Construction Workers Stumble Across Stunning Prehistoric Discovery

Construction workers in Southern California have uncovered the remains of a giant mammal that roamed the region around 40 million years ago—but scientists still don’t know exactly what it was. The fossils, found about 12 feet underground at a water infrastructure project, include massive limb bones, ribs, and other fragments believed to belong to a single animal, the city of Oceanside said in a statement . Paleontologist Joseph El Adli has narrowed the possibilities to two extinct groups: a “thunder beast,” a huge hoofed mammal related to modern horses and rhinos, or a “swamp rhino,” a barrel-bodied herbivore that lived partly in water. Researchers made the discovery on August 31 during a routine excavation in the fossil-rich Santiago Formation, but the animal’s identity remains elusive without a skull. El Adli is hoping workers uncover teeth or a lower jaw—crucial clues that could solve the mystery.