Loggerhead turtle and Marine turtle

Loggerhead turtle noun - Very large carnivorous sea turtle; wide-ranging in warm open seas.

Marine turtle and loggerhead turtle are semantically related. In some cases you can use "Marine turtle" instead a noun phrase "Loggerhead turtle".

Marine turtle noun - Any of various large turtles with limbs modified into flippers; widely distributed in warm seas.

Loggerhead turtle and marine turtle are semantically related. Sometimes you can replace phrase "Loggerhead turtle" with "Marine turtle", this phrases are similar.