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| Portellsaurus sosbaynati Santos-Cubedo, de Santisteban, Poza & Meseguer, 2021 |
Abstract
A new styracosternan ornithopod genus and species is described based on the right dentary of a single specimen from the Mirambell Formation (Early Cretaceous, early Barremian) at the locality of Portell, (Castellón, Spain). Portellsaurus sosbaynati gen. et sp. nov. is diagnosed by two autapomorphic features as well as a unique combination of characters. The autapomorphies include: the absence of a bulge along the ventral margin directly ventral to the base of the coronoid process and the presence of a deep oval cavity on the medial surface of the mandibular adductor fossa below the eleventh-twelfth tooth position. Phylogenetic analyses reveal that the new Iberian form is more closely related to the African taxon Ouranosaurus nigeriensis than to its synchronic Iberian taxa Magnamanus soriaensis and Iguanodon galvensis. In addition, Portellsaurus sosbaynati is less related to other Iberian taxa such as Iguanodon bernissartensis and Proa valdearinnoensis than to the other Early Cretaceous Iberian styracosternans Mantellisaurus atherfieldensis and Morelladon beltrani. A new phylogenetic hypothesis is proposed that resolves Iguanodon (I. bernissartensis, I. galvensis) with the Valanginian Barilium dawsoni into a monophyletic clade (Iguanodontoidea). The recognition of Portellsaurus sosbaynati gen. et sp. nov. as the first styracosternan dinosaur species identified from the Margas de Mirambell Formation (early Barremian–early late Barremian) in the Morella sub-basin (Maestrat Basin, eastern Spain) indicates that the Iberian Peninsula was home to a highly diverse assemblage of medium-to-large bodied styracosternan hadrosauriforms during the Early Cretaceous.
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| Fig 2. Right dentary (MQ98-II-1) of Portellsaurus sosbaynati. Labial (A), lingual (B), and occlusal (C) views. (D) Enlargement (2x) of a dental crown fragment at the tooth row. Scale bar equals 10 cm. |
Systematic palaeontology
Dinosauria Owen, 1842
Ornithischia Seeley, 1887
Ornithopoda Marsh, 1881
Iguanodontia Dollo, 1888 sensu Sereno, 2005
Ankylopollexia Sereno, 1986 sensu Sereno, 2005
Styracosterna Sereno, 1986 sensu Sereno, 2005
Hadrosauriformes Sereno, 1997 sensu Sereno, 1998
Hadrosauroidea Cope, 1870 sensu Sereno, 2005
Portellsaurus gen nov.
Portellsaurus sosbaynati sp nov.
Diagnosis of genus and species by monotypy.
Styracosternan hadrosauroid distinguished by two autapomorphies: the absence of a bulge along the ventral margin directly ventral to the base of the coronoid process, convergent with the two more derived hadrosauroids Altirhinus kurzanovi and Sirindhorna khoratensis, and the presence of a deep oval cavity on the medial surface of the mandibular adductor fossa below the eleventh-twelfth tooth position. Internally, the cavity connects with the last nutrient foramina (the most caudal).
It is also diagnosed by the following unique combination of features: (1) a straight morphology of the ventral margin of the rostral ramus (convergent with Iguanodon, Ouranosaurus, Barilium, Lanzhousaurus, Jinzhousaurus, Bolong, and Dakotadon); (2) rostral tip not raised respect to the ventral margin (unlike in Ouranosaurus, and Bolong); (3) dorsal and ventral margins parallels (unlike in I. galvensis, and O. nigeriensis with divergent dorsal and ventral margins); (4) presence of a diastema (unlike in Lanzhousaurus, and Dakotadon); (5) absence of a bulge along ventral margin directly ventral to the base of the coronoid process (unlike in Jinzhousaurus, and Ouranosaurus).
Holotype: MQ98-II-1, almost complete right dentary, stored at the Colección Museográfica de Cinctorres (Castellón, Spain).
