Smellyharry, Protozoan's wordplay is synonym of 'name' (verb) around a geological period with its last letter removed.
I thought I'd left it a little late to be attempting to crack this puzzle, but yours was just before this one, so I'm glad I'm kept going!
Thanks to Shark for a tough workout with this wonderfully constructed grid.
Cheers, everyone who posted hints; I didn't Thanks to Shark for a tough workout with this wonderfully constructed grid. them all, but each one I did use helped me to push on to the finishing line.
I still have a couple of queries though…
1 I have five "normal" clues with redundant words. The middle one is the first in the clue but doesn't seem to fit well with the other words. Am I correct?
2 In the final part of the endgame, the letter I've changed is in one of the words of the location which doesn't seem ideal. Is that right?