Lambeosaurini, previously known as Corythosaurini, is one of four

tribes The term tribe is used in many different contexts to refer to a category of human social group. The predominant worldwide usage of the term in English is in the discipline of anthropology. This definition is contested, in part due to conflic ...

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 ...

ornithopods Ornithopoda () is a clade of ornithischian dinosaurs, called ornithopods (), that started out as small, bipedal running grazers and grew in size and numbers until they became one of the most successful groups of herbivores in the Cretaceous world ...

from the family

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 ('' C ...

. It is defined as all lambeosaurines closer to ''

Lambeosaurus ''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 k ...

lambei'' than to ''

Parasaurolophus ''Parasaurolophus'' (; meaning "near crested lizard" in reference to '' Saurolophus)'' is a genus of herbivorous hadrosaurid ornithopod dinosaur that lived in what is now North America and possibly Asia during the Late Cretaceous Period, abou ...

walkeri,

Tsintaosaurus ''Tsintaosaurus'' (; meaning "Qingdao lizard", after the old transliteration "Tsingtao") is a genus of hadrosaurid dinosaur from China. It was about long and weighed . The type species is ''Tsintaosaurus spinorhinus'', first described by Chine ...

spinorhinus, or

Aralosaurus ''Aralosaurus'' was a genus of hadrosaurid dinosaur that lived during the Late Cretaceous in what is now Kazakhstan. It is known only by a posterior half of a skull (devoid of its mandible) and some post-cranial bones found in the Bostobe Formati ...

tuberiferus'', which define the other three tribes. Members of this tribe possess a distinctive protruding cranial crest. Lambeosaurins walked the earth for a period of around 12 million years in the Late

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...

, though they were confined to regions of modern-day

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

and

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an area ...

History of classification

The term Corythosaurini was first used by Brett-Surman in 1989, who characterized the taxon via reference to the premaxilary expansion into a hollow helmet-like cranial crest, as well as higher neural spines. The clade was formally defined via phylogenetic analysis by Evans and Reisz in 2007, and this was confirmed by multiple other analyses. In 2011, Sullivan ''et al.'' observed that by the rules of priority set by the

International Code of Zoological Nomenclature The International Code of Zoological Nomenclature (ICZN) is a widely accepted convention in zoology that rules the formal scientific naming of organisms treated as animals. It is also informally known as the ICZN Code, for its publisher, the ...

, the name of the tribe ought to be Lambeosaurini due to its containing the defining type genus (''Lambeosaurus'') of its superior taxon (Lambeosaurinae).

Anatomy

The current articulation of lambeosaurin anatomy is given by Prieto-Marquez ''et al.'', who characterised the tribe by the following traits: * "Vertical groove on lateral process of premaxilla, located rostral to dorsal process of maxilla and extending ventrally from small opening between premaxillary medial and lateral processes" * "Vertical groove bounded rostrally by triangular ventral projection of lateral process of the premaxilla" * "Nasal articulation surface for frontal shaped into rostroventrally-sloping platform" * "Nasal vestibule folded into S-loop in enclosed premaxillary passages rostral to dorsal process of maxilla" * "Lateral premaxillary process extending caudodorsal to prefrontal in adults" Lambeosaurines are classified into Lambeosaurini and

Parasaurolophini Parasaurolophini is a tribe of derived corythosaurian lambeosaurine hadrosaurids that are native to Asia, and North America. It is defined as everything closer to ''Parasaurolophus walkeri'' than to '' Lambeosaurus lambei''. It currently contain ...

based on the similarity with these characteristics or those defining Parasaurolophini. Another method of distinguishing the tribes is by the angle of the dural peak. Lambeosaurins possess a dural peak with an angle over 120°, while in parasaurolophins the angle is less than 90°. The anterior semicircular canals are also taller in parasaurolophins than lambeosaurins.

Phylogeny

Prieto-Marquez' analysis (2013) yielded the following cladogram, which shows the relative positions of the four Lambeosaurine tribes.

Nipponosaurus ''Nipponosaurus'' (meaning "Japanese lizard") is a lambeosaurine hadrosaur from sediments of the Yezo Group, in Sinegorsk on the island of Sakhalin, which was part of Japan at the time of the species' classification. The type and only species ...

has historically been considered to be a member of Lambeosaurini, but its position within the tribe is debated. A 2018 analysis by Takasaki et al. disputed this placement, instead placing Nipponosaurus in a clade with Arenysaurus and Blasisaurus as a sister taxa to Lambeosaurini. An alternative phylogenetic analysis by Xing et al. (2017) produced the following cladogram, which similarly places Arenysaurus outside Lambeosaurini.

References

{{Taxonbar, from=Q16707704 Lambeosaurines

History of classification

Anatomy

Phylogeny

See also

References