Locality and horizon: A site near Mas de Curolles, Portell, Castellón (Spain). The beds exposed belong to the Margas de Mirambell Formation, which is early Barremian to early late Barremian (~130–129 Ma) [18]. MQ98-II-1 was recovered in a sandstone layer between two siltstone strata that were deposited on a lagoon/washover environment (Fig 1). Universal Transverse Mercator (UTM) coordinates of the Mas de Curolles-II (MQ-II) site are: 30T 730302 4496335.
Etymology: The generic designation combines the name of Portell, the town in which the fossil was discovered, with the Greek sauros (lizard). The specific name is taken from Vicente Sos Baynat, a Spanish geologist born in Castelló de la Plana and the first scientist to be honoured with the title of “Doctor Honoris Causa” by Universitat Jaume I.
Conclusions:
This work describes and discusses the type specimen (MQ98-II-1) of the styracosternan hadrosauroid Portellsaurus sosbaynati gen. et sp. nov. from the Mirambell Formation, early Barremian (Early Cretaceous) Mirambell formation of Portell (Castellón, Spain). The holotype is described based upon cranial element, a nearly complete right dentary, of a large individual (6 to 8 m).
Two autapomorphies support the validity of the type species. In addition, Portellsaurus sosbaynati gen. et sp. nov. can be distinguished from other styracosternan hadrosauroids on the basis of a unique combination of characters. Regardless of the phylogenetic analysis carried out, it is clearly nested within the clade that contains Ouranosaurus and Bolong.
Taking into account the works of Norman [2013], McDonald [2012] and Verdú et al. [2018], we can state that Portellsaurus sosbaynati has more similarities with Ouranosaurus nigeriensis and Bolong yixianensis than with other hadrosauriforms like I. bernissartensis, I. galvensis, Proa valdearinnoensis, Koshisaurus katsuyama, Hypselospinus fittoni, and Mantellisaurus atherfieldensis. The morphology of the dentary from Portell is sufficiently different from these last-mentioned taxa, as it has shown in this work, to be considered a new taxon. Despite the similarities it offers with Ouranosaurus and Bolong, it is highly unlikely that the specimen from the early Barremian of Spain, was the same taxon as the late Barremian–early Aptian of China or the late Aptian of Niger.
Although dinosaur sites from the Margas de Mirambell Formation (early Barremian–early late Barremian) are abundant [Gasca, et al., 2017; Santos-Cubedo et al., 2016], to date it has not been possible to determine the presence of dinosaurs beyond the identification at the family and/or subfamily level [Gasca, et al., 2017; Santos-Cubedo et al., 2016]]. This is because, scarce material has been found in this geological formation. So, studies and publications are few. This is in contrast to the fact that the presence of other hadrosauriform dinosaurs have been described at a specific level in the Morella sub-basin e.g. Iguanodon bernissartensis, Mantellisaurus atherfieldensis, and Morelladon beltrani from the Arcillas de Morella Formation (late Barremian) of Morella (Castellón), or in neighbouring sub-basins, e.g. the Galve sub-basin: Iguanodon galvensis from the Camarillas Formation (early Barremian) of Galve (Teruel) and the Oliete sub-basin: Proa valdearinnoensis from the Escucha Formation (early Albian) of Ariño (Teruel). Hence, Portellsaurus sosbaynati gen. et sp. nov. is definitely the first styracosternan dinosaur species identified from the Margas de Mirambell Formation (early Barremian–early late Barremian) in the Morella sub-basin (Maestrat Basin, eastern Spain).
Andrés Santos-Cubedo, Carlos de Santisteban, Begoña Poza and Sergi Meseguer. 2021. A New Styracosternan Hadrosauroid (Dinosauria: Ornithischia) from the Early Cretaceous of Portell, Spain. PLoS ONE. 16(7): e0253599. DOI: 10.1371/journal.pone.0253599
