El MAU festeja sus 16 años con una réplica de Viavenator
0 comentarios Publicado por Leonardo Filippi en 11:33
El 20 de diciembre próximo, cuando la localidad de Rincón de los Sauces, Neuquén, Argentina, cumpla su 45º Aniversario, conjuntamente con el 16º Aniversario del Museo Argentino Urquiza, se hará la presentación oficial de la réplica del dinosaurio carnívoro Viavenator exxoni, en el marco de la inauguración del edificio de la nueva Casa de la Cultura del Bicentenario.
Para el Museo y su equipo, este es un momento sumamente trascendente, ya que es la presentación de la primera réplica del esqueleto completo de un dinosaurio recuperado de la zona.
Para el Museo y su equipo, este es un momento sumamente trascendente, ya que es la presentación de la primera réplica del esqueleto completo de un dinosaurio recuperado de la zona.
Este evento ocurrirá en horas de la tarde, previo al acto protocolar donde serán parte el Intendente Marcelo Rucci junto con el Gobernador Omar Gutierrez, además de otros funcionarios municipales y provinciales. A partir de las 19:00hs el dinosaurio quedará en la sala del nuevo edificio para que público pueda ingresar a conocerlo.
Concluye una nueva etapa en la recuperación del saurópodo de Cañadón Mistringa
0 comentarios Publicado por Leonardo Filippi en 7:31
Concluye la campaña de extracción de un nuevo dinosaurio saurópodo en el norte de Neuquén, Argenitna. Esta nueva etapa en la recuperación de este enorme ejemplar, hallado en el 2012, ha terminado satisfactoriamente. A pesar de que no se ha podido recuperar la totalidad de los materiales, se cumplió con el objetivo principal, el de retomar los trabajos de extracción en el sitio. Los numerosos materiales detectados en el último día de trabajo, plantean la necesidad de continuar las actividades en el 2017. Sólo queda dar comienzo al lento trabajo de preparación en el laboratorio del Museo Municipal Argentino Urquiza, Rincón de los Sauces, donde ya reposan los nuevos restos.
La réplica de Viavenator aguarda su presentación
0 comentarios Publicado por Leonardo Filippi en 7:00
La réplica del primer dinosaurio carnívoro, Viavenator exxoni, ya se encuentra depositada en las instalaciones del Museo Municipal Argentino Urquiza, Rincón de los Sauces, Neuquén, luego de su largo viaje desde la provincia de Buenos, Aires. Se trata de una réplica a tamaño natural del esqueleto de este nuevo abelisaurio, el cual fue dado a conocer a principios de este año. Para el MAU, es sumamente importante, ya que será la primera réplica de un dinosaurio de la colección que será montada en las instalaciones del Museo. Todo está previsto que la presentación oficial se lleve adelante el próximo 20 de diciembre, día donde se realizan no solo los festejos de aniversario de la localidad de Rincón de los Sauces, sino que además, el Museo cumple sus 16 años de vida. Una vez realizado esto, los visitantes podrán concurrir al mismo para apreciar a esta magnífica nueva pieza de la exhibición.
Un Peirosauridae (Mesoeucrocodylia) de la Formación Bajo de la Carpa (Santoniano, Cretácico Superior), en la localidad de Cerro Overo, Patagonia Norte.
0 comentarios Publicado por Leonardo Filippi en 12:46
Filippi, L., Barrios, F. y Arcucci, A.
La Formación
Bajo de la Carpa (Santoniano) de Norpatagonia es una unidad muy fosilífera, que
ha brindado restos de peces, quelonios, serpientes, dinosaurios saurópodos,
terópodos avianos y no-avianos, y principalmente cocodrilos. En la localidad de
Cerro Overo, al sudoeste de Rincón de los Sauces, provincia del Neuquén, hasta
el momento esta unidad solo brindó restos de Sauropoda (Overosaurus paradasorum
Coria et al., 2013). En esta
contribución se da a conocer el primer registro de un Crocodyliforme Mesoeucrocodylia
proveniente de dicha localidad. El espécimen corresponde a la
mitad anterior de ambas ramas mandibulares articuladas, integradas cada una por
los dentarios con algunos dientes preservados, y los espleniales. En base a
comparaciones encontramos similitudes morfológicas con Peirosauridae: por la
presencia de dientes zifodontes, sínfisis esplenial y foramen intermandibular oral
próximo a la región sinfiseal, particularmente de mandíbula elongada
antero-posteriormente, de forma espatulada en su extremo más anterior, comprimida
dorso-ventralmente, y con contacto dentario-esplenial en la región sinfiseal en
forma de cuña y extendido anteriormente. La morfología recuerda a Pepesuchus Campos et al., 2011, y principalmente a Itasuchus Price, 1955, que los
diferencia de otros peirosáuridos (e.g. Gasparinisuchus
Martinelli et al., 2012 y Montealtosuchus Carvalho et al., 2007), que presentan mandíbula
más robusta con una región sinfiseal tan ancha como larga, y superficie dorsal
cóncava. Sin embargo, la ausencia de alvéolos confluentes en el material de
Cerro Overo sugiere que se trata de un nuevo taxón, lo que aumentaría la
diversidad de Peirosauridae en el Cretácico de Patagonia.
