged
possessions of five digits
having four limbs: 2 connected to the pelvic gridle 2 to pectoral girdle
Two Skeletal Modifications
that allow for greater mobility of the skull: Atlas, modified to form atlantal cotyles which form joints with two occipital condyles
Dermal body armor
synapomorphies greatly reduced in tetrapoda
Muscular tongue
synapomorphy; allows for feeding out of the water
Middle ear components
synapomorphy tympanum and Stapes allow for transmission of sound
tympanum and Stapes allow for transmission of sound
Papilla amphibiorum
a special sensory area in the sacculus of the inner ear that allows them to detect sound below 1000Hz
Amphibia Synapamorphy
Two bones in the inner ear that are sometimes fused and are involved in transmitting sound
Amphibia Synapamorphy
Green rods
a special type of retinal cell
Amphibia Synapamorphy
Levator bulbi muscle structure
-the muscle structure is a thin sheet in the floor of the orbit that is innervated by the 5th cranial nerve
-causes the eyes to bulge outward, thereby enlarging the buccal cavity.
-Amphibia Synapamorphy
Pedicellate teeth
teeth in which the crown and base are composed of dentine and are separated by a narrow zone of uncalcified dentine or fibrous connective tissue
-Amphibia Synapamorphy
Three-chambered heart
which consists of two atrium and one ventricle
-Amphibia Synapamorphy
Skin Structure
moist permeable skin that allows for cutaneous respiration
-Amphibia Synapamorphy
How Do Mostly Terrestrial Amphibians Keep Moist?
Mucous glands, Kidneys, Behavior to reduce water loss and increase water uptake
Mucous glands
distributed all over the body of amphibia and produce mucopolysaccharide compounds
Amphibia kidneys
produce urine hyposmolal to the blood, so that the urine is in the bladder is dilute and water can be reabsorbed from the urine
Poison Glands
- found on dorsal surfaces and defense poses expose those surfaces
- Toxicity ranges from producing unpleasant sensation to death

- bright warning coloration to let predators know they are toxic
Poison dart frogs obtain their lethal compounds from...
the beetles and ants they consume
Aposematic coloration
Aposematic coloration
bright warning coloration to let predators know they are toxic
Batesian Mimicry
a non-toxic or palatable species mimics the coloration of a toxic or unpalatable species
Batesian Mimicry
Jordan's (Plethodon jordani) & Mountain Dusky (Desmognathus ochrophaeus)
Three Distinct Orders of Amphibia
Urodeles (Caudata)
Urodeles (Caudata)
Urodeles (Caudata)
frogs and toads
Urodela Characteristics
Elongate with four functional limbs
Walking-trot gait
adult retention of larval or juvenile traits: urodela characteristic
Paedomorphs retain
Tooth and bone patterns
Absence of eyelids
Functional lateral line system
External gills
sperm packet with a sperm cap and gelationous base
seen in Urodela
Plethodontid Salamanders
Lungless Salamanders
Family of Salamanders
Plethodontid Salamanders Characteristics
Lack of lungs, Nasiolabial grooves, dear enemy recognition
Nasiolabial grooves
Nasiolabial grooves
help direct pheromones to the chemoreceptors of the vomeronasal organ used for courtship and territorial behaviors
Plethodontid Territorial Behavior
Dear Enemy Recognition
Dear Enemy Recognition
recognizing territorial neighbors that are less threatening, thus decreasing its territorial aggression to reduce energy expenditure
Anuran Specializationsfor jumping:
Urostyle - posterior vertebrae fused into a solid rod
5-9 Pre-sacral vertebrae
Elongated Illium (part of pelvis)
Hindlimbs longer then forelimbs
Fusion of tibia and fibula
Fusion of radius and ulna
Elongated ankle bone
Two Anuran Mating systems
Explosive breeding
Prolonged breeding
Prolonged breeding
breeding season may extend for several months
Explosive breeding
breeding season is very short
Anuran Vocalizations
Advertisement calls used in courtship and territorial behavior
process in which the male Anuran uses his legs to clasp the female
In most anurans, fertilization is
Axillary amplexus
male Anuran clasps female's pectoral region
Inguinal amplexus
male Anuran clasps female's pelvic region
tadpoles increase in size with little change in form
hind legs appear and growth of the body continues at a slower rate
Metamorphic climax
fore legs emerge and the tail regresses
Gymnophiona Synapamorphys
-Absence of girdle and legs
-Eyes are greatly reduced and sometimes covered by skin or bone
-Annuli - conspicuous dermal folds that reflect body segmentation
-Pair of protrusible tentacles on each side of snout
-Protrusible copulatory organ in males
conspicuous dermal folds that reflect body segmentation
Chytrid Fungi
this is most likely the major cause for population decline and extinction. A fungus that can penetrate the skin of amphibians and interferes with their cutaneous respiration causing the amphibian to die
Anuran Characteristics
tail lost in adults
eyes large and forward on head
toothless dentary
catappult mechanism tongue sticky substance to trap prey
keratinous beaks and denticles on larval mouthparts
Gymnophiona reproduction
internal fertilization by male copulatory organ
25% are oviparous females coil around eggs
75% vivaparous and matrotrophic
Vivaparous matrotrophic gymnophiona
yolk is absorbed first
fetuses scrape the oviduct for uterine milk. other species offspring are born and scrape the mothers outer layer of skin for nutrients
some fetuses have bills terrestrial (branched) aquatic (sacklike)