Did Tyrannosaurus ever colonize the Eastern U.S. during the Late Cretaceous

[Joseph Fossil]

Tyrannosauridae Dinosaur diversity was unique in the Western and Eastern areas of the North American Continent during the Late Cretaceous era around 95-66 Million Years ago) as a result of a seaway the cut the continent in two (creating the continents of Laramidia (now Western North America) and Appalachia (now Eastern North America)).

 

By the Maastrichtian stage of the Cretaceous 68 Million Years ago, the seaway decreased in size and a land bride formed between Laramidia and Appalachia.

 

 

 

https://deeptimemaps.com/western-interior-seaway/

 

This is around the same time Tyrannosaurus rex emerged in Laramida and other Tyrannosauridae including the smaller Dryptosaurus lived in Appalachia. 

 

 

Map of the currently known Tyrannosaurus rex fossil discovery sites

 

 

 

 

 

Maps of the currently known Maastricthian Tyrannosauridae fossil discovery sites in Eastern North America (not shown on the maps here are Late Cretaceous Tyrannosauridae fossil sites in South Carolina and North Carolina)

https://paleobiodb.org/navigator/

 

 

What I'm wondering is even with this land bridge formed, what prevented Tyrannosaurus from colonizing the Eastern portion of North America during the Maastricthian Cretaceous? If it didn't prevent this, has there been any fossils found in the Eastern portion of North America that belong to the Tyrannosauridae genus Tyrannosaurus?

 

[Troodon]

1 hour ago, Joseph Fossil said:

Tyrannosauridae Dinosaur diversity was unique in the Western and Eastern areas of the North American Continent during the Late Cretaceous era around 95-66 Million Years ago)

I'm unaware of any tyrannosaurids being discovered in Appalachia especially Tyrannosaurus rex.  What evidence do you have that supports your claim?  

 

Dryptosaurus is not a Tyrannosaurid but a Tyrannosauroid

 

[Joseph Fossil]

20 hours ago, Troodon said:

I'm unaware of any tyrannosaurids being discovered in Appalachia especially Tyrannosaurus rex.  What evidence do you have that supports your claim?  

 

Dryptosaurus is not a Tyrannosaurid but a Tyrannosauroid

 

 

@TroodonYour right, meant to write Tyrannosauroidea (forgot the o)! Thanks for pointing that out!!

[Joseph Fossil]

@Troodon But what do you think about if the genus Tyrannosaurus ever was able to colonize Eastern North America during the Latest Maastrichtian Cretaceous and if not, why didn't this occur?

[Troodon]

There is no evidence that any tyrannosaurid existed in the east.  Have not studied why.  Might be as simple as the timing of the asteroid hit.

 

[PaleoNoel]

I believe that there is some debate as to the extent of the Western Interior Seaway's reduction by the end of the Maastrichtian. However, the presence of what appears to be a derived ceratopsid tooth found in the Owl Creek formation of Mississippi, suggests some degree of exchange during those last few million years. If T. rex did make to Appalachia, there is a good chance it could have out-competed the local tyrannosauroids like Dryptosaurus. Seeing as how Acrocanthosaurus is believed to have been ubiquitous across North America before it was bisected by the WIS, the same could have been true for the tyrant king if the environment was right to sustain them. We will never know for sure until the right fossils are found to suggest this course of events. Until then it's just an interesting hypothetical. 

 

Edited April 21, 2023 by PaleoNoel

[Joseph Fossil]

On 4/20/2023 at 12:27 PM, Troodon said:

There is no evidence that any tyrannosaurid existed in the east.  Have not studied why.  Might be as simple as the timing of the asteroid hit.

 

 

@Troodon Good Point about the astroid. Without the impact, I agree it's quite possible Tyrannosaurids could've colonized Eastern North America!