eohippus vs dawn horse

eohippus and dawn horse both are nouns.

Word	Noun	Adjective	Verb	Adverb
eohippus	Yes	No	No	No
dawn horse	Yes	No	No	No

As nouns, eohippus and dawn horse are synonyms defined as:

eohippus and dawn horse: earliest horse; extinct primitive dog-sized four-toed Eocene animal

eohippus (noun)	dawn horse (noun)
earliest horse; extinct primitive dog-sized four-toed Eocene animal	earliest horse; extinct primitive dog-sized four-toed Eocene animal