Restos de Allosauroideo (Theropoda, Tetanurae) de la formación sierra barrosa (Coniaciano Medio, Cretácico Superior), Patagonia, Argentina

La fauna de terópodos del Cretácico Tardío de América del Sur está compuesta por Abelisauridae, Noasauridae, Carcharodontosauridae, Spinosauridae, Megaraptora y Coelurosauria. Estos grupos incluyen mayormente taxones de pequeño (Noasauridae y Coelurosauria) y de mediano a gran tamaño (Abelisauridae, Carcharodontosauridae y Megaraptora). Algunos de estos linajes son predominantemente gondwánicos (Abelisauridae, Noasauridae, Carcharodontosauridae, Megaraptora) y poco representados en los continentes laurásicos. Particularmente, distintos terópodos han sido reportados desde la Patagonia, conocidos o por sus distintivas características anatómicas o por su grado de preservación, tales como Carnotaurus, Skorpiovenator, Giganotosaurus, Megaraptor, Alvarezsaurus y Unenlagia. Aquí describimos una nueva tibia incompleta (MAU-PV-CM-653) proveniente de la Formación Sierra Barrosa (Coniaciano medio, Cretácico Superior), Patagonia, Argentina. MAU-PV-CM-653 muestra una cresta cnemial reducida anteroposteriormente, que está fuertemente curvada lateralmente. Finalmente, la tibia carece de una extensión proximal de la cresta fibular. Estos rasgos hacen recordar una morfología de tetanuro y, junto con la procedencia estratigráfica de MAU-PV-CM-653, nos permite asignarla a un terópodo allosauroideo, y por ende mejorar el registro global de Allosauroidea para la parte media del Cretácico Tardío.The late Cretaceous theropod fauna of South America is composed of Abelisauridae, Noasauridae, Spinosauridae, Carcharodontosauridae, Megaraptora, and Coelurosauria. These groups include mostly small (Noasauridae and Coelurosauria) and medium to- tolarge-sized taxa (Carcharodontosauridae, Abelisauridae, and Megaraptora). Some of these lineages are predominantly Gondwanic (Abelisauridae, Noasauridae, Carcharodontosauridae, Megaraptora) and poorly represented in Laurasian landmasses. Particularly, several theropods have been reported from Patagonia, known either due to distinct anatomical features or due to their high degree of preservation, such as Carnotaurus, Skorpiovenator, Giganotosaurus, Megaraptor, Alvarezsaurus, and Unenlagia. here we describe a new incomplete tibia (MAU-PV-CM-653) from the Sierra Barrosa Formation (middle Coniacian, Upper Cretaceous), Patagonia, Argentina. MAU-PV-CM-653 shows an anteroposteriorly reduced cnemial crest that is strongly curved laterally. Finally, the tibia lacks a proximal extension of the fibular crest. These traits are reminiscent of tetanuran morphology and, together with the stratigraphic provenance of MAU-PV-CM-653, they allow us to assign it to an allosauroid theropod, thus improving the Allosauroidea global record for the middle Late Cretaceous.Fil: Baiano, Mattia Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Universidad Nacional de Río Negro; Argentina. Provincia del Neuquén. Municipalidad de Villa El Chocón. Museo Paleontológico "Ernesto Bachmann"; ArgentinaFil: Filippi, Leonardo Sebastián. No especifíca

