ridley vs sea turtle

ridley and sea turtle both are nouns.

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

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

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

Other hypernyms of ridley include marine turtle.

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