Hall of Ornithischian Dinosaurs

Stegosaurs and Ankylosaurs: Throphorans display- Armor section

Sauropelta edwardsi
(SOR-o-PEL-ta ED-ward-zi)
”Shielded reptile”

Sauropelta was one of the largest of the nodosaurs. It differs from more advanced ankylosaurs in lacking complex air passages in the skull, as well as a tail club. This exquisitely preserved specimen is one of the most complete ankylosaurs yet found. Fossils of Sauropelta have been collected from the same 107-million-year-old rocks in western North America that contain other herbivores (such as Tenontosaurus) and carnivores (such as the sickle-clawed Deinonychus). 

AMNH 3036, collected by B. Brown and P.C. Kaisen, 1932, 40 miles south of Billings, Montana. Sauropelta edwardsi lived 107 million years ago.


Corythosaurus casuarius 
(Ko-RIGHT-o-SO-rus kas-U-wear-e-us)
 “Corinthian-helmet reptile”

Another treasure discovered by Barnum Brown and Peter Kaisen, this magnificent Corythosaurus skeleton was collected in 1914 near the Red Deer River in Alberta, Canada. This virtually complete specimen has given researchers new insights into dinosaur anatomy, as its fine condition offers a wealth of detail uncommon in most fossils. Indeed, this individual’s skull is so well-preserved that even one of the toothpick-sized ear bones is intact, as are the evocative, paper-thin bones that surrounded its eyes. 

The Corythosaurus was an herbivore, and, like other hadrosaurs, it had a toothless beak with hundreds of small, interlocking teeth comprising its back jaw. It derives its name from the crest atop its head, which recalls the helmet of Corinthian soldiers in ancient Greece. 


Styracosaurus albertensis 
(sti-RAK-o-SO-rus al-BURT-en-sis)
 "spiked reptile" 

The Styracosaurus, with its massive, elaborate skull, is widely regarded as one of the most distinctive of all the horned dinosaurs. In addition to the enormous horn fixed above the oversized nostril, its substantial neck frill features at least four additional spikes. The function of this impressive ornamentation has been the subject of debate since the first horned dinosaurs were discovered, with theories ranging from utility in defense to temperature regulation and courtship. 

With a length of approximately 18 feet and weighing around 3 tons, the Styracosaurus had a massive body with powerful shoulders. Although large, Styracosaurus were herbivores, feeding on low growth and perhaps taller plants they knocked down with their horns, beak, and bulk. From the Late Cretaceous (75 million years ago), this Museum specimen was discovered by Barnum Brown and A. Johnson on a 1915 dig in Alberta, Canada


Stegosaurus stenops 
(STEG-o-SO-rus STEN-ops)
"plated reptile" 

This specimen was discovered during the Museum’s first major dinosaur excavation in Bone Cabin Quarry, Wyoming in 1901. Stegosaurus’s spiked tail and characteristic plates, which have grooves for blood vessels, indicating that they were covered in skin, render this iconic species immediately recognizable. Scientists have offered many theories about the presence of these plates, with some proposing they were used for defense, display, or regulating body temperature. 

At one point, paleontologists hypothesized that Stegosaurus possessed two brains, since its skull capacity was small for an animal of its size. Stegosaurus, however, managed with one brain, thriving during the Late Jurassic period, 150 to 155 million years ago. This unique mount includes both a fossil skeleton and a realistic model to show Stegosaurus in action. 

Corythosaurus casuarius 
(ko-RIGHT-o-SO-rus kas-U-wear-e-us)
“Corinthian-helmet reptile” 

This Corythosaurus is one of the finest dinosaur specimens ever found. Collected in 1912 from the Red Deer River in Alberta, Canada, this specimen boasts not only a nearly-complete skeleton, but also large areas of preserved skin impressions on both sides of the body, making it a scientifically-significant find. 

A landmark find by Barnum Brown and George Olsen, this Corythosaurus offers us an amazing textural portrait of dinosaurs. Thanks to this specimen, we now know that dinosaur skin was scaly, but unlike the scales found in lizard- and snake-skin, dinosaur scales did not overlap. This Corythosaurus features alternating patterns of scales that vary from round to polygonal, providing paleontologists with an extraordinary glimpse into the structure of this rarely-preserved aspect of dinosaurs. 

Edmontosaurus annectens
(ed-MON-to-SO-rus ah-NEK-tenz)
"reptile from the Edmonton Formation"

The Museum's Edmontosaurus specimen is a magnificent example of the rare “mummified” dinosaur fossil. Though no actual skin is preserved, distinct impressions of skin and other soft tissues were imbedded in the surrounding rock, which lends this individual a unique appearance and provides valuable scientific insights into dinosaur anatomy. 

Collected in 1908 by C.H. Sternberg in Niobrara County, eastern Wyoming, this fossil has been mounted as it was found–lying on its back with knees drawn up, head and neck twisted backward as the tendons dried out. Though the tail was never recovered, this specimen remains a landmark in our understanding of hadrosaurid—“duck-billed”—dinosaurs. Edmontosaurus lived 65 million years ago, during the Late Cretaceous. 


Relatives of the Triceratops 

The three skulls presented here are each related to Triceratops and are all part of the Ceratopsidae family. Recovered from Montana and Alberta, these specimens were found by some of the biggest names in the history of dinosaur hunting: Barnum Brown, George Olsen, Peter Kaisen, and Edward Drinker Cope. 

Herbivores from the Late Cretaceous (75 million years ago), these species all have a characteristically ornate skull complete with a large frill and a variety of different horns. In addition to its impressive nasal horn, Centrosaurus (left) featured a number of small hornlets around the edge of its frill. Its cousin Chasmosaurus (center and right) is known for the striking pair of horns above the eyes as well as the large openings in the oversized frill. Together, these three specimens demonstrate the vast extent of physical diversity among even the most closely-related dinosaurs. 

Triceratops horridus 
(tri-SER-ah-tops ho-RID-us) 
"three-horned face” 

This impressive mount features Triceratops horridus, a dinosaur that lived 65 million years ago during the Late Cretaceous. Although many Triceratops fossil bones have been found, complete skeletons are rare. This particular skeleton is composed of fossils from about six different specimens, collected from Seven Mile Creek in Niobrara County, Wyoming in 1902 and Sand Creek, near Lismas, Montana in 1909. 

The Triceratops horn—the hard, thick covering around the bone—was composed of a material similar to that of human fingernails, and was impressively about 40 percent larger than the bone underneath. The side of this Triceratops skull features a partially healed injury, perhaps caused by a conflict with another Triceratops


Anatotitan copei 
(ah-NAT-o-TI-tan KOP-e-i) 
"giant duck" 


This impressive mount features two complete fossils of Anatotitan copei, a dinosaur that lived during the Late Cretaceous, 65 million years ago. Though their characteristic bills might suggest an aquatic lifestyle, Anatotitan copei were in fact terrestrial, using their powerful jaws and hundreds of teeth to grind fibrous plants. 

The upright skeleton in this display was discovered by cowboys in Crooked Creek, Montana in 1904. Its location was eventually disclosed to famed fossil hunter Barnum Brown after a series of negotiations involving a six-shooter and $250. The 1906 excavation continued to be eventful, taking three weeks and involving the demolition of a hill. The collection of this specimen is attributed to Peter C. Kaisen, a trusted long-time member of Brown’s expedition team. 

The second skeleton, mounted in a feeding pose, was collected in 1882 in Moreau River, Black Hills, South Dakota by a field party working for the paleontologist Edward Drunker Cope, and was later purchased by the Museum.