Anatosaurus

Anatosaurus to the present

This confusing situation was temporarily resolved in 1942 by Richard Swann Lull and Nelda Wright. In their monograph on hadrosaurian dinosaurs of North America, they opted to settle the questions revolving around the AMNH duckbills, Marsh's Claosaurus annectens, and several other species, by creating a new generic name. They created the new genus Anatosaurus (meaning "duck lizard", because of its wide, duck-like beak; Latinanas = duck + Greeksauros = lizard), and made Marsh's species the type species, calling it Anatosaurus annectens. They also assigned Marsh's Trachodon longiceps to this genus, a pair of species that had been assigned to Thespesius under Gilmore's "Lance Formation hadrosaurid" conception (T. edmontoni from Gilmore in 1924 and T. saskatchewanensis), and Cope's Diclonius mirabilis. Lull and Wright decided to remove the AMNH specimens from Diclonius (or Trachodon), because they found no convincing reason to assign the specimens to either. Because this left the skeletons without a species name, Lull and Wright gave them their own species: Anatosaurus copei, in honor of Cope. Cope's original specimen, AMNH 5730, was made the holotype of the species, with Brown's AMNH 5886 as the plesiotype. Anatosaurus would come to be called the "classic duck-billed dinosaur".