Papers by Jose Ignacio Ruiz-Omeñaca
Spanish journal of palaeontology, Mar 3, 2021
Premaxillary, maxillary and dentary teeth from the Lower Cretaceous (upper Barremian-Aptian, Cast... more Premaxillary, maxillary and dentary teeth from the Lower Cretaceous (upper Barremian-Aptian, Castrillo de la Reina Formation) El Peñascal site, near to Salas de los Infantes (Burgos, northern Spain), are described. After a comparison with teeth of all ornithopod groups, it is deduced that they belong to an euornithopod, and that they could have belonged to an "hypsilophodontid" or a "rhabdomorphan". The teeth present differences with the described ones in all the genera of these groups, and are provisionally assigned to Euornithopoda indet. This taxon may represent a new undescribed euornithopod in the European Lower Cretaceous.
Estudios Geologicos-madrid, Jun 30, 2011
Delapparentia turolensis nov. gen et sp., un nuevo dinosaurio iguanodontoideo (Ornithischia: Orni... more Delapparentia turolensis nov. gen et sp., un nuevo dinosaurio iguanodontoideo (Ornithischia: Ornithopoda) en el Cretácico Inferior de Galve Delapparentia turolensis nov. gen et sp., a new iguanodontoid dinosaur (Ornithischia: Ornithopoda) from the Lower Cretaceous of Galve (Spain) J.I. Ruiz-Omeñaca 1, 2 RESUMEN Se redescribe un esqueleto postcraneal de dinosaurio ornitópodo asignado por Albert de Lapparent en 1960 a Iguanodon bernissartensis. Procede del yacimiento de La Maca 3, de edad Barremiense inferior (Formación Camarillas), y consta de varias vértebras cervicales, restos de la serie dorsal y sacra, varias vértebras caudales, fragmentos de costillas cervicales, dorsales, y esternales, chevrones y tendones osificados, y la hemipelvis izquierda incompleta. Se ha identificado como un «iguanodóntido» (i.e. un Iguanodontoidea no Hadrosauridae) por la presencia de una lámina prepubica alta y la ausencia de antitrocánter en el ilion. Se propone a partir de este material un nuevo taxón de iguanodontoideo, Delapparentia turolensis nov. gen et sp., caracterizado por las siguientes autapomorfías: 1) costillas dorsales posteriores con capítulo y tubérculo no fusionados, 2) costillas esternales osificadas, y 3) ilion con el proceso preacetabular torsionado y expandido lateromedialmente (compartida con Zalmoxes). Además presenta una combinación de costillas dorsales anteriores con un foramen neumático, e isquion grande en relación al ilion.
PLOS ONE, Sep 18, 2012
Background: Dakosaurus and Plesiosuchus are characteristic genera of aquatic, large-bodied, macro... more Background: Dakosaurus and Plesiosuchus are characteristic genera of aquatic, large-bodied, macrophagous metriorhynchid crocodylomorphs. Recent studies show that these genera were apex predators in marine ecosystems during the latter part of the Late Jurassic, with robust skulls and strong bite forces optimized for feeding on large prey. Methodology/Principal Findings: Here we present comprehensive osteological descriptions and systematic revisions of the type species of both genera, and in doing so we resurrect the genus Plesiosuchus for the species Dakosaurus manselii. Both species are diagnosed with numerous autapomorphies. Dakosaurus maximus has premaxillary 'lateral plates'; strongly ornamented maxillae; macroziphodont dentition; tightly fitting tooth-to-tooth occlusion; and extensive macrowear on the mesial and distal margins. Plesiosuchus manselii is distinct in having: non-amblygnathous rostrum; long mandibular symphysis; microziphodont teeth; tooth-crown apices that lack spalled surfaces or breaks; and no evidence for occlusal wear facets. Our phylogenetic analysis finds Dakosaurus maximus to be the sister taxon of the South American Dakosaurus andiniensis, and Plesiosuchus manselii in a polytomy at the base of Geosaurini (the subclade of macrophagous metriorhynchids that includes Dakosaurus, Geosaurus and Torvoneustes). Conclusions/Significance: The sympatry of Dakosaurus and Plesiosuchus is curiously similar to North Atlantic killer whales, which have one larger 'type' that lacks tooth-crown breakage being sympatric with a smaller 'type' that has extensive crown breakage. Assuming this morphofunctional complex is indicative of diet, then Plesiosuchus would be a specialist feeding on other marine reptiles while Dakosaurus would be a generalist and possible suction-feeder. This hypothesis is supported by Plesiosuchus manselii having a very large optimum gape (gape at which multiple teeth come into contact with a prey-item), while Dakosaurus maximus possesses craniomandibular characteristics observed in extant suction-feeding odontocetes: shortened tooth-row, amblygnathous rostrum and a very short mandibular symphysis. We hypothesise that trophic specialisation enabled these two large-bodied species to coexist in the same ecosystem.
