Understanding life through the traces left behind

By Javan Rivera

Dr. Alan Grant and Dr. Ellie Sattler slowly brush sand from around a perfectly preserved Velociraptor skeleton. The bones lie in perfect harmony, aligned as if the dinosaur simply laid down and died, unmoved by the forces of nature.

While it certainly makes for a good scene, the reality of paleontology is far from what is depicted in Hollywood’s “Jurassic Park.” In fact, it’s less about digging up perfectly preserved skeletal structures and more about making informed guesses about what life was like more than 200 million years ago.

This is exactly the type of work University of Utah graduate researcher Tommy Good does on a regular basis. It’s these educated guesses that form a more informed knowledge base than traditional fossils ever could.

Studying in the field of Ichnology, Good’s work revolves around the much more common trace fossils that are scattered around the Nugget Sandstone near Dinosaur National Monument here in Utah.

Trace fossils are simple impressions left by ancient life; including fossilized burrows, track patterns, and occasionally a footprint or two. While this might not seem like much, according to Good, trace fossils are often more informing about the past than traditional fossilized bones could ever be.

“They [trace fossils] give you clues to what could have been there even with the absence of body fossils,” Good said. “Organisms that don’t have bones usually don’t get preserved in the fossil record, but they do leave traces behind.”

So what exactly is Good studying?

For the most part, Nugget Sandstone is filled with small burrow traces and preserved track patterns left behind by 200 million year old invertebrates, such as insects, scorpions and spiders.

Having spent approximately 25 days in the field last year, Good was able to gather and study a number of trace fossils. Even the simplest of these fossils can often shed light on what life was like back then, something Good feels greatly adds to traditional paleontology.

“For all we know those dinosaurs [represented by preserved bones] just laid there until they died,” Good said. “Trace fossils give us an idea about what these creatures did. How they behaved while they were alive. Body fossils are only part of the story.”

Good explained that much can be gleaned from simple traces preserved in stone, but it’s difficult work trying to present findings about creatures that have been dead for hundreds of millions of years. Nonetheless, Good said he enjoys the freedom his field of study offers.

“Working with little more than educated guesses is extremely hard,” Good said. “There are so many animals that have gone extinct that a modern-day analogue may not even exist.”

It’s those modern day analogues that make Good’s work more than just random shots in the dark. Good said he does a lot of reading on modern-day ecology in order to better inform his studies. “The present is key to the past.” That’s the mantra of geology that regularly informs Good’s research.

However it’s not just the present that can inform the past, but the opposite can be true as well. One particular area of research is paleoclimate studies of which Good is interested in publishing.

Good explained that by studying things like the composition of the stone in which the trace fossils were left, he might be able to discern what the environment and even the climate was like. This may not seem like much, but when the possibility of tracking ancient climate change and comparing it to modern day weather patterns, the results could be truly enlightening.

Even beyond the specifics of beneficial findings, Good said he believes Ichnology, and paleontology in general, can act as a gateway for people to understand life, both past and present.

“By understanding and studying ancient life, I think people get a better understanding of life in general and where they come from,” Good said. “The history of life is a fascinating thing.”

With the summer months quickly approaching, Good intends to jump right back into the field to continue the field research he began last year.

Tommy Good standing next to an unnamed set of fossilized burrows in Dinosaur National Monument. Photo taken by Dan Chure.

Good, examining a set of another set of unnamed burrows in Dinosaur National Monument. Photo taken by Dan Chure.

Small synapsid reptile footprint traces found just outside Dinosaur National monument. Photo courtesy of Tommy Good.