Earth Science in the News

Footprint Fossils Offer Earliest Evidence of Dinosaurs’ Ancestors

A new report found that the first appearance of the dinosaur lineage appeared 250 million years ago. The newly found fossils are the oldest that have been found anywhere on earth. The information shows that dinosaurs replaced the animals on earth that died from an earlier extinction, preluding their own.

The footprint fossils give the researchers hope that they might find dinosaur bones within the rocks in the areas. Especially because they were all rare. Only 2 percent to 3 percent of the footprints at the sites were to be from these dinosaur cousins, which were far outnumbered by lizards, amphibians and crocodilian reptiles. The evidence provides proof that these dinosaur ancestors are some of the first to be around after the initial extinction. The footprints now allow scientist to create a timeline for dinosaurs’ existence.

This article fits nicely with a topic we just discussed, the Rock Cycle. These fossils could be preserved because the stone was a sedimentary rock. We learned that sedimentary rocks are formed when sediments cement and compacted together. Sometime during this process animals die in the mud. This mud begins to get covered with more sediment. The remains of the animal or plant become trapped in the sediment. Over time with more and more sediment building up the pressure builds and creates a solid hard stone, with the remains preserved in the rock. This preserves the fossils, which allow us to see back into our history. Technology has become so advanced that they can recreate the animal’s life, from basic life patterns to what the creature once looked like and what its closest relatives are.

I thought that this article was interesting because, it brings to light how valuable the rock cycle is to seeing our history. The fact that an animal could get trapped in the mud, a common substance we see all around. Then through the process of the sedimentary rock cycle it was able to preserve the dinosaur for 250 million years. The amazing sedimentary process is allowing us to see our past and what type of animals roamed the earth before us.

http://www.nytimes.com/2010/10/07/science/07dinosaurs.html?_r=1&ref=science

Joe Stinton