"Rhipidistians" Natural Recordings by Native Speakers
I couldn't find any information on the term "rhipidistians". It's possible that it's a misspelling, a made-up word, or a term from a very obscure or specialized context.
However, I did find a term "Rhipidistia", which is a group of ancient, armored fish that existed around 420-360 million years ago during the Devonian period. They were characterized by their ornamented scales and armor plates.