A new theropod dinosaur from the early cretaceous (Barremian) of Cabo Espichel, Portugal: Implications for spinosaurid evolution

Abstract

Spinosaurids are some of the most enigmatic Mesozoic theropod dinosaurs due to their unique adaptations to aquatic environments and their relative scarcity. Their taxonomy has proven to be especially problematic. Recent discoveries from Western Europe in general, specifically Iberia, provide some of the best specimens for the understanding of their phylogeny, leading to the description of the spinosaurid Vallibonavenatrix cani and the recognition of the Iberian dinosaur Camarillasaurus cirugedae as one of them. Portuguese associated spinosaurid remains (ML1190) from the Papo Seco Formation (early Barremian) were previously assigned to Baryonyx walkeri but new material recovered in 2020 along with new phylogenetic analyses suggests a different phylogenetic placement, making their revision necessary. Here we show that these remains are not attributable to Baryonyx walkeri, but to a new genus and species, Iberospinus natarioi, gen. et sp. nov. The new taxon is characterized by the presence of a single Meckelian foramen in the Meckelian sulcus, a straight profile of the ventral surface of the dentary and a distal thickening of the acromion process of the pubis between other characters. Iberospinus natarioi is recovered as a sister taxon of the clade formed by Baryonyx and Suchomimus, and outside Spinosaurinae when Vallibonaventrix cani is excluded from the analysis. The description of this taxon reinforces Iberia as a hotspot for spinosaur biodiversity, with several endemic taxa for the region. As expected for the clade, the dentary displays a highly vascularized neurovascular network. The morphometric analysis of parts of the skeleton (pedal phalanx and caudal vertebrae, among others) shows an intermediate condition between basal tetanurans and spinosaurines.

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

“…99 of Carrano & Sampson (2008) and concerning caudal neural spine morphology) was mis-scored and has been changed to state 1 to reflect their abbreviated state. All other scores and “OTUs” remained the same as in the Barker et al (2021) analysis, although we acknowledge the recent designation of the specimen ML 1190 as the holotype of the new spinosaurid taxon Iberospinus natarioi ( Mateus & Estraviz-López, 2022 ), which also includes some fragmentary new material.…”

“…However, as noted above, more convincing comparison can only take place when better corroboration pertaining to the proposed axial position of IWCMS 2018.30.3 occurs. Elsewhere on IWCMS 2018.30.3, the presence of pleurocentral depressions is also shared with the anterior caudal vertebrae of Vallibonavenatrix ( Malafaia et al, 2020b ) and Iberospinus ( Mateus & Estraviz-López, 2022 ), as well as the megalosaurids Torvosaurus , Megalosaurus and Wiehenvenator ( Rauhut, Huebner & Lanser, 2021 ; Rauhut & Pol, 2019 ).…”

Macroevolutionary patterns in the pelvis, stylopodium and zeugopodium of megalosauroid theropod dinosaurs and their importance for locomotor function

“…Monolophosaurus, Eustreptospondylus and Streptospondylus; have uncertain phylogenetic placement within Megalosauroidea, as well as Xuanhanosaurus, which was recovered as a piatnitzkysaurid by Rauhut et al [8] instead of a metriacanthosaurid as previously [6]. There recently has been an increase in the known biodiversity of Spinosauridae because some new taxa have been described, such as Ichthyovenator [13], Vallibonavenatrix [19], Ceratosuchops, Riparovenator [20] and Iberospinus [21].…”

“…[8] instead of a metriacanthosaurid as previously [6]. There recently has been an increase in the known biodiversity of Spinosauridae because some new taxa have been described, such as Ichthyovenator [13], Vallibonavenatrix [19], Ceratosuchops , Riparovenator [20] and Iberospinus [21].…”

Modified skulls but conservative brains? The palaeoneurology and endocranial anatomy of baryonychine dinosaurs (Theropoda: Spinosauridae)

“…Spinosauridae is an aberrant clade of long‐snouted, large‐bodied theropod dinosaurs, with representative taxa and key specimens known from the fossil records of Europe, Asia, Africa and South America (Allain et al, 2012; Barker et al, 2021; Charig & Milner, 1986; Dal Sasso et al, 2005; Ibrahim et al, 2014, 2020; Kellner et al, 2011; Malafaia et al, 2020; Mateus & Estraviz‐López, 2022; Sereno et al, 1998; Stromer, 1915; Sues et al, 2002). Generally limited to Lower to “mid” Cretaceous deposits (Bertin, 2010; Holtz et al, 2004), phylogenetic analyses nevertheless support a Jurassic origin for the clade (Barker et al, 2021; Carrano et al, 2012), although definitive material from this period remains unknown (Hendrickx et al, 2019; Soto et al, 2020).…”