A new dicraeosaurid sauropod from the Lower Cretaceous (Mulichinco Formation, Valanginian, Neuquén Basin) of Argentina

A new long-spined dinosaur from Patagonia sheds light on sauropod defense system

“…However, Bajadasaurus possesses anteriorly curved and slightly laterally pointed neural spines that differ from any other known sauropod. The centrum is two times longer than posteriorly tall and shallow undivided fossae are located along the lateral sides, as in Dicraeosaurus 2 , Amargasaurus (MACN-N 15), and Pilmatueia 10 (MLL-Pv-004). However, Pilmatueia (MLL-Pv-004) differs from Bajadasaurus in having three small foramina and a deep centrodiapophyseal fossa associated to the lateral excavation of the centrum.…”

“…At present, five other dicraeosaurid species are known from the Middle Jurassic of China ( Lingwulong shenqui 7 ), the Upper Jurassic of North America ( Suuwassea emiliae 8 ) and Central Patagonia ( Brachytrachelopan mesai 9 ), and the Early Cretaceous of North Patagonia ( Pilmatueia faundezi 10 and Amargatitanis macni 11,12 ), but only Brachytrachelopan contributed to the knowledge of the entire cervical column, confirming the proposed shortening in the neck length within the group.…”

Vertebral pneumatic structures in the Early Cretaceous sauropod dinosaur Pilmatueia faundezi from northwestern Patagonia, Argentina

“…The materials analysed in the present contribution include the holotype specimen of Pilmatueia faundezi (Coria et al ) consisting of an almost complete posterior dorsal vertebra (MLL‐Pv‐005) and the referred specimens to that taxon: MLL‐Pv‐002 (a posterior cervical vertebra), MLL‐Pv‐004 (a mid‐cervical vertebra) and MLL‐Pv‐016 (a mid‐caudal vertebra) (Fig. ).…”

“…The Family Dicraeosauridae comprises mostly small‐bodied sauropod dinosaurs that includes a handful of Jurassic and Early Cretaceous taxa in Laurasia and Gondwana, which is currently represented by Lingwulong shenqi (Yanan Formation, late Toarcian–Bajocian, Middle Jurassic; Xu et al ), Brachytrachelopan mesai (Cañadón Calcáreo Formation, Kimmeridgian–early Tithonian, Upper Jurassic; Rauhut et al ; Cúneo et al ), Dicraeosaurus hansemanni and Dicraeosaurus sattleri (Tendaguru Formation, Kimmeridgian–Tithonian; Janensch ), Suuwassea emiliae , the putative dicraeosaurids Dyslocosaurus polyonychius and Dystrophaeus viaemalae (Morrison Formation, Late Jurassic; Cope ; McIntosh et al ; Harris & Dodson ; Whitlock ; Tschopp et al ), Bajadasaurus pronuspinax (Bajada Colorada Formation, Berriasian–Valanginian, Lower Cretaceous; Gallina et al ), Pilmatueia faundezi (Mulichinco Formation, Valanginian, Lower Cretaceous; Coria et al ), and Amargasaurus cazaui and Amargatitanis macni (La Amarga Formation, Barremian, Lower Cretaceous; Salgado & Bonaparte ; Apesteguía ; Gallina ) (Fig. ).…”

“…The well‐preserved vertebral elements of the holotype and referred specimens of the recently described Early Cretaceous Patagonian dicraeosaurid, Pilmatueia faundezi (Coria et al ), provide relevant information about the delicate laminar architecture of the neural arches and centra, as well as their internal anatomy, which have been mostly unexplored in other South American dicraeosaurids. The descriptions provided here are based on both direct observations and computed tomography, which have generated the first quantitative analysis measure of the relative Air Space Proportion (ASP) in a dicraeosaurid sauropod.…”