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Brachiosauridae is a lineage of titanosauriform sauropods that includes some of the most iconic non-avian dinosaurs. Undisputed brachiosaurid fossils are known from the Late Jurassic through the Early Cretaceous of North America, Africa, and Europe, but proposed occurrences outside this range have proven controversial. Despite occasional suggestions that brachiosaurids dispersed into Asia, to date no fossils have provided convincing evidence for a pan-Laurasian distribution for the clade, and the failure to discover brachiosaurid fossils in the well-sampled sauropod-bearing horizons of the Early Cretaceous of Asia has been taken to evidence their genuine absence from the continent. Here we report on an isolated sauropod maxilla from the middle Cretaceous (Albian–Cenomanian) Longjing Formation of the Yanji basin of northeast China. Although the specimen preserves limited morphological information, it exhibits axially twisted dentition, a shared derived trait otherwise known only in brachiosaurids. Referral of the specimen to the Brachiosauridae receives support from phylogenetic analysis under both equal and implied weights parsimony, providing the most convincing evidence to date that brachiosaurids dispersed into Asia at some point in their evolutionary history. Inclusion in our phylogenetic analyses of an isolated sauropod dentary from the same site, for which an association with the maxilla is possible but uncertain, does not substantively alter these results. We consider several paleobiogeographic scenarios that could account for the occurrence of a middle Cretaceous Asian brachiosaurid, including dispersal from either North America or Europe during the Early Cretaceous. The identification of a brachiosaurid in the Longshan fauna, and the paleobiogeographic histories that could account for its presence there, are hypotheses that can be tested with continued study and excavation of fossils from the Longjing Formation.

Sauropod dinosaurs were an abundant and diverse component of the Upper Jurassic Morrison Formation of the USA, with 24 currently recognized species. However, some authors consider this high diversity to have been ecologically unviable and the validity of some species has been questioned, with suggestions that they represent growth series (ontogimorphs) of other species. Under this scenario, high sauropod diversity in the Late Jurassic of North America is greatly overestimated. One putative ontogimorph is the enigmatic diplodocoidAmphicoelias altus, which has been suggested to be synonymous withDiplodocus. Given thatAmphicoeliaswas named first, it has priority and thusDiplodocuswould become its junior synonym. Here, we provide a detailed re-description ofA. altusin which we restrict it to the holotype individual and support its validity, based on three autapomorphies. Constraint analyses demonstrate that its phylogenetic position within Diplodocoidea is labile, but it seems unlikely thatAmphicoeliasis synonymous withDiplodocus. As such, our re-evaluation also leads us to retainDiplodocusas a distinct genus. There is no evidence to support the view that any of the currently recognized Morrison sauropod species are ontogimorphs. Available data indicate that sauropod anatomy did not dramatically alter once individuals approached maturity. Furthermore, subadult sauropod individuals are not prone to stemward slippage in phylogenetic analyses, casting doubt on the possibility that their taxonomic affinities are substantially misinterpreted. An anatomical feature can have both an ontogenetic and phylogenetic signature, but the former does not outweigh the latter when other characters overwhelmingly support the affinities of a taxon. Many Morrison Formation sauropods were spatio-temporally and/or ecologically separated from one another. Combined with the biases that cloud our reading of the fossil record, we contend that the number of sauropod dinosaur species in the Morrison Formation is currently likely to be underestimated, not overestimated.

The Upper Cretaceous ‘upper’ Winton Formation of Queensland, Australia is world famous for hosting Dinosaur Stampede National Monument at Lark Quarry Conservation Park, a somewhat controversial tracksite that preserves thousands of tridactyl dinosaur tracks attributed to ornithopods and theropods. Herein, we describe the Snake Creek Tracksite, a new vertebrate ichnoassemblage from the ‘upper’ Winton Formation, originally situated on Karoola Station but now relocated to the Australian Age of Dinosaurs Museum of Natural History. This site preserves the first sauropod tracks reported from eastern Australia, a small number of theropod and ornithopod tracks, the first fossilised crocodyliform and ?turtle tracks reported from Australia, and possible lungfish and actinopterygian feeding traces. The sauropod trackways are wide-gauge, with manus tracks bearing an ungual impression on digit I, and anteriorly tapered pes tracks with straight or concave forward posterior margins. These tracks support the hypothesis that at least one sauropod taxon from the ‘upper’ Winton Formation retained a pollex claw (previously hypothesised for Diamantinasaurus matildae based on body fossils). Many of the crocodyliform trackways indicate underwater walking. The Snake Creek Tracksite reconciles the sauropod-, crocodyliform-, turtle-, and lungfish-dominated body fossil record of the ‘upper’ Winton Formation with its heretofore ornithopod- and theropod-dominated ichnofossil record.

We document an osteomyelitis in a posterior caudal vertebra of a Aeolosaurini titanosaur dinosaur from the Upper Cretaceous of Sao Paulo, in southeastern Brazil. Gross examination of the caudal vertebra revealed the presence of new bone formation with a woven bone surface texture, a characteristic feature of non-specific infection. This lesion was likely associated with inflammation of the M. caudofemoralis longus and it may have compromised the mobility of the animal. Although infections have been described in several extinct taxa, this is only the third case diagnosed in a sauropod dinosaur and the first in Brazil.

