ridley vs marine turtle

ridley and marine turtle both are nouns.

Word	Noun	Adjective	Verb	Adverb
ridley	Yes	No	No	No
marine turtle	Yes	No	No	No

As nouns, marine turtle is a hypernym of ridley; that is, marine turtle is a word with a broader meaning than ridley:

ridley: a marine turtle
marine turtle: any of various large turtles with limbs modified into flippers; widely distributed in warm seas

Other hypernyms of ridley include sea turtle.

ridley (noun)	marine turtle (noun)
a marine turtle	any of various large turtles with limbs modified into flippers; widely distributed in warm seas