11º Congreso de
la Asociación Paleontológica Argentina, Gral. Roca, Río Negro, Argentina, 2016.
A new titanosaur specimen with highly derived skull from the Santonian of northern Patagonia, Argentina
0 comentarios Publicado por Leonardo Filippi en 12:35
Filippi, L., Juárez Valieri, R., Gallina, P., Méndez, A., Gianechini, F. y Garrido, A.
Paleontological fieldworks carried out
on upper section of the Bajo de la Carpa Formation (Santonian, Upper Cretaceous)
at La Invernada area, near Rincón de los
Sauces city (northeast Neuquén Province), result in the discovery of several
specimens of derived titanosaurs, belonging to multiple
taxa. One of them, consists of an articulated modest-sized
individual with a nearly complete skull, the axial sequence from the atlas to
the last sacral vertebrae with their respective ribs, and both ilia.This
sequence is composed by thirteen cervical, ten dorsal and six sacral vertebrae.
The skull displays a spatulate snout morphology, with a straight anterior
margin, similar to the morphology previously recognized in other titanosaurs
such as Antarctosaurus, Bonitasaura and Brasilotitan. The neurocranial morphology is highly derived
compared with other titanosaur taxa with well-known skulls such as Sarmientosaurus, Nemegtosaurus, Tapuiasaurus
and Rapetosaurus, with displaced
frontals located behind the orbits, resulting in an opposite position to the
anterior margin of the snout. The occipital condyle is not preserved, but the
location of the neurocranial elements and the atlas-axis complex (found in anatomical
position) allow to infer a nearly perpendicular position for the tooth row
respect to the cervical sequence. This particular condition, confirmed for
first time in a derived titanosaur, is morphologically convergent with derived
rebbachisaurids such as Nigersaurus.
Besides, their respective biochrons are in agreement with the paleoecological
niche replacement of the rebbachisaurids by the spatulate snouted titanosaurs
in South America, as previously suggested in the post Turonian faunal turnover.
11º Congreso de la Asociación Argentina de Paleontología, Gral. Roca, Río Negro, Argentina 2016.
El MAU a punto de iniciar una nueva campaña en los alrededores de Rincón de los Sauces
0 comentarios Publicado por Leonardo Filippi en 12:22
El equipo del Museo Argentino Urquiza (Rincón de los Sauces, Neuquén, Argentina) realizó trabajos preliminares en el sitio de Cañadón Mistringa, para despejar varias toneladas de roca que cubrían un ejemplar de saurópodo parcialmente recuperado. Esta tarea, llevada adelante gracias al apoyo logístico del sector de Obras Públicas de la Municipalidad de Rincón de los Sauces, permitirá agilizar notablemente los trabajos de campo. Llega la época de campañas y la posibilidad de extraer definitivamente todo el material restante de este enorme dinosaurio.
Pterosaurs are an extinct group of highly modified flying reptiles that thrived during the Mesozoic. This group has unique and remarkable skeletal adaptations to powered flight, including pneumatic bones and an elongate digit IV supporting a wing-membrane. Two major body plans have traditionally been recognized: the primitive, primarily long-tailed paraphyletic “rhamphorhynchoids” (preferably currently recognized as non-pterodactyloids) and the derived short-tailed pterodactyloids. These two groups differ considerably in their general anatomy and also exhibit a remarkably different neuroanatomy and inferred head posture, which has been linked to different lifestyles and behaviours and improved flying capabilities in these reptiles. Pterosaur neuroanatomy, is known from just a few three-dimensionally preserved braincases of non-pterodactyloids (as Rhamphorhynchidae) and pterodactyloids, between which there is a large morphological gap. Here we report on a new Jurassic pterosaur from Argentina, Allkaruen koi gen. et sp. nov., remains of which include a superbly preserved, uncrushed braincase that sheds light on the origins of the highly derived neuroanatomy of pterodactyloids and their close relatives. A µCT ray-generated virtual endocast shows that the new pterosaur exhibits a mosaic of plesiomorphic and derived traits of the inner ear and neuroanatomy that fills an important gap between those of non-monofenestratan breviquartossans (Rhamphorhynchidae) and derived pterodactyloids. These results suggest that, while modularity may play an important role at one anatomical level, at a finer level the evolution of structures within a module may follow a mosaic pattern.
Codorniú L, Paulina Carabajal A, Pol D, Unwin D, Rauhut OWM. (2016) A Jurassic pterosaur from Patagonia and the origin of the pterodactyloid neurocranium. PeerJ 4:e2311 https://doi.org/10.7717/peerj.2311
El pasado fin de semana, el MAU, Museo Municipal Argentino Urquiza, Rincón de los Sauces, Neuquén, Argentina, realizó la evaluación de una denuncia de hallazgo de restos fósiles en el área La Invernada. Después de transitar por un camino de muy dificil acceso, se pudo dar con el lugar exacto de donde provenian los restos recuperados. Los materiales entregados al Museo correspondían a tres de los cinco huesos metacarpianos de una pata delantera de un dinosaurio saurópodo. La evaluación realizada en el lugar permitió determinar que el resto de los huesos faltantes aún estaban in situ, los cuales se encontraban muy bien preservados y articulados con el resto de dicha pata. En futuras salidas, el resto de los huesos serán recuperados y se evaluará si puede que el resto del dinosaurio se encuentre bajo la roca.
