A freestanding mounted cast of Tyrannosaurus rex is the centerpiece of the atrium in the UC Berkeley Valley Life Sciences Building. Unearthed in 1990, the skeleton is 90% complete, making it one of the most comprehensive T. rex specimens ever discovered. Credit: Yasin Id-Deen/UC Berkeley

In one corner of the mazelike, climate-controlled room at the heart of UC Berkeley, a triceratops horn rests on a shelf a few inches above the floor. The massive skull of a baleen whale that lived some 15 million years ago is fixed to a wooden plank bolted to a nearby wall. There are drawers upon drawers stuffed with skeletons and labeled with locations that dot the globe.

This story was produced by UC Berkeley and first published on Berkeley News

Anyone who enters the Valley Life Sciences Building has likely seen the replica Tyrannosaurus rex on the ground floor, in the circular stairwell. It’s but one of dozens of pieces on display just outside the museum doors, like the skeleton of Stenopterygius, a Jurassic marine reptile.

But it’s farther inside the museum where tens of millions of years of history unfold among the movable shelves of the University of California Museum of Paleontology. Normally off-limits to all but select researchers, the space is home to hundreds of thousands of pieces that range from massive dinosaur bones to minuscule invertebrate fossils. The state’s designated museum for California fossils, it is home to massive aquatic predators discovered in Shasta County and scores of specimens plucked from the La Brea tar pits in Los Angeles.

The skull of a whale that lived some 15 million years ago is fixed to a wooden plank bolted to the wall in the UC Museum of Paleontology. Credit: Yasin Id-Deen/UC Berkeley
Some specimens, like this haplomastodon skull, are shipped to museums and research institutions around the world. Credit: Yasin Id-Deen/UC Berkeley

Juan Liu, an assistant museum curator and assistant adjunct professor in the Department of Integrative Biology, recently guided a tour through part of the collection. 

It’s difficult not to get turned around in the floor-to-ceiling cabinets. 

It’s easy — perhaps encouraged — to get lost in the vastness of geologic time.

This skull of an adult Triceratops horridus was discovered in eastern Montana in 1970 by John Ruben, then a UC Berkeley graduate student. An herbivore, the horns were most likely used as a visual organ for species recognition and communication — not for combat purposes. Credit: Jason Pohl/UC Berkeley
The museum houses more than just unearthed bones. A file room is home to thousands of pages of researcher field notes dating back decades that can help contemporary researchers better understand the environment and circumstances around a discovery. Credit: Yasin Id-Deen/UC Berkeley
Juan Liu, one of the UC Museum of Paleontology curators, holds the linked-together vertebrae of a cougar. The vertebrae are chained by a thread so each piece is at its relative position in the spine. Credit: Yasin Id-Deen/UC Berkeley
Drawers upon drawers of specimens fill the museum, including these vertebrae fragments from mosasaurs, an extinct group of aquatic squamate reptiles that lived more than 66 million years ago. Researchers from around the world request access to the labeled specimens and can use them to help compare and better understand other discoveries. Credit: Yasin Id-Deen/UC Berkeley
The museum is also home to many casts of skulls, as evidenced by the more polished exteriors. This is a replica of a Leatherback turtle skull discovered near Bakersfield, California. The creature is believed to have lived some 15 million years ago. Credit: Yasin Id-Deen/UC Berkeley
Each specimen is cataloged with identifying tags that, among other things, detail where and when the piece was discovered, who logged it and the approximate age of the surrounding environment. Credit: Gretchen Kell/UC Berkeley
Every specimen, no matter how small, is cataloged and labeled before being warehoused in the array of moveable shelves, ensuring that researchers from around the world can access as much information as possible. Credit: Yasin Id-Deen/UC Berkeley
While many of the fossils have been carefully extracted from the rock that preserved them for millions of years, some remain a part of massive displays. These remnants of a toretocnemus, an extinct genus of ichthyosaur, were unearthed in 1931 in Shasta County. Credit: Yasin Id-Deen/UC Berkeley