The early Cenozoic era is a significant period in Earth's geological history, spanning from approximately 66 million years ago to 2.6 million years ago. Nebraska, a state in the Midwestern United States known for its vast prairies and rugged badlands, has yielded an impressive array of fossil finds from this era. In particular, the state's cities and towns have played host to numerous discoveries, shedding light on the evolution and diversity of life during this crucial period.

Among the most notable fossil discoveries in Nebraska are those from the Paleocene and Eocene epochs, which together encompass over 90% of the early Cenozoic era. The Paleocene epoch, spanning from 66 to 56 million years ago, has yielded a rich trove of marine fossils, particularly in the eastern part of the state. The Lincoln Formation, a marine deposit that stretches from Lincoln to Omaha, has produced fossils of ancient marine reptiles, such as the mosasaur, a carnivorous marine lizard that thrived in the Cretaceous period. In addition, the formation has also yielded fossils of early mammals, including the primordial primate Omomyx, which suggests a key evolutionary link between the earliest primates and modern apes.

The Eocene epoch, which followed the Paleocene, has also produced a wealth of fossil finds in Nebraska. The Whitney Member of the Brule Formation, located in the western part of the state, has yielded an impressive array of early mammalian fossils. Among these are the earliest known ancestors of modern horses, such as the Hyracotherium, which date back to the early Eocene. The Hyracotherium was a small, multi-toed forager that represented a key transitional step in the evolution of modern equines. Other notable Eocene fossils found in the state include the early rodents, such as the Paramys, which demonstrate significant advances in dental and cranial evolution.

Another notable site in Nebraska is the famous Ashfall Fossil Beds, located in Antelope County, near the town of Royal. This site has yielded an extraordinary array of early Cenozoic fossils, particularly from the Oligocene epoch, which spanned from 34 to 23 million years ago. Among the most significant finds at Ashfall are the massive femur bones of the titanothere, an extinct relative of modern rhinoceroses, which sported four giant, armored predators. The site has also produced fossils of early camelids, such as the Procamelus, which are thought to have played a significant role in shaping the evolution of modern camels and llamas.

The Ashfall Fossil Beds are particularly notable for their unique preservation conditions, which have allowed scientists to reconstruct an unusually complete picture of early Cenozoic ecosystems. The site has provided a fascinating glimpse of the complex interactions between ancient plants and animals, offering vital insights into the evolution of modern ecosystems.

The discovery of early Cenozoic fossils in Nebraska has provided a crucial window into the evolution of life on Earth. These finds have served to underscore the complex and dynamic nature of geological history, revealing the intricate web of interactions between plants, animals, and their environment.

Notable fossil discoveries from early Cenozoic Nebraska have had significant scientific and public interest. Establishing the state as a prime destination for fossils. Fossils show early mammals beginning to occupy niches left over from former periods in the Cenozoic.

The study of early Cenozoic fossils has greatly expanded our knowledge of the evolution of mammals and plants during this critical period.