A new tyrannosaur has joined the prehistoric world!
Paleontologists have described a new genus and species of tyrannosaur from the Oldman Formation of Alberta, Canada, adding another member to the diverse community of large predators that lived in western North America during the Late Cretaceous.
Meet Tromerosaurus solumons, a newly described tyrannosaur whose unusual combination of features may help scientists better understand the early evolution of the albertosaurines.
A Tyrannosaur from the Oldman Formation
The fossils of Tromerosaurus were discovered in Alberta's Oldman Formation, which dates to the middle Campanian stage of the Late Cretaceous Period, more than 76 million years ago.
At this time, western North America was home to multiple kinds of tyrannosaurs.
These included two important branches: the large, robust tyrannosaurines, which included dinosaurs such as Daspletosaurus and would later include Tyrannosaurus, and the generally more gracile albertosaurines, represented by dinosaurs such as Albertosaurus and Gorgosaurus.
Where Does Tromerosaurus Fit?
Tromerosaurus appears to belong to the albertosaurine subfamily, but its anatomy presents paleontologists with an interesting combination of characteristics.
According to the research, the new dinosaur possesses features associated with both albertosaurines and tyrannosaurines.
Despite this unusual mixture, researchers interpret Tromerosaurus as an early member of the albertosaurine lineage.
Discoveries like this can be particularly valuable because species near the beginnings of major evolutionary groups may preserve combinations of traits that help paleontologists investigate how those groups changed over time.
What's in a Name?
The new tyrannosaur was given the scientific name Tromerosaurus solumons.
Its name roughly translates to “frightful lizard in the lonely mountain.”
That's a pretty fitting name for a predatory dinosaur roaming what is now Alberta more than 76 million years ago!
Two Tyrannosaurs Sharing One Environment
Tromerosaurus wasn't the only tyrannosaur living in this ecosystem.
It shared its environment with the larger tyrannosaurine Daspletosaurus.
Having two different tyrannosaurs living in the same ecosystem raises an intriguing question: How did multiple large predators coexist without constantly competing for the same resources?
One possibility is something ecologists call niche partitioning.
Niche partitioning occurs when species living in the same environment use resources differently. In the case of these tyrannosaurs, different species may have focused on different types or sizes of prey or occupied somewhat different ecological roles.
The presence of Tromerosaurus alongside Daspletosaurus provides paleontologists with additional evidence to investigate how different tyrannosaurs may have divided resources within Late Cretaceous ecosystems.
What Fossils Have Been Found?
Tromerosaurus is known from several specimens, giving researchers more than just a few isolated bones to study.
The fossils include an impressive skull as well as a partial skeleton.
Among the preserved bones are gastralia, sometimes informally called “belly ribs.” These slender bones were located along the underside of the body and are relatively uncommon finds in tyrannosaur fossils.
Together, these specimens provide paleontologists with valuable anatomical information about this newly recognized predator.
Another Piece of the Tyrannosaur Story
Tyrannosaurs were not simply one type of giant predator culminating in the famous T-Rex. They were a diverse group that evolved into different forms and occupied different ecological roles throughout the Cretaceous Period.
The discovery of Tromerosaurus adds another piece to that story.
By comparing its unusual combination of anatomical traits with those of other tyrannosaurs, paleontologists can continue investigating how albertosaurines and tyrannosaurines evolved, diversified, and lived alongside one another millions of years before T-Rex appeared.
And with new fossils still being discovered and studied, there are almost certainly more tyrannosaurs waiting to be added to the family tree.
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