DEUTEROSTOMES & CHORDATES

Deuterostomia

Group of animals with radial cleavage and anus forming before mouth

Radial cleavage

Embryonic cells divide parallel or perpendicular to axis

Indeterminate cleavage

Cells retain ability to develop into complete organism

Blastopore

Opening formed during gastrulation

Deuterostome development

Blastopore becomes anus, mouth forms second

Echinodermata

Marine animals with spiny skin and internal skeleton

Water vascular system

System used for movement, feeding, and circulation

Tube feet

Structures used for movement and feeding in echinoderms

Hemichordata

Group including acorn worms with simple body plan

Chordata

Group of animals with key developmental features

Notochord

Flexible rod that provides support

Dorsal nerve cord

Hollow nerve cord that develops into CNS

Pharyngeal clefts

Openings used for feeding or respiration

Post-anal tail

Tail extending beyond anus used for movement

Cephalochordata

Lancelets that retain chordate traits as adults

Urochordata

Tunicates that show chordate traits as larvae

Vertebrata

Chordates with a backbone

Hagfish

Jawless marine chordates with no vertebrae

Lampreys

Jawless parasitic chordates

Chondrichthyes

Cartilaginous fish like sharks and rays

Actinopterygii

Ray-finned fish with bony skeletons

Sarcopterygii

Lobe-finned fish with limb-like fins

Tetrapods

Vertebrates with four limbs

Amphibia

Vertebrates that require water for reproduction

Amniotic egg

Egg with membranes that protect embryo on land

Amnion

Membrane that surrounds embryo in fluid

Yolk sac

Membrane that provides nutrients

Allantois

Membrane that stores waste

Chorion

Membrane for gas exchange

Reptilia

Group including reptiles and birds

Ectothermic

Body temperature depends on environment

Mammalia

Animals with hair and mammary glands

Monotremes

Egg-laying mammals

Marsupials

Pouched mammals

Eutherians

Placental mammals