New Megaraptoran Dinosaur (Dinosauria, Theropoda, Megaraptoridae) from Late Cretaceous of Patagonia
0 comentarios Publicado por Leonardo Filippi en 9:27
Rodolfo
A. Coria and Philip J. Currie
A skeleton discovered in the
Upper Cretaceous Sierra Barrosa Formation (Turonian-Coniacian) of Neuquén
Province, Argentina represents a new species of theropod dinosaur related to
the long snouted, highly pneumatized Megaraptoridae. The holotype specimen of Murusraptor
barrosaensis n.gen et n.sp. includes much of the skull, axial skeleton,
pelvis and tibia. Murusraptor is unique in having several diagnostic features
that include anterodorsal process of lacrimal longer than height of preorbital
process, and a thick, shelf-like thickening on the lateral surface of surangular
ventral to the groove between the anterior surangular foramen and the insert
for the uppermost intramandibular process of the dentary. Other characteristic
features of Murusraptor barrosaensis n.gen. et n. sp. include a large
mandibular fenestra, distal ends of caudal neural spines laterally thickened into
lateral knob-like processes, short ischia distally flattened and slightly
expanded dorsoventrally. Murusraptor belongs to a Patagonian radiation of
megaraptorids together with Aerosteon, Megaraptor and Orkoraptor. In spite
being immature, it is a larger but more gracile animal than existing specimens
of Megaraptor, and is comparable in size with Aerosteon and Orkoraptor. The
controversial phylogeny of the Megaraptoridae as members of the Allosauroidea
or a clade of Coelurosauria is considered analyzing two alternative data sets.
Coria RA, Currie PJ (2016) A
New Megaraptoran Dinosaur (Dinosauria, Theropoda, Megaraptoridae) from the Late
Cretaceous of Patagonia. PLoS ONE 11(7): e0157973. doi:10.1371/ journal.pone.0157973
An Unusual New Theropod with a Didactyl from Patagonia Argentina
0 comentarios Publicado por Leonardo Filippi en 9:18
Sebastián
Apesteguía, Nathan D. Smith, Rubén Juárez Valieri, Peter J. Makovicky
Late Cretaceous terrestrial
strata of the Neuquén Basin, northern Patagonia, Argentina have yielded a rich
fauna of dinosaurs and other vertebrates. The diversity of saurischian dinosaurs
is particularly high, especially in the late Cenomanian-early Turonian Huincul
Formation, which has yielded specimens of rebacchisaurid and titanosaurian
sauropods, and abelisaurid and carcharodontosaurid theropods. Continued
sampling is adding to the known vertebrate diversity of this unit.
A new, partially articulated
mid-sized theropod was found in rocks from the Huincul Formation. It exhibits a
unique combination of traits that distinguish it from other known theropods justifying
erection of a new taxon, Gualicho shinyae gen. et sp. nov. Gualicho possesses a
didactyl manus with the third digit reduced to a metacarpal splint reminiscent
of tyrannosaurids, but both phylogenetic and multivariate analyses indicate
that didactyly is convergent in these groups. Derived characters of the
scapula, femur, and fibula supports the new theropod as the sister taxon of the
nearly coeval African theropod Deltadromeus and as a neovenatorid carcharodontosaurian.
A number of these features are independently present in ceratosaurs, and
Gualicho exhibits an unusual mosaic of ceratosaurian and tetanuran
synapomorphies distributed throughout the skeleton.
Apesteguía S, Smith ND,
Juárez Valieri R, Makovicky PJ (2016) An Unusual New Theropod with a Didactyl
Manus from the Upper Cretaceous of Patagonia, Argentina. PLoS ONE 11(7):
e0157793. doi:10.1371/journal.pone.0157793
Hallan el primer dinosaurio ornitópodo del norte neuquino
0 comentarios Publicado por Leonardo Filippi en 8:51
Durante la semana pasada el equipo del MAU, Museo Municipal Argentino Urquiza de Rincón de los Sauces, Neuquén, realizó el inesperado hallazgo de los restos de un ejemplar de dinosaurio ornitópodo, el cual se encuentra en muy buen estado de preservación. Las tareas de campo permitieron recuperar los restos integrados por la porción anterior del cuerpo del animal, integrada por las últimas cervicales y las primeras siete dorsales, articuladas con sus correspondientes costillas y ambas escapulo-coracoides. Además, excepcionalmente se halló el miembro anterior derecho completo y articulado al cuerpo. Si bien se habían hallado restos en la zona de este grupo de dinosaurios ornitisquios, este es el primer ejemplar de relevancia hallado en la zona norte de la Provincia de Neuquén, por lo que permite engrosar el conocimiento de la fauna de dinosaurios de esta región. Actualmente el material esta siendo preparado en el laboratorio del Museo.
