Biology:Luopingosaurus

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Short description: Extinct genus of sauropterygian reptiles

Luopingosaurus
Temporal range: Middle Triassic (Anisian), ~244 Ma
Luopingosaurus holotype.jpg
Luopingosaurus holotype
Scientific classification edit
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Superorder: Sauropterygia
Family: Pachypleurosauridae
Genus: Luopingosaurus
Xu et al., 2023
Species:
L. imparilis
Binomial name
Luopingosaurus imparilis
Xu et al., 2023

Luopingosaurus (meaning "Luoping lizard") is an extinct genus of pachypleurosaurid sauropterygian from the Middle Triassic Guanling Formation of Yunnan Province, China. The genus contains a single species, L. imparilis, known from a well-preserved, nearly complete skeleton.[1]

Discovery and naming

Luopingosaurus skull

The Luopingosaurus holotype specimen, IVPP V19049, was discovered in sediments of the Guanling Formation, dated to the Anisian age (Pelsonian substage) of the middle Triassic period, in Luoping County, Yunnan Province, China. This specimen consists of a nearly complete, ventrally-exposed, articulated individual, lacking only the end of the tail. The preserved portion of the skeleton measures 46.2 centimetres (18.2 in) long.[1]

In 2023, Xu et al. described Luopingosaurus imparilis, a new genus and species of pachypleurosaurid, based on these fossil remains. The generic name, "Luopingosaurus", combines a reference to the type locality in Luoping County with the Greek word "saurus", meaning "lizard". The specific name, "imparilis", means "peculiar" and "unusual" in Latin.[1]

Description

Life restoration of the related, long-snouted Wumengosaurus

Luopingosaurus is one of the largest pachypleurosauroids, with an estimated total body length of 64 centimetres (25 in). It also has an unusually long snout compared to other pachypleurosaurids; the only related taxon with a longer snout is Wumengosaurus, which has occasionally been placed outside of Pachypleurosauroidea by other authors.[2] The evolution of this feature alongside the shorter-snouted keichousaurids may have occurred due to differences in foraging and feeding specializations. The elongated snout may have allowed Luopingosaurus to more effectively catch and hold prey.

Luopingosaurus represents the only known instance of hyperphalangy (an increase in the number of phalanges) in Pachypleurosauroidea, having five phalanges in the third digit as opposed to the plesiomorphic condition of four.[1]

Classification

Xu et al. (2023) recovered Luopingosaurus as a derived pachypleurosaurid member of the Pachypleurosauroidea, as the sister taxon to Honghesaurus. Their results are shown in the cladogram below:[1]

Sauropterygia

Placodontia

Hanosaurus

Eosauropterygia
Pachypleurosauroidea

Majiashanosaurus

Diandongosaurus

Dianmeisaurus

Dawazisaurus

Panzhousaurus

Keichousauridae

Dianopachysaurus

Keichousaurus

Pachypleurosauridae

Dactylosaurus

Anarosaurus

Odoiporosaurus

Serpianosaurus

Neusticosaurus

Prosantosaurus

Qianxisaurus

Wumengosaurus

Luopingosaurus

Honghesaurus

Eusauropterygia

Nothosauroidea

Pistosauroidea

References

  1. 1.0 1.1 1.2 1.3 1.4 Xu, G.-H.; Shang, Q.-H.; Wang, W.; Ren, Y.; Lei, H.; Liao, J.-L.; Zhao, L.-J.; Li, C. (2023). "A new long-snouted marine reptile from the Middle Triassic of China illuminates pachypleurosauroid evolution". Scientific Reports 13 (1): 16. doi:10.1038/s41598-022-24930-y. ISSN 2045-2322. 
  2. Chen, Xiao-hong; Motani, Ryosuke; Long, Chen; Jiang, Da-Yong; Rieppel, Olivier (2014). "The enigmatic marine reptile Nanchangosaurus from the Lower Triassic of Hubei, China and the phylogenetic affinities of Hupehsuchia". PLOS ONE 9 (7): e102361. doi:10.1371/journal.pone.0102361. PMID 25014493. Bibcode2014PLoSO...9j2361C. 

Wikidata ☰ Q116041293 entry