Why do museums engage you?
Tell us by participating in the 2025 Annual Survey of Museum Goers, sponsored by theÌý.
Fossil Eggs
The Karl Hirsch Fossil Eggshell Collection at the University of Colorado Museum of Natural History (UCM) was primarily built by amateur paleontologist Karl Hirsch. Initially interested in fossil invertebrates, especially ammonites, Hirsch shifted to fossil eggshells after discovering some with his wife, Hildegard, in the Willwood Formation of Wyoming. Unable to find a paleontologist to identify the eggshells and determine which animal may have laid them, he dedicated the next 20 years to researching and publishing on fossil eggshells.
Hirsch began building his collection by conducting fieldwork across western North America and abroad in Germany, England, Spain, and Portugal. He also acquired fossil and modern specimens through collaborations with researchers, zoos, research labs, and breeding facilities. By the end of his career, Hirsch had amassed over 3000 specimens from a diverse temporal and geographical range.
By the mid-1970s, Hirsch became affiliated with the UCM and became a Research Associate with the UCM Paleontology Section in 1984, enabling him to publish his research on fossil eggshells. His most significant contributions were developing a standardized vocabulary for fossil eggshell morphology and adding fossil eggshells to the existing taxonomic classification system for modern eggs. This provided researchers with a method to identify and name fossil eggshell specimens, laying the groundwork for understanding the importance of fossil eggshells in the study of extinct animals’ paleobiology.
Hirch began donating his collection to the UCM in 1979. The collection includes not only specimens but also specimen images, X-ray and CT scan data, thin sections, SEM stubs and negatives, radiographic images, and geochemical data. Thanks to Hirsch’s efforts and those of other collectors, UCM’s Karl Hirsch Fossil Eggshell Collection is now one of the largest and most diverse collections of its kind in the world.