Gargoyleosaurus: Beast of the Week

Ever look up at buildings in the city and see monsters carved out of stone that act as rainspouts?  Those are gargoyles.  Gargoyles are interesting because there are really no rules or guidelines for what they are supposed to look like, unlike a lot of other popular monsters.  Well, our dinosaur this week must have inspired something spooky in paleontologists because it is named after these fantastic stone guardians of the night...that also barf rain.  Check out Gargoyleosaurus parkpinorum!

Gargoyleosaurus fending off a group of Allosaurus.  Watercolor by Christopher DiPiazza.

Gargoyleosaurus lived during the Late Jurassic period between 154 to 150 million years ago in what is now Wyoming, USA.  It measured about 10 feet (3 meters) long from snout to tail and would have eaten plants when alive.  It was an ankylosaur, which means it had heavy bone armor all over its body like its more famous relative, Ankylosaurus.  Gargoyleosaurus is one of the oldest known ankylosaurs, having been from the Jurassic, whereas the vast majority of ankylosaurs on the fossil record lived later in the Cretaceous.  When alive, Gargoyleosaurus would have shared its environment with other dinosaurs, like Stegosaurus and Allosaurus.

Gargoyleosaurus skeleton on display at the Denver Museum of Nature and Science.

Gargoyleosaurus had a long, narrow snout and body was adorned with flat, triangular spikes running down each flank.  Most of the armor on its back consisted slightly keeled scutes, with a wide solid plate, called a sacral shield, over the hips.  The tail had some small spikes running down the sides as well, but lacked a bony club at the tip, commonly seen in more popular ankylosaurs.  Later on during the Cretaceous, we can see two distinct kinds of armored dinosaurs, the ankylosaurids, which had short snouts and bony tail clubs, and the nodosaurids, which had longer, narrower snouts, and typically had sharp spiky plates running down their sides with no tail club.  Gargoyleosaurus appears to have be part of the nodosaurid lineage of ankylosaurs, which suggests that nodosaurids appeared first, with the club-tailed ankylosaurids evolving later in the Cretaceous.

That's all for this week!  As always feel free to comment below or on our facebook page!

References

Carpenter, K., Miles, C. and Cloward, K. (1998). "Skull of a Jurassic ankylosaur (Dinosauria)." Nature 393: 782-783.

Foster, J. (2007). "Appendix." Jurassic West: The Dinosaurs of the Morrison Formation and Their World. Indiana University Press. pp. 327-329.

Killbourne, B. and Carpenter, K. (2005). "Redescription of Gargoyleosaurus parkpinorum, a polacanthid ankylosaur from the Upper Jurassic of Albany County, Wyoming". Neues Jahrbuch für Geologie und Paläontologie, 237, 111-160.

Soto-Acuña, Sergio; Vargas, Alexander O.; Kaluza, Jonatan; Leppe, Marcelo A.; Botelho, Joao F.; Palma-Liberona, José; Simon-Gutstein, Carolina; Fernández, Roy A.; Ortiz, Héctor; Milla, Verónica; Aravena, Bárbara (2021). "Bizarre tail weaponry in a transitional ankylosaur from subantarctic Chile". Nature. 600 (7888): 259–263.

Interview with Paleontologist: Evan Johnson-Ransom

Evan Johnson-Ransom is a vertebrate paleontologist, currently enrolled at the University of Chicago for his PhD. He received his Master’s from Oklahoma State University Center for Health Sciences in 2021, and his Bachelor’s from DePaul University in 2018. Evan’s research focuses on the functional morphology and feeding behavior of theropod dinosaurs such as Tyrannosaurus, Allosaurus, and Spinosaurus.

Evan with cast of the skull of Carnotaurus at the Field Museum.

Question 1: What was your earliest sign of interest in paleontology that you can remember?

EJ: I’ve been interested in dinosaurs since I was 2 years old. When I was in preschool I always cried when my mother dropped me off in the morning. She noticed my classmates would console me with dinosaur toys. That year for my birthday and Christmas, my family gave me dinosaur toys and I was quickly enamored by dinosaurs. My grandmother and mother took me to dinosaur museums, in addition to me watching dinosaur documentaries, and reading books about dinosaurs.

Question 2: Did you have anyone who served as a role model when you were younger?  Do you still have any now?

