Neuroanatomy of titanosaurid dinosaurs from the Upper Cretaceous of Patagonia, with comments on endocranial varibility within Sauropoda

The purpose of this study is to provide a detailed description of the neuroanatomy of Bonatitan, Antarctosaurus, and an unnamed titanosaur from Río Negro, Argentina including the first observations on the inner ear of the two first taxa using CT scans. The materials were compared with previously described sauropod endocasts and other less complete titanosaur braincases from Argentina. The cranial endocasts show the general morphology of other sauropods being bulbous, anteroposteriorly short and transversely wide, and with enlarged and posteroventrally projected pituitary body. Particular titanosaur traits are the extremely short and horizontal olfactory tract, the absence of a floccular process and a single root for cranial nerve XII. In addition, in the basicranium the abducens nerve (CN VI) does not penetrates the pituitary fossa and the internal carotid artery enters the medial aspect of the basipterygoid process, resulting in an external opening for this vessel that is not visible in lateral view of the braincase. The titanosaurid inner ear also exhibits particular traits, such as robust semicircular canals, and anterior and posterior semicircular canals that are subequal in size. The variation observed in the sauropod endocranium indicates an evolutionary tendency in titanosaurs toward the anteroposterior shortening of the midbrain, and the reduction in size of the semicircular canals of the inner ear, in particular the anterior semicircular canal. This, together with the lack of floccular process suggests a narrower range of movements of the head for this clade.Fil: Paulina Carabajal, Ariana. Provincia del Neuquén. Municipalidad de Plaza Huincul. Museo "Carmen Funes"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Confluencia; Argentin

The endocranial morphology and inner ear of the abelisaurid theropod Aucasaurus garridoi

A partial cranial endocast and right inner ear of the Cretaceous abelisaurid dinosaur Aucasaurus garridoi were digitally reconstructed from CT scans. The forebrain, midbrain, and hindbrain resemble the morphology described for the abelisaurids Majungasaurus and Indosaurus. However, Aucasaurus exhibits a floccular process that is relatively larger than that of Majungasaurus. In Aucasaurus the flocculus is enclosed in an 8-shaped floccular recess, similar in shape and size to that observed in Abelisaurus, suggesting that the two Patagonian taxa were capable of a slightly wider range of movements of the head. Here we describe the second inner ear known for the Abelisauridae. The labyrinth of the inner ear is similar in shape and size to the semicircular canals of Majungasaurus, although the lateral semicircular canal is shorter in Aucasaurus.Fil: Paulina Carabajal, Ariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Provincia del Neuquén. Municipalidad de Plaza Huincul. Museo ; ArgentinaFil: Succar, Cecilia Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Provincia del Neuquén. Municipalidad de Plaza Huincul. Museo ; Argentin

Secretos guardados en la cabeza de animales extintos

¿Qué tan inteligentes eran los dinosaurios? ¿Cómo era el cerebro de una tortuga que vivió hace 150 millones de años? ¿Se puede saber qué tan bien olían, veían y/o escuchaban los animales extintos? Los paleontólogos tratan de responder estas preguntas a través de la paleoneurología, una rama de la paleontología que se dedica al estudio del sistema nervioso de animales extintos mediante el estudio de de moldes endocraneanos, copias tridimensionales del espacio que ocupaban el cerebro y otros tejidos blandos asociados que no se preservan generalmente en el registro fósil

Re-description of the braincase of the rebbachisaurid sauropod limaysaurus tessonei and novel endocranial information based on CT scans

CT scans of the type braincase of Limaysaurus tessonei (MUCPv-205) allowed the first study of the endocranial cavities (brain and inner ear) for this South American taxon. Comparisons of the cranial endocast of L. tessonei with other sauropods indicate that 1) South American rebbachisaurids are more similar to each other than to Nigersaurus, and 2) certain association of traits are present in all known rebbachisaurid cranial endocasts, such as lack of an enlarged dorsal expansion, poorly laterally projected cerebral hemispheres, presence of a small flocculus of the cerebellum, markedly long passage for the facial nerve (CN VII), markedly inclined pituitary, and presence of a passage for the basilar artery communicating the floor of the endocranial cavity and the pituitary fossa. The relatively enlarged olfactory region indicates that smell was an important sense for this group of dinosaurs, suggesting different olfactory capabilities when compared to coeval titanosaurs.Fil: Paulina Carabajal, Ariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Calvo, Jorge Orlando. Universidad Nacional del Comahue. Centro Paleontológico Lago Barreales; Argentina. Universidad Nacional del Comahue. Museo de Geología y Paleontología; Argentin

A New Specimen of Autroraptor cabazai Novas, Pol. Canale, Porfiri and Calvo, 2008 (Dinosauria, Theropoda, Unenlagiidae) from the Latest Cretaceous (Maastrichtian) of Río Negro, Argentina

There were considerable differences in Late Cretaceous faunas of the Northern and Southern Hemispheres, although the differences were breaking down during Campanian and Maastrichtian times with the appearance of hadrosaurids in Antarctica and South America, and titanosaurids in North America. However, theropods continued to be separated into northern and southern faunas until paravians were discovered in the Southern Hemisphere (Novas and Puerta, 1997; Forster et al. 1998; Calvo et al. 2004; Makovicky et al. 2005; Novas and Pol, 2005; Novas et al. 2008). During the 2008 field season, a joint expedition to the Bajo de Santa Rosa (Río Negro, Argentina) recovered a second, slightly smaller specimen of Austroraptor cabazai Novas, Pol, Canale, Porfiri and Calvo, 2008 (Novas et al. 2008; Paulina Carabajal et al., 2009). The specimen was identified on the basis of the morphology of the humerus, metatarsal III and pedal phalanx IV-2 (originally identified as IV-1 in the holotype, MML 195). Although the skeleton is incomplete, it preserves bones (radius, ulna, and elements of the metacarpus, metatarsus and pes) that were not recovered with the holotype of this large dromaeosaurid. The description of this second specimen is intended to complement the description of the holotype (Novas et al., 2008), adding information about the limb morphology, particularly the forelimb and foot of this dinosaur.Fil: Currie, Philip J.. University of Alberta; CanadáFil: Paulina Carabajal, Ariana. Provincia del Neuquen. Municipalidad de Plaza Huincul. Museo "carmen Funes"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

