Showing posts with label Allosaurus. Show all posts
Showing posts with label Allosaurus. Show all posts

Wednesday, July 17, 2024

Unearthing Ancient Fossils: A Reflection on the Giants in My Life

By Steven Wade Veatch

I remember a scorching summer afternoon in 1992, when, with my new wife Shelly and mother-in-law Karen, I walked on a trail that meandered down the hill known as Cope’s Nipple—named after the 19th-century paleontologist who explored this site for dinosaur bones. People refer to the area as Garden Park, and it is located a few miles north of Cañon City, Colorado. 

With my mother-in-law in tow, I took the lead and attempted to be on my best behavior. She was visiting us from Interlochen, Michigan. As we walked, her presence loomed over me, casting a shadow that seemed to stretch endlessly. The air was heavy with her silent intensity, making the surroundings feel eerily quiet. I imagined a pleasing scent in the air. It reminded me of my mother-in-law's garden in Michigan. This added a mysterious touch to the atmosphere. It felt as if every step we took was heavy, as if her presence alone had a gravitational pull. My thoughts went back and forth between making a good impression on her and conjuring in my mind—since we were walking on a dinosaur graveyard—a spike-tailed Stegosaurus defending himself from an Allosaurus.

Depiction of an Allosaurs prowling about in Garden Park
during the Jurassic Period. AI generated image.

As I walked through this area, memories flooded back from two years before when I had explored it with a friend. As we made our way up a hill on that sunny day my friend and I unexpectedly came across a hilltop ornamented with an abundance of petrified wood. The sight was mesmerizing, with the hill covered in these ancient, hardened remains of trees. The wood appeared as if frozen in time, its intricate patterns and textures on full display. The crisp sound of our footsteps echoed through the stillness of the hilltop, adding an eerie ambiance to the scene. A faint scent of earthiness lingered in the air, reminding us of the long history embedded in these petrified remains. As we gently touched the wood, a cool, smooth sensation greeted our fingertips, connecting us to the past. We were the first ones to see all of this petrified wood. If someone had been there before us, all the wood would probably have been taken.

Shelly and Karen kept up with me as we continued to descend Cope’s Nipple. The scorching sun baked everything in a relentless heat. While we were going down a gentle slope, Shelly and Karen talked about how different this landscape was than the woodlands and humid air of northern Michigan. Shelly vividly recounted to her mother the harrowing encounter she had had a year before, when a venomous rattlesnake unexpectedly lunged at her on an earlier trip here. She urged her mother to remain vigilant and attentive while going down the pathway.

It was the hottest part of the day as we continued to walk along the trail that now cut through a dark-red disintegrated siltstone, part of the world-famous Jurassic-age Morrison Formation. Insects buzzed under an intense Colorado blue sky. A scorpion scurried with a quick dart beneath a cracked slab of siltstone, its jagged edges leaning against a smooth cobble of quartz. Time seemed to slow down in the heat, and seconds lingered in the dry air. 

I had been here in the spring of 1991 with a prospector buddy. On that day, while ascending a ravine, we stumbled upon huge heaps of bentonite clay. It had rained the night before, and the clay had swollen up to five times its normal size. Nodules of a lilac-purple St. Stephen’s agate were bulging out of the swollen, wet clay. I crawled up the side of a clay mound and plucked out one of these agates. As I held it to the sunlight to see the concentric layers inside, I slipped and slid down the slick clay on my backside. Wet, cement-like clay covered my back to my head. There was no way to wash it off, and it was solidifying in the arid air. My wife had a lot to say about this when I returned home. She also wanted to see this place, Garden Park, the next time I went.

