If you want prehistoric....theres always the Bowfin (Choupique down here in the swamps). Small gape, ferocious fighters and actually not bad eating if you know how to cook them. Every bit as toothy too! And they get quite large.
I'm definitely thinking about these guys.
Shovelnose sturgeon would be a cool "dinosaur" fish to put in a pond. They might kick up some sediment but they would be good for cleaning up the bottom.
These guys are awesome, but do you think it would be possible to sustain a breeding population in a pond? My understanding is that they like flowing water, at least for spawning.