Fil: Coria, Rodolfo Anibal. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Patagonia Confluencia; Argentina. Provincia del Neuquen. Municipalidad de Plaza Huincul. Museo "Carmen Funes"; Argentina

The titanosaur sauropod record of Patagonia, mainly recovered from Upper Cretaceous strata, is probably the richest worldwide. Here we present a new sauropod dinosaur, Ninjatitan zapatai gen. et sp. nov., from the Lower Cretaceous Bajada Colorada Formation (Berriasian–Valanginian) of north Patagonia (Neuquen Province, Argentina), from which postcranial remains are preserved. The anatomical analysis and comparisons performed in this specimen evidence strong affinity with titanosaur sauropods. This assumption is corroborated with the inclusion of the new taxon in an updated phylogenetic data matrix. The cladistic analyses indicate that Ninjatitan could be considered the earliest known titanosaur sauropod. The combination of features such as the presence of procoelous anterior caudal centra, the pneumatized neural arch of anterior caudal vertebrae, and the posterodorsal border of the scapular acromion near the glenoid level supports its titanosaur affinities. The presence of a basal titanosaurian sauropod in the lowermost Cretaceous of Patagonia supports the hypothesis that the group was established in the Southern Hemisphere and reinforces the idea of a Gondwanan origin for Titanosauria. The Bajada Colorada sauropod fauna represents one of the most diverse and unique associations from the lowermost Cretaceous worldwide recorded.

La presente Tesis Doctoral tiene como objeto de estudio los materiales fósiles de dinosaurios saurópodos procedentes de los afloramientos cretácicos de la Formación Lohan Cura (Aptiano-Albiano), ampliamente expuestos en la localidad de Cerro de los Leones, al sureste de la ciudad de Picún Leufú (Provincia del Neuquén, Patagonia, Argentina). Estos materiales, junto a numerosos otros fósiles de vertebrados e invertebrados, fueron recolectados durante las campañas paleontológicas realizadas desde el 1996 hasta el 2004 bajo la dirección del Dr. José Bonaparte (1928-2020), y están representados por diferentes ejemplares de saurópodos de gran tamaño, algunos de los cuales en buenas condiciones de preservación y parcialmente articulados. El objetivo principal de esta tesis es contribuir al conocimiento osteológico, morfológico y filogenético de estos ejemplares de dinosaurios saurópodos, entre los cuales se reconocen dos taxones formalmente establecidos, Agustinia ligabuei Bonaparte, 1999 y Ligabuesaurus leanzai Bonaparte et al., 2006, así como materiales inéditos recolectados en diferentes sectores y niveles fosilíferos del Cerro de los Leones. Para lograr con el objetivo principal, se realizaron distintas tareas, tanto de campo, como de laboratorio y de gabinete, y cuyos resultados se encuentran sintetizados en la presente Tesis Doctoral. A tal propósito, entre el 2014 y el 2016 se organizaron cinco campañas paleontológicas en el Cerro de los Leones, dos de exploración y tres de excavación, las cuales permitieron reconocer nuevos sitios fosilíferos y hallar materiales inéditos referibles a Ligabuesaurus leanzai. Estas campañas se llevaron a cabo en colaboración con el Museo Municipal “Carmen Funes” de Plaza Huincul y fueron en parte financiadas por los subsidios otorgados por la “Jurassic Foundation” (Grant 2014). Paralelamente, más de veinte ejemplares fósiles, entre dientes, elementos axiales y apendiculares, la mayor parte de los cuales inéditos, fueron preparados mecánicamente en las instalaciones del Museo Municipal de Plaza Huincul. Además, se realizaron estudios paleohistológicos sobre diez cortes delgados obtenidos de las estructuras óseas atribuidas a Agustinia como osteodermos, los cuales permitieron descartar dicha asignación y revaluar la mayor parte de dichas estructuras como costillas cervicales y dorsales incompletas y alteradas diagenéticamente.Se visitaron cinco repositorios paleontológicos dentro de la Provincia del Neuquén (MUC-PV, MCF, MMCH, MOZ, MAU), y tres dentro del territorio Nacional (MACN, IANIGLA, CRILAR), lo que permitió acceder de manera directa a más de treinta ejemplares de dinosaurios saurópodos, de los cuales se obtuvieron medidas, fotos, y datos morfológicos fundamentales para la codificación de los caracteres y los análisis filogenéticos correspondientes. Con el desarrollo de esta tesis doctoral se amplía el conocimiento anatómico de los saurópodos de la Formación Lohan Cura, permitiendo así la revisión y el incremento de los datos morfológicos, así como análisis filogenéticos más detallados y actualizados. Con el objetivo de establecer una determinación taxonómica más precisa y definir las relaciones filogenéticas de los taxones de Cerro de los Leones dentro de Sauropoda, se elaboró una matriz de datos de 96 taxones de dinosaurios saurópodos y 471 caracteres morfológicos craneanos y postcraneanos. Los resultados de los análisis filogenéticos aquí presentados permitieron poner a prueba las hipótesis iniciales relativas a Agustinia ligabuei como una forma de diplodocoideo y a Ligabuesaurus leanzai como un titanosaurio basal. Por lo que concierne Agustinia ligabuei, se completó la preparación mecánica de algunos elementos del ejemplar holotipo y se realizó una revisión de la osteología, la cual permitió modificar la diagnosis del taxón. De esta forma, la re-descripción y la caracterización del ejemplar holotipo permitieron actualizar y ajustar el análisis filogenético y redefinir la posición de Agustinia ligabuei dentro de Sauropoda, que se recuperó como taxon hermano de Zapalasaurus bonapartei Salgado et al., 2006 en la base de la familia Rebbachisauridae. Por otro lado, la reactivación de los trabajos de campo en la localidad de donde proceden los ejemplares holotipo y la preparación de materiales inéditos, permitieron ampliar el conocimiento osteológico de Ligabuesaurus leanzai y reconsiderar los caracteres diagnósticos del taxón. De esta forma se pudo incrementar el número de caracteres codificados y realizar un análisis filogenético novedoso que recuperó a Ligabuesaurus leanzai como taxon hermano de Andesaurus Calvo y Bonaparte, 1991 estrechamente relacionado a la evolución temprana de los Titanosauria. Por último, en esta tesis se presentan los elementos apendiculares de un ejemplar de dinosaurio saurópodo inédito procedentes del mismo nivel fosilífero que el holotipo de Ligabuesaurus leanzai, cuyos caracteres permiten diferenciarlo de los otros taxones del Cerro de los Leones, indicando una diversidad de saurópodos más amplia que la anteriormente conocida. Fil: Bellardini, Flavio. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche; Argentina.