EJ: When I was younger, most of my paleontology role models included Drs. Paul Sereno, Thomas Holtz Jr., Phillip J. Currie, Jack Horner, Mark Norell, Xu Xing, Larry Witmer, and Robert Bakker. These were paleontologists who influenced my paleontology journey, growing up. Upon seeing them in-person at the Society of Vertebrate Paleontology conference, was a “dream come true”. 

Question 3: You primarily work with theropods.  Did you choose them or did they choose you? (in a sense) 

EJ: During my undergraduate, I volunteered at the Field Museum as a docent for Sue the T. rex. Most of my talks with the museum guests included discussing Tyrannosaurus’ biology. Upon reading Dave Hone’s “The Tyrannosaur Chronicles”, I was fascinated with the evolution of tyrannosauroids and their feeding behavior. I always pondered how tyrannosauroids evolved their powerful bite forces from the small Guanlong to the large T.rex. During my Master’s, I became enamored with theropod studies that entailed theropod feeding behavior and bite force mechanics.

Evan with the Tyrannosaurus family at the Los Angeles County Museum of Natural History.

Question 4: Was there anything you did or learned as you were on your way to your current career that you feel got you to where you are?  What sort of field experience, a class, networking with the right people, or possibly something different?

EJ: During my undergraduate, I initially thought of being  a college professor who taught paleontology and evolutionary biology. Upon taking anatomy classes at Oklahoma State University, I started to notice a “connection” with anatomy and my research in dinosaur feeding mechanics. I was fascinated with the muscles that were responsible for the body’s actions such as biting, walking, kicking, etc, in addition to how muscles impact the skeletal performance. After taking anatomy classes, I currently aspire to be an anatomy professor who teaches anatomy to medical students, but relates the anatomy teaching to research in vertebrate paleontology (e.g., feeding and jaw muscle performance in dinosaurs).

Question 5: What would your advice be to anyone trying to make a career in paleontology (or science in general)

EJ: I would advise someone to partake in outreach events such as volunteering at a museum’s exhibits, contacting the museum curators for possible internships, doing volunteer work in the collections, and attending conferences where paleontologists and other scientists present their work. I highly recommend students attend conferences, which serves as an excellent networking opportunity.

Question 6: What was or is your favorite project so far?

EJ: I am currently publishing my Master’s thesis. One of my Master’s thesis projects involves using 3D models of various tyrannosauroid skulls (e.g., T. rex, Gorgosaurus, Alioramus, Yutyrannus, Dilong, and Proceratosaurus) to evaluate the cranial performance and evolution of feeding function in Tyrannosauroidea. This is my favorite project, because this is the first broad comparative study that looks at the evolution of feeding function in various tyrannosauroids, in addition to the incorporation of small, early tyrannosauroids (Dilong and Proceratosaurus). This will offer insight into the evolution of feeding in a dinosaur clade. 

Evan taking measurements from the Allosaurus at the Smithsonian National Museum of Natural History.

Question 7: Do you have a favorite destination when it comes to fossils?  Why?

EJ: I don’t have a particular destination when it comes to fossils. Every fossil locality such as the Hell Creek Formation, Morrison Formation, and the Kem Kem Beds are unique with the fossil taxa that have been discovered. 

Question 8: A popular image of paleontologists is that they are constantly out in the field digging up fossils, which is true sometimes  What people don’t realize is that a lot of paleontology work is conducted in a lab as well.  In your experience how much time have you spend in the lab and in the field?  What do you prefer?

EJ: With fieldwork, paleontologists will travel to a locality that has previously yielded fossils with the goal of recovering fossils and taking them back to the lab to be prepared for further study or exhibition. The fossil preparation takes months to years, depending on the size and number of fossils brought back to the lab. The preparators and paleontologists will examine the prepared dinosaur(s) and evaluate what features it may have in common with other dinosaurs.

I have had previous field experience in Montana (2014), Wyoming (2018), and Alaska (2021). I was in the field for a week. I mostly conduct lab work. The lab work that I conduct involves scanning the skulls of dinosaurs and converting them into 3D models through imaging software. Following this I run computer simulations to evaluate the cranial performance of the dinosaur’s skull when biting. For one dinosaur skull, the process can take about two weeks. The first week is devoted to the scanning and processing the model for biomechanical analyses, and the second week is devoted to using biomechanical simulations on the dinosaur skull. I mostly prefer lab work as opposed to field work.

Evan scanning the skull of Ceratosaurus at the Smithsonian..

Question 9: Are there any fossils you’d like to work with that you haven’t yet?

