"...maybe an alternate geology where dwarf dinosaurs survive on an island not far north of Antarctica?" I've been thinking about what it would take to get some dino survival (after having watched the entire "When Dinosaurs Ruled" series on TLC this last week).

First of all, forget big sauropods, carnosaurs, or hadrosaurs. Ceratopsians are right out. In fact, forget anything larger than about 150-200 pounds, max. The effects of the impact at Chicxulub made it almost given that if you were big, you - in some way - starved to death before it was all over (assuming you survived the impact in the first place, of course). In fact, 200 pounds is probably stretching it: I'd expect survival more in the 20-50 pound range, at best - which seems to be a limited number of dinosaur types.

Forget plant eaters. Even the small ones are going to have it rough finding food what with the mix of impact fires, acid rain, six months of darkness, a major "cold snap" followed by a major heat wave. You'll want something that can survive on what's around for the next couple of years - which will be dead bodies, bugs, and even smaller animals that live off the first two (read: lizards and mammals).

You can begin to understand why birds survived, but not their larger cousins.

Thirdly, we'll want our dinos as far away from Chicxulub as we can get them. Given the location of the continents at the time, this would be somewhere in Antarctica/Australia or India. Islands are right out, as there will be worldwide tsunamis pretty much flooding most of those.

So what have we got. We've got the possibility of a few small species, dog-size and under, surviving the K/T event in Australia and/or Antarctica (I think there's still a connection between the two 65 mybp) and maybe India. India's probably a loss, though, just too much competition from all the other Eurasian animals.

(Farther from there and closer to Chicxulub, you get the survival of similar, but even smaller species. Almost certainly, OTL, all those niches were taken up by birds - we'll assume it holds true on this ATL too)

In fact, it's possible that there was some localized survival of small dinos of this type on OTL - the birds did it after all - and that they were later (within a million or so years) replaced by mammals/birds/reptiles, leaving little palentological trace. Individual species of dinosaurs had gone extinct all the time - it's just this time, they'd be the last.

But on this ATL the dice fall the other way.

Let's call our primary species here a survivaraptor. It's a small coelurosaur-like dinosaur, about fifteen to twenty-five pounds in weight. It's primarily carnivorous, but sees nothing wrong with the occasional egg, cockroach, or rotting lizard. When pushed, it'll even eat fruits, but it's not really adapted to this very well.

Our POD here is a mother survivarapter winning its tug of war with the a bird over a "possum," rather than losing as on OTL. It goes on to feed its current nestlings and have lots more before the crocodile gets it a few year later.

Her children, however, live up to their name "survivaraptors" and do just that: Survive.

And as the millennium role by, they begin to radiate into new niches and grow larger, just like their 200 my distant ancestors did. By 55 mybp, they've developed into a number of medium to large bipedal carnivores in Australia, much like birds did in the Americas. In fact, except for the teeth and arms, they probably look much like the "Terror Birds" of the Americas. There are also a larger number of small to medium omnivores roaming the pre-Outback.

Ten million years after that, and we get the development of some cow-sized herbivores, which eventually push what would have been the larger kangaroos out of the picture.

Over the next 45 million years till the present, they expand into most niches on the continent. Mammals are once again relegated to their smaller roles. Flight, however, remains a providence of birds and (somewhat later) bats, though a few gliding species of "Australiosaurs" develop. Crocodilians - and later cetacea and seals - prevent any real push towards aquatic living except for one small diving insectivore that pushes the last of the monotremes to extinction.

And when man arrives in Australia, he finds a world of where the medium to large animals are dinosaurs, rather than weird pouched-mammals. Oh, they'll only resemble pre-K-T dinosaurs in the same way that modern mammals resemble, say, those in the Eocene.

But they'll be dinosaurs.

---