BackgroundMegaloolithid eggs have long been associated with sauropod dinosaurs. Despite their extensive and worldwide fossil record, interpretations of egg size and shape, clutch morphology, and incubation strategy vary. The Pinyes locality in the Upper Cretaceous Tremp Formation in the southern Pyrenees, Catalonia provides new information for addressing these issues. Nine horizons containing Megaloolithus siruguei clutches are exposed near the village of Coll de Nargó. Tectonic deformation in the study area strongly influenced egg size and shape, which could potentially lead to misinterpretation of reproductive biology if 2D and 3D maps are not corrected for bed dip that results from tectonism.Methodology/findingsDetailed taphonomic study and three-dimensional modelling of fossil eggs show that intact M. siruguei clutches contained 20-28 eggs, which is substantially larger than commonly reported from Europe and India. Linear and grouped eggs occur in three superimposed levels and form an asymmetric, elongate, bowl-shaped profile in lateral view. Computed tomography data support previous interpretations that the eggs hatched within the substrate. Megaloolithid clutch sizes reported from other European and Indian localities are typically less than 15 eggs; however, these clutches often include linear or grouped eggs that resemble those of the larger Pinyes clutches and may reflect preservation of incomplete clutches.Conclusions/significanceWe propose that 25 eggs represent a typical megaloolithid clutch size and smaller egg clusters that display linear or grouped egg arrangements reported at Pinyes and other localities may represent eroded remnants of larger clutches. The similarity of megaloolithid clutch morphology from localities worldwide strongly suggests common reproductive behaviour. The distinct clutch geometry at Pinyes and other localities likely resulted from the asymmetrical, inclined, and laterally compressed titanosaur pes unguals of the female, using the hind foot for scratch-digging during nest excavation.

Dzharatitanis kingi gen. et sp. nov. is based on an isolated anterior caudal vertebra (USNM 538127) from the Upper Cretaceous (Turonian) Bissekty Formation at Dzharakuduk, Uzbekistan. Phylogenetic analysis places the new taxon within the diplodocoid clade Rebbachisauridae. This is the first rebbachisaurid reported from Asia and one of the youngest rebbachisaurids in the known fossil record. The caudal is characterized by a slightly opisthocoelous centrum, ‘wing-like’ transverse processes with large but shallow PRCDF and POCDF, and the absence of a hyposphenal ridge and of TPRL and TPOL. The neural spine has high SPRL, SPDL, SPOL, and POSL and is pneumatized. The apex of neural spine is transversely expanded and bears triangular lateral processes. The new taxon shares with Demandasaurus and the Wessex rebbachisaurid a high SPDL on the lateral side of the neural spine, separated from SPRL and SPOL. This possibly suggests derivation of Dzharatitanis from European rebbachisaurids. This is the second sauropod group identified in the assemblage of non-avian dinosaurs from the Bissekty Formation, in addition to a previously identified indeterminate titanosaurian.

The Late Cretaceous dinosaur record in southern South America has been improved recently; particularly with findings from Chorrillo and Cerro Fortaleza formations, both bearing ankylosaur remains, a clade that was not previously recorded in the Austral Basin. The dinosaur fauna of the type locality of Cerro Fortaleza Formation is known from -and biased to- large-sized sauropod remains and a single described taxon, the titanosaur Dreadnoughtus schrani. Here, we report the taxonomic composition of a site preserving thirteen isolated teeth and several osteoderms belonging to three dinosaur clades (Abelisauridae, Titanosauria, and Nodosauridae), and at least one clade of notosuchian crocodyliforms (Peirosauridae). They come from sediments positioned at the mid-section of the Cerro Fortaleza Formation, which is Campanian-Maastrichtian in age, adding valuable information to the abundance and biodiversity of this Cretaceous ecosystem. Since non-titanosaur dinosaur bones are almost absent in the locality, the teeth presented here provide a window onto the archosaur biodiversity of the Late Cretaceous in southern Patagonia. The nodosaurid tooth and small armor ossicles represent the first record of ankylosaurs for this stratigraphic unit. The peirosaurid material also represents the most austral record of the clade in South America.

