Related by context. Frequent words. (Click for all words.) 66 cartilaginous 66 bony plates 62 pectoral fins 59 membranous 59 bird beak 59 outer layer 58 acetabulum 58 forelimb 58 carapace 58 collagen fibers 58 serrations 58 braincase 58 dorsal fin 58 dorsal 58 pectoral fin 57 ventral 57 sepals 57 cartilages 57 oviduct 56 setae 56 striations 56 mouthparts 56 lamina 56 caudal 55 tetrapod 55 fossa 55 transversely 55 hind limbs 55 sclera 55 protrusion 55 waxy substance 55 tubules 54 dorsal fins 54 theropod 54 ellipsoid 54 threadlike 54 morphologically 54 calcaneus 54 glans 54 mottled brown 54 stiffeners 54 hollow tubes 54 synovial 54 maxillary 54 anthers 54 filamentous 53 greenish brown 53 gill 53 glenoid 53 featherless 53 convex 53 armholes 53 rib cages 53 iliac 53 serrated teeth 53 backshell 53 curvatures 53 pelvic bones 53 toothed whales 53 nylon mesh 53 mesoderm 53 hemispherical 53 otolith 52 insulating layer 52 epithelium 52 rhodopsin 52 ovoid 52 flatworms 52 collagen matrix 52 protuberances 52 lobed 52 globular 52 calcareous 52 conjunctiva 52 cuboid 52 snail shells 52 anal canal 52 Xenopus 52 thorax 52 outer shell 51 anatomical structures 51 whorls 51 distal 51 leathery skin 51 baseplate 51 spheroid 51 lowermost 51 ridged 51 occipital 51 crocodilians 51 sea anemones 51 hind limb 51 motile 51 Scar tissue 51 outer membrane 51 forelimbs 51 concave 51 planktonic 51 hydroxyapatite 51 marine invertebrates 51 hourglass shaped