2005/02/10 by Thomas H. Rich, James A. Hopson, Anne M. Musser +2 · 1 citation
Earth and Planetary Sciences · Agricultural and Biological Sciences · #Evolution and Paleontology Studies #Paleontology and Evolutionary Biology #Bat Biology and Ecology Studies #Anatomy #Biology #Middle ear #Monotreme #Theria #Mandible (arthropod mouthpart) #Evolution of mammals #Zoology #Paleontology
paper · doi:10.1126/science.1105717
openalex publication_date 2005/02/10 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
A dentary of the oldest known monotreme, the Early Cretaceous Teinolophos trusleri, has an internal mandibular trough, which in outgroups to mammals houses accessory jaw bones, and probable contact facets for angular, coronoid, and splenial bones. Certain of these accessory bones were detached from the mandible to become middle ear bones in mammals. Evidence that the angular (homologous with the mammalian ectotympanic) and the articular and prearticular (homologous with the mammalian malleus) bones retained attachment to the lower jaw in a basal monotreme indicates that the definitive mammalian middle ear evolved independently in living monotremes and therians (marsupials and placentals).