A recent publication of fossil bones of titanosaurs assigned to Aeolosaurini from the Morro do Cambambe site (Mato Grosso state, Brazil, Upper Cretaceous) reported anomalous growth in some of them. Here, we present osteohistological sections of elements to understand not only the microstructure and growth of such bones, but also the nature of those anomalies. Among them, we selected one cervical and one mediumposterior dorsal rib, and a haemal arch. The primary bone of all specimens consisted of a variation of the fibrolamellar complex, with the inner cortex being rich in woven bone with dispersed longitudinal canals, while the outer cortex was parallel-fibred with rows of longitudinal canals, interlayered by Lines of Arrested Growth. We identified a maximum of two Lines of Arrested Growth in the cervical rib and haemal arch, and four in the dorsal rib. The haemal arch shows an External Fundamental System in most sections. The advanced remodelling and variation of the fibrolamellar bone in the cortex suggests that all the specimens represent individuals that reached sexual maturity. However, the haemal arch was distinct due to the wide distribution of External Fundamental System. Based on the microstructure, we identified a subadult semaphoront, and probably an adult. The dorsal rib exhibited periosteal and endosteal outgrowth. Such microstructure was assigned to a reactive bone due to an intra-thoracic infection (a pneumonia, probably related to a tuberculosis), which is the first report in a non-avian dinosaur. The microstructure resembles the medullary bone recovered in dinosaurs, which suggests that further studies of medullary bone in thoracic bones should also regard the pathological cases. En una reciente publicación de los huesos fósiles de titanosaurios asignados al clado Aeolosaurini provenientes del yacimiento de Morro do Cambambe (estado de Mato Grosso, Brasil, Cretácico Superior), se reconocieron anormalidades en el crecimiento de algunos de ellos. En el presente trabajo presentamos cortes osteohistológicos de elementos para entender no sólo la microestructura y crecimiento de los mismos, sino también la naturaleza de aquellas anomalías. Entre ellos, seleccionamos una costilla cervical y una costilla dorsal media posterior, así como un arco hemal. El hueso primario de todos los especímenes comprendía una variación del complejo fibrolamelar, siendo la corteza interna rica en tejido reticular óseo con canales longitudinales dispersos, mientras que la corteza externa tenía fibras paralelas con hileras de canales longitudinales, intercaladas por líneas de crecimiento detenido. Identificamos un máximo de dos líneas de crecimiento detenido tanto en la costilla cervical como en el arco hemal, y cuatro en la costilla dorsal. El arco hemal muestra un Sistema Externo Fundamental en la mayoría de las secciones. La remodelación avanzada y la variación del hueso fibrolamelar en la corteza, se sugiere que todas los especímenes alcanzaron la madurez sexual. Sin embargo, el arco hemal fue distinto debido a la amplia distribución de Sistema Externo Fundamental. Con base en la microestructura, identificamos un semaforonte subadulto, y probablemente a un adulto. La costilla dorsal mostró una excrecencia perióstica y endosteal. Dicha microestructura se ha identificado con un hueso reactivo a una infección intratorácica (una neumonía, probablemente relacionada con una tuberculosis), que es el primer informe de un dinosaurio no aviano. La microestructura se asemeja al hueso medular recuperado en los dinosaurios, lo que sugiere que los estudios posteriores del hueso medular en los huesos torácicos también deberían considerar los casos patológicos.

