It is through this identification of juveniles that the growth of Lambeosaurus is well-known, with the crest developing late but expanding in height by an order of magnitude by the time individuals reached adulthood.

Dental wear suggests that Lambeosaurus would have avoided competition with Prosaurolophus by occupying different feeding niches, preferring more closed habitats and browsing lower to the ground with a more generalist diet.

The habitat Lambeosaurus lived in was a coastal plain where meandering river separated regions of dense vegetation, covered in a diversity of conifers, ferns and other shrubs, and occupied by plentiful invertebrates, fishes, mammals and reptiles, especially other megaherbivorous dinosaurs.

[8] In the same publication, American palaeontologist Henry Fairfield Osborn summarized the fauna of the mid-Cretaceous across North America, and even provided the possible new subgenus name Didanodon for T.

[6] In, 1942, American paleontologists Richard Swann Lull and Nelda E. Wright reviewed the extensive number of hadrosaur genera and species to consolidate the available information into a single consistent source.

This specimen had been found in 1961 at the Shakh-Shakh locality 45 km (28 mi) north of Tashkent, as the most complete dinosaur discovered in Kazakhstan, and came from the Santonian aged Dabrazinskaya Svita.

[19] In 1975, American palaeontologist Peter Dodson assessed how crest shape changed during growth in lambeosaurines based on comparisons with modern reptiles and by assuming that smaller individuals were younger.

Dodson reassessed the 12 named species of Lambeosaurus, Procheneosaurus and Corythosaurus believed to have lived together in the Oldman Formation (historic Belly River series), analysing the crests of a total of 36 individuals.

[32] In 1979, American palaeontologist John R. Horner assigned partial jaw bones from the Bearpaw Formation of Montana to L. magnicristatus, representing the first lambeosaur specimen from marine sediments.

[34] British and American paleontologists David B. Norman and Hans-Dieter Sues, on the other hand, argued that Jaxartosaurus was too separate in time and space from Procheneosaurus convincens, and that although its validity was questionable, it could not be assigned to any known genera.

The type, CMN 8705, was originally a largely complete skeleton and skull when excavated, but prior to being named by Sternberg it was significantly damaged by water, destroying much of the limbs and girdles which were discarded.

After being acquired by the PMAA, it was prepared for exhibition, with the better-preserved right side being exposed and bolted into a large wooden frame with styrofoam blocks cut out to hold it in place.

It was more distant from the species of Lambeosaurus, and showed enough anatomical differences that they gave it the new genus name Magnapaulia after Paul G. Haaga Jr. for his support of the Natural History Museum of Los Angeles County.

[31][47][48] It was a large hadrosaurid, with highly developed jaws full of grinding teeth, a long tail stiffened by ossified tendons that prevented it from drooping, and more elongate limbs suggesting they were semi-quadrupedal and could move on both two legs and all fours as shown by footprints of related animals.

The surangular is the larger of the bones behind the dentary, with a robust central region supporting the jaw joint and a shallow but distinct triangular depression for muscle attachment.

The teeth of both jaws are typical for lambeosaurines, being very tall relative to their width, having very faint crenellations along their edges, and showing a single strong keel along the center of the side possessing enamel.

The opposite end of the ischium is sharply expanded into a pendant foot, which, though large and unique to lambeosaurines, is similar between Lambeosaurus species as being smaller than Parasaurolophus and Hypacrosaurus.

[5] German palaeontologist Friedrich von Huene supported similar relationships in his classifications of hadrosaurs, but elevated the subfamilies to family rank creating Lambeosauridae in 1948 and Cheneosauridae in 1956.

Early studies suggested that hadrosaurs were amphibious, but they are now understood to have been facultative bipeds that walked quadrupedally when moving slowly or standing still, but adopted a bipedal stance to run.

[72] Hadrosaur teeth show more pit marks than ceratopsids which are known to have consumed high-fibre diets and also have dental batteries, providing more evidence for the consumption of fruits and seeds in Lambeosaurus.

[13][26] Alternative suggestions have included ideas that the crest served to assist with underwater feeding, an improved sense of smell (olfaction), thermoregulation, sodium regulation, communication, or sexual identification.

Under this hypothesis, juveniles with smaller crests would have produced higher-frequency vocalizations, while adults would make lower sounds that would be able to travel across greater distances to assist in socialization.

[50] In 2006, David Evans conducted the first detailed study of the available braincase material of lambeosaurines in an effort to support or disprove the possibility that the crest aided in smell suggested by Ostrom.

The youngest faunal zone coincides with the presence of bituminous coal at 75.098 mya, and the replacement of the common megaherbivores from older beds with the much rarer L. magnicristatus, and ceratopsids including Chasmosaurus irvinensis and a form like Achelousaurus.

The rivers of the coastal plain were lined with narrow zones of dense vegetation, and as the seaway approached some areas would see periodic flooding or even standing swamps or mires that accumulated into the coal deposits.

[79] A rich and diverse vertebrate assemblage is known from the Dinosaur Park Formation, with the lower region, excluding the Lethbridge Coal Zone, being formed by terrestrial and coastal deposits.

[81] In the lower Dinosaur Park Formation, assemblages of crevasse sites show that mollusks were commonly dominated by the freshwater clam Sphaerium, which occurred with abundant gastropods of the genera Goniobasis and Lioplacodes.

The ray Myledaphus is characteristic of the formation and lived alongside the less common shark Hybodus montanensis, and paddlefish, sturgeons, bowfins, the aspidorhynchid Belonostomus, the gar Lepisosteus, and small teleosts including Paratarpon and Cretophareodus.

[82] At least nine forms of amphibians were present in the Dinosaur Park Formation, including the salamander-like Albanerpeton, frogs, and salamanders from the genera Scapherpeton, Lisserpeton, Opisthotriton, Habrosaurus.

[86] The major types of Cretaceous mammals have been found in the Dinosaur Park Formation: the multituberculates Cimexomys, Cimolodon, Cimolomys, Meniscoessus, and Mesodma, the marsupials Alphadon, Eodelphis, Pediomys, and Turgidodon, and the placentals Cimolestes, Gypsonictops, and Paranyctoides.