Francisco Ortega

A New Basal Sauropod Dinosaur from the Middle Jurassic of Niger and the Early Evolution of Sauropoda

Background The early evolution of sauropod dinosaurs is poorly understood because of a highly incomplete fossil record. New discoveries of Early and Middle Jurassic sauropods have a great potential to lead to a better understanding of early sauropod evolution and to reevaluate the patterns of sauropod diversification. Principal Findings A new sauropod from the Middle Jurassic of Niger, Spinophorosaurus nigerensis n. gen. et sp., is the most complete basal sauropod currently known. The taxon shares many anatomical characters with Middle Jurassic East Asian sauropods, while it is strongly dissimilar to Lower and Middle Jurassic South American and Indian forms. A possible explanation for this pattern is a separation of Laurasian and South Gondwanan Middle Jurassic sauropod faunas by geographic barriers. Integration of phylogenetic analyses and paleogeographic data reveals congruence between early sauropod evolution and hypotheses about Jurassic paleoclimate and phytogeography. Conclusions Spinophorosaurus demonstrates that many putatively derived characters of Middle Jurassic East Asian sauropods are plesiomorphic for eusauropods, while South Gondwanan eusauropods may represent a specialized line. The anatomy of Spinophorosaurus indicates that key innovations in Jurassic sauropod evolution might have taken place in North Africa, an area close to the equator with summer-wet climate at that time. Jurassic climatic zones and phytogeography possibly controlled early sauropod diversification.

Ampliación de la distribución geográfica y temporal de Elochelys convenarum (Chelonii, Bothremydidae) en el Cretácico Superior de la Península Ibérica

Abstract. Expansion of the geographical and temporal range of Elochelys convenarun (Chelonii Bothremydidae) from de Upper Cretaceous of the Iberian Peninsula. The Campanian and Maastrichtian chelonian fauna of Western Europe was mainly composed of endemic taxa. The Bothremydidae-represented by the genera Rosasia, Foxemys, Polysternon and Elochelys-are very abundant in this record. Elochelys is known through relatively scarce material consisting only of isolated plates and carapaces, which are presently assigned to two species, i.e., Elochelys perfecta and Elochelys convenarum. In France, two specimens from the Campanian of Fuveau, Provence, have been assigned to the species Elochelys perfecta; one carapace is now taken to be the holotype of the species, while the anterior half of another carapace was described as the paratype. The holotype of Elochelys convenarum consists of a carapace from the upper Maastrichtian at Cassagnau-2 (Haute-Garonne), and specimens from the upper Campanian-lower Maastrichtian at Fox Amphoux, Provence, have been tentatively assigned to this genus. In Spain, the only reference to this genus is ?Elochelys sp. from the upper Campanian fossil site of Laño, in Treviño County, Burgos. Abundant specimens of pleurodiran turtles have been recognized at the new Upper Cretaceous fossil locality of Lo Hueco (Fuentes, Cuenca, Spain). Herein, we refer to Elochelys convenarum a carapace from this site. This carapace is the most complete specimen referred to Elochelys and constitutes the first robust evidence of the presence of this genus in the Iberian Peninsula, expanding the chronostratigraphic distribution of the species to the late Campanian-early Maastrichtian.

The eosauropterygian fossils from the Middle Triassic of Canales de Molina (Guadalajara, Spain)