EJ: While I have worked on fossil fish and dinosaurs, I would like to work on the feeding mechanics of synapsids such as the sail-backed Dimetrodon. I am currently taking a class on Mammal Evolution taught by Drs. Kenneth Angielczyk and Zhe-Xi Luo. Their lecture on the evolution of synapsids made me realize the unique cranial diversity of early synapsids with implications on the evolution of feeding function in Mammalia. 

Dimetrodon grandis

Question 10: Do you ever get criticized on any of your work?  How do you handle it?

EJ: I have not been criticized for any of my work.

Question 11: A common idea is that paleontology is just a “for fun” science, with no real impact or noticeable effect that helps the world.  Do you think paleontology has a bigger part to play to than this?  How?

EJ: Paleontology allows us to understand the evolutionary history of Earth and the animals and plants that inhabited it. Fossils of animals and plants, as well as sedimentary analyses allows us to comprehend the changes Earth went through, in addition to allowing us to infer what future humans may have on Earth. 

Question 12: Who was the first paleontologist you met?  How was that interaction?

EJ: The first paleontologist that I met was Dr. Paul Sereno in 2009. Dr. Sereno was giving a presentation on his new documentary “When Crocs Ate Dinosaurs”. My mother took me to the event, as she was aware that I was a fan of Dr. Sereno’s work. When I saw Dr. Sereno, I talked about how I was a fan of his work and it was a pleasure seeing him in person. Dr. Sereno was flattered by my compliments. 

Question 13: What is your favorite prehistoric animal?  Was it different when you were younger? 

EJ: My favorite prehistoric animal has always been Tyrannosaurus rex. Movies such as “Jurassic Park” portrayed T. rex as a formidable predator which has persisted throughout my childhood and studies.

Evan with "Sue" the T.rex at the Field Museum.

Question 14: If you could use a time machine to go back and pick only one prehistoric animal to bring back from history and observe alive and in person, which would it be and why?

EJ: I would probably bring back Spinosaurus. Spinosaurus has underwent various morphological descriptions where it had short legs with a large paddle-like tail, and spent its life swimming in the water. Paleontologists have debated Spinosaurus’ life history. The idea of seeing a real-life Spinosaurus in the 21st century and observing its feeding and locomotive behavior would be relieving to paleontologists.

Spinosaurus aegyptiacus

Question 15: Back to the time machine.  This time you can go back to any place and time period and have a look at what the environment was really like.  Which one would you pick and why?

EJ: I would look at the environmental aftermath of the Permian Extinction. Paleontologists refer to Permian Extinction as the worst extinction event of Earth’s history. I would be curious as to what animals and plants were able to survive and endure the Permian Extinction, especially in lieu of the appearance of early dinosaurs and early crocodilian relatives.

Fieldwork in Alaska.

Question 16: Which is your favorite museum?  Why?

EJ: My favorite museum would have to be the American Museum of Natural History in New York City. Growing up I found the American Museum of Natural History to be a phenomenal museum because it displays dinosaur fossils from “The Bone Wars”, Barnum’s Brown’s expeditions in the Upper Cretaceous formations of North America, and Roy Chapman Andrew’s fossil expeditions in Mongolia. The dinosaur fossil displays are divided into two different sections, the Hall of Saurischian Dinosaurs and the Hall of Ornithischian Dinosaurs. The saurischian hall displays a comprehensive collection of theropods, sauropods, and sauropodomorphs. The ornithischian hall displays numerous beaked dinosaurs ranging from ceratopsians, thyreophorans, to hadrosaurids. I have visited the AMNH twice (2007 and 2018), but I always yearn to visit it again.

Question 17: What hobbies do you have?  (Don’t have to be paleo-related.)

EJ: My hobbies include playing Pokemon and Yugioh, walking, writing and drawing (paleoart and manga/anime). 

Question 18: You have a book coming out!  Tell us about that.

EJ: The book is called “Dinosaur World”. The details information on every dinosaur that has been discovered to date with information on their size, diet, ecology, and significance in paleontology. In addition to the dinosaur descriptions, the book also talks about the biology of dinosaurs (feeding behavior and anatomy), museums that house dinosaur specimens and biographies of prolific and aspiring paleontologists from diverse and under-represented backgrounds. The book can be pre-ordered on websites such as Amazon, Barnes and Noble, Books a Million, Simon & Schuster, and Indie Bound. It’s best to search for the book by its ISBN: 9781646433162. You can preorder the book now and it will be released February 2023.