Now my adventure with my wife and mother-in-law heated up. The dirt-covered path, lined by piñon pine, was in the middle of a dinosaur graveyard and was under the protection of the Bureau of Land Management—no fossil collecting allowed. I couldn’t imagine dinosaurs once ruled this dry, semi-arid land covered with yucca and cactus. As we walked along the trail Shelly’s voice poked into my consciousness. She had just bent down to pick something up from the side of the path. She was describing it to her mother: “It’s cone-shaped with a subtle curve. It has a pointed end.” She continued, “The other part of this is not pointed. There is a serrated edge.” The word SERRATED thundered across my consciousness. I asked her if I could see it. She handed it to me. I knew at once she had stumbled upon an extraordinary find—a pristine Allosaurus tooth, a relic from a formidable dinosaur that once reigned supreme in Garden Park’s prehistoric ecosystem. The ancient fossil, with its sharp edges and intricate ridges, exuded a sense of raw power. As I held it in my hand, I could feel the weight of its history, imagining the ferocious battles it had fought. The sight of the tooth gleaming in the sunlight transported all of us back to a time when mighty dinosaurs roamed the land. The faint scent of earth and ancient fossils lingered in the air, arousing a sense of awe and excitement. 

It was now time to finish the hike. We left the hotter, drier landscape for a riparian environment. Four Mile Creek greeted us as it sliced its way through a scenic valley adorned with cascading layers of limestone, siltstone, and sandstone. The gentle sound of flowing water filled the air, harmonizing with the rustling of cottonwood leaves along the creek bank. The earthy scent of wet soil along the stream mingled with the refreshing aroma of the nearby vegetation. As we stood there, we couldn’t help but feel a sense of awe and wonder at the natural beauty surrounding us. 

The day changed, it shifted into something new. Shelly’ discovery was important. You don’t find an Allosaurus tooth every day. My mother-in-law had a breakthrough in how she thought about me. She enjoyed our day together and listening to me talking about a vanished ecosystem filled with dinosaurs.

And I discovered how fortunate I was to have these two women in my life.


Saturday, November 19, 2016

Stegosaurus: Colorado’s State Fossil


By Destin Bogart, guest blogger

As the state dinosaur of Colorado and one of the most iconic members of Dinosauria, Stegosaurus has earned this spot due to its fascinating history and its large number of fossil remains that allow paleontologists to understand more about Stegosaurus than other dinosaur genera that have a more fragmentary fossil record.

The first remains of Stegosaurus were uncovered during a period in the late 1870s known as, “The Bone Wars,” which intensified the collection efforts between two rival paleontologists—Othniel Charles Marsh and Edward Drinker Cope. Marsh initially discovered Stegosaurus in 1877 near Morrison, Colorado. Marsh first thought those remains belonged to a turtle-like animal, but soon revised this finding as more Stegosaurus fossils were unearthed.

O.C. Marsh's 1891 illustration of Stegosaurus ungulatus
Paleontologists now place the arrangement of the back 
plates in two alternating rows and oriented vertically. 
Copyright: public domain.
The largest Stegosaurus could stand four meters (12 feet) high at the tallest back plate and could reach lengths of up to nine meters (~30 feet). But the size alone is not what sets Stegosaurus apart from the other animals it shared its ecosystem with; rather the plates that line the spine of Stegosaurus make this dinosaur recognizable to everyone. Yet the plates remain an enigma; paleontologists have put forth many theories regarding how the plates are positioned. When Othniel Marsh first found the remains, he thought the plates lay flat against the body like the armor of a Pangolin (looks like a scaly anteater).

Through the years, paleontologists have refined the theory regarding the exact configuration of these plates, which went from two lines of identical plates on the back, to one row of plates that alternate. Scientists now place the arrangement of the back plates in two alternating rows and oriented vertically.

Stegosaurus stenops from the Late Jurassic of North America, 
pencil drawing by Nobu Tamura. Copywrite: Image license through the 
courtesy of Creative Commons.
What these plates were used for is still up for debate and has remained so since the animal’s discovery. Robert Bakker, a world-renowned paleontologist and curator of the Houston Museum of Nature and Science, speculates the plates of Stegosaurus were the inside, or core, of a bigger plate made of keratinous material. Bakker also suggests these plates were semi-movable and the animal used them as a defense, splaying them out to the sides to deter predators from coming too close. Other scientists have claimed the back plates were used to attract a mate or to control body temperature.

