Bio III Ch 32

5 major animal lineages

sponges, comb jellies, coral/jellyfish, protosomes, deuterosomes

original classifiction of deuterosomes

important features of embryonic development - anus produced before mouth

what is used now to classify deuterosomes vs protosomes

molecular/DNA - better than embryonic development alone

3 phyla of deuterosomes

Echinodermata, Hemichordata, Chordata

__________ make up over 95% of animals and dominate the deuterostomes

invertabrates

Echinoderms

“spiny-skins” - named for spines or spikes observed in many species

good generalization for echinoderms

all are marine animals - sea stars and sea urchins

how many species of echinoderms have been describes

7000

3 synapomorphies echinoderms as a monophyletic group

• Radial symmetry in adults

• Endoskeleton of calcium carbonate

• Water vascular system and tube feet`

all deuterostomes are _______ symmetric

bilaterally (at some point)

symmetry of echinoderms during larva is _______ during adult is ______

bilateral; pentaradial (5 sided radial symmetry)

where is endoskeleton located in echinoderm

inside thin layer of epidermal tissue

how does endoskeleton form in echinoderm

secretion of calcium carbonate plates inside the skin

echinoderms water vascular system

• Series of branching, fluid-filled tubes and chambers

• Sea water flows in and out of system

tube feet

Elongated fluid-filled appendages of the echinoderm water vascular system consisting of an internal ampulla and an external tube-like podium

5 key lineages of the echinoderms

Crinoidea, Asteroidea, Ophiuroidea, Echinoidea, Holothuroidea

Crinoidea

feather stars and sea lilies

Asteroidea

sea stars

Ophiuroidea

brittle stars and basket stars

Echinoidea

sea urchins and sand dollars

Holothuroidea

sea cucumbers

chordates have these 4 morphological features at some stage

1. Openings into throat called pharyngeal gill slits

2. Dorsal hollow nerve cord that runs the length of body, comprised of projections from neurons

3. Stiff and supportive but flexible rod, called notochord, runs the length of body

4. Muscular post-anal tail

Three Chordate “Subphyla”

Cephalochordates, Urochordates, Vertebrates

Cephalochordates

Small, torpedo shaped animals with “fish-like” appearance

how do Cephalochordates eat

suspension feeders

role of notochord in Cephalochordates

• Stiffens the body

• Muscle contractions on either side result in fishlike movement

tunic

external coat of polysaccharide - Covers and supports body of adult

Urochordates

tunicates

Vertebrates

hagfish, lampreys, sharks and rays, bony fishes, amphibians, mammals, and reptiles (including birds)

Pharyngeal pouches

Structures in vertebrate embryos that develop into gills in aquatic species but not terrestrial species

Dorsal hollow nerve cord

Develops into the spinal cord in vertebrates

Notochord in vertebrates

Structure in all embryos that helps organize the body plan by stimulating somite formation

Somites

Segmented blocks of tissue that develop into vertebrae, ribs, and skeletal muscles

what are the 2 synapomorphies in vertebrates

Vertebrae and cranium

Vertebrae

protects spinal cord

Column of cartilaginous or bony structures

Forms along dorsal side of most species

Cranium

protects brains and sensory organs - Bony, cartilaginous, or fibrous case encloses brain

what to the vertebrae and cranium do together

protect the central nervous system and key sensory structures

The most species-rich and ecologically diverse vertebrates

ray-finned fishes and tetrapods

Ray-finned fishes

Goldfish, tuna, and salmon - Fins supported by bony rods

Tetrapods

Reptiles, amphibians, and mammals - Large herbivores and predators in terrestrial environments

Key innovations in evolution of vertebrates

origin of: cranium, vertebrae, jaw, limb, amniotic egg, lactation and fur

all vertebrates except ______ have jaws

jawless fishes

what did the origin of the jaw allow

mass feeding for carnivores and herbivores

what did limbs evolve from

fins

amniotic egg is a synapomorphy of __________

reptiles and mammals

what is the advantage of the amniotic egg

protective covering minimizes drying out

reptile key innovation

scales and feathers made of keratin

4 major lineages of reptiles

lizards/snakes, turtles, croc/alligators, birds

evolution of flight

convergent evolution in birds, bats, and lizards

3 major lineages of mammals

monotremes, marsupials, placental mammals

montemes

mammals that lay eggs - platypus

marsupials

very immature offspring in pouch - kangaroo, opossum, koala

placental mammals

birth basically mature offspring, human, orangutan

parental care trade off

mammals/birds take care of their offspring with the trade off of fewer offspring

jawless fish

monophyletic group apart of vertebrates - dont have jaws or paired appendages - consist of hagfish and lampreys

jawed fish

sharks and rays, ray finned fishes, coelacanths, lungfishes

sharks and rays

no bones - skeleton is cartilage

ray finned fishes

lungs modified into swim bladder

coelacanths

lobed fins

lungfishes

lobed fins, functional lungs

tetrapods

amphibians - frogs, toads, salamanders, caecilians

most adult amphibians are ______

carnivores

most amphibians go through

metamorphosis