echinoid

noun 0.615

ooid

noun 0.602

ophiolite

noun 0.551

echinoderm

noun 0.549

nautiloid

noun 0.547

crinoid

noun 0.542

oyster

noun 0.542

opisthobranch

noun 0.540

brachiopod

noun 0.536

osteoid

noun 0.534

ovoid

noun 0.534

opus

noun 0.529

otolith

noun 0.528

isopod

noun 0.527

osteocyte

noun 0.525

xiphoid

noun 0.518

opisthotic

noun 0.518

oolite

noun 0.517

osteo

noun 0.516

ossicle

noun 0.515

oystercatcher

noun 0.514

hydroid

noun 0.512

octopod

noun 0.512

orbitosphenoid

noun 0.511

ornithischian

noun 0.511

brittle star

noun 0.510

osteophytosis

noun 0.509

echinus

noun 0.509

trilobite

noun 0.508

pinnule

noun 0.504

pearl oyster

noun 0.500