The Bible reads like Grimm’s Fairy Tales complete with Dragons and Unicorns. These were the beliefs at the time of the Bible’s creation by a backward and ignorant people who were trying to explain their world. Many people try to explain these passages away or ignore them entirely.
The King James Version of the bible is the edition most Christians rely on and study extensively. This version of the bible is full of these references.
I guess the Unicorns and Dragons must not only have not made it on the Ark but were also unlucky enough to never had left any fossil evidence of their existence.