PurposeAbundant isolated remains of vertebrate fossils were recovered in 1980 in Middle Triassic strata (Muschelkalk Facies) of Canales de Molina (Guadalajara, Spain). However, none of them was figured or described in detail. The careful study of these fossils is performed here.MethodsThe eosauropterygian remains from Canales de Molina are described and figured in detail, and compared with the Iberian record of Eosauropterygia.ResultsThe study of these elements allows us to identify abundant eosauropterygian remains, including vertebrae, teeth, femora, and a partial humerus. This humerus presents a combination of characters traditionally considered as exclusive affinity of the genus Nothosaurus. Other relatively large elements from this site are also compatible with the bones of this genus. Isolated teeth and a neural arch are identified as belonging to indeterminate nothosaurs. The other elements studied here are poorly informative, and can be only assigned to indeterminate members of Eosauropterygia of small to medium size.ConclusionsThe presence of Nothosaurus or a related form is confirmed in Canales de Molina. Other fossils from the site do not allow to assess if more taxa are present.ResumenObjetivoAbundantes restos aislados de vertebrados fueron recuperados en 1980 en los niveles del Triásico Medio (Muschelkalk Facies) de Canales de Molina (Guadalajara, España). Sin embargo, ninguno de ellos se ha figurado o descrito detalladamente hasta ahora. El estudio detallado de estos fósiles es llevado a cabo aquí.MétodosLos restos de eosauropterigios de Canales de Molina son descritos y figurados en detalle, y comparados con el registro ibérico de Eosauropterygia.ResultadosEl estudio de estos elementos nosxa0permite identificar abundantes restos de eosauropterigios, incluyendo vértebras, dientes, fragmentos de fémures y parte de un húmero. Este húmero presenta una combinación de caracteres tradicionalmente considerada exclusiva del géneroxa0Nothosaurus. Otros elementos relativamente grandes de este yacimiento son también compatibles con este género. Dientes aislados y un arco neural se identifican como pertenecientes a notosaurios indeterminados. Los otros elementos estudiados aquí son poco informativos, y sólo pueden ser asignados a miembros indeterminados de Eosauropterygia de pequeño a mediano tamaño.ConclusionesLa presencia de Nothosaurus o de una forma cercanamente emparentada es confirmada en Canales de Molina. Otros fósiles del yacimiento no permiten asegurar si hay otros taxones presentes.

Pelvic and femoral anatomy of the Allodaposuchidae (Crocodyliformes, Eusuchia) from the Late Cretaceous of Lo Hueco (Cuenca, Spain)

PurposeThe fossil record of postcranial remains assigned to Allodaposuchidae is currently sparse. However, the Late Cretaceous paleontological site of Lo Hueco (Cuenca, Spain), from where two new taxa of allodaposuchid have been described, has yielded numerous postcranial remains assignable to this clade. Among them, the large amount of pelvic and femoral material is notable, providing the opportunity to study these allodaposuchid elements and assess their morphological similarity with other eusuchian remains.MethodsThe comparison with extant crocodylians was accomplished using traditional morphometric techniques, whereas the comparison with other fossils and establishment of morphotypes was done using morphological criteria.ResultsThe results of the cluster and principal components analyses show morphological differences between extant crocodylians and allodaposuchids from Lo Hueco, allowing the segregation of these lineages. The similarities found between the pelvic and femoral remains from Lo Hueco, and those referred to Allodaposuchus precedens and other putative allodaposuchids from the Iberian Peninsula, allows referral of these remains to allodaposuchids. The differences found among the femoral and pelvic remains of Lo Hueco enables us to recognize two morphotypes per each element.ConclusionsThis study allows a better understanding of allodaposuchid postcranial elements that were previously poorly known. The ilia, ischia and femora from Lo Hueco allodaposuchids are distinct from those of other crocodylian lineages. Finally, the fact that there are two morphotypes per each element at Lo Hueco is congruent with the presence of two different allodaposuchids at the site.ResumenPropósitoEl registro fósil contiene escasos restos postcraneales asignados a Allodaposuchidae. Sin embargo, en el yacimiento paleontológico del Cretácico Superior de Lo Hueco (Cuenca, España), del cual se han descrito dos nuevas especies de alodaposúquido, se han recuperado numerosos restos fósiles postcraneales asignables a este clado. Entre ellos destaca la cantidad de restos pélvicos y fémorales recuperados. Esto ofrece la oportunidad de estudiarlos y evaluar su semejanza morfológica con restos de otros eusuquios.MétodosLa comparación con cocodrilos actuales se realizó empleando técnicas morfométricas tradicionales, mientras que la comparación con otros restos fósiles y el establecimiento de morfotipos se efectuó utilizando criterios morfológicos.ResultadosLos resultados de los análisis de clúster y de componentes principales muestran que existen diferencias morfológicas entre los restos de cocodrilos actuales y los restos de los alodaposúquidos de Lo Hueco, permitiendo la segregación de estos linajes. La similitud encontrada entre los restos pélvicos y femorales de Lo Hueco, y aquellos asignados a Allodaposuchus precedens y otros supuestos alodaposúquidos de la península ibérica, permite asignar estos restos a alodaposúquidos. Las diferencias encontradas entre el material femoral y pélvico de Lo Hueco permite reconocer dos morfotipos para cada elemento postcraneal estudiado.ConclusionesEl presente estudio posibilita un mejor entendimiento de estos restos postcraneales en alodaposúquidos, previamente poco conocidos. Los iliones, isquiones y fémures de los alodaposúquidos de Lo Hueco son distintos de los de miembros de los linajes de Crocodylia. Por último, el hecho de que existan dos morfotipos de cada elemento estudiado de Lo Hueco es congruente con la presencia de dos especies distintas de alodaposúquido en el yacimiento.

