Pablo A. Gallina, Sebastián Apesteguía, Alejandro Haluza y Juan I. Canale

Diplodocids are by far the most emblematic sauropod dinosaurs. They are part of Diplodocoidea, a vast clade whose other members are well-known from Jurassic and Cretaceous strata in Africa, Europe, North and South America. However, Diplodocids were never certainly recognized from the Cretaceous or in any other southern land mass besides Africa. Here we report a new sauropod, Leikupal laticauda gen. et sp. nov., from the early Lower Cretaceous (Bajada Colorada Formation) of Neuquèn Province, Patagonia, Argentina. This taxon differs from any other sauropod by the presence of anterior caudal transverse process extremely developed with lateroventral expansions reinforced by robust dorsal and ventral bars, very robust centroprezygapophyseal lamina in anterior caudal vertebra and paired pneumatic fossae on the postzygapophyses in anterior-most caudal vertebra. The phylogenetic analyses support its position not only within Diplodocidae but also as a member of Diplodocinae, clustering together with the African form Tornieria, pushing the origin of Diplodocoidea to the Middle Jurassic or even earlier. The new discovery represents the first record of a diplodocid for South America and the stratigraphically youngest record of this clade anywhere.

 

Los descubrimientos de nuevos fósiles y huesos de dinosaurios son algo constante en la vida de los paleontólogos. Lo que no es tan constante, ni tan común es encontrarse con el dinosaurio más grande sobre la tierra todos los días… y eso es precisamente lo que les ha pasado a un grupo de investigadores de huesos en la Patagonia (Argentina). Han descubierto los restos de un dino tan sumamente grande, que hace que las personas que se encuentran alrededor parezcan poco más que diminutas hormigas.

Rúben Cúneo, director del instituto de paleontología y jefe de la expedición asegura que los restos tienen aproximadamente 90 millones de años y que pertenecieron a un ejemplar colosal de la familia de los saurópodos, el cual, le ha venido a robar el trono al Argentinosaurus como el dinosaurio “más grande que jamás haya existido sobre la faz de la tierra”.

El animal era un herbívoro (de la familia de los “cuelli largos” para los más pequeños) y tenía una longitud entorno a los 40 metros de largo. Algo que no tiene nada que ver con ningún ser vivo de la época actual.

 

 

 

 

G. Lio¹, R. Juarez Valieri², L. S. Filippi³ and F. L. Agnolín^1,4

The clade Peirosauridae is mainly a Gondwanan group composed by mid to large sized terrestrial crocodyliforms. The peirosaurid here reported comes from the upper levels of the Portezuelo Formation (Turonian-Coniacian, Upper Cretaceous) at Añelo fossiliferous locality, Neuquén Province, Argentina. This specimen consists on an incomplete skeleton composed by a left dentary and splenial, right maxilla, right jugal, a dorsal vertebra, a dorsal osteoderm, and right humerus. Its referral to Peirosaurideae is sustained by: posterior maxillary teeth low and globular, with a clear neck and serrated carinae, festooned maxillary and dentary ornamentation, and the presence of amphicoelous vertebral centra with large hypapophyses. The new specimen is related to Gasparinisuchus in having mandibular symphysis extending posteriorly to the level of eight tooth and with a large participation of the splenials. Anyhow some differences may be observed: in the new specimen the maxillary teeth are not separated in discrete alveoli, the dentary symphysis is very elongate and compressed and surpasses the level of the ninth tooth, the fourth dentary tooth is caniniform, very large, acute and transversely compressed (much larger than other peirosaurids), and the anterior dentary teeth exhibit less globular, and sharp serrated crowns. This suggests that the specimen here reported had greater heterodont dentition when compared with remaining taxa. With this addition, we elevate to four the number of Patagonian peirosaurids, increasing the diversity for the clade in this landmass. Moreover, it represents the only peirosaurid described for the Portezuelo Formation.

 

Resumenes XXVIII Jornadas Argentinas de Paleontología de Vertebrados, Zapala-Chocón, Neuquén, Argentina. 21 al 23 de Mayo del 2014.

 

Foto: sólo a modo de ilustración.

