Where are Tyrannosaurus Rex Fossils Found? Some Key Sites

Tyrannosaurus rex, commonly known as T.rex, is undoubtedly one of the most famous dinosaurs on Earth. Who would not know the prominent character from Jurassic World that indeed lives up to its name as the tyrant lizard king? Let us travel back to the Cretaceous period and understand where the most powerful T. rex lived and where most of their fossils are unearthed. 

A large number of Tyrannosaurus rex was discovered by scientists in Hell Creek Formation in Montana. One of the most famous fossils discovered in this formation is Sue. Another known dinosaur fossil land is the Morrison Formation in Colorado which housed several species of dinosaurs, including T.rex. 

In this article, we will be talking about the origins of our tyrant lizard king, the Tyrannosaurus rex. We will discuss where most of these amazing creatures lived and what kind of environment they occupied in the past. We will also get to know some of the famous T.rex fossils that reigned during the Cretaceous era and the recent discoveries of T.rex fossils and other relative creatures found mostly in North America and China. 

Geological Formations that T. Rex Occupied in the USA

Most T.rex fossils in the USA were found and unearthed in North American geological formations, namely the Hell Creek Formation and the Morrison Formation. 

Hell Creek Formation of Garfield county, Montana, is a thoroughly studied formation of mostly Upper Cretaceous and some lower Paleocene rocks in North America near Jordan Montana.

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The formation extends to portions of Montana, North and South Dakota, and Wyoming covering about 175 meters of thick sandstones and shales, deposited as coastal-plain sediment during the withdrawal of the Cretaceous seas.

Remains of many animals, including dinosaurs, were found in the Hell Creek Formation. Vertebrates discovered here include pterosaurs, crocodiles, champsosaurus, lizards, and snakes. Some notable dinosaur fossil finds here are the Tyrannosaurus, Triceratops, and a variety of small theropods.

Hell Creek Formation is one of the best-studied ancient environments with a subtropical, warm and moist climate. The formation represents different sections of the western shore of the shallow sea, and these swampy lowlands were the habitat of various animals during that time. The presence of crocodilians suggests a subtropical climate for this rich fossil site. There is also an abundance of flowering plants in Hell Creek, with conifers, palmettos, and ferns found in swamps.

Another known geological formation that T.rex has occupied is the Morrison Formation in Colorado. The formation is made of a sequence of Upper Jurassic sedimentary rock in the western United States and is considered the most fertile source of dinosaur fossils in North America. 

The Morrison Formation is made of mudstone, sandstone, siltstone, and limestone, colored light gray, green, gray, or red. Most of the fossils are found in the green siltstone beds and lower sandstone, rivers, and floodplains. 

YouTube Video About One of The Best Preserved T. Rex Skeletons

YouTube video by DWEuromaxx which the discovery and exhibition of the Tristan Otto T. Rex skeleton – AdventureDinosaurs

Centered in Wyoming and Colorado, the Morrison Formation further extends to Montana, North and South Dakota, Nebraska, and Kansas. It covers an area of a massive 1.5 million square meters, but only a small portion of the land is exposed and open for geologists and paleontologists to study.

The overall climate in Morrison Formation was dry, where conifers are the dominant plants together with ginkgos, cycads, and tree ferns. This formation is a home for hundreds of dinosaur fossils, including theropods, sauropods, and the surprising embryos of Camptosaurus. The presence of many species indicates that the formation is a good breeding environment and not just home for migratory animals. 

The Abundance of T. Rex Skeletons in North America and China

Tyrannosaurus is a larger tyrannosaurid that lived in the late Cretaceous era, of which fossils are found in the North American geological formations. Albertosaurus, a relative T.rex, are more lightly built and have lived in the early Cretaceous and late Jurassic, where fossils are mostly found in Western China.   

T. Rex Skeletons Found in North America

Scientists have discovered about 100 fossils of T.rex, most found in Dakotas, Montana, and Colorado. Thirty-two of those fossils are largely complete skeletons located in various Museums around the world. 

More than two dozen T.rex specimens are discovered in western North America. Some are complete, and some are under private collections and are therefore lost to further studies. Wankel Rex and Sue are two of the most complete T.rex specimens found in 1990.

Wankel rex is an 85 percent complete T.rex skeleton displayed at the Museum of the Rockies in Bozeman, Montana. It was discovered by a local rancher Kathy Wankel in Hell Creek sediments on an island in the Charles M. Russel National Wildlife Refuge of Montana. The skeleton includes the dinosaur’s skull and the considered first-ever complete T.rex forelimb. 

Sue, the 90 percent complete specimen, is considered the best-preserved T.rex ever known in Science. The dinosaur’s specimen is displayed at the Field Museum in Chicago. These T.rex remains were also found in the Hell Creek Formation by Susan Hendrickson of the Black Hills Institute.