Fil: González, Romina. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas y Naturales y Agrimensura; Argentina. Fil: Cerda, Ignacio Alejandro. Universidad Nacional de Río Negro. Instituto de Investigaciones en Paleobiología y Geología; Argentina. Fil: Salgado, Leonardo. Universidad Nacional de Río Negro. Instituto de Investigaciones en Paleobiología y Geología; Argentina. Fil: Zurita, Alfredo Eduardo. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas y Naturales y Agrimensura; Argentina. Fil: Zurita, Alfredo Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Ecología Aplicada del Litoral; Argentina. El clado Titanosauriformes comprende a un grupo de dinosaurios saurópodos macronarios con diversos tamaños corporales, incluyendo tanto formas de talla modesta (alrededor de cuatro toneladas) como gigantes (más de 60 toneladas). El estudio de la biología de los saurópodos representa un enorme desafío dada la ausencia de formas análogas modernas. Una de las disciplinas que ha permitido ampliar sustancialmente el conocimiento paleobiológico de los saurópodos (y otros grupos fósiles) es la paleohistología. Esta disciplina se basa en el estudio de la estructura microscópica de los huesos u otras partes duras en formas fósiles a partir de la obtención de cortes delgados, utilizando para ello, técnicas petrográficas y de la histología ósea moderna.La importancia de esta disciplina estriba en el hecho de que distintos tejidos y estructuras histológicas tienen un origen y significado biológico común entre los tetrápodos, lo que permite inferir procesos y fenómenos biológicos en grupos extintos. Si bien una gran parte de los estudios paleohistológicos han sido enfocados en dinosaurios saurópodos, existen muchas hipótesis que han sido propuestas por diversos autores que no han sido debidamente testeadas (p.ej., posible incremento de la tasa relativa de remodelación secundaria en Titanosauria), o bien muchos tópicos han sido pobremente explorados (histología dental, paleopatologías) o directamente no han sidoestudiados (histología de láminas neurales). El objetivo general de la presente Tesis es contribuir al conocimiento paleobiológico de los dinosauriosTitanosauriformes de Argentina a partir del estudio de la estructura fina (microanatomía e histología), tanto de su esqueleto postcraneal como de sus dientes y estructuras vinculadas.Adicionalmente, se pretende estudiar anomalías óseas en huesos postcraneales de Titanosauriformes. Se estudiaron, entre elementos óseos y dientes, más de 200 secciones delgadas y se indagó (principalmente desde la paleohistología) sobre: 1- los rasgos histológicos que caracterizan a los Titanosauriformes, 2- los cambios que ocurren a nivel histológico durante la ontogenia, 3- la correlación temporal entre las variaciones histológicas y anatómicas durante la ontogenia, 4-el valor de las costillas y arcos hemales para su utilización en estudios esqueletocronológicos, 5- la microestructura de las láminas neurales y 6- la microestructura dental. Además, se describieron e interpretaron (principalmente a nivel macroscópico) anomalías óseas de origen patológico en diferentes elementos postcraneales. Entre los resultados más relevantes se destaca que la histología de Titanosauriformes no revela importantes diferencias con el tejido cortical reportado para otros Sauropoda. En términos generales, el tejido cortical de los Titanosauriformes se caracteriza por exhibir tejido fibrolamelar altamente vascularizado y sin marcas de crecimiento durante etapas tempranas de la ontogenia, en tanto que en etapas tardías del crecimiento, se evidencian marcas de crecimiento en el tejido primario y la tasa de remodelación secundaria tiende a ser alta. El reconocimiento de la variación de ciertos parámetros histológicos permitió establecer cuatro patrones histológicos que caracterizan cuatro etapas distintas del crecimiento ontogenético. El análisis en conjunto de rasgos histológicos y los cambios anatómicos ocurridos durante la ontogenia reveló que la maduración sexual ocurre previamente a la completa fusión de las suturas neurocentrales de la columna vertebral, en tanto que la madurez somática (momento en que un individuo alcanza el tamaño adulto) ocurre con posterioridad a dicha fusión. Por otra parte, se encontró que existe variación respecto al momento en el cual ocurre la maduración sexual y se produce la fusión de las suturas neurocentrales en las distintas regiones de la columna. Los elementos axiales no resultaron ser los elementos que mejor registran el crecimiento ontogenético, por lo cual carecen de valor para su utilización en estudios esqueletocronológicos. Se encontró que Saltasaurinae carece del denominado “tejido lamelar modificado”, el cual ha sido previamente reportado para otras formas de talla corporal reducida. El tejido cortical de Titanosauria presenta un alto grado de remodelación secundaria, sustentando la hipótesis de que este carácter podría ser un rasgo común del grupo. La histología de las láminas neurales revela que la mayoría de ellas posiblemente tenian alguna función en el sostén de los paquetes musculares y sólo unas pocas estarían vinculadas a los divertículos del sistema neumático. Se identificaron anomalías óseas de posible origen patológico en cinco ejemplares de titanosaurios. Las paleopatologías se encuentran con mayor frecuencia en los elementos axiales y posiblemente su etiología se corresponde con enfermedades degenerativas (p. ej. espondiloartropatías) e infecciones. El análisis de la microestructura dental permitió identificar unidades estructurales primarias y secundarias en la dentina y el esmalte, se estimó una tasa de reemplazo dental de entre 36 y 54 días para un Titanosauria indeterminado. Los rasgos microestructurales del esmalte estudiados mediante MEB, presentan potencial para su utilización en estudios sitemáticos. Por lo tanto, el presente trabajo aporta información novedosa y amplía el conocimiento paleobiológico sobre Titanosauriformes, en particular sobre los titanosaurios de Argentina.

