Feb 9, 2011 12:07 GMT  ·  By
Deeper footprints have a higher chance of getting fossilized than shallower ones, a new research demonstrates
   Deeper footprints have a higher chance of getting fossilized than shallower ones, a new research demonstrates

For years, experts have been discovering fossilized dinosaur footprints at a wide variety of locations, but these remains appeared to be exclusive. This means that only large prints were found, and no smaller ones. A new research now clarifies the mystery, opening the door for a new interpretation on those ancient habitats.

Because of those discoveries, many paleontologists believed that some habitats were only home to large dinosaurs, and not the smaller species as well. But the new discovery shows that is not the case.

In fact, investigators say, it may be that the only reason why larger footprints remained preserved for millions of years is that they met the necessary conditions to get turned to stone.

It could be for example that the soil on which the animals walked had a density and consistency that only allowed for certain animals to leave their prints behind. Large animals would leave deeper indentations, that would have a lot more chances of getting preserved.

Conversely, smaller creatures would only leave shallow marks, that would wash away at the first serious rain. If this turns out to be true, then it means that scientists severely underestimated the number of animals that lived in a wide range of habitats.

The research was conducted by expert Dr. Peter Falkingham, who holds an appointment at the University of Manchester, in the United Kingdom, Daily Galaxy reports. The main conclusion of the work was that the weight of dinosaurs was the determining factor in their ability to affect the soil.

Larger, heavier animals compressed the soil more, leaving deeper marks that had higher chances of surviving rains. As such, a large footprint may have been treaded on by numerous smaller animals without getting damaged or erased.

Applying the new knowledge – which is somewhat obvious – to famous track sites such as the Paluxy River in Texas, or Fumanya, in Spain, could reveal a population density and biodiversity well beyond what paleontologists first believed.

“By using computer modeling, we were able to recreate the conditions involved when a 30-tonne animal makes a track. That's very hard to do with physical modeling, more so when you need to do it 20 times in 20 different types of mud,” the team leader says.

“But the real advantage of computer modeling is that everything is controllable. We were able to ensure that in every simulation we could look at the effects of each variable (for instance, the shape of the foot, or the weight of the animal) independently,” Falkingham adds.

“Now we can use this 'Goldilocks' effect as a baseline for exploring more complicated factors such as the way dinosaurs moved their legs, or what happens to tracks when a mud is drying out,” he concludes.