Alioramini

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Alioramins
Temporal range: Late Cretaceous,
~70–66  Ma
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Alioramus altai skull at AMNH.jpg
Holotype skull of Alioramus altai
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: Theropoda
Family: Tyrannosauridae
Subfamily: Tyrannosaurinae
Tribe: Alioramini
Olshevsky, 1995
Type species
Alioramus remotus
Kurzanov 1976
Genera
Size comparison of three alioramin species with a human Alioramini Scale.svg
Size comparison of three alioramin species with a human

Alioramini is a tribe of long-snouted tyrannosaurine tyrannosaurids from the Late Cretaceous epoch. It includes the tyrannosaurid genera Alioramus and Qianzhousaurus . Although tyrannosaurids are known from a variety of places around the globe, alioramins are currently restricted to Asia in mostly Maastrichtian strata. [1]

Contents

Alioramins were medium-sized tyrannosaurids, reaching around 5–7 m (16–23 ft) in length. [2] [3] Their snouts were much shallower and gracile than other tyrannosaurids, such as the massive Tarbosaurus or Tyrannosaurus . Most notably, their nasal bones were ornamented with a series of rugose, pointy bumps on its top surface. [4]

The tribe Alioramini was first coined in 1995 by George Olshevsky only to contain the at-the-time uncertain Alioramus. [5] In 2014 the tribe was formally defined as a clade-based branch containing all tyrannosaurids more related to Alioramus than to Albertosaurus , Proceratosaurus , and Tyrannosaurus. Hence, the tribe Alioramini consists of three species, namely Alioramus altai, Alioramus remotus, and Qianzhousaurus sinensis. [1]

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 with other tyrannosaurids. [6] [7] The characteristic elongated snout morphology of alioramins was likely maintained throughout their ontogeny (growth), as opposed to large/robust tyrannosaurids, whose juveniles underwent drastic skull changes. [7]

See also

Related Research Articles

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<i>Alioramus</i> Tyrannosaurid theropod dinosaur genus from the Late Cretaceous period

Alioramus 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 three foot bones recovered from the Mongolian Nemegt Formation, which was deposited in a humid floodplain about 70 million years ago. These remains were named and described by Soviet paleontologist Sergei Kurzanov in 1976. A second species, A. altai, known from a much more complete skeleton also from the Nemegt Formation, was named and described by Stephen L. Brusatte and colleagues in 2009. Its relationships to other tyrannosaurid genera were at first unclear, with some evidence supporting a hypothesis that Alioramus was closely related to the contemporary species Tarbosaurus bataar. However, the discovery of Qianzhousaurus indicates that it belongs to a distinct branch of tyrannosaurs, namely the tribe Alioramini.

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<span class="mw-page-title-main">Timeline of tyrannosaur research</span>

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References

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