Paleontology News
The two new horned dinosaurs, Navajoceratops and Terminocavus. © Ville Sinkkonen & Denver Fowler
Gaps in Long Frilled Ceratopsid Dinosaur Evolution Filled in by Two New Transitional Species
Two new dinosaur skulls from New Mexico fill in the evolutionary gap between two lineages of long frilled ceratopsid dinosaurs. This research also pinpoints the evolutionary splitting event between the two lineages.
Summary Points
The parietal frill of Navajoceratops as originally found in new Mexico.
Navajoceratops sullivani and Terminocavus sealeyi are two new Long Frilled Ceratopsid Dinosaurs from New Mexico.
These new dinosaurs fill the evolutionary gap between Utahceratops, Pentaceratops, and Anchiceratops.
Long Frilled Ceratopsids underwent an evolutionary split around 85-83 million years ago when Northern and Southern populations were separated due to sea level rise.
Two new dinosaur skulls fill an evolutionary gap in Ceratopsid evolution
This article is based on a Press Release from the Dickinson Museum Center - June 5, 2020
The new dinosaurs form critical intermediate species linking Utahceratops, Pentaceratops, and Anchiceratops. Copyright: Ville Sinkkonen & Denver Fowler
There was a wide diversity of Ceratopsids, which had distinctive frills and horns, in the Late Cretaceous of North America. One group was the Long Frilled Ceratopsid dinosaurs. Some types of Long Frilled Ceratopsids, like Pentaceratops in New Mexico, had a deep notch in its frills, while others, like Anchiceratops, had a no notch. It had been unclear why they had these different frill shapes and how closely related they were.
By studying Long Frilled Ceratopsid skulls from the Kirtland Formation in New Mexico, paleontologists Denver Fowler and Elizabeth Freedman Fowler found two new transitional forms between these groups of dinosaurs, showing they are closely related.
The two new transitional forms are named Navajoceratops Sullivan, the "Navajo horned face," and Terminocavus sealeyi, the "Closing cavity."
These new specimens are intermediate in age between the Pentaceratops and Anchicertops. Pentaceratops has a distinctively deep notch while Anchiceratops, which lived 3.8 million years later in Canada, has no notch. What these new specimens show is the notch became deeper and deeper until it closed in on itself.
Subtle differences in the frill shape distinguish between different species. Copyright: Robert Boessenecker
They also pinpointed an event, early on between 85-83 million years ago, that caused them to evolve differently. At that time, unusually high sea levels cut off the northern and southern dinosaur populations for a few million years.
The Paleontologists said "For hundreds of miles across what is now central Utah to southern Alberta, the coastal plain would have been as little as 5-10 km wide, providing very little habitat for dinosaurs. This would have effectively cut off northern and southern populations, which then probably evolved in isolation into two distinct lineages."
A few million years later, the sea levels dropped and the two populations were able to intermix again.
This news article and images are based on a Press Release from the Dickinson Museum Center.
The Full Journal Article is Available Here (Free):
Fowler DW, Freedman Fowler EA. 2020. Transitional evolutionary forms in chasmosaurine ceratopsid dinosaurs: evidence from the Campanian of New Mexico. PeerJ 8:e9251 https://doi.org/10.7717/peerj.9251.
Recommended Dinosaur Books and Educational Items:
The Rise and Fall of the Dinosaurs: A New History of a Lost World
Steve Brusatte, 2019
This dinosaur book is light-hearted and easy to read. The author, a renowned Paleontologist, does a great job at engaging the reader. It is packed with details without being overwhelming. Check out the reviews; it's a great new dinosaur book! Available in Kindle, Paper, and Audio.
Dinosaurs Rediscovered: The Scientific Revolution in Paleontology
Michael J. Benton, 2019
This is a great general book on dinosaurs. It's up-to-date and goes over the new discoveries over the last 20 years that has completely changed our views on dinosaurs. The book is broken up into easy chapters that goes over their colors, speeds, bite force, child caring, and more... stuff we didn't know just years ago! Check out the reviews and the sample pages. Available in Kindle, Paper, and Audio.
Nifeliz Dinosaur Fossils Building Kit
From 8 dinosaurs to choose from, The Nifeliz Dinosaur sets are nearly 500 pieces. They are a great gift for those 12+ who enjoy solo or group building with LEGOs. Constructing these models enhances hand-eye coordination and creativity. Perfect for family or friends, It's also compatible with existing LEGO pieces, facilitating the creation of a personalized toy museum! Check out the reviews!
Additional Images:
Figure 4 from the research: The parietal frill of new species Navajoceratops sullivani
Figure 5 from the research: The parietal frill of new species Terminocavus sealeyi
Figure 10 from the research: The new species suggest chasmosaurine ceratopsids split into divergent evolutionary lineages approximately 83 million years ago.
Arjan Boere and Denver Fowler stand over part of the frill of Navajoceratops. 2002 Photo by R Sullivan.
Browse More Paleontology News
High quality Dinosaur teeth by Fossilera
