Alioramini is a

tribe 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 confli ...

of long-snouted

tyrannosaurine The tyrannosaurines (Tyrannosaurinae) is an extinct subfamily of Tyrannosauridae a family of coelurosaurian theropod dinosaurs that consists of at least three tribes and several genera. All fossils of these genera have been found in the Late Cret ...

tyrannosaurids Tyrannosauridae (or tyrannosaurids, meaning "tyrant lizards") is a family (biology), family of coelurosaurian Theropoda, theropod dinosaurs that comprises two subfamilies containing up to thirteen genus, genera, including the eponymous ''Tyrannos ...

from the

Late 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'', ...

epoch. It includes the tyrannosaurid genera ''

Alioramus ''Alioramus'' (; meaning 'different branch') is a genus of tyrannosaurid theropod dinosaurs from the Late Cretaceous period of Asia. It currently contains two species. The type species, ''A. remotus'' is known from a partial skull and thre ...

'' and '' Qianzhousaurus''. Although tyrannosaurids are known from a variety of places around the globe, alioramins are currently restricted to

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 are ...

in mostly

Maastrichtian The Maastrichtian () is, in the ICS geologic timescale, the latest age (uppermost stage) of the Late Cretaceous Epoch or Upper Cretaceous Series, the Cretaceous Period or System, and of the Mesozoic Era or Erathem. It spanned the interval ...

strata. Alioramins were medium-sized tyrannosaurids, reaching around in length. Their snouts were much shallower and gracile than other tyrannosaurids, such as the massive ''

Tarbosaurus ''Tarbosaurus'' ( ; meaning "alarming lizard") is a genus of tyrannosaurid dinosaur that flourished in Asia about 70 million years ago, at the end of the Late Cretaceous Period, considered to contain a single known species, ''Tarbosaurus ba ...

'' or ''

Tyrannosaurus ''Tyrannosaurus'' is a genus of large theropod dinosaur. The species ''Tyrannosaurus rex'' (''rex'' meaning "king" in Latin), often called ''T. rex'' or colloquially ''T-Rex'', is one of the best represented theropods. ''Tyrannosaurus'' live ...

''. Most notably, their nasal bones were ornamented with a series of rugose, pointy bumps on its top surface. The tribe Alioramini was first coined in 1995 by George Olshevsky only to contain the at-the-time uncertain ''Alioramus''. In 2014 the tribe was formally defined as a clade-based branch containing all tyrannosaurids more related to ''Alioramus'' than to ''

Albertosaurus ''Albertosaurus'' (; meaning "Alberta lizard") is a genus of tyrannosaurid theropod dinosaurs that lived in western North America during the Late Cretaceous Period, about 71 million years ago. The type species, ''A. sarcophagus'', wa ...

'', ''

Proceratosaurus ''Proceratosaurus'' is a genus of carnivorous theropod dinosaur from the Middle Jurassic ( Bathonian) of England. ''Proceratosaurus'' was a small dinosaur, measuring in length and in body mass.Holtz, Thomas R. Jr. (2008) ''Dinosaurs: The Mos ...

'', and ''Tyrannosaurus''. Hence, the tribe Alioramini consists of three species, namely ''Alioramus altai'', ''Alioramus remotus'', and ''Qianzhousaurus sinensis''. Alioramins were likely specialized in hunting small-sized prey with quick turns, as indicated by their relative gracile build and long snouts. Such feeding strategy may have avoided direct

competition Competition is a rivalry where two or more parties strive for a common goal which cannot be shared: where one's gain is the other's loss (an example of which is a zero-sum game). Competition can arise between entities such as organisms, indiv ...

with other tyrannosaurids. The characteristic elongated snout morphology of alioramins was likely maintained throughout their

ontogeny Ontogeny (also ontogenesis) is the origination and development of an organism (both physical and psychological, e.g., moral development), usually from the time of fertilization of the egg to adult. The term can also be used to refer to the s ...

(growth), as opposed to large/robust tyrannosaurids, whose juveniles underwent drastic skull changes.

References

External links

* *
Skeletal reconstructions of ''Alioramus'' and ''Qianzhousaurus''
at

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{{Taxonbar, from=Q17620750 Tyrannosaurs Maastrichtian extinctions

See also

References

External links