Nuevo registro de ornitópodos provenientes de la Formación Plottier, Rincón de los Sauces, Neuquén
0 comentarios Publicado por Leonardo Filippi en 8:32
Penélope
Cruzado-Caballeroa, Leonardo S. Filippi, Ariel H. Méndez, Alberto C. Garrido
and Rubén D. Juárez Valieri
Ornithopods are the
least known dinosaurs within the Upper Cretaceous record of Argentina. For this
rea-son every new record is very important to know their evolution in South
America. Here, we describe a new remain of an indeterminate ornithopod recovered
in the Petrobrasaurus quarry of the
Puesto Hernández area, northeastern Neuquén province (Argentina), late
Coniacian–early Santonian in age. MAU-Pv-PH-458 is the northernmost bone record
of an ornithopod in Argentina. This is a fragmentary neural arch fromthe middle
section of the dorsal series of similar size to Macrogryphosaurus gondwanicus. MAU-Pv-PH-458 has typical ornithopod
characters such as a lateromedial narrow neural spine and transverse
processes dorsoposteriorly to posteriorly oriented. It shares with Macrogryphosaurus the presence of a deep
cannel between the bases of the postzygapophysis, which is a continuation of
the channel that separates the postzygapophyses in posterior view. MAU-Pv-PH-458
increases the ornithopod record from the Plottier Formation.
Cruzado-Caballero, P.,
et al., New record of ornithopod dinosaur from the Plottier Formation (Upper
Cretaceous), Patagonia, Argentina. Annales de Paléontologie (2016), http://dx.doi.org/10.1016/j.annpal.2016.02.003
New rebbachisaurid cranial remains (Sauropoda, Diplodocoidea) from the Cretaceous of Patagonia
0 comentarios Publicado por Leonardo Filippi en 15:32
Ariana
Paulina Carabajal, Juan I. Canale, and Alejandro Haluza
Report a new
rebbachisaurid material recovered from the Candeleros Formation (Cenomanian) of
northwest Patagonia, Argentina. The cranial remains consist of a partial
braincase and a right quadrate. Fractures in the braincase exposed the
endocranial cavity, allowing the first study of the brain and inner ear
morphologies of a South American rebbachisaurid. The braincase and cranial
endocast both exhibit traits similar to those observed in the Cretaceous
rebbachisaurs Nigersaurus from Africa and Limaysaurus from Argentina, although
in terms of osteology, the South American taxa are highly similar. The endocast
is more similar to that of Nigersaurus than to those of Diplodocus and
Camarasaurus, suggesting some probable rebbachisaurid features such as the
noteworthy presence of the flocculus. The overall morphology of the quadrate
shows similarities with Limaysaurus and Nigersaurus. However, differences such
as the broader posterior fossa and the shape and orientation of the head and
the pterygoid process indicate that the new specimen could represent a distinct
taxon.
Ariana Paulina
Carabajal, Juan I. Canale & Alejandro Haluza (2016): New rebbachisaurid
cranial remains (Sauropoda, Diplodocoidea) from the Cretaceous of Patagonia, Argentina,
and the first endocranial description for a South American representative of
the clade, Journal of Vertebrate Paleontology, DOI:
10.1080/02724634.2016.1167067
The skull of the titanosaur Tapuiasaurus macedoi, from the Lower Cretaceous of Brazil
0 comentarios Publicado por Leonardo Filippi en 8:25
Jeffrey
A. Wilson, Diego Pol, Alberto B. Carvalho & Hussam Zaher
Although Titanosauria
is the most diverse and late-surviving sauropod lineage, cranial elements are
known for just over 24 of its 70+ genera – the vast majority of which are
fairly fragmentary and restricted to the Late Cretaceous. Only three complete
titanosaur skulls have been described to date; two of these are from the latest
Cretaceous (Nemegtosaurus, Rapetosaurus), and the third, Tapuiasaurus, is from
the Early Cretaceous (Aptian). In this contribution, we build on the initial
treatment of the taxon by providing a complete description of the cranial
elements that benefits from additional preparation and computed tomography
imaging. We identify six additional features diagnosing Tapuiasaurus macedoi,
including a jugal with an elongate lacrimal process forming much of the
posteroventral border of the antorbital fenestra, a lateral temporal fenestra
divided by a second squamosal–postorbital contact, and upper jaw teeth with
labial wear facets. We directed the new morphological data in Tapuiasaurus as
well as other observations towards a re-analysis of its phylogenetic position
within Titanosauria. Our analysis yielded 34 most parsimonious trees, most of
which recovered Tapuiasaurus in a basal position adjacent to the Early
Cretaceous taxa Malawisaurus and Tangvayosaurus, but two trees recovered it
within Late Cretaceous nemegtosaurids. We explored the effects of missing data
and missing stratigraphic ranges on our results, concluding that (1) when
missing data levels are high, resolution of even small amounts of that missing
data can have dramatic effects on topology, (2) taxa that are mostly scored for
characters that cannot be scored in other taxa may be topologically unstable
and (3) there were several suboptimal trees that had greatly improved
stratigraphic fit with relatively little compromise in terms of tree length.
Jeffrey A. Wilson,
Diego Pol, Alberto B. Carvalho and
Hussam Zaher (2016) The skull of the titanosaur Tapuiasaurus macedoi
(Dinosauria: Sauropoda), a basal titanosaur from the Lower Cretaceous of Brazil.
