The dinosaur quarry has been excavated since the 1920's. Off the record, the paleontologists exploring the area were led to the site by ranchers who basically knew that the bones weren't from missing cows. Thus, they really didn't care that much.
But the paleontologists were blown away.
After all, they had just stumbled across the densest concentration of Jurassic dinosaur bone ever found. That doesn't happen every day.
Mapping wasn't very good back then; in fact, most of them just wanted to mount a dinosaur.
The years went by, and the quarry was picked over on and off both by professionals and amateurs. Then one day, the excavation was picked up by Stokes (from Princeton University) picked up the project, actually kind of wanting to figure out what happened at the site. Realizing the amount of work that needed to go into the project, he started the Cooperative Dinosaur Project, saying that any museum or university that sent help or money would receive a mountable dinosaur.
Though he held on to bones that had interesting pathology and were needed for research, what he did had legal issues. You see, this was in the later 30's and early 40's. There were actually some laws about fossils in place at this point. And basically, he was selling dinosaur bones. That's actually kind of (by kind of, I mean IS) illegal. Except that everyone was getting dinosaur bones, so no one was going to call him out on it.So more information was lost.
Finally the 60's rolled around, and people at least made attempts at decent collecting and mapping at this point. Because now they were kind of curious about what had happened.
After all, now everyone had an allosaur. No one else just wanted dinosaurs for the sake of having dinosaurs.
So the hypotheses started to form. Today there are about five based on what data we do have, and all are both supported and countered by information we find here.
DATA!
1. There's a ridiculously high predator-prey ratio. Basically, there are about two allosaurs of every three dinosaurs found.... and a grand total of 90% predators.2. There is a relatively high diversity of animals.
3. Turtles and crocs are present. No, not shoes.4. No bite marks are on the bones, with only one exception.
5. The animals are buried in siltstone and clay, which alternates between being in layers and mixed.
6. The bones are scattered, but with a small amount of articulation, and in beautiful shape.7. Every age group of allosaur, with the exception of the hatchlings, is present.
8. No plants or pollen are present. That said, that's pretty much true for the entire Morrison Formation...9. One bone was found crushed, implying the ground beneath was hard at one point.
10. The bones don't seem to be in any particular orientation.
Hypothesis 1: DROUGHT!
Droughts bring animals to watering holes. And due to the silt, clay, limestone over the quarry, and turtles and crocodiles, we would think there was at least a little water here. It would attract a wide variety of animals. That said, bones would be trampled, bite marks would be frequent from scavenging, and there would be a much more realistic ratio of predators to prey (like, one predator for every ten prey.) Even when the prey is way bigger than the predator, they need a decent population to continue to survive as a species. Ecology 101.
Hypothesis 2: FLOOD! or at least a riverbed.
Makes sense, right? Instant death, deposition, bones would all land in a low spot, no reason for there to be bite marks.
Or, if it was just a river bed, the animals died, floated down stream, bloated up, and lost bones one at a time as they decomposed.
But again, the ratio is wrong, Plus, the bones would be oriented from the water pushing them in one direction. We see what this SHOULD look like at Dinosaur National Monument. Some of the bones are still articulated, much more so than we have here.
Plus, the experiments that have been done to support this weren't exactly solid. They watched a salt water crocodile decompose in fresh water. Of course it fell apart, the body chemistry is design to be in SALT water...
Ok.... so...
Hypothesis 3: POISONING
The animals died from the water in the lake being bad. Or the plants. Or something.
Again. The ratio is wrong. You have to understand, my ecology background really doesn't like that ratio being wrong.
The bones would be more articulated. And they would be around the shoreline instead of throughout the water.
Plus, show me your chemical evidence. No? ....back to the drawing board...
Hypothesis 4: PREDATOR TRAP!
FINALLY the bizarre ratio is explained. Like at La Brae tar pits, the carnivores way out number the prey because a single prey animal (dead) was enough to attract multiple predators to their death of being stuck in the mud.
One math study suggested that sauropods wouldn't have gotten stuck as easily as therapods because their weight was better spread out, further helping with the weird ratio.
The problem... its just mud. And likely not very much mud. And there should be limbs stuck in the mud upright.
So how did the animals get stuck? We don't have tar here. Or quicksand.
So the mystery continues!
Cast your votes!! Your guess is as good as ours....
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