On a glorious spring morning last March, I met a remarkable boy who was so inquisitive and observant that I’m convinced he’ll be the next John Muir or maybe Albert Einstein. It was the first time I’d assisted a hike at Buescher State Park, and I didn’t know what to expect. At the appointed start time, a small family wandered up to the trailhead. Then I feel like I blinked and suddenly a group of about 20 boys and men materialized to join the hike. Benjamin, the hike leader, seemed completely unfazed by this turn of events and proceeded to direct the group down the trail, masterfully keeping everyone engaged with stories of mammals that can be found in the park. Or, I should say, everyone but one boy who kept falling behind because he stopped to look at every little thing. I was the sweep – the last hiker in the group – so I had a chance to talk with him and answer his many questions about plants, birds, rocks…as I tried to nudge him along to keep the group together.
At some point, we saw animal tracks and somehow the conversation turned to dinosaur tracks and dinosaurs. The depth of his knowledge was impressive. He lamented, though, that so many of his friends only knew about T. Rex.
“T. Rex is boring,” he said, “there are so many more dinosaurs out there that are so much cooler! ..and flying reptiles – pterosaurs! And, er, what’s that big pterosaur…um, I think it lived in West Texas….??”
“Quetzalcoatlus?” I offered, dredging up a word I heard in a class maybe 30 years ago. His eyes lit up and I think I made a new best friend with that correct answer. He also told me to be careful when learning about dinosaurs and researching things on the internet.
“Don’t believe everything you see,” he explained. “You have to go to good websites, and make sure the page is backed up with references.” Good advice from a 10-year-old!
That conversation inspired me to do some of my own research into dinosaurs. Here’s some of the highlights and fun facts I found (I’ve included websites so you can read more).
When did dinosaurs live?
Dinosaurs are prehistoric reptiles that appeared about 230 million years ago. They went extinct about 66 million years ago. Most scientists believe that the extinction was triggered by an asteroid impact in the Yucatan. Read more here https://www.history.com/topics/pre-history/dinosaurs-an-introduction and https://ig.utexas.edu/marine-and-tectonics/chicxulub-crater/
Because dinosaur fossils are usually found embedded in rocks, geologists associate dinosaurs with the geologic period in which they lived and in which the rocks were deposited. The “Age of the Dinosaurs” is known as the Mesozoic Era, which is made up of the Triassic (237 – 201 mya), Jurassic (201 – 145 mya), and Cretaceous (145 – 66 mya) Periods. The largest dinosaurs like Tyrannosaurus Rex did not emerge until the Cretaceous. Read more here https://www.thoughtco.com/the-three-ages-of-dinosaurs-1091932
What other plants and animals lived in the Mesozoic Era?
Technically, the word “dinosaur” refers to a group of extinct, meat- or plant-eating reptiles that had hind limbs that extended directly beneath the body. The group included members that lived on land and walked on two or four feet. Dinosaurs had a lot of company back then, including other land animals, marine animals, flying animals, and plants. Read more here https://www.thoughtco.com/the-three-ages-of-dinosaurs-1091932 and https://science.howstuffworks.com/environmental/earth/geology/dinosaur-contemporary.htm
Excerpt from the USGS Geologic Time Spiral
Source: https://pubs.usgs.gov/gip/2008/58/
What did Texas look like in this timeframe?
During the Mesozoic Era, the continents looked very different than they look today. This reconstruction of the land masses that existed at the time is based on a huge amount of scientific research. The red dot is where Bastrop plots on the maps. If you owned land in the area back then, you might have had beachfront property!
The Earth during the Triassic, Jurassic, and Cretaceous Periods
Source: https://dinosaurpictures.org/ancient-earth#240
Would you expect dinosaur fossils in Bastrop or Caldwell County?
No. The surface geology of Bastrop and Caldwell Counties is dominated by rocks of Eocene or younger ages. At about 50 million years old or less, the rocks are too young; they were deposited after the dinosaurs became extinct.
To find evidence of dinosaurs such as bones or tracks, you have to go where the rocks are older; that is, further away from the coast. You don’t have to go far to see evidence of the Age of the Dinosaurs, though. The band of rocks running roughly through San Antonio/Austin and on up to Dallas are of Cretaceous age, and many Cretaceous critters have been discovered. A mosasaur skeleton has been found in Onion Creek in an area east of the Austin-Bergstrom airport, and dinosaur tracks can be seen in Leander, Canyon Lake Gorge, and other areas. Read more here https://www.beg.utexas.edu/geowonders/dinosaur and https://www.bluebonnet.coop/meet-onion-creek-mosasaur
Onion Creek Mosasaur
Ornithopod Tracks (near Leander)
Acrocanthosaurus Tracks in Canyon Lake Gorge
Texas dinosaurs continue to make the news. As a result of last year’s drought, multiple new, well-preserved acrocanthosaurus tracks were discovered in Dinosaur Valley State Park near Glen Rose, Texas (https://www.nbcnews.com/news/us-news/drought-reveals-new-dinosaur-tracks-texas-rcna44533). And just in the last couple of weeks, brand new discoveries have been reported. For the first time, bones of a Jurassic age marine reptile, a plesiosaur, have been documented in Texas (https://www.sciencedaily.com/releases/2023/06/230627191544.htm).
These are exciting times for geologists, paleontologists, and fossil fans of all ages!
By Lila Beckley, LPMN Class of 2023