Zoological Journal of the Linnean Society
DOI: 10.1111/zoj.12420
A Basal Lithostrotian Titanosaur with a Complete Skull from Patagonia, Argentina
0 comentarios Publicado por Leonardo Filippi en 12:05
Rubén
D. F. Martínez, Matthew C. Lamanna, Fernando E. Novas, Ryan C. Ridgely, Gabriel
A. Casal, Javier E. Martínez, Javier R. Vita & Lawrence M. Witmer
We describe Sarmientosaurus
musacchioi gen. et sp. nov., a titanosaurian sauropod dinosaur from the Upper
Cretaceous (Cenomanian - Turonian) Lower Member of the Bajo Barreal Formation
of southern Chubut Province in central Patagonia, Argentina. The holotypic and
only known specimen consists of an articulated, virtually complete skull and
part of the cranial and middle cervical series. Sarmientosaurus exhibits the
following distinctive features that we interpret as autapomorphies: (1) maximum
diameter of orbit nearly 40% rostrocaudal length of cranium; (2) complex
maxilla-lacrimal articulation, in which the lacrimal clasps the ascending ramus
of the maxilla; (3) medial edge of caudal sector of maxillary ascending ramus
bordering bony nasal aperture with low but distinct ridge; (4) ‘tongue-like’ ventral
process of quadratojugal that overlaps quadrate caudally; (5) separate foramina
for all three branches of the trigeminal nerve; (6) absence of median venous
canal connecting infundibular region to ventral part of brainstem; (7)
subvertical premaxillary, procumbent maxillary, and recumbent dentary teeth;
(8) cervical vertebrae with ‘strut-like’ centroprezygapophyseal laminae; (9)
extremely elongate and slender ossified tendon positioned ventrolateral to
cervical vertebrae and ribs. The cranial endocast of Sarmientosaurus preserves some
of the most complete information obtained to date regarding the brain and
sensory systems of sauropods. Phylogenetic analysis recovers the new taxon as a
basal member of Lithostrotia, as the most plesiomorphic titanosaurian to be
preserved with a complete skull. Sarmientosaurus provides a wealth of new
cranial evidence that reaffirms the close relationship of titanosaurs to
Brachiosauridae. Moreover, the presence of the relatively derived lithostrotian
Tapuiasaurus in Aptian deposits indicates that the new Patagonian genus
represents a ‘ghost lineage’ with a comparatively plesiomorphic craniodental
form, the evolutionary history of which is missing for at least 13 million
years of the Cretaceous. The skull anatomy of Sarmientosaurus suggests that
multiple titanosaurian species with dissimilar cranial structures coexisted in
the early Late Cretaceous of southern South America. Furthermore, the new taxon
possesses a number of distinctive morphologies such as the ossified cervical
tendon, extremely pneumatized cervical vertebrae, and a habitually downward facing
snout that have rarely, if ever, been documented in other titanosaurs, thus broadening
our understanding of the anatomical diversity of this remarkable sauropod clade.
The latter two features were convergently acquired by at least one
penecontemporaneous diplodocoid, and may represent mutual specializations for
consuming low-growing vegetation.
Martínez RDF,
Lamanna MC, Novas FE, Ridgely RC, Casal GA, Martínez JE, et al. (2016) A Basal
Lithostrotian Titanosaur (Dinosauria: Sauropoda) with a Complete Skull:
Implications for the Evolution and Paleobiology of Titanosauria. PloS ONE
11(4): e0151661. doi:10.1371/journal. pone.0151661
A Norian lagerpetid dinosauromorph from the Quebrada del Barro Formation, Argentina
0 comentarios Publicado por Leonardo Filippi en 13:34
Ricardo
N. Martínez, Cecilia Apaldetti, Gustavo A. Correa, And Diego Abelín
The early evolution of
Ornithodira the clade including pterosaurs and dinosaurs is poorly known. Until
a decade ago, the basal radiation of Dinosauromorpha, the clade including
dinosaurs and birds, was poorly understood because of the poor fossil record
restricted to specimens known from the Ladinian Chañares Formation in
Argentina. Over the last years the discovery of several non-dinosaurian
dinosauromorphs dramatically expanded this record and also demonstrated that
this group –previously restricted to de Middle Triassic survived at least well
into the Norian. Although Norian non-dinosaurian dinosauromorphs have been
reported from several regions around the world, the only known Norian non-dinosauriform
dinosauromorphs Dromomeron romeri Irmis, Nesbitt, Padian, Smith, Turner, Woody,
and Downs and Dromomeron gregorii Nesbitt, Irmis, Parker, Smith, Turner, and
Rowe come from North America. We report here the first record from the Southern
Hemisphere of a non-dinosauriform dinosauromorph, Dromomeron gigas sp. nov.,
from the Norian Quebrada del Barro Formation, northwestern Argentina. A
phylogenetic analysis recovers Dromomeron gigas nested into the monophyletic
group Lagerpetidae, and as the sister taxon to Dromomeron romeri. The inclusion
of D. gigas within Lagerpetidae suggests that body size increased in this
lineage over time, as was previously demonstrated for Dinosauriformes as a
whole, and that lagerpetids reached a larger size than previously thought.
Finally, the new finding provides new information on the basal radiation of
Dinosauromorpha constituting the first record of a Norian association of
dinosaurs with non-dinosauriform dinosauromorphs outside North America.
Ricardo N. Martínez,
Cecilia Apaldetti, Gustavo A. Correa, Diego Abelín (2016). A Norian lagerpetid
dinosauromorph from the Quebrada del Barro Formation, northwestern Argentina.
