Indeterminate hadrosaurid, nodosaurid, dinosaur egg, and ornithomimosaur fossils are known from Mooreville Chalk outcrops in Alabama.[1] The nodosaurid remains most likely belong to a new taxon.[5]
A. antecessor was originally described as Plegadornis antecessor, but the generic name Plegadornis was preoccupied, so the genus Angelinornis was erected to contain the species. It was later demonstrated that Angelinornis was a junior synonym of Ichthyornis, although the new combination I. antecessor was held to be valid for a while following the sinking of Angelinornis into Ichthyornis. Later the species would later be considered a junior synonym of the Ichthyornis type species, I. dispar.[1]
The species I. antecessor was made the type species of the genus Angelinornis in 1962. Later, I. antecessor and Angelinornis were shown to be junior synonyms of the Ichthyornis type species, I. dispar[1]
The name Plegadornis antecessor was applied to a fossil believed to represent a new bird species, but the generic name Plegadornis was preoccupied, so the genus Angelinornis was erected to contain the "new" species. It was later demonstrated that Angelinornis was a junior synonym of Ichthyornis, although the new combination I. antecessor was held to be valid for a while following the sinking of Angelinornis into Ichthtyornis. Later the species would later be considered a junior synonym of the Ichthyornis type species, I. dispar.[1]
^ abcdefghijklmnopWeishampel, David B; et al. (2004). "Dinosaur distribution (Late Cretaceous, North America)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 574-588. ISBN0-520-24209-2.
^ abcdefChiappe, Luis; Lamb, James P.; Ericson, PER G. P. (2002). "New enantiornithine bird from the marine Upper Cretaceous of Alabama". Journal of Vertebrate Paleontology. 22 (1): 170–174. doi:10.1671/0272-4634(2002)022[0170:NEBFTM]2.0.CO;2.
^Albert Prieto-Márquez, Gregory M. Erickson & Jun A. Ebersole, 2016, "A primitive hadrosaurid from southeastern North America and the origin and early evolution of ‘duck-billed’ dinosaurs", Journal of Vertebrate Paleontology DOI:10.1080/02724634.2015.1054495
^"Table 11.1," in Weishampel, et al. (2004). Page 213.