Let's meet these fossils (and their less colossal modern cousins)

The capybara's now the largest rodent on the planet

But Earth once housed a mighty mouse ten times more titanic

With twelve inch long incisors - J. monesi wins the prize

It truly was a rodent of a most unusual size

You think this hog is homely? Well you better brace yourself!

Cause here's a hippo relative they call the pig from hell

As burly as a big bad wolf, with emphasis on big

The Daeodon had all the strength of thirty little pigs

The wombat is Australian. It has a rock-hard rear

In combat with its ancient kin it wouldn't win, I fear

Both wonders from down under raised their young inside of pouches

But only one marsupial is bigger than most couches.

Behold the crafty crocodile complete with toothy grin

Now see a Sarcosuchus smile — five feet from cheek to chin

And speaking of dentition this big shark's name means big teeth

So it's "now extinct" condition should be a huge relief

If sloth's a sin then someone hurry up and call a priest

Cause here's a Megatherium - four tons of sloth, at least.

With jumbo tongue, colossal claws, and tail braced on the ground

It grazed for leaves high in the trees where modern sloths are found

The rhino you and I know weighs at least a couple tons

But if you dare — compare a Paraceratherium

The largest vegetarian you'd ever care to see

It was hornless and quite harmless ... unless you were a tree

And that's just the beginning. There's more — I could go on!

Stupendous Stupendemys! Don't forget Procoptodon!

The armoured Doedicorus! Meganeura's foot long wings!

The plus sized penguin from Peru they call the Water King!

But there's one beast that bests them all, in fact it breaks the scale:

Balaenoptera musculus. It's common name? Blue whale!

Four hundred thousand pounds - the largest creature known to science

And so today we still can say we share the earth with giants