apatosaurus vs apatosaur

apatosaurus and apatosaur both are nouns.

Word	Noun	Adjective	Verb	Adverb
apatosaurus	Yes	No	No	No
apatosaur	Yes	No	No	No

As nouns, apatosaurus and apatosaur are synonyms defined as:

apatosaurus and apatosaur: huge quadrupedal herbivorous dinosaur common in North America in the late Jurassic

Other synonyms of apatosaurus include Apatosaurus excelsus, brontosaur, brontosaurus, thunder lizard.

apatosaurus (noun)	apatosaur (noun)
huge quadrupedal herbivorous dinosaur common in North America in the late Jurassic	huge quadrupedal herbivorous dinosaur common in North America in the late Jurassic