Timeline of hadrosaur research

Scientific research on hadrosaurs began in the 1850s,[1] when Joseph Leidy described the genera Thespesius and Trachodon based on scrappy fossils discovered in the western United States.

[2] The early 20th century saw such a boom in hadrosaur discoveries and research that paleontologists' knowledge of these dinosaurs "increased by virtually an order of magnitude" according to a 2004 review by Horner, Weishampel, and Forster.

This period is known as the great North American Dinosaur rush because of the research and excavation efforts of paleontologists like Brown, Gilmore, Lambe, Parks, and the Sternbergs.

[3] In 1942 Richard Swann Lull and Wright published what Horner, Weishampel, and Forster characterized as the "first important synthesis of hadrosaurid anatomy and phylogeny".

In 2000, Horner and others found that hatchling Maiasaura grew to adult body sizes at a rate more like a mammal's than a reptile.