L.S. Filippi¹, R.D. Juarez Valieri² y C.A. Garrido³

We report a new abelisaurid theropod specimen, which represent the most complete abelisaurid theropod skeleton yet reported from the Bajo de La Carpa Formation. It comes from the La Invernada area, located 50 kilometers south from Rincón de los Sauces, Neuquén Province. The partially excavated material is well preserved and display scarce signs of deformation. The pieces recovered comprises a partial skull with complete basicranium, both frontals, postorbitals and squamosals, four cervical vertebrae including atlas, eight dorsals and eigth caudals, cervical and dorsal ribs, an haemal arch, and indeterminate pieces. The frontals are flat, opposite to the condition present in Abelisaurus, Aucasaurus and Carnotaurus. The postorbitals present slightly convex and ornamented dorsal margins, in contrast to Ekrixinatosaurus and Skorpiovenator. The jugal process of the postorbitals is anteriorly recurved thus enclosing the orbit, a character proposed as autapomorphic of Brachyrostra. The cervical vertebrae show anterior processes on the epipophysis and reduced neural spines as in Carnotaurus. The anterior and middle caudal vertebrae are tipical of derived abelisaurids, with strong centrodiapophyseal laminae and with laterodorsally projected and distally expanded transverse processes. Is evident the presence of hyposphene-hypantrum in the anterior caudals as in Aucasaurus and Carnotaurus, but it appear absent in the preserved middle caudals, similar to Ilokelesia. This new specimen is relevant both anatomically and phylogenetically, contributing to the knowledge of the abelisaurid theropods, and increasing the diversity of the Cretaceous vertebrates from the Bajo de la Carpa Formation.

¹ Museo Municipal Argentino Urquiza. Jujuy y Chaco s/n, 8319, Rincón de los Sauces, Neuquén, Argentina.

² Secretaría de Cultura de la Provincia de Río Negro, 8332 General Roca, Río Negro, Argentina.

³  Museo Provincial de Ciencias Naturales Prof. Dr. Juan Olsacher, Dirección Provincial de Minería. Etcheluz y Ejército Argentino, 8340, Zapala, Neuquén, Argentina.

 

Resumenes XXVIII Jornadas Argentinas de Paleontología de Vertebrados, Zapala-Chocón, Neuquén, Argentina. 21 al 23 de Mayo del 2014.

L.S. Filippi¹, R.D. Juarez Valieri² y C.A. Garrido³

Here we report the recovery of a new terrestrial vertebrate assemblage coming from Bajo de la Carpa Formation levels at La Invernada, an oil-field area located 50 kilometers southwestern Rincón de los Sauces city, Neuquén, Argentina. These specimens were detected due to a project of the Museo Argentino Urquiza and Exxon Mobil Company, whose principal objective is the protection of the paleontological legacy from the area. The assemblage is composed by: (1) at least two individuals (one of them juvenile) of titanosaurian sauropods, including cervical, dorsal, and caudal vertebrae, an incomplete sacrum articulated to the right ilium and a portion of the left one, a juvenil rigth ilium, rigth pubis and isquium, articulated left scapula and humerus, distal end of  the left ulna, three left metacarpals (one incomplete), and dorsal ribs; (2) a partial but well-preserved specimen of abelisaurid theropod, composed by a complete braincase fused to the frontals, postorbitals and squamosals, cervical, dorsal and caudal vertebrae, cervical and dorsal ribs, and a distal chevron; and finally (3) a specimen of chelid turtle with a complete caparace of 68 centimeters long. Although the specimens come from different points separate about 300 meters each other, all the remains are located in the same approximate levels of the Bajo de la Carpa Formation, allowing us to infer that the represented species cohabited and probably interacted during Santonian – ealy Campanian times.

¹ Museo Municipal Argentino Urquiza. Jujuy y Chaco s/n, 8319, Rincón de los Sauces, Neuquén, Argentina.

² Secretaría de Cultura de la Provincia de Río Negro, 8332 General Roca, Río Negro, Argentina.

³  Museo Provincial de Ciencias Naturales Prof. Dr. Juan Olsacher, Dirección Provincial de Minería. Etcheluz y Ejército Argentino, 8340, Zapala, Neuquén, Argentina.

 ^{Resumenes XXVIII Jornadas Argentinas de Paleontología de Vertebrados, Zapala-Chocón, Neuquén, Argentina. 21 al 23 de Mayo del 2014.}