Morphology and histology of osteoderms from a Peirosaurid from the Neuquen basin

Se describen osteodermos de un nuevo ejemplar de crocodyliforme hallado en un afloramiento correspondiente a niveles de la Formación Plottier (Coniaciano tardío) de la localidad de Puesto Hernández, en inmediaciones de la localidad de Rincón de los Sauces, Provincia del Neuquén. Los osteodermos estudiados, que son parte del material hallado, están integrados por: región dorso-sacra, osteodermos apendiculares asociados al fémur derecho, región proximoventral de osteodermos caudales articulados y osteodermos aislados. La histología de los osteodermos permitió determinar que están constituidos por una corteza compacta que circunda una región interna más porosa. Fue posible reconocer marcas de crecimiento (annuli) en prácticamente todo el tejido compacto, pudiendo determinarse una edad mínima de 18 años para el espécimen estudiado. Los osteodermos exhiben caracteres que permiten preliminarmente asignar al ejemplar MAU-Pv-PH-437, como un Mesoeucrocodylia cercanamente relacionado con Peirosauridae.Osteoderms of a new crocodyliform specimen recovered from the Puesto Hernández locality are described here, found in sediments of the Plottier Formation (late Coniacian), near Rincón de los Sauces city, Neuquén Province. The studied osteoderms, that are part of the associated material, include: dorso-sacral region, appendicular osteoderms associated to the right femur, proximoventral region of articulated caudal osteoderms, and isolated osteoderms. The histology of the osteoderms allowed determining they have a compact cortex that surrounds a more cancellous internal region. It was possible to recognize growth marks (annuli) in the entire compact tissue, indicating a minimum age of 18 years for the studied specimen. The osteoderms have characters that allow preliminarily assigning the specimen MAU-Pv-PH-437 to Mesoeucrocodylia closely related to Peirosauridae.Fil: Filippi, Leonardo Sebastián. Museo Municipal “Argentino Urquiza"; ArgentinaFil: Cerda, Ignacio Alejandro. 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; Argentina. Universidad Nacional del Comahue. Museo de Geología y Paleontología; ArgentinaFil: Garrido, Alberto Carlos. Provincia de Neuquén. Ministerio de Energía, Ambiente y Servicios Públicos. Dirección Provincial de Minería. Museo Provincial de Ciencias Naturales Prof. "Dr. Juan A. Olsacher"; Argentin

New remains of Prochelidella in the Anacleto Formation (Campanian levels) of Neuquén basin, Patagonia, Argentina

The new turtle remains presented here were recovered from the Anacleto Formation (Campanian) exposed in the Aguada Grande site. This area is located 10 km south of Rincón de Los Sauces city, inthe north of the province of Neuquén, Patagonia, Argentina. The specimen (MAU-Pv-AG-452)consists of a partially preserved skull, carapace remains, an almost complete plastron, and a leftilium. The new specimen is assigned to Pleurodira because its ilium is sutured to the carapace. Both Parietals, the posterior part of frontals and post orbitals, the dorsal region of the supraoccipital, both pterygoids, the basisphenoid, and part of the prootics are recognized in the skull. The carapace remains are represented by a left first costal bone in articulation with a peripheral bone, a left paired costal bone, and another fragmented coastal. The plastron is represented by both epiplastra, theen plastron, left hyoplastron, both hypoplastra, and the left xiphiplastron. The skull shows somecharacters that allow its referral to Prochelidella spp. (e.g., a developed retropterygoid foramen, and a big muscle attachment area over the basisphenoid). The visceral view of the first costal bone exhibitslong auxiliary buttresses that extend 2/3 of the costal width. This condition is also observed in the costal bone of Prochelidella buitreraensis from the Candeleros Formation (Cenomanian). The scutepattern observed in the anterior lobe of the plastron shows a large gular that extends along theentoplastral length and small extragulars over the epiplastra. In contrast, on the scheme observed inProchelidella cerrobarcinae and Prochelidella portezuelae, the gular does not extend beyond the first third of the entoplastron. The material recovered from the Anacleto Formation represents the most complete specimen outside the Prochelidella peak of diversity range (Albian Cenomanian) and the second skull recognized in this genusFil: Maniel, Ignacio Jorge. Universidad Tecnologica Nacional. Facultad Reg.san Rafael. Instituto de Evolucion, Ecologia Historica y Ambiente. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Mendoza. Instituto de Evolucion, Ecologia Historica y Ambiente.; ArgentinaFil: de la Fuente, Marcelo Saul. Universidad Tecnologica Nacional. Facultad Reg.san Rafael. Instituto de Evolucion, Ecologia Historica y Ambiente. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Mendoza. Instituto de Evolucion, Ecologia Historica y Ambiente.; ArgentinaFil: Filippi, Leonardo Sebastián. No especifíca;Simposio de Evolución de TortugasTrelewArgentinaMuseo Paleontológico Egidio FeruglioAsociación Paleontológica Argentin

