A new specimen of the theropod dinosaur Baryonyx from the early Cretaceous of Portugal and taxonomic validity of Suchosaurus

Abstract

Although the Late Jurassic of Portugal has provided abundant dinosaur fossils, material from the Early Cretaceous is scarce. This paper reports new cranial and postcranial material of the theropod dinosaur Baryonyx walkeri found in the Barremian (Papo Seco Formation) of Portugal. This specimen, found at Praia das Aguncheiras, Cabo Espichel, consists of a partial dentary, isolated teeth, pedal ungual, two calcanea, presacral and caudal vertebrae, fragmentary pubis, scapula, and rib fragments. It represents the most complete spinosaurid yet discovered in the Iberian Peninsula and the most complete dinosaur from the Early Cretaceous of Portugal. This specimen is confidently identified as a member of Baryonychinae due to the presence of conical teeth with flutes and denticles in a dentary rosette. The specimen ML1190 shares the following characteristics with Baryonyx walkeri: enamel surface with small (nearly vertical) wrinkles, variable denticle size along the carinae, 6–7 denticles per mm, wrinkles forming a 45 degree angle near the carinae, and tooth root longer than crown. In addition, dubious taxa based on teeth morphology such as Suchosaurus cultridens (Owen, 1840–1845), and Suchosaurus girardi (Sauvage 1897–98; Antunes & Mateus 2003) are discussed, based on comparisons with well-known material such as Baryonyx walkeri Charig & Milner, 1986. Suchosaurus cultridens and S. girardi are considered as nomina dubia due to the lack of diagnostic apomorphies, but both specimens are referred to Baryonychinae incertae sedis.

A Century of Spinosaurs - A Review and Revision of the Spinosauridae with Comments on Their Ecology

“…Additional finds have been related to named taxa (e.g. Buffetaut, 2008;Mateus et al, 2011) has also extended our knowledge and may yet yield new taxa (see Naish, 2011).…”

“…Material now recognised as spinosaur in origin in fact was first described by Richard Owen in the early 1840s based on teeth he obtained from Gideon Mantell (see Buffetaut, 2010 for details). These teeth were considered at the time to belong to a crocodilian (and indeed spinosaur teeth are similar to crocodilians) but may now be referred to Baryonyx (Buffetaut, 2010, Mateus et al, 2011. Similarly, fragmentary teeth from Algeria that belong to Spinosaurus predate Stromer's discoveries (Buffetaut, 2010) and material recovered from the Tendaguru expeditions of the 1920s were only identified as spinosaurid in origin nearly a century later (Buffetaut, 2008), although this referral is controversial (Rauhut, 2011).…”

“…Despite the poor fossil record for this clade, the spinosaurs have enjoyed a recent increase in scientific interest with a number of new taxa described in recent years (Kellner et al, 2011;Allain et al, 2012) and new finds of existing taxa bolstering the number of specimens (Dal Sasso et al, 2005;Mateus et al, 2011;Naish, 2011;Ibrahim et al, 2014) and increasing their known temporal and geographic ranges Buffetaut, 2012). Given their apparent aberrant morphology and behavior as well as their unusual local distributions (frequently either vanishingly rare, or quite abundant) the spinosaurids are perhaps some of the most ecologically interesting of theropods.…”

New theropod remains from the Tiourarén Formation (?Middle Jurassic, Niger) and their bearing on the dental evolution in basal tetanurans

“…Spinosaurid teeth are also characterized by numerous minute denticles: 7/mm in Baryonyx Milner, 1986, 1997), 6/mm in Suchomimus (Smith et al, 2005: database), and 5-13/mm in indeterminate isolated teeth (Hone et al, 2010;Mateus et al, 2011;Ruiz-Omeñaca et al, 2005), and some are reported unserrated (Spinosaurus Stromer, 1915 andIrritator Sues et al, 2002). TP4-2 has only 2.2 denticles/mm (Fig.…”

A new species of Brodiechelys (Testudines, Pan-Cryptodira) from the Early Cretaceous of Spain: Systematic and palaeobiogeographic implications

“…1996;Escaso et al 2005;Torcida Fernández-Baldor 2006;Pereda-Suberbiola et al 2007;Sánchez-Hernández et al 2007;Buscalioni et al 2008;Gasulla et al 2009Gasulla et al , 2011Mateus et al 2011). Holtz et al (2004 proposed that the Greater Wealden, comprising localities of the Lower Cretaceous of England and continental Europe, as well as comparable faunas of southern and central Europe, western North America, and Africa, share a common composition of dinosaur faunas.…”