dawn horse vs eohippus

dawn horse and eohippus both are nouns.

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

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

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

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