In the past months, dinosaur tracks dating back 113 million years have been found in Dinosaur Valley State Park in the US state of Texas. It has been announced that these traces, which emerged due to drought, belong to a dinosaur species called “Acrocanthosaurus”.
The dinosaur was estimated to have averaged 5 meters in length and weighed 7 tons. It was a surprise to everyone that these footprints, of which 60 out of 140 were easily seen, did not deteriorate all these years.
So how is it that these traces reach the present day without deteriorating?
As creatures step on a muddy road, the ground under their feet or hands is compressed by the pressure. Footprints can reach several layers. Over time, these footprints fill with tiny pebbles or sand. After a while, the filled places begin to petrify.
Petrified footprints can be preserved for millions of years and people cannot notice them because of the layers on them. That is, until it rises above the ground under the influence of drought.
There are various factors that cause footprints to turn into fossils.
The consistency and density of the ground affects the shape, size and depth of footprints. For a perfect trace, the ground should not be too hard or soft.
If the ground is very hard, the pressure will be indistinct. It doesn’t show details and doesn’t give much information about what the shape looks like. If the ground is too soft, tracks can easily deteriorate or collapse into itself.
What do dinosaur footprints tell us?
The footprints of dinosaurs are also a type of fossil. These traces are evidence of their activity when alive, but they are not part of them. By looking at these tracks, scientists can guess which dinosaur group they belonged to by examining their size and shape. Additionally, they can recognize when they stand on two or all fours.
Archaeologists trying to make assumptions from the traces can make more accurate estimates by considering the geographical location and the age of the surrounding rocks.
- Sources: Natural History Museum, Science Focus, National Park Service.
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