Spanish journal of palaeontology, Mar 3, 2021
The fi rst dinosaur discovery in Spain is a presumed theropod tooth from the Upper Jurassic of As... more The fi rst dinosaur discovery in Spain is a presumed theropod tooth from the Upper Jurassic of Asturias. It was described in 1858 as a shark tooth by the German mining engineer Guillermo Schulz and referred to the dinosaur Megalosaurus by the Navarrese geologist Justo Egozcue in 1873. However, the whereabouts of this fossil is currently unknown. In 1872 and 1873, the Valencian naturalist Juan Vilanova was the fi rst to specifi cally mention the discovery of dinosaur fossil remains from Spain. He described Iguanodon bones from the Lower Cretaceous of Utrillas (Teruel) and Morella (Castellon). The Vilanova collection, currently kept in the Museo Nacional de Ciencias Naturales of Madrid, consists of fi ve fragmentary remains from Morella and, tentatively, one from Utrillas, but none is referable to Iguanodon. One of the Morella fossils is interpreted as a theropod vertebral centrum, a second one could represent the distal end of the neural spine of a diplodocoid sauropod, the other three remains are indeterminate bone fragments. The two "long bones" from Utrillas mentioned by Vilanova correspond to fragments of a theropod tibia, now lost, but recognizable from a drawing made around the 1920ʼs by the Castellonese palaeontologist José Royo Gómez. The study of dinosaurs in Spain was not highlighted during the 1800ʼs and the fi rst signifi cant discoveries were not made until the late 1910ʼs.
Lethaia, 2013
Here, we present evidence of possible vertebrate predation on freshwater bivalves from the Lower ... more Here, we present evidence of possible vertebrate predation on freshwater bivalves from the Lower Cretaceous strata of the Cameros Basin (Spain). The described collection contains the largest number of vertebrate-inflicted shell injuries in freshwater bivalve shells yet reported in the Mesozoic continental record. Several types of shell damage on fossil shells of Protopleurobema numantina (Bivalvia: Unionoida) are described and their respective modes of formation interpreted in the context of morphological attributes of the shell injuries and the inferred tooth morphology of predators that could have inflicted such injuries. Detailed study of these bite marks shows similarities with the well-documented injuries in the shells of marine molluscs, namely ammonoids, that have likewise been attributed to reptilian predators. The most parsimonious interpretation suggests crocodiles as the vertebrates interacting with the bivalves in the Cameros Basin. h Barremian-Aptian; bite marks; freshwater bivalves; predation; reptile; Unionoida.
The first theropod skeletal remain from the Iberian Cenomanian: the tooth from Limanes (Oviedo, A... more The first theropod skeletal remain from the Iberian Cenomanian: the tooth from Limanes (Oviedo, Asturias, N Spain) José Ignacio Ruiz-Omeñaca (1) , Romain Vullo (2) , Enrique Bernárdez (3) y Ángela D. Buscaloni (4) (1) Museo del Jurásico de Asturias (MUJA), E-33328 Colunga; y Grupo Aragosaurus-IUCA (www.aragosaurus.com), Paleontología,
Canadian Journal of Earth Sciences, Dec 1, 2010
Blasisaurus canudoi gen. et sp. nov. is described on the basis of disarticulated skull and lower ... more Blasisaurus canudoi gen. et sp. nov. is described on the basis of disarticulated skull and lower jaw remains found in the Blasi 1 locality of Arén (Huesca, south-central Pyrenees of Spain), located in the upper part of the Arén Formation, late Maastrichtian in age. This new lambeosaurine hadrosaurid is characterized by a jugal combining a hook-like dorsal edge of the posterior process and a narrow, D-shaped infratemporal fenestra. Blasisaurus differs from Arenysaurus from the Blasi 3 site of Arén mainly by the absence of secondary ridges in the dentary teeth, and from Koutalisaurus (probably a junior synonym of Pararhabdodon ) from the Isona region of Lleida by the anteriormost portion of the dentary that is modestly deflected ventrally. A phylogenetic analysis places Blasisaurus as closely related to Arenysaurus in a clade of basal lambeosaurines more derived than Tsintaosaurus and Jaxartosaurus ; this clade forms part of a polytomy with Amurosaurus and with more derived lambeosaurines. Palaeobiogeographically, the presence of Blasisaurus and other hadrosaurids in the Maastrichtian European archipelago suggests one or, more probably, a series of dispersal events from Asia across intermittent land bridges during the second half of the Late Cretaceous.
Journal of Iberian Geology, May 8, 2015
Geological Magazine, Feb 16, 2009
The theropod teeth from the Berriasian (Early Cretaceous) site of Anoual (N Morocco) are describe... more The theropod teeth from the Berriasian (Early Cretaceous) site of Anoual (N Morocco) are described. The assemblage is important in that it comes from one of the very few dinosaur sites of this age globally and the only one for the whole of Gondwana. The theropod teeth from Anoual are morphologically diverse. Most of the material possibly belongs to the clade Dromaeosauridae, which would be an early occurrence for this taxon. The palaeogeographic position of Anoual enables it to provide data on the dispersal events that affected terrestrial faunas during Mesozoic times. A Laurasian influence is evidenced by the presence of Velociraptorinae and, on the whole, the theropod fauna from Anoual provides support for the existence of a trans-Tethyan passage allowing terrestrial faunal interchanges during Late Jurassic and/or earliest Cretaceous times. Additionally, Anoual records the existence of diminutive theropods. However, it cannot yet be determined whether the small size of the specimens is genetic or ontogenetic.
