PHYLUM CHORDATAPHYLUM CHORDATA

THREE COMMON CHARACTERISTICSTHREE COMMON CHARACTERISTICS I. NOTOCHORD; a cartilage supportI. NOTOCHORD; a cartilage support rod sometime during development.rod sometime during development.

II. DORSAL NERVE CORD ;central II. DORSAL NERVE CORD ;central nerve or ‘spinal’ cord along the back.nerve or ‘spinal’ cord along the back.

III. PHARYNGEAL GILL SLITS; III. PHARYNGEAL GILL SLITS; Pharynx=throat region, some time Pharynx=throat region, some time

during development (embryo)during development (embryo)

SUBPHYLUM SUBPHYLUM UROCHORDATAUROCHORDATA

CLASS ASCIDIA; Sea squirtsCLASS ASCIDIA; Sea squirts sessile filter feeders on dock floats sessile filter feeders on dock floats

and dock pilings.and dock pilings. CLASS THALIACEA; TunicatesCLASS THALIACEA; Tunicates colonial, sessile and pelagic filter colonial, sessile and pelagic filter

feedersfeeders Salps, pelagic, Salps, pelagic,

transparent barrel shaped filter feeders.transparent barrel shaped filter feeders.

SUBPHYLUM SUBPHYLUM CEPHALOCHORDATACEPHALOCHORDATA

LANCELETS; LANCELETS; Amphioxus, Amphioxus, small small fish like ancestors of vertebrates.fish like ancestors of vertebrates.

Filter feeders living in sandy Filter feeders living in sandy bottoms.bottoms.

SUBPHYLUM VERTEBRATASUBPHYLUM VERTEBRATATHE VERTEBRATESTHE VERTEBRATES

VERTEBRAL COLUMN of VERTEBRAL COLUMN of bone or cartilage.bone or cartilage.

SKULL enclosing brain etc.SKULL enclosing brain etc.

CLASS AGNATHACLASS AGNATHAThe Jawless FishesThe Jawless Fishes

LAMPREYS; salt and LAMPREYS; salt and freshwater parasites on freshwater parasites on other fishes.other fishes.

HAGFISH; deeper water HAGFISH; deeper water scvengers and parasites.scvengers and parasites.

Lamprey