Ameghiniana 53: 1–13.
A new specimen of Velocisaurus unicus from Río Negro Province, Argentina
0 comentarios Publicado por Leonardo Filippi en 14:05
Federico
Brissón Egli, Federico L. Agnolín, And Fernando Novas
Abelisauroids are the
most abundant theropods in the Cretaceous beds of Patagonia. They are
traditionally subdivided into large-sized Abelisauridae and smaller
Noasauridae. Here, we describe a new specimen of the small enigmatic abelisauroid
Velocisaurus unicus Bonaparte, 1991,
which was previously known from a single incomplete specimen from Neuquén City,
Neuquén Province, Patagonia. The new material comes from the Santonian Bajo de
la Carpa Formation (Late Cretaceous) at the Paso Córdoba locality, Río Negro
Province. It comprises an almost complete left hind limb and offers novel
information about the anatomy of this poorly known abelisauroid. The new
material shows that Velocisaurus is remarkable in having a very short, stout,
and anteriorly bowed femur, which has a notably subtriangular cross-section at
its proximal end. The tibia is long and slender, and the anterior surface of
the distal end is anteroposteriorly flat and transversely expanded, with an
enlarged surface for the ascending process of the astragalus. The pes has a
stout third metatarsal, rod-like metatarsals II and IV, and highly modified
phalanges of digit IV. The unique combination of characters of Velocisaurus indicates
that this taxon belongs to a still poorly understood radiation of
gracile-limbed abelisauroids. The inclusion of Velocisaurus in a comprehensive phylogenetic analysis recovers a
monophyletic Noasauridae, but with only very weak support. Detailed analysis of
features supporting the inclusion of Velocisaurus
within Noasauridae is discussed, and their implications for abelisauroid
phylogeny are revisited.
Federico Brissón Egli,
Federico L. Agnolín & Fernando Novas 2016. A new specimen of Velocisaurus
unicus (Theropoda, Abelisauroidea) from the Paso Córdoba locality (Santonian),
Río Negro, Argentina, Journal of Vertebrate Paleontology, DOI: 10.1080/02724634.2016.111915
Presentan un nuevo dinosaurio en el MAU: Viavenator exxoni
0 comentarios Publicado por Leonardo Filippi en 20:26
En el día de ayer, se llevó adelante la presentación formal del nuevo dinosaurio del MAU, Museo Municipal Argentino Urquiza, Rincón de los Sauces, Neuquén: Viavenator exxoni, un nuevo género y especie de abelisaurio que aporta información relevante que permite avanzar en el conocimiento de este grupo de terópodos.
Este ejemplar, corresponde al primer dinosaurio carnívoro de la colección del MAU, por lo que todo el equipo del trabajo del museo y los colegas que han participado de su estudio, se encuentran muy satisfechos. Si bien el potencial del área La Invernada, en el cual se viene trabajando desde hace un poco más de tres años, es inmenso, la publicación de este dinosaurio, representa el primero de una serie de otros ejemplares que han sido recuperados allí, entre los que se mencionan, varios dinosaurios titanosaurios, una descena de ejemplares de tortugas y peces.
Los huesos orginales de Viavenator se encontrarán temporalmente exhibidos al público en el laboratorio del Museo hasta fines de Marzo.
Este ejemplar, corresponde al primer dinosaurio carnívoro de la colección del MAU, por lo que todo el equipo del trabajo del museo y los colegas que han participado de su estudio, se encuentran muy satisfechos. Si bien el potencial del área La Invernada, en el cual se viene trabajando desde hace un poco más de tres años, es inmenso, la publicación de este dinosaurio, representa el primero de una serie de otros ejemplares que han sido recuperados allí, entre los que se mencionan, varios dinosaurios titanosaurios, una descena de ejemplares de tortugas y peces.
Los huesos orginales de Viavenator se encontrarán temporalmente exhibidos al público en el laboratorio del Museo hasta fines de Marzo.
A new Upper Cretaceous Titanosaur nesting site from La Rioja, Argentina
0 comentarios Publicado por Leonardo Filippi en 13:24
E. Martin
Hechenleitner, Lucas E. Fiorelli, Gerald Grellettinner, Léa Leuzinger, Giorgio Basilici, Jeremías R.
A. Taborda, Sergio R. De La Vega And Carlos A. Bustamante
Cretaceous titanosaur nesting sites
are currently known only from Europe, Asia and South America. In the latter,
only the Auca Mahuevo and Sanagasta nesting sites have been confidently
assigned to this clade of sauropod dinosaurs. Here we report the discovery of
the first eggs and egg clutches found at Tama, a new Upper Cretaceous fossiliferous
locality in the Los Llanos Formation, Sierra de Los Llanos (La Rioja, NW
Argentina). At least five egg clutches, several partially preserved, isolated
eggs and many eggshell fragments were discovered in a single outcrop of a
sandstone horizon which represents a cumulative palaeosol profile. Although the
mechanical and digital preparation of eggs did not reveal any embryonic remains
in ovo, the morphology of the eggs and eggshells closely matches that of
titanosaur eggs and eggshells found worldwide. The morphology and spatial
grouping of the titanosaur eggs from Tama, along with geological observations
support a burrow-nesting strategy for these dinosaurs. Although the Sanagasta
and Tama eggs were found in the same stratigraphical unit and share several
morphological characters, they clearly differ in shell thickness and egg size.
