Key Evolutionary Traits

Land plants

Protected embryo; adaptations to terrestrial life

Nonvascular Plants

No vascular tissue; gametophyte dominant

Vascular Plants

Vascular tissue; lignin

Seedless vascular plants

Vascular tissue; sporophyte dominant; no seeds/pollen

Seed Plants

Seeds; pollen

Gymnosperms

Seeds; pollen; naked seeds

Angiosperms

Flowers; fruits; double fertilization

Animals

Multicellularity; heterotrophy; extracellular matrix (collagen)

Porifera

No true tissues; choanocytes

Ctenophora

Comb rows of fused cilia (ctenes)

Cnidaria

Cnidocytes (stinging cells)

Bilateria

Bilateral symmetry; three germ layers

Protosomes

Blastopore becomes mouth

Deuterosomes

Blastopore becomes anus

Ecdysozoa

Cuticle; molting (ecdysis)

Arthropoda

Chitinous exoskeleton; jointed appendages; segmentation

Mollusca

Mantle; muscular foot; visceral mass

Annelida

Segmentation; many have chaetae

Echinodermata

Water vascular system; adult pentaradial symmetry; CaCO3 endoskeleton

Chordata

Notochord; dorsal hollow nerve cord; pharyngeal slits/pouches; post-anal tail

Vertebrata

Vertebral column; cranium

Jawed vertebrates

Jaws

Bony Vertebrates

Internal bony skeleton

Tetrapoda

Four limbs with digits

Amniota

Amniotic egg

Mammalia

Hair/fur; mammary glands; endothermy

Aves

Feathers; endothermy

Reptilia

Keratinized epidermal scales