Species: agilis (MARSH, 1872) MARSH, 1890
Etymology: Latin, agilis, "agile, nimble."
= Hadrosaurus agilis MARSH, 1872
= Trachodon agilis (MARSH, 1872) KUHN, 1936
Holotype: YPM 1190
Locality: Near Smokey Hill River, SE. 29 or 29, T13S, R34W, 26 m E of Fort Wallace, Logan County, Kansas.
Horizon: Smoky Hill Chalk Member, Niobrara Formation.
Age: Santonian or Campanian Stage, Senonian Subepoch, Gulf Epoch, Late Cretaceous.
Material: Parts of maxillae and dentary, the vertebreal column practically
complete, right scapula, both sternals, both humeri, both radii and ulnae,
right ilium, both femora, 1 fibula and both feet.
Note: BROWN, 1907 reports 3 gastroliths found near the front legs, but he may be referring to an Edmontosaurus sp skeleton and not this specimen.