What would you ride into battle?

[Ladette]

I already ride a Grue to and from work every day, so i'd go with that.

 

[Harbinger_]

I would ride Sparklelord Kudos to anyone who knows what he's from.

 

[Subbies]

All hail the giant snail. Imagine that the awesomeness of the 50 m tall beast and all that space for eventual equipment.

 

[yunalasca]

Well, I know exactly what I'd charge into battle on.

The Sphinx. Not the mythical creature, the actual monument. All I need are several thousand slaves to cut down thousands of trees in order to move my mount like druids moving parts of Newgrange.

{http://www.esatclear.ie/~holly1/page9.html (Newgrange is the Irish equivalent of Stonehenge, only its about 5000 years older)}

But the thing is if I have enough wealth to ride the Sphinx into battle like some glorious idiot, then it stands to reason I'd have enough money to pay servants to move it for me.
Problem solved.

 

[Lazy Kitty]

Depends on the battle and my mood.

Maybe a dragon, maybe a giant spider...
Maybe something like Tengen Toppa Gurren Lagann...

 

[Mr. Fancy Pants]

T-Rex, duh. What better to make my enemies shit themselves and run?

 

[Flippincrazy]

I'd go with a good old fashioned stallion. And they say the calvary divisions are useless... WELL I'LL SHOW THEM!!!

 

[Hamish Durie]

Chuck norris(sorry coudn't resist)

 

[Marcilla]

A giant armor clad badger. Imagine the awesomeness.

 

[trouble_gum]

Remind me what era those existed because I cant seem to recall it being real.

Call me a picky internetz forum pedant (you'd be right), but the OP at no point stipulated your extinct animal had to be a real extinct animal. Aaaaand, if I recall correctly, there's a passage in Return of The King in which the fell beasts that the Nazgûl ride are described which broadly implies they're dinosaurs. Middle Earth dinosaurs, but dinosaurs nonetheless.

Oh, it's this bit:

"... it was a winged creature: if bird, then greater than all other birds, and it was naked, and neither quill nor feather did it bear, and its vast pinions were as webs of hide between horned fingers; and it stank. A creature of an older world maybe it was ...."

Apparently ole J.R.R also stated that "[it was] obviously ... pterodactylic and owes much [to the] new ... mythology of the 'Prehistoric'...a last survivor of older geological eras."

Thanks, Wikipedia.

Meanwhile, back on the topic...I choose nodocephalosuarus. Plenty of space on that armour plated back for a small commander's tower and a howdah for archers.

Spoiler: It Looks Like This

[img=http://scienceblogs.com/tetrapodzoology/Tarchia%20M.%20Shiraishi.jpg]http://scienceblogs.com/tetrapodzoology/Tarchia%20M.%20Shiraishi.jpg[/img]