Eeob

Front 1

Phylum Hemichordata

Back 1

Arrow worms; not off of Chordata. they are sediment or filter feeders that burrow or make shelters and use probiscis to gather food

Front 2

Phylum Chordata

Back 2

have 5 characteristics. 1) notochord 2. pharyngeal slits 3. endostyle 4. dorsal nerve cord 5. muscular, postanal tail. no vertebrate column or brain. all 5 seen in development

Front 3

Notochord

Back 3

formed by turgid cells inside fibrous sheath. segmented muscles bend it with a pulling motion instead of body shortening which produces undulatory motion for swimming

Front 4

Pharyngeal slits

Back 4

originally used in filter feeding, but later adapted for gas exchange(gill slits)

Front 5

Endostyle

Back 5

primitive version was used to secret mucus to trap particles. vertebrates use the thyroid gland(endostyle) for energy and thermoregulation

Front 6

Dorsal, hollow nerve cord

Back 6

most protosomes have a ventral, solid, paired nerve cord(arthropods)

Front 7

Postanal tail

Back 7

used for locomotion in aquatic environments. used as defense and balance in terrestrial. used for defense and grasping in arboreal(tree)

Front 8

Subphylum Urochordata (tunicates, sea squirts)

Back 8

notochord does not extend to head! suspension feeders(mistaken for sponges). free swimming larvae and becomes sessile as adult. nervous system and notochord degenerate and tunic* surrounds body.

Front 9

Subphylum Cephalochordata (lancelets)

Back 9

notochord does extend to the head! suspension feeders that can swim well and usually lie half buried in the sand. closed CS pumps thru PhyS, segmented trunk muscles, small amount of cephalization.

Front 10

Subphylum Vertebrata (craniates)

Back 10

possess endoskeleton. no molt, but have loss of protection. well developed head, eyes and brain. Key developments: neural crest and ectodermal placodes, cranium & forbrain, senses, CSm myelin sheath

Front 11

Superclass agnatha

Back 11

no jaws

Front 12

superclass myxini (hagfish)

Back 12

only craniates w/out vertebrate. scavengers

Front 13

superclass petromyzontida (lampreys)

Back 13

only vertebrates w/out jaws. parasitize fish

Front 14

gnathostomata

Back 14

all vertebrates except lamprey. they have paired limbs for maneuverability, muscular jaws(gill arches). started arms race

Front 15

Chondrichthyes(carilagenous fish; sharks, rays)

Back 15

bony from mineralized cartilage, replaced w/only a lining of calcified hard tissue(lighter) large livers filled w/oil, and skin covered w/ placoid scales

Front 16

osteichthyes(bony fish)

Back 16

freshwater origin w/ no electrosensative organ. primitive lungs that helped in drying out or low oxygen(became swim bladder). two clades: actinopterygii and sarcopterygii

Front 17

actinopterygii(ray finned)

Back 17

most abundant, extra hox genes, mostly freshwater, most suck in prey

Front 18

sarcopterygii(lobe finned)

Back 18

fins w/ sturdy bones at base*, 1st tetrapods(stocky predators), but still mostly aquatic(tail fin, eyes on top). needed movable neck, sturdier limbs, and connection of limbs to axial skeleton to move to land

Front 19

amphibians

Back 19

mucus gland in skin help reduce water loss, needed lungs to breathe b/c of mucus, metamorphosis common

Front 20

amniotes

Back 20

amniotic egg*, has internal fertilization, skin resistant to water loss, lipids for waterproofing, keratinized scales, ribs & better lungs, longer limbs, strong ankle, large feet