A European giant: a large spinosaurid (Dinosauria: Theropoda) from the Vectis Formation (Wealden Group, Early Cretaceous), UK

Abstract

Postcranial elements (cervical, sacral and caudal vertebrae, as well as ilium, rib and limb bone fragments) belonging to a gigantic tetanuran theropod were recovered from the basal unit (the White Rock Sandstone equivalent) of the Vectis Formation near Compton Chine, on the southwest coast of the Isle of Wight. These remains appear to pertain to the same individual, with enormous dimensions similar to those of the Spinosaurus holotype and exceeding those of the largest European theropods previously reported. A combination of features—including the presence of spinodiapophyseal webbing on an anterior caudal vertebra—suggest that this is a member of Spinosauridae, though a lack of convincing autapomorphies precludes the identification of a new taxon. Phylogenetic analysis supports spinosaurid affinities but we were unable to determine a more precise position within the clade weak support for a position within Spinosaurinae or an early-diverging position within Spinosauridae were found in some data runs. Bioerosion in the form of curved tubes is evident on several pieces, potentially related to harvesting behaviour by coleopteran bioeroders. This is the first spinosaurid reported from the Vectis Formation and the youngest British material referred to the clade. This Vectis Formation spinosaurid is unusual in that the majority of dinosaurs from the Lower Cretaceous units of the Wealden Supergroup are from the fluviolacustrine deposits of the underlying Barremian Wessex Formation. In contrast, the lagoonal facies of the upper Barremian–lower Aptian Vectis Formation only rarely yield dinosaur material. Our conclusions are in keeping with previous studies that emphasise western Europe as a pivotal region within spinosaurid origination and diversification.

Isolated tooth reveals hidden spinosaurid dinosaur diversity in the British Wealden Supergroup (Lower Cretaceous)

“…Most British spinosaurid skeletal ( i.e., non-dental) material has been recovered from the Barremian strata of Surrey (Upper Weald Clay Formation) and the Isle of Wight (Wessex Formation and base of the Vectis Formation) ( Barker et al, 2021 ; Barker et al, 2022 ; Charig & Milner, 1986 ; Charig & Milner, 1997 ; Martill & Hutt, 1996 ; Milner, 2003 ). However, spinosaurid teeth are relatively common throughout the Wealden Supergroup ( Fowler, 2007 ; Turmine-Juhel et al, 2019 ).…”

“…“ Suchosaurus cultridens ” is currently considered a nomen dubium , being best interpreted as an indeterminate spinosaurid ( Mateus et al, 2011 ; Salisbury & Naish, 2011 ). More recent finds from the Wealden Supergroup succession on the Isle of Wight include the incomplete skeletons of the baryonychine taxa Ceratosuchops inferodios and Riparovenator milnerae from the Wessex Formation ( Barker et al, 2021 ), and the as-yet-unnamed “White Rock” spinosaurid (a possible spinosaurine) from the overlying Vectis Formation ( Barker et al, 2022 ).…”

“…Attributing these various Wealden teeth to Baryonyx (or cf. Baryonyx ) was a reasonable proposal in view of knowledge of Wealden spinosaurid diversity at the time but recent finds demonstrate higher diversity across the supergroup ( Barker et al, 2021 ; Barker et al, 2022 ). In addition, it should be noted that these fossils come from strata spanning a time frame (∼25 million years) not considered typical for the duration of a genus-level dinosaur taxon ( Naish, 2011 ).…”

Família Spinosauridae (Dinosauria: Theropoda): Taxonomia, Paleobiogeografia E Paleoecologia (Uma Revisão)

“…A sua posição dentro de Spinosauridae é incerta, Vallibonavenatrix foi originalmente recuperado como um Spinosaurinae em Malafaia et al (2019), enquanto em análises de Barker et al (2021), ele foi recuperado como um espinossaurídeo basal fora das duas subfamílias, e também como um Baryonychinae basal, dependendo do tipo de análise. Já em Mateus & Estraviz-López (2022) e Barker et al (2022) a sua presença nas análises gera uma politomia, enquanto em Sereno et al (2022) ele é recuperado como um Spinosaurinae novamente.…”

“…A posição de Iberospinus ainda é incerta dentro Spinosauridae, pois dependendo da quantia de táxons utilizados na análise ele pode resultar como irmão do ramo formado por Baryonyx e Suchomimus, ficar agrupado com Spinosaurinae ou resultar em uma politomia de Spinosauridae, mais elementos são necessários para esclarecer sua posição, apesar de seu holótipo ser mais completo do que o de outros espinossaurídeos (Arden et al, 2019;Barker et al, 2021Barker et al, , 2022Mateus & Estraviz-López, 2022).…”