The Vertebrate Paleontology Collection

Geographically, the Denver Museum of Nature & Science vertebrate paleontology collection primarily originates from the Rocky Mountain region; however, we also have world-class fossil vertebrate collections from Madagascar and other parts of the globe. In the framework of geologic time, our collection consists predominantly of Cenozoic mammals, Jurassic and Cretaceous dinosaurs, and Cretaceous seaway fishes and reptiles. The collection has now grown to almost 300,000 cataloged specimens, more than 280,000 of which have been collected from the Rocky Mountain Region since 1988; the majority of them are of fossil mammals. This significant growth has been accomplished using modern geological and paleontological field techniques as well as acquisition of established, catalogued collections. As a result, the collections are extremely well documented and of high value in addressing contemporary research questions related to the history of life, evolution, paleobiogeography, paleoclimate, and paleoecology.

The collection is divided into (1) exhibit specimens targeted at the museum visitor in Prehistoric Journey and elsewhere in the Museum and (2) research collections that are used by Museum scientists as well as visiting researchers and students from around the world. Specimens related to ongoing research projects are currently being collected from the Morrison Formation of Colorado; the Kaiparowits and Wahweap formations of Utah; the Fruitland and Kirtland formations of New Mexico; the Hell Creek and Fort Union formations of North Dakota, South Dakota, and Montana; the Lance Creek Formation of Wyoming; the Laramie and Denver formations of Colorado; the Wind River, Willwood, and Bridger formations of Wyoming; the Maevarano Formation of Madagascar; and various Paleogene and Neogene localities in Colorado. Since 1988, more than 500 books, scientific papers, abstracts, and popular articles have been published on the Museum’s vertebrate fossil collections. The collection includes many complete and extraordinarily well-preserved skeletons and preserves 74 holotypes, which serve as the morphological standards for various species. It also contains several institutional icons, including the skeletons of the plesiosaur Thalassomedon and several dinosaurs such as DiplodocusAllosaurusStegosaurus (Colorado’s state fossil), and Torosaurus as well as several large mammals such as MegaceropsAmebelodon phippsi, and Mammut (mastodon). 

Four recently acquired collections are highlighted below.


Ice Age Fossils from the Colorado Mountains

Discovered in 2010 during excavation of a reservoir outside Snowmass Village, Colorado, the Museum’s Snowmastodon Project, in partnership with the State of Colorado and Snowmass Village Water and Sanitation, uncovered an unexpected trove of Ice Age (Pleistocene) fossils. Diverse animal and plant fossil specimens from this site represent the best high-elevation window into the Ice Age in North America, documenting nearly 50,000 years of change from a warm interglacial fauna dominated by American mastodon (Mammut americanum), giant ground sloth (Megalonyx jeffersonii), and long-horned bison (Bison latifrons) to a cold glacial fauna dominated by Columbian mammoth (Mammuthus columbi), American camel (Camelops), and ancient bison (Bison antiquus).

The collection from Snowmass consists of over 5,000 large vertebrate remains and more than 50,000 microvertebrate remains. The fossils were carefully mapped during the project, providing insights into ecological transitions during major climatic shifts prior to the colonization and modification of North America by humans. These fossils have been carefully studied by scientists and students from around the world and continue to reveal secrets about Colorado’s recent fossil past.


Treasure Island

Bizarre Dinosaurs and Other Vertebrates from Madagascar

The vertebrate fossil collection from Madagascar, made in collaboration with the University of Antananarivo and during the course of 13 highly successful expeditions since 1993, are near the end of the Age of Dinosaurs. The collection includes approximately 20,000 specimens of fishes, frogs, turtles, lizards, snakes, crocodyliforms, pterosaurs, dinosaurs, birds, and mammals. Many of the taxa exhibit bizarre anatomical features, a reflection of having lived in isolation on the island for tens of millions of years. To date, 20 new species have been described. The collection includes many exquisitely preserved, complete skeletons that have provided, and continue to provide, important information on the anatomy, life habits, and relationships of individual taxa and crucial new implications for the biogeographic and plate tectonic history of Gondwana during the Mesozoic Era.

Research on the Madagascar collection is a key focus of several of our curators as well as approximately 100 researchers from around the globe. Specimens from this collection have been displayed, in addition to the Ultimate Dinosaurs exhibition at the Denver Museum of Nature & Science (2017–2018), in numerous museums and other institutions in the United States, Canada, Madagascar, Europe, and Asia.

The Rose Collection

The Origin of Modern Mammals

Kenneth Rose, PhD, professor emeritus of Johns Hopkins University and a Denver Museum of Nature & Science research associate, recently donated an unparalleled collection of some 20,000+ fossil mammal specimens from the Lower Eocene Willwood Formation of the Bighorn Basin, Wyoming. This collection, amassed over a 40-year research career by Dr. Rose and his field research teams, includes some of the most complete and best-preserved specimens of the first representatives of several modern orders of mammals (e.g., perissodactyls, artiodactyls, primates). The skeletal remains in particular are providing key new insights into the anatomy, behavior, paleobiology, and relationships of these early modern mammals. The collection is impeccably well documented, with tight stratigraphic control, and thus will continue to play a strong role in testing hypotheses related to the tempo and mode of evolution at the species level. 

The Rose Collection will attract researchers from around the world and is an important complement to the collections previously made by curator emeritus Richard Stucky from slightly younger horizons in the Wind River and Bridger formations and currently being made by curators Tyler Lyson and Ian Miller from older horizons (Paleocene) in the Denver Formation.

The Hankla Family Collection

A Wyoming Dinosaur Bonebed

Collected from a single, extraordinary bonebed in the Lance Creek Formation of eastern Wyoming, the disarticulated remains of dozens of duck-billed dinosaurs (Edmontosaurus annectens) are intermixed with the fossils of other animals that lived alongside them more than 66 million years ago. Likely killed, scavenged, and buried en masse, the site preserves a single snapshot of life in the Western Interior of North America at a time when Tyrannosaurus rex and Triceratops ruled the continent. The strength of the collection is the ontogenetic cross-section of a single dinosaur population, with dozens of individual elements from each part of the skeleton derived from juveniles, subadults, and adults. Mixed among the remains of Edmontosaurus are the teeth of scavengers (crocodiles, tyrannosaurs) and other denizens of the Late Cretaceous floodplains and rivers (Triceratops, turtles, fish).

Generously donated in 2018 by the Hankla family of Danville, Kentucky, the collection is still being carefully prepared in Museum labs and studied by Museum researchers and scientists from around the world.


Joseph Sertich, PhD

Associate Curator of Dinosaurs

Tyler R. Lyson, PhD

Associate Curator of Vertebrate Paleontology

David W. Krause, PhD

Senior Curator of Vertebrate Paleontology

Kristen A. MacKenzie, MS

Earth Sciences Collections Manager

Nicole Neu-Yagle, MS

Earth Sciences Assistant Collections Manager

Libby Couch

Business Support Specialist III

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