Xenoposeidon is the earliest known rebbachisaurid sauropod dinosaur

Xenoposeidon proneneukos is a sauropod dinosaur from the Early Cretaceous Hastings Group of England. It is represented by a single partial dorsal vertebra, NHMUK PV R2095, which consists of the centrum and the base of a tall neural arch. Despite its fragmentary nature, it is recognisably distinct fr...

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Main Author: Michael P. Taylor
Format: Article
Language:English
Published: PeerJ Inc. 2018-07-01
Series:PeerJ
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Online Access:https://peerj.com/articles/5212.pdf
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author Michael P. Taylor
author_facet Michael P. Taylor
author_sort Michael P. Taylor
collection DOAJ
description Xenoposeidon proneneukos is a sauropod dinosaur from the Early Cretaceous Hastings Group of England. It is represented by a single partial dorsal vertebra, NHMUK PV R2095, which consists of the centrum and the base of a tall neural arch. Despite its fragmentary nature, it is recognisably distinct from all other sauropods, and is here diagnosed with five unique characters. One character previously considered unique is here recognised as shared with the rebbachisaurid diplodocoid Rebbachisaurus garasbae from the mid-Cretaceous of Morocco: an ‘M’-shaped arrangement of laminae on the lateral face of the neural arch. Following the more completely preserved R. garasbae, these laminae are now interpreted as ACPL and lateral CPRL, which intersect anteriorly; and PCDL and CPOL, which intersect posteriorly. Similar arrangements are also seen in some other rebbachisaurid specimens (though not all, possibly due to serial variation), but never in non-rebbachisaurid sauropods. Xenoposeidon is therefore referred to Rebbachisauridae. Due to its inferred elevated parapophysis, the holotype vertebra is considered a mid-posterior dorsal despite its elongate centrum. Since Xenoposeidon is from the Berriasian–Valanginian (earliest Cretaceous) Ashdown Formation of the Wealden Supergroup of southern England, it is the earliest known rebbachisaurid by some 10 million years. Electronic 3D models were invaluable in determining Xenoposeidon’s true affinities: descriptions of complex bones such as sauropod vertebrae should always provide them where possible.
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spelling doaj.art-df95b75739ba4c11867f37226499e9942023-12-02T21:54:01ZengPeerJ Inc.PeerJ2167-83592018-07-016e521210.7717/peerj.5212Xenoposeidon is the earliest known rebbachisaurid sauropod dinosaurMichael P. TaylorXenoposeidon proneneukos is a sauropod dinosaur from the Early Cretaceous Hastings Group of England. It is represented by a single partial dorsal vertebra, NHMUK PV R2095, which consists of the centrum and the base of a tall neural arch. Despite its fragmentary nature, it is recognisably distinct from all other sauropods, and is here diagnosed with five unique characters. One character previously considered unique is here recognised as shared with the rebbachisaurid diplodocoid Rebbachisaurus garasbae from the mid-Cretaceous of Morocco: an ‘M’-shaped arrangement of laminae on the lateral face of the neural arch. Following the more completely preserved R. garasbae, these laminae are now interpreted as ACPL and lateral CPRL, which intersect anteriorly; and PCDL and CPOL, which intersect posteriorly. Similar arrangements are also seen in some other rebbachisaurid specimens (though not all, possibly due to serial variation), but never in non-rebbachisaurid sauropods. Xenoposeidon is therefore referred to Rebbachisauridae. Due to its inferred elevated parapophysis, the holotype vertebra is considered a mid-posterior dorsal despite its elongate centrum. Since Xenoposeidon is from the Berriasian–Valanginian (earliest Cretaceous) Ashdown Formation of the Wealden Supergroup of southern England, it is the earliest known rebbachisaurid by some 10 million years. Electronic 3D models were invaluable in determining Xenoposeidon’s true affinities: descriptions of complex bones such as sauropod vertebrae should always provide them where possible.https://peerj.com/articles/5212.pdfXenoposeidonRebbachisauridaeSauropodaDinosauriaLaminaeWealden
spellingShingle Michael P. Taylor
Xenoposeidon is the earliest known rebbachisaurid sauropod dinosaur
PeerJ
Xenoposeidon
Rebbachisauridae
Sauropoda
Dinosauria
Laminae
Wealden
title Xenoposeidon is the earliest known rebbachisaurid sauropod dinosaur
title_full Xenoposeidon is the earliest known rebbachisaurid sauropod dinosaur
title_fullStr Xenoposeidon is the earliest known rebbachisaurid sauropod dinosaur
title_full_unstemmed Xenoposeidon is the earliest known rebbachisaurid sauropod dinosaur
title_short Xenoposeidon is the earliest known rebbachisaurid sauropod dinosaur
title_sort xenoposeidon is the earliest known rebbachisaurid sauropod dinosaur
topic Xenoposeidon
Rebbachisauridae
Sauropoda
Dinosauria
Laminae
Wealden
url https://peerj.com/articles/5212.pdf
work_keys_str_mv AT michaelptaylor xenoposeidonistheearliestknownrebbachisauridsauropoddinosaur