{"pk":62358,"title":"Extinct Carnivores Entombed in 20 Million Year Old Dens, Agate Fossil Beds National Monument, Nebraska","subtitle":null,"abstract":"This study documents the discovery and analysis of 20-million-year-old carnivore dens at Agate Fossil Beds National Monument, Nebraska—the oldest known evidence of denning behavior in large mammalian carnivores. Originally excavated in 1905 and rediscovered in 1981, Carnegie Quarry 3 yielded an unusually high concentration of carnivore fossils, particularly of the amphicyonid \"beardog\" Daphoenodon superbus. Subsequent excavations revealed a complex of burrows and partially articulated skeletons, providing compelling evidence that the site served as an ancient denning area. The discovery of multiple burrows with stratified infill, disarticulated remains, and a range of individual ages supports the hypothesis of repeated use by successive generations of carnivores. These findings offer unprecedented insights into the behavioral ecology of extinct mid-Cenozoic predators and mark the earliest documented instance of such behavior in the fossil record. Continued research at the site may further illuminate the ecological dynamics and evolutionary history of these ancient carnivores.","language":"eng","license":{"name":"","short_name":"","text":null,"url":""},"keywords":[],"section":"Article","is_remote":true,"remote_url":"https://escholarship.org/uc/item/52b230s3","frozenauthors":[{"first_name":"Robert","middle_name":"","last_name":"Hunt","name_suffix":"","institution":"","department":""}],"date_submitted":null,"date_accepted":null,"date_published":"1984-01-01T18:00:00Z","render_galley":null,"galleys":[{"label":"PDF","type":"pdf","path":"https://journalpub.escholarship.org/gwf/article/62358/galley/48195/download/"}]}