How Common Are Lesions on the Tails of Sauropods? Two New Pathologies in Titanosaurs from the Late Cretaceous of Argentine Patagonia

Studies of the paleopathology of the vertebrae provide an interesting, oblique approach to their paleobiology and even paleoethology. They tell us about possible ethological causes such as accidental blows with objects, social interactions within a group, and defense against predators, etc. There are numerous works on the anatomical and phylogenetic aspects of sauropod dinosaurs, and in recent years paleopathological studies have also increased. Here, we describe the injuries recorded in the caudal vertebrae of two indeterminate titanosaurids, and undertake a compilation and analysis of the pathological fossil record worldwide, focusing on the tails of sauropods. Two pathologies have been identified as present in the indeterminate titanosaurids under study: a possible case of spondyloarthropathy in MAU-Pv-LI-601, and a case of suppurative spinal osteomyelitis in MAU-Pv-LJ-472/1. Both titanosaurids are from Gondwana. In the world registry of pathologies associated with the tails of sauropod dinosaurs, it is observed that titanosaurs are the sauropods with the highest percentage of diagnosed pathologies (69% including the two new records from the province of Neuquén) and that all of these have been described in Gondwanan specimens

New abelisaurid skeletal remains from La Invernada (Bajo de la Carpa Formation, Santonian), northwestern Patagonia, Argentina

The La invernada fossil area (Bajo de la Carpa Formation, Santonian) has provided abundant dinosaur remains, which are mainly represented by titanosauriform sauropods and abelisaurid theropods. The latter include Viavenator exxoni and other partial skeletons. Recently a new abelisaurid specimen (MAu-Pv-Li-665) was found in La invernada, which consists of three vertebrae (anterior cervical, cervico-dorsal and dorsal) and cervical and dorsal ribs, found closely associated.Fil: Gianechini, Federico Abel. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Departamento de Bioquímica y Ciencias Biológicas. Área de Zoología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; ArgentinaFil: Méndez, Ariel Hernán. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico de Geología y Paleontología; ArgentinaFil: Filippi, Leonardo Sebastián. Gobierno de la Provincia del Neuquén. Municipalidad de Rincón de Los Sauces. Secretaria de Turismo y Patrimonio. Museo Municipal Argentino Urquiza; ArgentinaFil: Juarez Valieri, Ruben Dario. Gobierno de la Provincia de Río Negro. Ministerio de Turismo, Cultura y Deporte. Secretaría de Cultura; Argentina1º Reunión Virtual de Comunicaciones de la Asociación Paleontológica ArgentinaBuenos AiresArgentinaAsociación Paleontológica Argentin

A new giant basal titanosaur sauropod in the Upper Cretaceous (Coniacian) of the Neuquén Basin, Argentina

A new basal sauropod titanosaur, Kaijutitan maui gen. et sp. nov., is described. The holotype of this species, which comes from the Sierra Barrosa Formation (upper Coniacian, Upper Cretaceous), consists of cranial, axial, and appendicular elements presenting an unique combination of plesiomorphic and apomorphic characters. The most notable characteristic observed in Kaijutitan is the presence of anterior cervical vertebrae with bifid neural spines, a condition that would have evolved several times among sauropods. The phylogenetic analysis places Kaijutitan as a basal titanosaur, the sister taxon of Epachthosaurus + Eutitanosauria. The new species supports the coexistence, in the Late Cretaceous (Turonian-Santonian), of basal titanosaurs and eutitanosaurian sauropods, at least in Patagonia.Fil: Filippi, Leonardo Sebastián. Provincia de Neuquén. Museo Municipal Argentino Urquiza; ArgentinaFil: Salgado, Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación en Paleobiología y Geología; Argentina. Universidad Nacional de Río Negro. Sede Alto Valle. Instituto de Investigaciones en Paleobiología y Geología; ArgentinaFil: Garrido, Alberto Carlos. Provincia de Neuquén. Ministerio de Energía, Ambiente y Servicios Públicos. Dirección Provincial de Minería. Museo Provincial de Ciencias Naturales Prof. "Dr. Juan A. Olsacher"; Argentina. Universidad Nacional del Comahue. Facultad de Ingeniería. Departamento de Geología y Petróleo; Argentin

