Tomognathus was a halecomorph fish related to the modern bowfin that lived in the Cretaceous Period. It was named by Dixon in 1850. The name Tomognathus was also later applied to a modern species of ant by Mayr in 1861. But since the name was already taken it came instead to be classified as Harpagoxenus. References Cavin, Lionel; Giner, Stephen (2012). "A large halecomorph fish (Actinopterygii: Holostei) from the Valanginian (Early Cretaceous) of southeast France". Cretaceous Research. 37: 201–208. doi:10.1016/j.cretres.2012.03.020....