This, coupled with the interpretation of different sedimentary contexts for
these nesting sites, strongly suggests that at least two different titanosaur
species nested in La Rioja during the Late Cretaceous, using different nesting
strategies. The occurrence of this new titanosaur nesting site in a semiarid
palaeoenvironment represents an interesting case study for the reproductive
biology of the titanosaur dinosaurs, particularly their labile nesting
behaviour.
Hechenleitner,
EM, Fiorelli, LE, Grellettinner, G,
Leuzinger, L, Basilici, G, Taborda, JRA,
De La Vega, SR And Bustamante, CA. 2016. A new Upper Cretaceous
Titanosaur nesting site from La Rioja (Nw Argentina), with implications for
Titanosaur nesting strategies. Palaeontology,
pp. 1–14.
Shell bone histology of the long-necked chelid Yaminuechelys (Testudines: Pleurodira) from the late Cretaceous-early Palaeocene of Patagonia
0 comentarios Publicado por Leonardo Filippi en 6:56
Juan
Marcos Jannello, Ignacio A. Cerda, Marcelo S. de la Fuente
Yaminuechelys is
a long-necked chelid turtle whose remains have been recovered from outcrops of
the Santonian- Maastrichtian and Danian of SouthAmerica.With the purpose of
providing data about shell sculpturing origin and palaeoecology, the bone
histology of several shell elements (including neural, costal, peripheral and
plastral plates) of Yaminuechelys is
described herein. Histological analysis reveals that Yaminuechelys shares with Chelidae the presence of interwoven
structural fibre bundles in the external cortex, and parallel-fibred bone of
the internal cortex. The presence of resorption lines in several samples
indicates that the particular ornamentation of the external surfaces
originated, at least in part, by focalized resorption and new bone deposition.
This mechanism for ornamentation origin and maintenance is here described for
the first time in a turtle. Compactness of the shell bones is consistent with
an aquatic habitat, which supports previous hypothesis based on palaeoenvironmental
and morphological data.
Janello, JM, Cerda, IA
& de la Fuente, MS. 2016. Shell bone histology of the long-necked chelid Yaminuechelys (Testudines: Pleurodira)
from the late Cretaceous—early Palaeocene of Patagonia with comments on the
histogenesis of bone ornamentation. Sci Nat. 103:26.DOI
10.1007/s00114-016-1346-3.
New Peirosaurid from Cerro Lisandro Formation, Neuquén Group, Patagonia Argentina
0 comentarios Publicado por Leonardo Filippi en 6:36
Francisco Barrios,
Ariana Paulina-Carabajal y Paula Bona
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.
Barrios,
F. Paulina-Carabajal, A, y Bona Paula. 2016. A new Peirosaurid
(Crocodyliformes, Mesoeucrocodylia) from the Upper Cretaceous of Patagonia,
Argentina. Ameghiniana 53 (1):14-25.
El Museo Municipal Argentino Urquiza ya tiene su primer dinosaurio terópodo
Ya se encuentra publicado en versión online el trabajo sobre este dinosaurio carnívoro, un nuevo abelisaurio, que proviene de La Invernada (Neuquén, Argentina) de rocas de la Formación Bajo de la Carpa. La excelente preservación y la significativa información que aportó el ejemplar resultaron relevantes para avanzar en el conocimiento de este grupo de terópodos, los abelisaurios. Viavenator ("cazador del camino") exxoni gen. et sp. nov. es el primero dado a conocer de una serie de ejemplares que han sido recuperados en la zona de La Invernada gracias al enorme apoyo de la empresa Exxonmobil.
Filippi, LS, Méndez, AH, Juárez Valieri, R. & Garrido, AC. 2016. A new brachyrostran with hypertrophied axial structures reveals an unexpected radiation of latest Cretaceous abelisaurids. Creataceous Research 61:209-219.
Gigantic new dinosaur from Argentina, Mendoza Province
0 comentarios Publicado por Leonardo Filippi en 12:40
Bernardo J. González Riga, Matthew C. Lamanna,
Leonardo D. Ortiz David,
Jorge O. Calvo & Juan
P. Coria
Titanosauria is an exceptionally diverse, globally-distributed clade of
sauropod dinosaurs that includes the largest known land animals. Knowledge of
titanosaurian pedal structure is critical to understanding the stance and
locomotion of these enormous herbivores and, by extension, gigantic terrestrial
vertebrates as a whole. However, completely preserved pedes are extremely rare
among Titanosauria, especially as regards the truly giant members of the group.
Here we describe Notocolossus gonzalezparejasi gen. et sp. nov.
from the Upper Cretaceous of Mendoza Province, Argentina. With a powerfully-constructed
humerus 1.76 m in length, Notocolossus is one of the largest known
dinosaurs. Furthermore, the complete pes of the new taxon exhibits a strikingly
compact, homogeneous metatarsus—seemingly adapted for bearing extraordinary
weight—and truncated unguals, morphologies that are otherwise unknown in
Sauropoda. The pes underwent a near-progressive reduction in the number of
phalanges along the line to derived titanosaurs, eventually resulting in the reduced
hind foot of these sauropods.