Early growth dynamics of titanosaur sauropods inferred from bone histology

Histological studies have proven to be a powerful tool for addressing sauropod paleobiology, with most focus on adult and subadult individuals. The aim of this study is to describe long bone histology (femur) in early juvenile titanosaur sauropods, to expand our knowledge about early stages of development. The material consists of two small femora of indeterminate titanosaurs from the Upper Cretaceous Bajo de la Carpa and Allen formations of Argentina. Both femora from juvenile specimens show predominant fibrolamellar bone tissue with plexiform vascularization pattern, suggesting a fast growth rate. Despite the early stage of development of the studied specimens, secondary remodelling is evident in one of them. In the other sample, a growth mark is observed, which suggests unexpected cyclical growth and a possible departure from the typical growth strategy of sauropod dinosaurs. In addition, we examine indeterminate long bones of titanosaur embryos from the Anacleto Formation of Argentina. The embryos shows poor development of cortical bone, high density of large simple canals and presence of Kastschenko's line suggest that these individuals died during an early stage of ossification. This study reveals that the early growth of at least some titanosaurs departs from the reported in neosauropod dinosaurs.Fil: González, Romina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Cerda, Ignacio Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación en Paleobiología y Geología; Argentina. Universidad Nacional de Río Negro. Sede Alto Valle. Instituto de Investigaciones en Paleobiología y Geología; Argentina. Museo Provincial Carlos Ameghino; ArgentinaFil: Filippi, Leonardo Sebastián. Gobierno de la Provincia del Neuquén. Municipalidad de Rincón de Los Sauces. Secretaria de Turismo y Patrimonio. Museo Municipal Argentino Urquiza; ArgentinaFil: Salgado, Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación en Paleobiología y Geología; Argentina. Universidad Nacional de Río Negro. Sede Alto Valle. Instituto de Investigaciones en Paleobiología y Geología; Argentin

A new peirosaurid from the Bajo de la Carpa Formation (Upper Cretaceous, Santonian) of Cerro Overo, Neuquén, Argentina

In this article we present a new peirosaurid crocodyliform: Kinesuchus overoi gen. et sp. nov. The specimen was recovered from the Bajo de la Carpa Formation (Santonian, Upper Cretaceous) and is composed of an incomplete mandible consisting of dentaries, splenials, and portion of the left surangular. The specimen shares some features with the peirosaurids Hamadasuchus, Pepesuchus and Itasuchus, including a narrow symphyseal region in lateromedial and dorsoventral views with a planar dorsal surface and an anterior projection of the splenial. This new material increases the diversity of peirosaurids in the Neuquén Group, and the faunal richness of the Bajo de la Carpa Formation.Fil: Filippi, Leonardo Sebastián. Provincia de Neuquén. Museo Municipal "Argentino Urquiza"; ArgentinaFil: Barrios, Francisco. Provincia de Neuquén. Ministerio de Energía, Ambiente y Servicios Públicos. Dirección Provincial de Minería. Museo Provincial de Ciencias Naturales Prof. "Dr. Juan A. Olsacher"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Garrido, Alberto Carlos. Provincia de Neuquén. Ministerio de Energía, Ambiente y Servicios Públicos. Dirección Provincial de Minería. Museo Provincial de Ciencias Naturales Prof. "Dr. Juan A. Olsacher"; Argentin

A new chelid turtle, Prochelidella palomoi sp. nov., from campanian Anacleto Formation, Neuquén Basin, North-Western Patagonia, Argentina

