''Stephanosaurus'' (meaning "crown lizard") is a

dubious Doubt is a mental state in which the mind remains suspended between two or more contradictory propositions, unable to be certain of any of them. Doubt on an emotional level is indecision between belief and disbelief. It may involve uncertainty ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

hadrosaurid Hadrosaurids (), or duck-billed dinosaurs, are members of the ornithischian family Hadrosauridae. This group is known as the duck-billed dinosaurs for the flat duck-bill appearance of the bones in their snouts. The ornithopod family, which inclu ...

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...

with a complicated

taxonomic Taxonomy is the practice and science of categorization or classification. A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. ...

history.

Trachodon (Pteropelyx) marginatus ulna and radius

In 1902,

Lawrence Lambe Lawrence Morris Lambe (August 27, 1863 – March 12, 1919) was a Canadian geologist, palaeontologist, and ecologist from the Geological Survey of Canada (GSC). His published work, describing the diverse and plentiful dinosaur discoveries from th ...

named a new set of hadrosaurid limb material and other bones (originally GSC 419) from Alberta as '' Trachodon marginatus''. Paleontologists began finding better remains of hadrosaurids from the same rocks in the 1910s, in what is now known as the

late Campanian The Campanian is the fifth of six ages of the Late Cretaceous Epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campanian ...

-age (

Upper Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the ...

)

Dinosaur Park Formation The Dinosaur Park Formation is the uppermost member of the Belly River Group (also known as the Judith River Group), a major geologic unit in southern Alberta. It was deposited during the Campanian stage of the Late Cretaceous, between about 76. ...

. Lambe assigned two new skulls to ''T. marginatus'', and based on the new information, coined the genus ''Stephanosaurus'' for the species in 1914. Lambe retained the original species ''marginatus'', so the

type specimen In biology, a type is a particular wiktionary:en:specimen, specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to a ...

of ''Stephanosaurus'' was the original, scrappy limb bones and crushed skull fragments, not the two new skulls. However, the limb bones and skull fragments could not be reliably said to come from the same animal as the complete skulls, or differentiated from other hadrosaurs. Because there was very little to associate the complete skulls with the scrappy earlier ''marginatus'' material, in 1923 William Parks proposed a new genus and species for the skulls, with both generic and specific names honoring Lambe: ''

Lambeosaurus lambei ''Lambeosaurus'' ( , meaning " Lambe's lizard") is a genus of hadrosaurid dinosaur that lived about 75 million years ago, in the Late Cretaceous period (Campanian stage) of North America. This bipedal/quadrupedal, herbivorous dinosaur is kn ...

'' (

NMC 2869, originally GSC 2869). Stephanosaurinae, a group which Lambe named in 1920, was also renamed

Lambeosaurinae Lambeosaurinae is a group of crested hadrosaurid dinosaurs. Classification Lambeosaurines have been traditionally split into the tribes or clades Parasaurolophini (''Parasaurolophus'', ''Charonosaurus'', others (?).) and Lambeosaurini (''Coryt ...

References

{{Taxonbar, from=Q1291538 Late Cretaceous dinosaurs of North America Hadrosaurs Nomina dubia Paleontology in Alberta Campanian genus first appearances Campanian genus extinctions Ornithischian genera it:Stephanosaurus

See also

References