Before I forget, there's another critter you need to have added to your prehistoric beastie roster. Andrewsarchus is known from a single skull, but according to what we can deduce from that skull it had jaws like nothing else that has ever existed and was the largest mammalian land predator ever.



eta: Please note that 'Ursus maritimus' in the above picture is not an extinct animal. That's the Latin name for polar bears.