Leinkupal is a genus of diplodocine sauropod known from the Early Cretaceous (Late Berriasian to Early Valanginian stage) of the Bajada Colorada Formation, southeastern Neuquén Basin in the Neuquén Province of Argentina. It contains a single species, Leinkupal laticauda.[1]

Leinkupal
Temporal range: Early Valanginian
~136.4 Ma
Cervical and dorsal vertebrae
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: Sauropodomorpha
Clade: Sauropoda
Superfamily: Diplodocoidea
Family: Diplodocidae
Subfamily: Diplodocinae
Genus: Leinkupal
Gallina et al., 2014
Type species
Leinkupal laticauda
Gallina et al., 2014
Synonyms

History of discovery

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Excavation of the holotype
 
Mid caudal vertebrae

In 2010 and 2012, at Picún Leufu in Neuquén Province, remains were uncovered of several types of dinosaurs. One of these was a diplodocoid sauropod new to science.[1]

In 2014, the type species Leinkupal laticauda was named and described by Pablo Gallina, Sebastián Apesteguía, Alejandro Haluza and Juan Canale. The generic name combines the Mapudungun lein, "vanishing", and kupal, "family", in reference to Leinkupal being the last, or youngest, known species of the Diplodocidae. The specific name is derived from Latin, latus, "wide", and cauda, "tail", in reference to the broad caudal vertebrae.[1]

The holotype, MMCH-Pv 63-1, was found in a layer of the Bajada Colorado Formation dating from the BerriasianValanginian. It consists of a front tail vertebra. As paratypes were assigned: MMCH-Pv 63-2/3: two front tail vertebrae; MMCH-Pv 63-4: a hind tail vertebra, MMCH-Pv 63-5: a front dorsal vertebra, MMCH-Pv 63-6: a front tail vertebra; and MMCH-Pv 63-7/8: two vertebrae of the middle tail. Additional possible material has been discovered but was not referred as its identity was uncertain.[1]

A possible second specimen from the Bajada Colorada Formation, MMCh-Pv-232 (a braincase), was described in 2022 as Leinkupal cf.[2]

Description

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Leinkupal was a relatively small sauropod, with an estimated body length of 9 metres (30 ft).[3] Several unique derived traits, or autapomorphies, could be established. The front tail vertebrae have extremely well-developed transverse processes, as long as the width of the vertebral body, expanded sideways and to below, and possessing robust reinforcing ridges on their top and bottom surfaces. The front tail vertebrae have very robust ridges running between the vertebral body and the front joint processes, the prezygapophyses. The front tail vertebrae have rear joint processes, postzygapophyses, with two paired pneumatic openings at their inner bases, opposite from the joint facets.[1]

Classification

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Anterior caudal vertebrae

Leinkupal was placed in the Diplodocinae within the Diplodocidae. A cladistic analysis indicated it was a possible sister species of Tornieria, discovered in Africa. As the latter genus lived much earlier, during the Late Jurassic, this would imply that the Diplodocoidea had an early origin, no later than the Middle Jurassic. The affinity between Leinkupal and Tornieria could be explained by either an early radiation of diplodocines or a later colonising of South-America from Africa. Leinkupal is the only known unequivocal diplodocid from South-America and the youngest unequivocal diplodocid globally, the only known from the Cretaceous.[1]

Cladogram of the Diplodocidae after Tschopp, Mateus, and Benson (2015).[4]

Diplodocidae

Palaeoenvironment

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Leinkupal was discovered in the Bajada Colorada Formation. This formation is composed of red and greenish brown sandstones and conglomerates of fine to coarse grain, in addition to prominent bands of tan siltstones and reddish claystones. These deposits represent a fluvial environment with braided rivers. Paleosols and channels with cross-stratification are present. Leinkupal shared its habitat with several theropods including basal tetanurans, possible deinonychosaurians, and possible abelisauroids, in addition to the dicraeosaurid sauropod Bajadasaurus[1][5] and the early titanosaur Ninjatitan.

References

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  1. ^ a b c d e f g Gallina, P. A.; Apesteguía, S. N.; Haluza, A.; Canale, J. I. (2014). "A Diplodocid Sauropod Survivor from the Early Cretaceous of South America". PLOS ONE. 9 (5): e97128. Bibcode:2014PLoSO...997128G. doi:10.1371/journal.pone.0097128. PMC 4020797. PMID 24828328.
  2. ^ Garderes JP, Gallina PA, Whitlock JA, Toledo N (2022). "Neuroanatomy of a diplodocid sauropod dinosaur from the Lower Cretaceous of Patagonia, Argentina". Cretaceous Research. 129: Article 105024. Bibcode:2022CrRes.12905024G. doi:10.1016/j.cretres.2021.105024. S2CID 239658409.
  3. ^ Gallina, Pablo A.; Apesteguía, Sebastián; Carballido, José L.; Garderes, Juan P. (2022). "Southernmost spiny backs and whiplash tails: Flagellicaudatans from South America". In Otero, Alejandro; Carballido, José L.; Pol, Diego (eds.). South American Sauropodomorph Dinosaurs. Springer International Publishing. pp. 209–236. ISBN 978-3-030-95958-6.
  4. ^ Tschopp, E.; Mateus, O. V.; Benson, R. B. J. (2015). "A specimen-level phylogenetic analysis and taxonomic revision of Diplodocidae (Dinosauria, Sauropoda)". PeerJ. 3: e857. doi:10.7717/peerj.857. PMC 4393826. PMID 25870766.
  5. ^ Gallina, P. A.; Apesteguía, S.; Canale, J. I.; Haluza, A. (2019). "A new long-spined dinosaur from Patagonia sheds light on sauropod defense system". Scientific Reports. 9 (1): 1392. Bibcode:2019NatSR...9.1392G. doi:10.1038/s41598-018-37943-3. PMC 6362061. PMID 30718633.
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