A new giant sauropod, Australotitan cooperensis gen. et sp. nov., represents the first record of dinosaurs from the southern-central Winton Formation of the Eromanga Basin, Australia. We estimate the type locality to be 270–300 m from the base of the Winton Formation and compare this to the semi-contemporaneous sauropod taxa, Diamantinasaurus matildae Hocknull et al., 2009, Wintonotitan wattsi Hocknull et al., 2009 and Savannasaurus elliottorum Poropat et al., 2016. The new titanosaurian is the largest dinosaur from Australia as represented by osteological remains and based on limb-size comparisons it reached a size similar to that of the giant titanosaurians from South America. Using 3-D surface scan models we compare features of the appendicular skeleton that differentiate Australotitan cooperensis gen. et sp. nov. as a new taxon. A key limitation to the study of sauropods is the inability to easily and directly compare specimens. Therefore, 3-D cybertypes have become a more standard way to undertake direct comparative assessments. Uncoloured, low resolution, and uncharacterized 3-D surface models can lead to misinterpretations, in particular identification of pre-, syn- and post-depositional distortion. We propose a method for identifying, documenting and illustrating these distortions directly onto the 3-D geometric surface of the models using a colour reference scheme. This new method is repeatable for researchers when observing and documenting specimens including taphonomic alterations and geometric differences. A detailed comparative and preliminary computational phylogenetic assessment supports a shared ancestry for all four Winton Formation taxa, albeit with limited statistical support. Palaeobiogeographical interpretations from these resultant phylogenetic hypotheses remain equivocal due to contrary Asian and South American relationships with the Australian taxa. Temporal and palaeoenvironmental differences between the northern and southern-central sauropod locations are considered to explain the taxonomic and morphological diversity of sauropods from the Winton Formation. Interpretations for this diversity are explored, including an eco-morphocline and/or chronocline across newly developed terrestrial environments as the basin fills.

Although sauropodomorph dinosaurs have been known for a long time from the Late Triassic of central Europe, sauropodomorph diversity and faunal composition has remained controversial until today. Here we review sauropodomorph material from the Canton Schaffhausen, Switzerland. The material comes from three different but geographically close localities and represents at least three different taxa. Apart from the common genusPlateosaurus, the material includes remains of two different large, robustly built sauropodomorphs. One of these is described as a new taxon,Schleitheimia schutzin. gen. et sp., on the basis of an unusual ilium and associated axial and appendicular material.Schleitheimiarepresents a derived basal sauropodiform and possibly the immediate outgroup to Sauropoda, and thus is the most derived sauropodomorph known from the Late Triassic of Europe. These results thus highlight the diversity of sauropodomorphs in the Late Triassic of central Europe and further indicate widespread sauropodomorph survival across the Triassic-Jurassic boundary.

Middle Jurassic sauropod taxa are poorly known, due to a stratigraphic bias of localities yielding body fossils. One such locality is Cerro Cóndor North, Cañadón Asfalto Formation, Patagonia, Argentina, dated to latest Early−Middle Jurassic. From this locality, the holotype of Patagosaurus fariasi Bonaparte 1986 is revised. The material consists of the axial skeleton, the pelvic girdle, and the right femur. Patagosaurus is mainly characterised by a combination of features mainly identified on the axial skeleton, including the following: (1) cervical centra with low Elongation Index, (2) high projection of the postzygodiapophyseal lamina, (3) deep anterior pleurocoels that are sometimes compartmentalized in cervicals, (4) high projection of the neural arch and spine in dorsal vertebrae and anterior(most) caudal vertebrae, (5) deep pneumatic foramina in posterior dorsals which connect into an internal pneumatic chamber, (6) anterior caudal vertebrae with ‘saddle’shaped neural spines. Diagnostic features on the appendicular skeleton include (7) a transversely wide and anteroposteriorly short femur, (8) a medial placement of the fourth trochanter on the femur, and (9) an anteroposteriorly elongated ilium with a rounded dorsal rim, with hook-shaped anterior lobe. The characters that are diagnostic for Patagosaurus are discussed, and the osteology of Patagosaurus is compared to that of Early and Middle Jurassic (eu)sauropods from both Laurasia and Gondwana.

Sauropod dinosaurs include the largest terrestrial vertebrates that have ever lived. Virtually every part of the sauropod body is heavily modified in association with gigantic size and associated physiological alterations. Sauropod skulls are no exception: they feature elongated, telescoped facial regions connected to tilted neurocrania and reoriented jaw adductor muscles. Several of these cranial features have been suggested to be adaptations for feeding on the one hand and the result of paedomorphic transformation near the base of Sauropoda on the other. However, the scarcity of sauropodomorph ontogenetic series has impeded further investigation of these hypotheses. We re-evaluated the cranial material attributed to the early sauropodomorph Anchisaurus, which our phylogenetic analyses confirm to be closely related to sauropods. Digital assembly of μCT scanned skulls of the two known specimens, a juvenile and an adult, permitted us to examine the detailed ontogeny of cranial elements. The skull anatomy of Anchisaurus is distinguished by a mosaic of ancestral saurischian and sauropod-like characters. Sauropod-like characters of the braincase and adductor chamber appear late in ontogeny, suggesting that these features first evolved by the developmental mechanism of terminal addition. Shape analyses and investigation of allometric evolution demonstrate that cranial characters that appear late in the ontogeny of sauropodomorphs closely related to sauropods are already present in the embryos and juveniles of sauropods, suggesting a predisplacement-type shift in developmental timing from the ancestral anchisaurian condition. We propose that this developmental shift relaxed prior constraints on skull morphology, allowing sauropods to explore a novel range of phenotypes and enabling specializations of the feeding apparatus. The shift in timing occurred in concert with the evolution of gigantism and physiological and locomotory innovations. This article is protected by copyright. All rights reserved.

