ankylosaur vs ankylosaurus

ankylosaur and ankylosaurus both are nouns.

Word	Noun	Adjective	Verb	Adverb
ankylosaur	Yes	No	No	No
ankylosaurus	Yes	No	No	No

As nouns, ankylosaur and ankylosaurus are synonyms defined as:

ankylosaur and ankylosaurus: having the back covered with thick bony plates; thought to have walked with a sprawling gait resembling a lizard's

ankylosaur (noun)	ankylosaurus (noun)
having the back covered with thick bony plates; thought to have walked with a sprawling gait resembling a lizard's	having the back covered with thick bony plates; thought to have walked with a sprawling gait resembling a lizard's