Largirostrornis is a Genus of enantiornithine bird. One species is known, Largirostornis sexdentoris. It lived during the Early Cretaceous and is known from fossils found in the Jiufotang Formation in Liaoning province, People's Republic of China. Some researchers believe this species to be a synonym of the similar Cathayornis yandica. It is known from one fossil, slab and counterslab, found in the Jiufotang Formation in Liaoning province, People's Republic of China. The Jiufotang Formation is dated to the Early Cretaceous period, Aptian age, 120.3 +/-0.7 million years ago.