High sauropod diversity in the upper Barremian Arcillas de Morella Formation (Maestrat Basin, Spain) revealed by a systematic review of historical material

Purpose and methodsSince the second half of the 19th century, the Arcillas de Morella Formation (late Barremian) has yielded abundant vertebrate fossil material from several outcrops of the Morella region (Maestrat Basin, Castellón, eastern Spain). Several historical specimens of fossil reptiles, so far unpublished or not studied in detail, are housed in the Museo Nacional de Ciencias Naturales in Madrid (Spain). In fact, many of the first dinosaur specimens discovered in Spain, from Morella, are part of the vertebrate palaeontology collection of that institution. Herein, this sauropod material is described and discussed in order to study the diversity of the sauropod fauna during the late Barremian on the Maestrat Basin.ResultsThe specimens include both axial and appendicular elements. The systematic study of this material suggests the presence of indeterminate titanosauriforms, some of which have somphospondylan and ‘laurasiform’ affinities. Comparative analysis of two isolated humeri from Morella (MNCN 59703 and MNCN 68484) and a humerus subsequently found in this area, indicates the presence of three titanosauriform taxa in the upper Barremian of the Maestrat Basin, two of which have somphospondylan affinities.ConclusionsThe sauropod diversity of the Arcillas de Morella Formation recognized herein, in particularly considering the titanosauriforms, is greater than that previously considered, at least three taxa.ResumenObjetivos y métodosNumerosos especímenes de vertebrados fósiles han sido identificados, desde la segunda mitad del siglo XIX, en varios yacimientos de la Formación Arcillas de Morella (Barremiense superior) situados en la localidad de Morella (Cuenca del Maestrazgo, Castellón, este de España). Varios ejemplares clásicos, correspondientes a fósiles de reptiles procedentes de Morella, pero que permanecían hasta ahora inéditos y que no habían sido detalladamente analizados, están depositados en el Museo Nacional de Ciencias Naturales (Madrid). De hecho, varios de los primeros especímenes de dinosaurios descubiertos en España, procedentes de Morella, forman parte de la colección de paleontología de vertebrados de dicha institución. El material de saurópodos es descrito y discutido en este trabajo, con el objetivo de analizar la diversidad de este grupo de dinosaurios registrada en el Barremiense superior de la Cuenca del Maestrazgo.ResultadosLos ejemplares analizados incluyen tanto elementos axiales como apendiculares. El estudio sistemático de este material permite reconocer la presencia de titanosauriformes indeterminados, identificándose formas afines a Somphospondyli y ‘Laurasiformes’. El análisis comparativo de dos húmeros clásicos aislados de Morella (MNCN 59703 y MNCN 68484), y de un tercer húmero hallado con posterioridad en esta región, permite reconocer la presencia de tres miembros de Titanosauriformes en el Barremiense superior de la Cuenca del Maestrazgo, dos de ellos compatibles con Somphospondyli.ConclusionesLa diversidad de saurópodos de la Formación Arcillas de Morella reconocida aquí, compuesta por miembros de Titanosauriformes, es mayor que aquella hasta ahora notificada, estando integrada por, al menos, tres taxones.