Tag Archives: geology

Walking With the Dinosaurs: An Exploration of Dinosaur Ridge

One of my favorite things about working for the Havasi Wilderness Foundation is that they share my love and curiosity of all things wild. These past few weeks have been a whirlwind of travel and adventure for me. From the goliath mountains in Zion National Park to the prehistoric fossils in Morisson Colorado, there has been little time to rest in the presence of such giants.  Follow our upcoming blog and journey together with me through Utah, Colorado, Tulum, Mexico and the ruins of Chichen Itza.


This week’s adventures begin in Morisson, Colorado: home of the Dinosaur Ridge National Natural Landmark. Located west of Denver and approximately 1 mile from the acclaimed Red Rock Amphitheater, Dinosaur Ridge is one of the world’s most celebrated fossil districts.

Just off of highway C-470, a sign advertising dinosaur footprints caught my eye.  The dinosaur-lover in me prompted a mission to explore the area more thoroughly. The visitor center offered my partner and I a free map and told us that we could either pay to be driven up the mountain or climb it ourselves. Welcoming the opportunity to stretch our legs, we chose the latter.  I was met with a seemingly inconspicuous road and a slow incline of dirt-colored rock that betrayed none of its priceless contents at first glance. As I began the journey up a steep, paved path, my gaze slid over a patch of rock that rippled with a ribboned pattern.  A nearby sign indicated that lines were an impression of preserved microbial mats in which microorganisms turned the sediment layers found in the supratidal zone into spongy, pock-marked mats on the ocean floor.  According to the park, some form of rapid burial helped preserve the wavy shape of the microbial mat while millions of years hardened the sand into stone.  I swung around to study the incline of the mountain on which I stood and paused to reflect on its past-life as an ocean floor.

Microbial mat at Dinosaur Ridge. Photo Credit: Lola West.

Microbial mat at Dinosaur Ridge. Photo Credit: Lola West.

My eyes traveled across the rock to an imprint larger than my head. The deep three-pronged grove was smooth, shaded in black and reminded me of the mark a seagull makes as it walks across wet sand.  I turned to a posted sign nearby and discovered that the print was likely made by an an ostrich-sized carnivore like Ornithomimus.

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Alongside this print were more than 330 other prints comprising 37 different trackways. A trackway is a succession of prints made by an individual dinosaur. In addition to the bird-like three-pronged print, I saw a more bulbous print made by an herbivorous duck-billed dinosaur such as an Iguanodon. Each of the dinosaurs lived in the Cretaceous period (145.0 million to 66 million years ago).

There are over 37 different trackways at Dinosaur ridge.

There are over 37 different trackways at Dinosaur ridge.

Ornithomimus fossil

Ornithomimus fossil

 

While fossils tell the stories behind the way that dinosaurs died, the tracks reveal important information about the way they lived. Colorado has been a hub of dinosaur exploration since 1877, when Arthur Lakes, a professor at the Colorado School of Mines, spotted an enormous vertebra embedded in a block of sandstone at Dinosaur Ridge.

As I came to the middle of the rock exhibition, I noticed the layers of rock beginning to peel away. The sign posted implored us to look closely at deep scars hewn into the surface of the stony landscape.  I studied the scars and a 45 million-year-old story began to take shape.  In contrast to the dinosaur footprints the scars on this rock were jagged and long and took the appearance of being scratched from a large, clawed animal. The Deinosuchus was far larger than any modern crocodile or alligator and at 35 feet, this apex predator was likely capable of hunting large dinosaurs. As the crocodile passed its body through the shallow waters of the prehistoric marine environment, it pressed its claws deep into the sand leaving behind an enchanting story.

Prehistoric crocodile markings. photo credit: Lola West

Prehistoric crocodile markings.
photo credit: Lola West

Prehistoric Crocodile

Prehistoric Crocodile

 

How were these prints preserved?

Though now a sprawling mountainside, Dinosaur Ridge was once an area of marshlands located near a beach. The topography of the marshlands was composed of thick layers of mud-covered sand. As dinosaurs and crocodiles walked through the mud, their prints were depressed into the sandy layers below the mud. The mud hardened into mudstone and millions of years of erosion eventually exposed the sandstone layer that maintained the shape of the footprints. Since Colorado experiences all four seasons, these prints are often exposed to unkind weather conditions. Each time snow covers the prints and melts away it endangers the print itself. In 2010, the community surrounding the Dinosaur National Monument began a campaign to protect and preserve these precious pieces of our prehistoric puzzle.

 

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