González
Riga, BJ., Lamanna, MC., Ortiz David, LD., Calvo, JO. & Coria, JP. 2016 A
gigantic new dinosaur from Argentina and the evolution of the sauropod hind
foot. Nature. Scientific Reports. DOI: 10.1038/srep19165
Continúan las tareas de preparación de fósiles en el MAU
Quienes visitan en estas vacaciones de verano el Museo Municipal Argentino Urquiza, Rincón de los Sauces, Neuquén, tienen la posibilidad de observar muy de cerca como se estan preparando los materiales recuperados en la última campaña paleontológica. Se trata de un ejemplar de dinosaurio Titanosaurio, conocido comunmente como "cuello largo", el cual se encontraba completo y articulado desde el cráneo hasta la cadera. Tanto la cola como las extremidades no fueron halladas en el sitio. Se espera que a finales de este año el ejemplar este completamente limpio para dar inicio a su estudio.
Quienes visitan en estas vacaciones de verano el Museo Municipal Argentino Urquiza, Rincón de los Sauces, Neuquén, tienen la posibilidad de observar muy de cerca como se estan preparando los materiales recuperados en la última campaña paleontológica. Se trata de un ejemplar de dinosaurio Titanosaurio, conocido comunmente como "cuello largo", el cual se encontraba completo y articulado desde el cráneo hasta la cadera. Tanto la cola como las extremidades no fueron halladas en el sitio. Se espera que a finales de este año el ejemplar este completamente limpio para dar inicio a su estudio.
New fossil tooth assemblage from the Bajo de la Carpa Formation
0 comentarios Publicado por Leonardo Filippi en 7:49
Filippi, L. S,
Martinelli, A & Garrido, A. C.
In this contribution, a fossil tooth assemblage from the Bajo de la Carpa
Formation (Santonian, Upper Cretaceous) in a different paleoenvironmental
context from that recorded at the Neuquén city and Paso Córdova
localities (Patagonia, Argentina), is here presented. It includes isolated teeth of Dipnoi, represented by the
species Ceratodus kaopen and Atlantoceratodus
patagonicus; mesoeucrocodylian isolated teeth referred to Peirosauridae; and isolated teeth of Abelisauridae theropods and Titanosauria
sauropods. The Mesoeucrocodylia, Abelisauridae and Titanosauria taxa are
consistent with the fossil record of the region, represented by the Coloradoan tetrapod
assemblage of Santonian to early Campanian age. However, the lungfish A. patagonicus represents the first
occurrence for the Bajo de la Carpa Formation, being this record the oldest one for this taxón.
Filippi,
L.S, Martinelli, A.G. y Garrido, A.C. 2015. Una nueva asociación de
dientes vertebrados para la Formación Bajo de la Carpa (Santoniense, Cretácico
Superior) en Rincón de los Sauces, Neuquén, Argentina. Revista Española de Paleontología 30 (2): 223-238.
A new cretaceous crocodyliform from La Rioja Province, Argentina
0 comentarios Publicado por Leonardo Filippi en 8:06
Lucas E. Fiorelli, Juan M. Leardi, E. Martín Hechenleitner, Diego
Pol, Giorgio Basilici & Gerald Grellet-Tinner.
The Cretaceous
witnessed the greatest diversity of Gondwanan notosuchian crocodyliforms, which
displayed high levels of diversity and a notable array of specialized forms
that developed in different ecological niches. Among this diversity, the
advanced notosuchians are a clade of mid body sized forms which displays a
remarkable abundance but is restricted to two lithological units from the Late
Cretaceous of South America, the Adamantina Formation in southeastern Brazil
and the Bajo de la Carpa Formation in Patagonia (Argentina). The only
exceptions known so far were the Late Cretaceous Labidiosuchus from the Marilia
Formation in Brazil and Yacarerani from the Cajones Formation in Bolivia. Herein
we report a new Cretaceous crocodyliform, Llanosuchus tamaensis gen. nov. et
sp. nov., found in the Los Llanos Formation (Campanian?) in northwestern
Argentina (La Rioja Province). The small specimen includes well preserved
fragments of the cranium and mandible with an estimated skull size of about 9
cm lengths. This crocodyliform shares several derived characters with
Notosuchus terrestris from the Bajo de la Carpa Formation (Patagonia) and it
was found in a weakly developed sandy paleosol profile formed in wet local
conditions but in a region characterized by semi-arid climate and active eolian
sedimentation. The presence of a new advanced notosuchian in the Cretaceous of
western Gondwana, and its intermediate geographical region between the known
South American species (Brazil, Argentina and Bolivia), has interesting
implications, and adds another record of an advanced notosuchian in deposits with
inferred warm climates and semi-arid paleoenvironments. Finally, Llanosuchus
tamaensis supports a Late Cretaceous age for Los Llanos Formation with
important geological implications for La Rioja Province.
L.
E. Fiorelli, J. M. Leardi, E. M. Hechenleitner, D. Pol, G. Basilici & G.
Grellet-Tinner 2016. A new Late
Cretaceous crocodyliform from the western margin of Gondwana (La Rioja
Province, Argentina). Cretaceous Research
60: 194-209.
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