coccygomorph
/ˌkɒksɪˈɡɒmfɔrət/Definitions
1. noun
A fish with a tail resembling a human coccyx (tailbone).
“The unique coccygomorph of the extinct fish species was a key factor in its identification.”
2. noun
An organism with a tailbone-like structure.
“The fossilized coccygomorph of the ancient creature was discovered in the latest excavation.”