释义 |
palaeo·spondylus \| ̷ ̷ ̷ ̷ ̷ ̷+\ noun Usage: capitalized Etymology: New Latin, from pale- + -spondylus : a genus of extinct primitive vertebrates that are known from a single form (P. gunni) of the Devonian of Scotland that is usually about one inch long with a large skull, branchial arches and jaws highly modified or possibly absent, a segmented vertebral column, and the caudal fin and limb girdles well-developed, and that is usually placed among the Placodermi but sometimes considered a cyclostome — see cycliae |