limb, vertebrates, limbs, groups, evolution, fauna, vertebrate, pattern, extinctions, supports, gait, condition, vertebrae, classes, fossils, faunas, families, phylogeny, type, skull, transition, ear, ancestors, skeleton, plan, assemblages, development, vessels, record, ancestor, herbivory, species, girdle, lineage, dish, foot, musculature, footprints, lung, assemblage, skulls, tongue, taxa, bowls, line, history, origins, lineages, group, reptiles, locomotion, structure, bioenergetics, embryos, gaits, trackways, bowl, forelimb, vessel, event, relationships, characters, base, bones, muscles, appendages, heart, diversity, descendants, stapes, trackway, feeding, genera, girdles, ears, eminence, stage, origin, thigh, stem, feet, bladder, prolactins, ribs, embryo, joint, sternum, ancestry, selection, jars, forelimbs, somatotropins, head

primitive, early, earliest, first, devonian, other, terrestrial, typical, ancestral, lower, true, generalized, basal, limbless