1) Transitional fossil
Found on
https://www.crosswordclues.com/clue/bactritida
The Bactritida form a small order of more or less straight-shelled (orthoconic) cephalopods that first appeared during the Emsian stage of the Devonian period (390 million years ago) and persisted until the Carnian stage of the Triassic period (235 million years ago). They are considered ancestors of the ammonoids, as well as of the coleoids (octo...
Found on
http://en.wikipedia.org/wiki/Bactritida
No exact match found.