The new turtle remains were found in the Anacleto Formation (Campanian) exposed in the Aguada Grande site. This area is located 10 km from the south of the city of Rincón de Los Sauces, in the north of the province of Neuquén, Patagonia, Argentina. The specimen (MAU-Pv-AG-452) consists of a partially preserved skull, carapace remains, an almost complete plastron, and a left ilium. The skull shows some features (a developed retropterygoid foramen, and a big muscle attachment area over the basisphenoid) that allow us to refer this specimen to the genus Prochelidella. The visceral view of the first costal bone exhibits deeper axillary buttresses that extend 2/3 of the costal width. This condition is also observed in the costal bone of Prochelidella buitreraensis from the Candeleros Formation (Cenomanian). The scute pattern observed in the anterior lobe of the plastron shows a large gular that extends along the entoplastra length, and small extragulars over the epiplastra. In contrast with the scute scheme observed in Prochelidella cerrobarcinae and Prochelidella portezuelae where the gular does not extend beyond the first 1/3 of the entoplastron. The phylogenetic analyses performed recovered this new species as a member of Prochelidella. The material recovered from the Anacleto Formation represents the first undoubtedly finding of Prochelidella in the late Cretaceous (Campanian) and the second skull recognized for the genus.Fil: Maniel, Ignacio Jorge. Universidad Tecnologica Nacional. Facultad Reg.san Rafael. Instituto de Evolucion, Ecologia Historica y Ambiente. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Mendoza. Instituto de Evolucion, Ecologia Historica y Ambiente.; ArgentinaFil: de la Fuente, Marcelo Saul. Universidad Tecnologica Nacional. Facultad Reg.san Rafael. Instituto de Evolucion, Ecologia Historica y Ambiente. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Mendoza. Instituto de Evolucion, Ecologia Historica y Ambiente.; ArgentinaFil: Filippi, Leonardo Sebastián. Gobierno de la Provincia del Neuquén. Municipalidad de Rincón de Los Sauces. Secretaria de Turismo y Patrimonio. Museo Municipal Argentino Urquiza; Argentin

Una vértebra caudal no furileusauriana de la formación bajo de la carpa (santonian) y variación morfológica en la cola de los abelisauridae

The Cerro Overo-La Invernada area in north Patagonia has provided a rich record of Cretaceous continental tetrapods in the last two decades, mainly from the Bajo de la Carpa Formation (Upper Cretaceous, Santonian). The dinosaur fauna from this area is diverse, including several new taxa, with abelisaurid theropods particularly abundant. Recently, a new isolated caudal vertebra (MAU-Pv-CO-598) was here recovered. Although fragmentary, it shows features that differentiate it from other abelisaurid remains previously found in this area. It is considered a mid-caudal vertebra and is mainly characterized by a longitudinal groove on the ventral surface of the centrum; a scarcely elevated transverse process with an anteroposteriorly expanded and laterally concave distal end; a longitudinal dorsal crest anteriorly extended from the anterior border of the neural spine; and small tubercles extended from the ends of the zygapophyses, which are considered as accessory interlocking structures between vertebrae. Some characters, such as the dorsal longitudinal crest and the accessory tubercles of the zygapophyses, are present also in the non-brachyrostran abelisaurid Majungasaurus. However, the transverse process is similar to that of caudal vertebrae of non-furileusaur brachyrostrans, such as Ilokelesia, Ekrixinatosaurus, and Skorpiovenator. A phylogenetic analysis here conducted clusters MAU-Pv-Co-598 with the latter three taxa. MAU-Pv-CO-598 comes from lower levels of the Bajo de la Carpa Formation than the furileusaurs Viavenator and Llukalkan. The presence of a specimen with non-furileusaurian affinities in this formation indicates that a possible replacement from non-furileusaur to furileusaur brachyrostrans occurred during the Santonian, after the proposed Turonian faunal turnover.Fil: Gianechini, Federico Abel. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis; ArgentinaFil: Filippi, Leonardo Sebastián. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; ArgentinaFil: Méndez, Ariel Hernán. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; ArgentinaFil: Garrido, Alberto Carlos. Provincia de Neuquén. Ministerio de Energía, Ambiente y Servicios Públicos. Dirección Provincial de Minería. Museo Provincial de Ciencias Naturales Prof. "Dr. Juan A. Olsacher"; Argentin