A new peirosaurid (Crocodyliformes, mesoeucrocodylia) from the Upper Cretaceous of Patagonia, Argentina

Fil: Barrios, Francisco. Museo Municipal Carmen Funes. Plaza Huincul. Neuquén; ArgentinaFil: Paulina-Carabajal, Ariana. Museo Municipal Carmen Funes. Plaza Huincul. Neuquén; ArgentinaFil: Bona, Paula. División Paleontología Vertebrados. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; Argentin

Un nuevo peirosáurido (Crocodyliformes, Mesoeucrocodylia) del Cretácico Superior de Patagonia, Argentina

Peirosaurids are a group of Cretaceous continental crocodyliforms from Gondwana. Two species are known from the Neuquén Group in Argentina: Lomasuchus palpebrosus (Portezuelo Formation, late Turonian–early Coniacian) and Gasparinisuchus peirosauroides (Bajo de la Carpa and Anacleto formations, Santonian and early Campanian, respectively). Here, we describe the first peirosaurid from the Cerro Lisandro Formation, Bayomesasuchus hernandezi gen. et sp. nov. The material corresponds to a fragmentary skull and mandible. Although fragmentary, this is the most complete crocodyliform specimen recorded for the Cerro Lisandro Formation. In a phylogenetic analysis Bayomesasuchus is depicted in a polytomy together with South American peirosaurids and the African form Hamadasuchus rebouli.Los peirosáuridos constituyen un grupo de crocodiliformes continentales del Cretácico de Gondwana. Para el Grupo Neuquén, Argentina, se conocen dos especies: Lomasuchus palpebrosus (Formación Portezuelo, Turoniano tardío–Coniaciano temprano) y Gasparinisuchus peirosauroides (Formaciones Bajo de la Carpa y Anacleto, Santoniano y Campaniano temprano, respectivamente). Aquí, describimos el primer peirosáurido identificado para la Formación Cerro Lisandro, Bayomesasuchus hernandezi gen. et sp. nov. El material corresponde a cráneo y mandíbula fragmentarios. Aunque fragmentario, este es el espécimen de crocodiliforme más completo registrado para la Formación Cerro Lisandro. En un análisis filogenético, Bayomesasuchus es agrupado en una politomía junto con los peirosáuridos sudamericanos y la forma africana Hamadasuchus rebouli.Facultad de Ciencias Naturales y Muse

3D model related to the publication: The endocranial anatomy of the stem turtle Naomichelys speciosa from the Early Cretaceous of North America

The present 3D Dataset contains the 3D model analyzed in the following publication: Paulina-Carabajal, A., Sterli, J., Werneburg, I., 2019. The endocranial anatomy of the stem turtle Naomichelys speciosa from the Early Cretaceous of North America. Acta Palaeontologica Polonica, https://doi.org/10.4202/app.00606.2019.Fil: Paulina Carabajal, Ariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Sterli, Juliana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Museo Paleontológico Egidio Feruglio; ArgentinaFil: Werneburg, Ingmar. Eberhard Karls Universität Tübingen; Alemani

A new theropod (Dinosauria) from the Huincul Formation (Late Cretaceous) of north Patagonia, Argentina

The theropod diversity of the Huincul Formation (Neuquén Group) includes the abelisaurids Ilokelesia and Skorpiovenator, and the carcharodontosaurid Mapusaurus. Here we report the remains of a recently collected theropod specimen (MOZ-PV-7200) from sediments assigned to this unit, which consists in 14 vertebral elements (including fragments of cervical, 2 complete dorsals, several isolated dorsal centra, one complete anterior caudal, one anteriormid caudal haemal arch, and several isolated caudal centra), a sacrum formed by 5 fused vertebrae and two isolated sacral centra, a complete right ilium and both pubes lacking the distal foot. The remains represent a mediun size, sub-adult specimen that exhibit some features that have not been described in any other previously recorded theropod form, such as a long preacetabular process of the ilium strongly projected ventrally beyond the distal end of the pubic peduncle. The presence of sacral neural spines completely fused to each other in a single longitudinal bone-sheet has been observed in the noasaurid Masiakasaurus. An ilium with a squared outlined postacetabular process with a concave distal border is a character present in most abelisaurids like Carnotaurus, Aucasaurus and Majungasaurus. Some morphological elements of the pubis remind the putative noasaurid Bahariasaurus, although further comparisons are difficult due the lost of the type specimen of this African form. By other hand, the absence of lateral pleurocoels in dorsal vertebrae reminds the condition observed in Ilokelesia aguadagrandensis Coria and Salgado. However, the sacrum formed by 5 fused elements with its centra dorsoventrally depressed and laterally wide, pubis with anteroposteriorly narrow shafts and opened obturator notch, and the absence of fusion between ilium and pubis are plesiomorphic stages for abelisaurids. The cladistic analysis currently conducted will shed light on the phylogenetical and taxonomical implications of this new specimen on the theropod diversity of the Huincul Formation.Sesiones libresFacultad de Ciencias Naturales y Muse