Sauropodomorpha were herbivorous saurischian dinosaurs that incorporate Sauropoda and early-diverging sauropodomorphs. The oldest sauropodomorph remains are known from Late Triassic deposits, most of them Gondwanan. The Laurasian record comprises some Triassic forms, but the bulk is Jurassic in age. Among the 14 Jurassic non-sauropodan sauropodomorphs from Laurasia described in the past, 8 are from China. Here we describe a new non-sauropodan sauropodomorph, Irisosaurus yimenensis gen. et sp. nov., from the Early Jurassic Fengjiahe Formation of China. Nearly all of the non-sauropodan sauropodomorph genera currently known from China were first reported from the Lufeng Formation. The Fengjiahe Formation is its Southern equivalent, bringing a fauna similar to that of the Lufeng Formation to light. The new genus is defined based on an incomplete but unique maxilla, with a premaxillary ramus higher than long prior to the nasal process, a large and deep neurovascular foramen within the perinarial fossa, and a deep perinarial fossa defined by a sharp rim. Phylogenetic analysis places Irisosaurus at the very base of Sauropodiformes, as the sister-taxon of the Argentinean genus Mussaurus. This specimen adds to a growing assemblage of Chinese Jurassic non-sauropodan sauropodomorphs that offers new insight into the Laurasian evolution of this clade.

International audience; We describe a large, nearly completely preserved sauropod humerus from the Lower 23 Cretaceous Xinlong Formation of Napai Basin, Fusui County, Guangxi Zhuang Autonomous 24 Region, southern China. It was excavated from the quarry that produced the holotypic specimen of 25 the titanosauriform Fusuisaurus zhaoi and is considered here to belong to the same individual as 26 the holotype of Fusuisaurus zhaoi. With a preserved length of 183.5 cm, the newly collected 27 humerus provides additional evidence suggesting the presence of a giant sauropod (i.e., 28 Fusuisaurus zhaoi) during the late Early Cretaceous of Guangxi, China, which increases our 29 knowledge of the diversity of giant titanosauriforms from the late Early Cretaceous of Asia. 30 31

Dinosaur locomotion and biomechanics, especially of their pelvic girdles and hindlimbs, have been analyzed in numerous studies. However, detailed volumetric musculoskeletal models of their tails are rarely developed. Here, we present the first detailed three-dimensional volumetric reconstruction of the caudal epaxial and hypaxial musculature of the Late Jurassic sauropod Giraffatitan brancai, and highlight the importance and necessity of 3D modeling in musculoskeletal reconstructions. The tail of this basal macronarian is relatively short compared to diplodocids and other coexisting macronarians. The center of mass lies well in front of the hindlimbs, which support only ca. half the body weight. Still, our reconstruction suggests a total weight for the entire tail of ca. 2500 kg. We conclude that the hypaxial and tail-related hindlimb muscles (most specifically the M. caudofemoralis longus and its counterpart the M. ilioischiocaudalis) in Giraffatitan were well developed and robustly built, compensating for the shorter length of the M. caufodemoralis longus, the main hindlimb retractor muscle, in comparison with other sauropods. Our methodology allows a better-constrained reconstruction of muscle volumes and masses in extinct taxa, and thus force and weight distributions throughout the tail, than non-volumetric approaches.

En este trabajo se realiza una aproximación a la paleohistología de dos dinosaurios saurópodos, Galvesaurus herreroi Barco et al., 2005 y un saurópodo indeterminado. El primero procede del yacimiento Cuesta Lonsal de Galve (Teruel) de edad Kimmeridgiense superior mientras que el segundo se ha encontrado en el yacimiento La Peñuela en Camarillas (Teruel) cuya de edad es Berriasiense. Las observaciones histológicas realizadas a partir de láminas delgadas de los restos óseos en microscopio óptico, han permitido determinar el estadio ontogenético de los saurópodos en el momento de su muerte, tratándose en Galvesaurus y el saurópodo de La Peñuela de ejemplares adulto y senil, respectivamente. Así mismo, se ha realizado un estudio mineralógico de las muestras paleohistológicas combinando la microscopía óptica y electrónica de barrido de emisión de campo (FESEM). En el estudio se observa que los procesos diagenéticos son similares en los restos óseos de los dos ejemplares. El apatito que compone los huesos no ha sido modificado durante la diagénesis. Los rellenos en los canales y cavidades vasculares son mayoritariamente cementos calcíticos, granos detríticos y óxidos. El hecho de que los procesos observados sean similares en los distintos individuos se debe probablemente a la similitud litológica y de historia geológica de las formaciones en las que los ejemplares fueron encontrados. In this work a paleohistological approach to two sauropod dinosaurs, Galvesaurus herreroi Barco et al., 2005 and an undescribed specimen have been performed. The former comes from the Cuesta Lonsal site in Galve (Teruel) and it is late Kimmeridgian in age whereas the latter have been found in La Peñuela site in Camarillas (Teruel) and it is Berriasian in age. The histological observations of the skeletal remains that were made from the thin sections in an optical microscope have allowed to determine the ontogenetic stage of the sauropods at the time of their death: Galvesaurus and the sauropod of La Peñuela were adult and senile specimens, respectively. A mineralogical study of the paleohistological samples has also been carried out, combining optical and field emission scanning microscopy (FESEM). In the study it is observed that the diagenetic processes are similar in the bone remains of the two specimens. The apatite of the bones has not been modified during diagenesis. The fillings in vascular channels and cavities are mainly calcite cements, detrital grains and oxides. The fact that the observed processes are similar in the two individuals is probably due to the lithological similarity and the geological history of the formations in which the specimens were collected.