The almost complete T.rex skeleton features 250 of approximately 380 known bones in T.rex skeleton, including the furcula (wishbone) and gastralia (a set of rib-like bones). Sue is also dubbed as one of the largest T.rex specimens ever found.

Another addition to the T.rex fossils’ definitive list is the world’s biggest T.rex discovered in 1991 at a fossil site in Saskatchewan, Canada. The specimen was nicknamed Scotty, weighing an estimated 19,500 pounds in life. The skeleton is about 65 percent complete, including the skull, hips, ribs, leg bones, and tail bones.

An assistant curator for the Department of Vertebrate Paleontology in the American Museum of Natural History, Barnum Brown discovered the first T.rex skeleton. He recovered a partial skeleton of T.rex in 1902 at the Hell Creek Formation in Montana. The discovered skeleton became the holotype specimen of T.rex (a single specimen designated as the name-bearing representative of q new species).

Six years later, Barnum discovered another nearly complete T.rex skeleton at the Big Dry Creek, Montana. The skeleton was named AMNH 5027 and is on view at the Museum’s Hall of Saurischian Dinosaurs. The rock around this skeleton was blasted with dynamite revealing a specimen with a perfectly preserved skull.

Five T.rex specimens were unearthed at the Hell Creek Formation in 2000 and are now displayed at the Museum of the Rockies. One notable specimen in this discovery is the B-rex. It has preserved soft tissues and a medullary bone which indicates that the specimen is a female dinosaur. The soft tissue preserves the transparent and hollow blood vessels containing small round microstructures (presumably red blood cells). B-rex is one of the amazing preserved fossils recorded to date.

Some Famous T. Rex Skeletons Discovered in China

Here are some of the most known T.rex discoveries in China.

Guanlong, a three-meter dinosaur who lived in the late Jurassic, was found in Xinjiang, western China. It is the first and earliest known fossil of Albertosaurus, a large Tyrannosaurus discovered in 2002 and was described and named in 2006. Guanlong has primitive and unique features, a complex skull crest, and hollow bone running in the midline of its skull. 

Dilong, a tyrannosaur that measures five feet long, was found in the Liaoning deposits of north-eastern China. The fossil was discovered by Chinese paleontologist Dr. Xu Xing in 2004. It has a nearly complete skull and skeleton, preserved with protofeathers, seen in fossilized skin impressions near the jaw and tail.

T. Rex Fossils: The Continued Discovery

T. rex fossils continue to rise to discovery up to this day. There have been some findings of newly found fossils of both T.rex and its possible relatives in recent years.

It took more than two decades for scientists to find T.rex remains as massive bones were firmly attached to extremely hard rocks. It is difficult to find them and dig up for studies, but there has been an increasing number of T.rex discoveries during the recent year that surprised Science.

The dueling dinosaur fossil found at Garfield County, Montana, in 2006 was discovered by Claton Phipps. The fossils show an intertwined specimen of Tyrannosaurus rex and Triceratops. Studies are still done to know why the two dinosaurs are preserved and tangled with each other. The best-of-its-kind dinosaur fossils were believed to have been dueling when they died and fossilized together.

The Reaper of Death, discovered in a Tyrannosaur graveyard, Alberta, in 2008, was found by Sandra and John De Groot along the shore of Oldman River and Bow River. The jaw fossils had vertical ridges lining the upper jaw and a scar on its face. It also had an oval-shaped cheekbone and aspects of its skull.

Discovery of a T.rex relative was found on the Isle of Wight. Four bones were found at three separate locations at Shanklin beach in 2019. The bones were believed to belong to a new species of theropod dinosaur who lived in the Cretaceous period, 115 million years ago. The dinosaur was estimated to be four meters long and displayed at Dinosaur Isle Museum at Sandown.

A team of paleontologists from the University of Washington and its Burke Museum of Natural History and Culture unearthed four dinosaur fossils. The fossils were found in north-eastern Montana in the summer of 2021 and will be brought to the Burke Museum for a public display where people can watch paleontologists remove the surrounding rock in the fossil.

One of the four fossils is the ilium, the hipbone of an ostrich-sized theropod of which T.rex belongs. The fossil is still not studied as paleontologists still remove the fossils from the rocks attached to it. But it can be a related T.rex dinosaur as the fossil is under the same group. 

Conclusion 

The studies and recent findings of the fossil discoveries of T.rex clearly showed that the dinosaur did not live in one place only but was able to occupy scattered places around the planet. It further explains scientists’ claims that T.rex may have been migratory animals and roamed around the world where their fossils were recovered when they died. These facts are a great addition to the long list of discovered dinosaurs in the past decade.