Magus55

Thats the point. Calzaer asked if they were killed by the flood, why weren't there others around those two? Possibly the same reason there wasn't for any other scenario. And do we know there aren't any more fossils in the area? Excavating fossils in a desert doesn't sound like an easy task. I'm sure plenty of fossils were buried even deeper from the constant moving and blowing sand.

Calzaer

I didn't mean "more RIGHT THERE", I meant "more ANYWHERE."

Magus55

Probably because alot of fossils, are either still buried ( like deep in the desert, constantly covered up by drifting sand), or the flood waters destroyed them.

Doubting Didymus

but kept these particular ones in perfect nick?

ps418

First of all, forget sandstorms. Think slumping of oversteepened sand dunes. The sedimentary dynamics or dunes are such that their lee (opposite of windward) slopes are always building up at the steepest possible angle of repose, like 30 degrees or so, and then failing, and then building back up again, then failing again, etc. In fact, one of the processes of dune migration is the constant failure of the lee slope, resulting in a cascade of sand down into the interduen area.

A big dune may be tens of meters high. When its lee slope fails, a large volume of sand is dumped essentially instantly into the interdune valley, burying whatever happens to be there. Here's a plausible scenario. Either due to dinos fighting in the interdune area (the valley between the dunes) or to rain or to wind, the oversteepened dune slumps and buried the interdune area to a depth of a couple of meters or more. I haven't read anything on the sedimentary structures of the Gobi sands these specimens come from, but sedimentary structures in both modern and fossil sand dunes contain abundant evidence of slumping (e.g. Loope et al, 2001).

The process can be enhanced if the sand is moist. Moisture increases the cohesiveness of the sand, allowing the lee slope to become even steeper and thus making the lee slope failure even more dramatic. In these cases, you can actually have a thick sheet of sand slide down the lee slope as a coherent body (e.g. Hunter et al, 1983), burying interdunes areas even more effectively.

Hunter et al, 1983. Storm-controlled oblique dunes of the Oregon Coast. GSA Bulletin 94, 1450-1465.

Loope et al, 2001. Annual monsoon rains recorded by Jurassic dunes. Nature 412, 64 - 66.

Patrick

ps418

Yes, there are other fossils in the same Cretaceous sandstones from Mongolia that show evidence of rapid burial. The most famous example is the Brooding Oviraptor, which is preserved in an avian brooding position sitting directly atop a neatly-arranged, circular clutch of eggs. Which is interesting, since the Cretaceous is placed by most flood geologists at the very end of the flood, and once can only wonder how, even at the very end of the flood, Oviraptors are still walking around on the earth's surface, depositing eggs in nice, circular clutches. . .

Theropod nests

Fossil Oviraptor with Eggs

Patrick