Erliansaurus

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Erliansaurus
Temporal range: Late Cretaceous,
~96  Ma
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Erliansaurus mount.jpg
Mounted skeleton cast
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: Theropoda
Superfamily: Therizinosauroidea
Family: Therizinosauridae
Genus: Erliansaurus
Xu et al. 2002
Type species
Erliansaurus bellamanus
Xu et al. 2002

Erliansaurus (meaning "Erlian lizard") is a genus of therizinosaur theropod dinosaur that lived in Asia during the Cenomanian stage of the Late Cretaceous period in what is now Nei Mongol, Iren Dabasu Formation.

Contents

Discovery and naming

Skeletal restoration Erliansaurus skeleton.jpg
Skeletal restoration

The remains of Erliansaurus were found near Sanhangobi in Inner Mongolia in 1999. The type species, Erliansaurus bellamanus, was described by Xu Xing, Zhang Xiaohong, Paul Sereno, Zhao Xijin, Kuang Xuewen, Han Jun and Tan Lin in 2002. The generic name refers to the town of Erlian and the specific name is derived from Latin bellus, "beautiful", and manus, "hand", in reference to the exquisite preservation of the forelimb. [1]

The holotype, LH V0002, was uncovered in the Iren Dabasu Formation dating from the Cenomanian stage. It consists of a partial skeleton belonging to a subadult individual. It includes two cervical, one dorsal and two caudal vertebrae; a right scapula; a left forelimb only lacking the carpus; a partial right ilium and a fragmented ischium and pubis; the right femur; both tibiae, a right fibula and partial metatarsals. No skull traces were found. [1]

Description

Life restoration Erliansaurus bellamanus.jpg
Life restoration

The holotype specimen represents a not fully-grown individual based on one unfused caudal vertebra, and therefore its adult size may be larger than the contemporary Neimongosaurus . [1] It was a small to medium-sized therizinosaur with an estimated length from 2.6 to 4 m (8.5 to 13.1 ft) and a weight of 91 to 400 kg (201 to 882 lb). [2] [3]

Erliansaurus was a bipedal herbivore. For a therizinosauroid, its cervicals were rather short. The preserved femur was very straight and had a very rounded femoral head; it measures 41.2 cm (412 mm). The tibia was relatively elongated, measuring 37.3 cm (373 mm) long. Its fibula had an uncommon form, with a very high front edge and a concave top. The left arm is exceptionally preserved with almost every element intact, its hands bore enormous, strongly recurved and pointed claws of which the thumb claw was the largest, however, the carpal bones are missing. [1]

Classification

Erliansaurus was by the describers assigned to the Therizinosauroidea, in a basal position and likely not a therizinosaurid. [1] The cladistic analysis performed by the revision of Zanno in 2010 recovered it as a therizinosauroid. [4] Some early cladistic analyses however, have recovered it as a basal member of the Therizinosauridae. The cladogram below is the result of the recently performed phylogenetic analysis of the Therizinosauridae by Hartman et al. 2019. [5]

Therizinosauridae

Suzhousaurus

Neimongosaurus

Therizinosaurus

Erliansaurus

Nanchao embryos

Nanshiungosaurus

Segnosaurus

AMNH 6368

Erlikosaurus

Nothronychus graffami

Nothronychus mckinleyi

See also

Related Research Articles

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<i>Erlikosaurus</i> Extinct genus of therizinosaurid dinosaur from the Late Cretaceous

Erlikosaurus is a genus of therizinosaurid that lived in Asia during the Late Cretaceous period. The fossils, a skull and some post-cranial fragments, were found in the Bayan Shireh Formation of Mongolia in 1972, dating to around 96 million and 89 million years ago. These remains were later described by Altangerel Perle and Rinchen Barsbold in 1980, naming the new genus and species Erlikosaurus andrewsi. It represents the second therizinosaur taxon from this formation with the most complete skull among members of this peculiar family of dinosaurs.

<i>Neimongosaurus</i> Extinct genus of dinosaurs

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<i>Nanshiungosaurus</i> Extinct genus of reptiles

Nanshiungosaurus is a genus of therizinosaurid that lived in what is now Asia during the Late Cretaceous of South China. The type species, Nanshiungosaurus brevispinus, was first discovered in 1974 and described in 1979 by Dong Zhiming. It is represented by a single specimen preserving most of the cervical and dorsal vertebrae with the pelvis. A supposed and unlikely second species, "Nanshiungosaurus" bohlini, was found in 1992 and described in 1997. It is also represented by vertebrae but this species however, differs in geological age and lacks authentic characteristics compared to the type, making its affinity to the genus unsupported.

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<i>Suzhousaurus</i> Extinct genus of dinosaurs

Suzhousaurus is a genus of large therizinosauroid dinosaur from the Early Cretaceous of China. The genus is known from two specimens discovered on the Xiagou Formation and Zhonggou Formation—which are situated in the Xinminbao Group. These findings were made during field-works in 1999 and 2004. Though Suzhousaurus is known from these two specimens, an earlier named and described therizinosauroid from the adjacent basin, "Nanshiungosaurus" bohlini, may be synonymous with the former. However, Suzhousaurus can not be compared to this species due to non-overlapping material and the loss of the same. Moreover, this synonymy will result in Suzhousaurus bohlini with "N". bohlini having priority.

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Timeline of therizinosaur research

The timeline of therizinosaur research is a chronological listing of events in the history of paleontology focused on therizinosaurs. They were unusually long-necked, pot-bellied, and large-clawed herbivorous theropods most closely related to birds. The early history of therizinosaur research occurred in three phases. The first phase was the discovery of scanty and puzzling fossils in Asia by the Central Asiatic Expeditions of the 1920s and Soviet-backed research in the 1950s. This phase resulted in the discovery of the Therizinosaurus cheloniformis type specimen. Soviet paleontologist Evgeny Maleev interpreted these unusual remains as belonging to some kind of gigantic turtle.

References

  1. 1 2 3 4 5 Xu, X.; Zhang, Z.-H.; Sereno, P. C.; Zhao, X.-J.; Kuang, X.-W.; Han, J.; Tan, L. (2002). "A new therizinosauroid (Dinosauria, Theropoda) from the Upper Cretaceous Iren Dabasu Formation of Nei Mongol" (PDF). Vertebrata PalAsiatica. 40: 228–240.
  2. Holtz, T. R.; Rey, L. V. (2007). Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages . Random House. ISBN   9780375824197. Genus List for Holtz 2012 Weight Information
  3. Paul, G. S. (2016). The Princeton Field Guide to Dinosaurs (2nd ed.). Princeton, New Jersey: Princeton University Press. pp. 151−152. ISBN   9780691167664.
  4. Zanno, L. E. (2010). "A taxonomic and phylogenetic re-evaluation of Therizinosauria (Dinosauria: Maniraptora)". Journal of Systematic Palaeontology. 8 (4): 503–543. doi:10.1080/14772019.2010.488045. S2CID   53405097.
  5. Hartman, S.; Mortimer, M.; Wahl, W. R.; Lomax, D. R.; Lippincott, J.; Lovelace, D. M. (2019). "A new paravian dinosaur from the Late Jurassic of North America supports a late acquisition of avian flight". PeerJ. 7: e7247. doi: 10.7717/peerj.7247 . PMC   6626525 . PMID   31333906.