Genus: Angulomastacator WAGNER & LEHMAN, 2009
Etymology: Latin, Angulus, 'corner, angle'; in reference both to the unusual morphology of the maxilla and the Big Bend of the Rio Grande, and Greek, 'jaw, mouth', and Latin, tor, signifying agency; preferred translation 'bend chewer'.

Species: daviesi WAGNER & LEHMAN, 2009
Etymology: In honor of Kyle L. Davies, first to suggest the presence of a lambeosaurine in the Aguja Formation, in recognition of his significant contribution to the study of hadrosaurs of Big Bend, and in gratitude for his generous assistnace to both authors of this work.

Holotype: TMM 43681-1

Locality: TMM 43681, near Dawson Creek, Big Bend, Brewster County, Texas.

Note: Precise locality information for qualified researchers on file at the TMM.

Horizon: Upper shale member, Aguja Formation.

Biostratigraphy:

Age: Campanian Stage, Senonian subepoch, Upper Gulf epoch, Late Cretaceous.

Material: Incomplete left maxilla.