chapter 28 vertebrates - in class

3 chordate subphyla

1. urochordata (tunicates)

2. cephalochordata (lancelets)

3. vertebrata - fishes, amphibians, reptiles, birds, mammals

urochordata (chordates) species

tunicates

cephalochordata (chordates) species

lancelets

vertebrata (chordates) species

fishes, amphibians, reptiles, birds, mammals

tunicates (urochordata) (chordates)

• larvae vs adults - possess chordate characteristics only as larvae

• adults are sessile

• most use pharyngeal slits for filter feeding

lancelets (cephalochordata) (chordates)

retain chordate features throughout life

most chordates are…

vertebrates

vertebrates vs. other chordates

• vertebral column - cartilage

  • replaces notochord

  • encloses dorsal nerve chord

• endoskeleton

• head with skull

endoskeleton

an internal structural frame—typically made of bone and cartilage—that supports an animal's body from the inside and is overlaid by soft tissues and skin.

exoskeleton

an external biological skeleton in animals

fishes are the…

earliest vertebrates

fish 5 characteristics

1. vertebral column with skull (partial in hagfish and lampreys)

2. jaws and paired appendages - not in lampreys or hagfish

3. internal gills

4. single-loop blood circulation - heart—> gills——> body

5. nutritional deficiencies - certain amino acids

hagfish (chordates)

• lack jaws and paired appendages

• partial vertebral column with skull

• predators and scavengers with slime

lampreys

• partial vertebral column with skull

• lack jaws and paired appendages

• parasites

jaws evolved from…

anterior gill arches

• teeth - scales

• sharks were the first vertebrates to have teeth

chondrichthyes (cartilaginous fishes)

• became dominant predators during the Carboniferous

• sharks, skates, and rays

• mostly predators and scavengers

• skeleton - calcified cartilage strengthened by calcium carbonate granules

  • shark teeth modified scales, so not embedded in jaw

    • easily lost and replaces

sharks and fishes

• have a lateral line system

• canal with sensors that detect water movement and pressure

• also usually electroreceptors (also some aquatic amphibians)

vertebrates so far

• jawless fishes

• cartilaginous fishes

• bony fishes

  • bony fishes evolved around the same time as Chondrichthyes, but have a bony skeleton

swim bladders

• allow bony fishes to regulate their buoyancy

• some fill the swim bladder by gulping air

• some fill the swim bladder by secreting gasses to and from the blood

• the operculum allows most bony fishes to move water over the gills while stationary

• operculum - a protective, door-like, or flap-like anatomical structure

• bone fishes were the most direct ancestor of the tetrapods

  • limbs derived from fins

  • lungs developed from swim bladder

operculum

a protective, door-like, or flap-like anatomical structure

amphibians

• the first vertebrates to walk on land

  • moist habitats - eggs and aquatic larvae

amphibians five distinguishing features

1. legs - adaptation to life on land

2. often both lungs

3. cutaneous respiration

4. pulmonary veins

5. 3 chambered heart, double circulation, 2 circuits

double circulation

a circulatory pattern in birds and mammals where blood passes through the heart twice during each complete circuit of the body, traveling through two separate pathways: the pulmonary circuit and the systemic circuit

single loop circulation

a type of blood flow system where blood passes through the heart only once during each complete circuit of the body

3 modern amphibian orders

1. anura (frogs and toads)

2. caudata

3. apoda (caecilians

frogs (order anura)

• long legs

• smooth, moist skin,

• mostly near or in water

toads (order anura)

• short legs

• bumpy, dry skin

• drier environments

frogs and toads shared characteristics

• no tails

• legs modified for jumping

• external fertilization

• lay their eggs in water primarily because their eggs lack a hard, protective shell and would quickly dry out and die on land

• tadpole - swimming larvae form

• gradual metamorphis

order caudata

• caudates

• lay eggs

• larvae vs adult

  • body - Caudata (salamanders and newts) larvae feature prominent external feathery gills, gill slits, and a caudal fin (tail fin) for aquatic respiration and swimming, whereas adults typically lose gills and fins and develop lungs, limbs, and terrestrial or semi-aquatic bodies

  • respiration - gills as larvae, lungs as adults

  • aquatic/terrestrial - larvae are aquatic, gilled juveniles, while adults are typically semi-aquatic or terrestrial

  • food - drastically shifts

caudata species

salamanders and newts

order apoda (caecilians)

• tropical, burrowing amphibians

• legless, tiny eyes and jaws with teeth

• fertilization is internal

amniotes 3 key features

• waterproof amniotic eggs

• dry skin

• thoracic breathing

endothermy

he ability of an animal to generate and control its own body heat from the inside through metabolism

ectothermy

an organism—often called "cold-blooded"—that relies on external environmental heat sources rather than internal metabolic processes to regulate its body temperature

the amniotic egg

• 4 membranes

• fertilization

• what prevents dessication?

amniotes can be classified by an anatomical feature

• synapsids (1 hole behind the eye) - mammals

• diapsids (2 holes behind the eye) - reptiles, birds

• anapsids (0 holes behind the eye) - turtles

synapsids

• (1 hole behind the eye) - mammals

diapsids

(2 holes behind the eye) - reptiles, birds

anapsids

(0 holes behind the eye) - turtles

reptiles

• ectothermic

• circulation

  • double loop

  • heart with septum

order chelonia (reptiles)

• shell

• turtles vs tortoises -

  • turtles - mostly live in water, omnivores

  • tortoises - live on land, herbivores

• no teeth, sharp beaks instead

all reptilia orders

1. chelonia

2. squamata

3. rhynchocephalia

4. crocodilians

order squamata (reptilia)

lizards and snakes

order rhynchocephalia (reptilia)

• only on islands near New Zealand

• about 3 feet long

order crocodilians (reptilia)

• typically nocturnal

• tropical and subtropical

• 4 chambered heart

• alligators. - only two species

• eyes on top of head and nostrils on tip of snout for hunting

class aves (amniotes)

• most diverse of terrestrial vertebrates

• retain amniotic eggs and scales on legs

• no teeth

• adaptations that facilitate flight

  • no urinary bladder

  • wings and feathers for insulationn

  • thin, hollow bones

  • endothermic

  • efficient respiration, rapid metabolism

mammals (amniotes)

amniotes that have hair and produce milk

• endothermic

• efficient respiratory and circulatory systems

  • 4 chambered heart

  • respiration using diaphragm

• derived characteristics

  • milk and hair

  • differentiated teeth

2 subclasses of mammals

1. monotermes

2. viviparous mammals

   1. marsupials or pouched mammals

   2. placental mammals

viviparous

organisms that give birth to live young that develop inside the body of the female parent,

monotremes

• lay eggs (shared by reptiles)

• 1 species of platypus, 4 species of echidnas

• only in Australia and New Guinea

• like reptiles

  • shelled eggs

  • cloaca

• lacks well developed nipples

marsupials and placental mammals

• derived characters of marsupials and placental mammals not in monotremes

  • nipples

  • live birth (viviparity)

  • placenta

• birth stage

• Australia, Americas

primates traits

• have binocular vision and grasping hands

• aboreal insectivore - an animal that lives primarily in trees (arboreal) and feeds mainly on insects and other small arthropods (insectivore).

primates

• lemurs, lorises, and tarsiers

• anthropods - monkeys, apes, humans

• hominids - apes and humansw

• hominins - bipedal