This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. The functional morphology of sauropod dinosaur long necks has been studied extensively, with virtual approaches yielding results that are difficult to obtain with actual fossils, due to their extreme fragility and size. However, analyses on virtual fossils have been questioned on several of their premises, such as the ability to accurately reconstruct intervertebral tissue with only skeletal data; or whether zygapophyseal overlap can be used to determine the limits of range of motion, since some extreme neck poses in extant giraffes have been claimed not to retain any zygapophyseal overlap. We compared articulation and range of motion in extant giraffes with the exceptionally well-preserved and complete basally branching eusauropod Spinophorosaurus nigerensis from the Middle (?) Jurassic of Niger, under the same virtual paleontology protocols. We examined the articulation and range of motion on grown and young specimens of both Spinophorosaurus and giraffes in order to record any potential changes during ontogeny. Also, the postures of virtual giraffes were compared with previously published data from living animals in the wild. Our analyses show that: (i) articulation of virtual bones in osteologically neutral pose (ONP) does enable accurate prediction of the amount of inter-vertebral space in giraffes and, roughly, in Spinophorosaurus; (ii) even the most extreme neck postures attained by living giraffes in the wild do not require to disarticulate cervical vertebrae; (iii) both living giraffes and Spinophorosaurus have large intervertebral spaces between their cervical centra in early ontogenetical stages, which decrease as ontogeny advances; and (iv) that grown specimens have a greater osteological range of motion in living giraffes and Spinophorosaurus, Research was supported by the project CGL2015-68363-P of the Spanish Ministerio de Economía y Competitividad (MINECO). DV's research is funded by a predoctoral FPI UNED Grant (Ref. 0531174813 Y0SC001170). PM's research is funded by FCT/MCTES for one CEEC Individual contract (CEECIND/00726/2017)

Epachthosaurus sciuttoi is a basal titanosaur from the early Late Cretaceous of central Patagonia, Argentina. Here, we present the reconstruction of the pelvic and hindlimb musculature of this titanosaur, based on the soft tissue data of extant archosaurs. The majority of the pelvic, hindlimb and pes muscles are within a decisive and positive level of inference. Comparison with a derived titanosaur such as Neuquensaurus, shows several morphological differences which are directly related with the muscular attachments, supporting differences about the musculature arrangement between these two sauropod dinosaurs. For example, the anterior projection of the preacetabular process of Neuquensaurus extends more laterally, whereas in Epachthosaurus the preacetabular process is laterally less extended. The fibular lateral tuberosity in Neuquensaurus is closer to the fibular head than it is in Epachthosaurus. The femoral fourth trochanter in Neuquensaurus is closer to the femoral head than it is in Epachthosaurus. Likewise, the caudofemoralis longus may have extended more distally in the tail in Epachthosaurus.These differences, among others, may have influenced the muscular arrangement and, therefore, the locomotor function abilities of these titanosaurs. Finally, this myological description of Epachthosaurus, where twenty one muscles were reconstructed, constitutes useful data for researches interested in functional anatomy. Fil: Ibiricu, Lucio Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico de Geología y Paleontología; Argentina Fil: Martínez, Rubén Darío. Universidad Nacional de la Patagonia "San Juan Bosco"; Argentina Fil: Casal, Gabriel. Universidad Nacional de la Patagonia "San Juan Bosco"; Argentina

This analysis of the long bone microstructure of Antetonitrus ingenipes fills a crucial gap in our understanding of the growth dynamics of sauropodomorph dinosaurs. The bone histology of basal Sauropodomorpha are often characterized by zonal tissue, and contrasts with that of more derived sauropod taxa which show a shift toward the deposition of uninterrupted fibrolamellar bone (with lines of growth being either absent or only present in the outer circumferential layer). In Antetonitrus, growth patterns in the youngest individuals exhibit uninterrupted fibrolamellar bone without any growth marks. Sub-adult individuals, also exhibit highly vascularized fibrolamellar bone throughout the cortex, as in more derived Sauropods and Mussaurus, but growth lines occur intermittently (although not regularly) throughout the cortex as in Lessemsaurus. This indicates that Antetonitrus does not exhibit the growth dynamics previously considered characteristic of Sauropoda. Despite this, the largest (and possibly the oldest femur, NMQR 1705/163) does show an incipient external fundamental system (EFS). Our findings further suggest that growth marks are decoupled from bone size, which indicates a level of developmental plasticity in this taxon. Modulations or textural shifts in the pattern of vascular channel arrangements throughout the fibrolamellar bone in the cortex may be related to periods of resource limitations, although the lack of consistency of these modulations suggest that it is unlikely due to seasonal fluctuations. Localized bands of radial fibrolamellar bone, followed by resumption of normal growth in two samples are interpreted as evidence of a disease infliction, and subsequent recovery thereof. Anat Rec, 301:1506-1518, 2018. © 2018 Wiley Periodicals, Inc.