Even if the plates of Stegosaurus were not used for defense, Stegosaurus carried with it four spike-like osteoderms (bone embedded in the skin) on the end of its tail. These spikes (informally called thagomizers) bent out to the sides and backward and were likely an incredible defense against many large predators of the Morrison Formation. 

In 2014, Robert Bakker found a large open hole in the lower-front portion of the pelvis of a mounted Allosaurus skeleton at the Glenrock Paleontological Museum. The hole fits the tail spike of a Stegosaurus. This is evidence of just how formidable the tail of a Stegosaurus was as a defensive weapon when it struck the crotch of an Allosaurus. Evidence suggests bacteria, broken bone, and other debris remained in the wound, causing an infection that eventually killed the animal. According to Robert Bakker, “A massive infection ate away a baseball-sized sector of the bone, probably this infection spread upwards into the soft tissue attached here, the thigh muscles and adjacent intestines and reproductive organs.” 

The brain of Stegosaurus, although not quite walnut-sized, was unusually small compared to its body mass. So far, Stegosaurs claims the smallest brain size to body mass of any other dinosaur. This small brain presented a problem—how could it survive without more intelligence? It seems the large plates on its back and the spikes of its thagomizer were keys to its survival against predators. Also, Stegosaurs behavior played a role. Paleontologist Matthew Mossbrucker discovered in 2007, footprints of adult, juvenile, and hatchling specimens in the Morrison Formation that suggest Stegosaurs stayed together in small groups, most likely for protection against predators. 

Stegosaurus is the rhinoceros of the Late Jurassic as it was both an herbivore and highly dangerous to anything it perceived as a threat. Stegosaurus died out near the end of the Jurassic, leaving only fossils and footprints as a reminder of its existence. However, paleontologists can, using fossils and a little bit of educated guesswork, begin to understand how this animal behaved, how it lived, and how it died.

Author’s Bio: Destin Bogart is 16 years old and ever since he can remember he has had a passion for paleontology. He is an Earth Science Scholar with the Colorado Springs Mineralogical Society and is a junior IB World Student at Pueblo West High School. Destin is planning a career in vertebrate paleobiology.







References:

Castro, Joseph. "Stegosaurus: Bony Plates & Tiny Brain." LiveScience. Purch, 08 Dec. 2014. Web. 18 June 2015.

Holtz, Thomas R. Jr. (2012) Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages, Winter 2011 Appendix.

Lambert, D (1993). The Ultimate Dinosaur Book. Dorling Kindersley, New York. pp. 110–29. ISBN 1-56458-304-X.

Carpenter, K (1998). "Armor of Stegosaurus stenops, and the taphonomic history of a new specimen from Garden Park Colorado". The Upper Jurassic Morrison Formation: An Interdisciplinary Study. Part 1. Modern Geol. 22. pp. 127–44.

Carpenter, K and Galton PM (2001). "Othniel Charles Marsh and the Eight-Spiked Stegosaurus". in Carpenter, Kenneth. The Armored Dinosaurs. Indiana University Press. pp. 76–102. ISBN 0-253-33964-

Pastino, Blake De. "Allosaurus Died from Stegosaur Spike to the Crotch, Wyoming Fossil Shows." Western Digs. Western Digs, 23 Oct. 2014. Web. 20 June 2015.
"Stegosaurus; Colorado State Fossil." State Symbols USA. STATE SYMBOLS USA, n.d. Web. 21 June 2015.

Jacobson, Rebecca. "First Steps of a Baby Stegosaurus, Captured in 3-D." PBS. PBS, 16 July 2014. Web. 22 June 2015.