arms bumps echinoderms endoskeletons five five arms outer shell pitted rough sea sea creatures sea stars shapes skeleton starfish surface textures tube feet brown burr Castanea chestnut chinkapin chinquapin Fagaceae fruit green grove inner marron nature outer quill quills saavem sativa shell skin sweet texture tree abstract appearance breakable broken calcification calcium calcium-carbonate color colors colour colours cook cooking dried dry egg egg-shells eggs eggshells empty external food fragile fragility fragmentary fragments hard-shelled hollow idiomatic-expressions idioms inside internal leftover leftovers life outer-covering outside oval ovoid Remains scattered scattering speckled surfaces white yolk