Collection Highlights

The Dinosaur Institute holds a vast collection of specimens from the Mesozoic era. A wide array of some of the most interesting specimens have been detailed below, including one of the Dinosaur Institute's most exciting finds, a Tyrannosaurus rex known more affectionately as "Thomas".

Edmontosaurus annectens

Collection Number: LACM 23502.
Collector: Harley J. Garbani.
Geographic Location: Garfield County, Montana.
Geologic Formation: Hell Creek Formation
Time Period: Late Cretaceous (approximately 65 million years ago).

Significance: This skull is one of a few that preserves evidence of the beak structure that covered the jaws of duckbilled dinosaurs.

Fruitafossor windscheffeli

Collection Number: LACM 150948.
Collector: Wally Windscheffel and Charles Safris.
Geographic Location: Mesa County, Colorado.
Geologic Formation: Tom's Place locality, Morrison Formation.
Time Period: Late Jurassic (approximately 155 million years ago).


Significance: This holotype specimen is the most complete mammal known from the Jurassic of North America. It is also the first known mammal to exhibit massive forearms that were adapted for a digging lifestyle as well as ever-growing molars for feeding on communal insects.

Lambeosaurus laticaudus

Collection Number: LACM 17712.
Collector: William J. Morris.
Geographic Location: El Rosario, Baja California Del Norte, Mexico.
Geologic Formation: El Gallo Formation (El Diesacado Member).
Time Period: Late Cretaceous (approximately 70 million years ago).

Significance: Patches of fossilized skin were discovered in association with the skeleton (LACM 17715) of this gigantic duck-billed dinosaur, which is the most complete dinosaur from Baja California.

Morenosaurus stocki

Collection Number: CIT 354/2802.
Collector: A. B. Drescher and party.
Geographic Location: Fresno County, California.
Geologic Formation: Moreno Formation
Time Period: Late Cretaceous (approximately 65 million years ago).

Significance: This holotype specimen—specimens used to name new species—is exceptionally complete for a Californian plesiosaur. Gastroliths or 'stomach stones' were also found preserved in its stomach.

Plesiotylosaurus craddidens

Collection Number: CIT 2759.
Collector: R. M. Leard and party.
Geographic Location: Fresno County, California.
Geologic Formation: Mosasaur Locality, Moreno Formation
Time Period: Late Cretaceous (approximately 65 million years ago).

Significance: This well preserved holotype specimen represents one of the largest mosasaurs. It was also one of the best adapted to aquatic life.

Saurolophus sp.

Collection Number: LACM CIT 2852.
Collector: Chester Stock.
Geographic Location: San Benito, California.
Geologic Formation: Moreno Formation
Time Period: Late Cretaceous (approximately 65 million years ago).

Significance: Very few dinosaurs have been collected in California. This specimen is the most complete dinosaur fossil ever found thus far in the entire State of California.

Tyrannosaurus rex

Collection Number: LACM 150167 ("Thomas").
Collector: Luis M. Chiappe and party.
Geographic Location: Carter County, Montana.
Geologic Formation: Hell Creek Formation
Time Period: Late Cretaceous (approximately 65 million years ago).

Significance: Among the most complete Tyrannosaurus rex specimens ever found, this skeleton with skull ranks as one of the geologically youngest T. rex specimens known, discovered very near the Cretaceous/Tertiary boundary.

Tyrannosaurus rex

Collection Number: LACM 2841.
Collector: Harley J. Garbani.
Geographic Location: F. S. McKeever Ranch, Garfield County, Montana.
Geologic Formation: Hell Creek Formation
Time Period: Late Cretaceous (approximately 65 million years ago).

Significance: This specimen is the youngest known Tyrannosaurus rex specimen. It is believed to represent a two-year-old baby, with an estimated body mass of 60 pounds (30 kilograms).