Brontomerus (from Greek bronte meaning "thunder", and merós meaning "thigh") is a possibly dubious genus of camarasauromorph sauropod which lived during the early Cretaceous (Aptian or Albian age, approximately 110 million years ago). It was named in 2011 and the type species is Brontomerus mcintoshi. It is probably a fairly basal camarasauromorph, though the taxon is difficult to resolve due to incompleteness of the material. It is most remarkable for its unusual hipbones, which would have supported the largest thigh muscles, proportionally, of any known sauropod. The specific name is in honor of physicist and North American sauropod guru John "Jack" Stanton McIntosh.