The Villar del Arzobispo Formation (Tithonian-Berriasian) in Teruel and Valencia provinces (SE Ib... more The Villar del Arzobispo Formation (Tithonian-Berriasian) in Teruel and Valencia provinces (SE Iberian Range) has yielded abundant skeletal remains of dinosaurs, mainly of sauropods and stegosaurs. Three vertebrae collected in the locality of Cerrito del Olmo I (Alpuente, Valencia province), two of them previously referred to the stegosaurid Dacentrurus armatus, belong in fact to an ornithopod. The material consists of one cervical and two caudal centra that preserve the base of the neural arch fused to the centrum. These remains are here assigned to Ornithopoda indet. on the basis of the combination of several characters more frequent in ornithopods than in stegosaurs. This is the first description of ornithopod skeletal remains from the Villar del Arzobispo Formation.
Resto mandibular de ornitópodo iguanodontoideo (Dinosauria) del Cretácico Inferior de Salas de lo... more Resto mandibular de ornitópodo iguanodontoideo (Dinosauria) del Cretácico Inferior de Salas de los Infantes (Burgos) en las colecciones del Institut für Geowissenschaften de Tubinga (Alemania) A dentary fragment of an iguanodontoid ornithopod (Dinosauria) from the Early Cretaceous of Salas de los Infantes (Burgos, Spain) in the collections of the Institut für Geowissenschaften of Tübingen (Germany)
We describe a dinosaur caudal centrum from an outcrop of the Vega Formation (Kimmeridgian) in Col... more We describe a dinosaur caudal centrum from an outcrop of the Vega Formation (Kimmeridgian) in Colunga (Asturias Principality, Northern Spain). It is very similar to the centra of mid-caudal vertebrae of some stegosaurs, like Dacentrurus and Stegosaurus, which are characterized by the presence of well developed haemal processes on the posteroventral corner. Because this character is not diagnostic to the generic level, the vertebral centrum is assigned to Stegosauria indet. This is the first evidence of stegosaurs in this geological formation.
Journal of Iberian Geology, 2010
New stegosaurian remains have been recently recovered from the Jurassic-Cretaceous transition san... more New stegosaurian remains have been recently recovered from the Jurassic-Cretaceous transition sandstones of the Villar del Arzobispo Formation (Tithonian-Berriasian) in the Valencia province, eastern Spain. Specimens consist of two partially articulated (or closely associated) postcranial skeletons. The Baldovar specimen is composed of appendicular bones (scapula, femur) and two pairs of dermal tail spines, two of them articulated with two distal caudal vertebrae. The second specimen, unearthed in the vicinity of La Yesa village, consists of dorsal vertebrae and ribs, fragments of caudal centra and an incomplete femur. The new specimens are tentatively referred to the clade Dacentrurinae and may belong to Dacentrurus on the basis of features observed on the dorsal vertebrae and caudal dermal spines. Stegosaurs are represented so far in the Jurassic-Cretaceous transition of Spain by Dacentrurus. The presence of other taxa (Stegosaurus, Miragaia) in Spain, recently documented in the Late Jurassic of Portugal, cannot be attested on the basis of the currently recorded material.
Journal of Iberian Geology, 2010
Estudios Geológicos, 2012
En 1928, José Royo Gómez informó del hallazgo de "dos dientes idénticos a los de los Dinosaurios ... more En 1928, José Royo Gómez informó del hallazgo de "dos dientes idénticos a los de los Dinosaurios terópodos del Secundario" en el Eoceno de Llamaquique (Cuenca de Oviedo, Asturias). Royo Gómez era consciente del interés de este descubrimiento, "pues serían los restos más modernos que se conocerían de estos gigantescos reptiles". Según la documentación conservada en el Archivo del Museo Nacional de Ciencias Naturales en Madrid, hasta ahora inédita, Royo Gómez fotografió en abril de 1932 cinco dientes de Llamaquique que él consideraba pertenecientes a terópodos. Este material se encuentra actualmente en paradero desconocido. No obstante, la revisión de la colección paleontológica de Llamaquique en el mencionado museo ha permitido recuperar un diente comprimido labiolingualmente y provisto de carenas denticuladas (condición zifodonta). Se descarta que el diente pertenezca a un terópodo, asignándose a un Mesoeucrocodylia indeterminado. Se trata de la primera mención del hallazgo de cocodrilos zifodontos en el Paleógeno de Asturias.
Cretaceous Research, Jun 1, 2009
The first vertebrate remains from the Upper Cretaceous locality El Anfiteatro (northern Río Negro... more The first vertebrate remains from the Upper Cretaceous locality El Anfiteatro (northern Río Negro, Patagonia, Argentina) are described. Fossil remains were recovered in beds of Cerro Lisandro, Portezuelo, and Plottier formations. From the Cerro Lisandro Formation, remains of large fishes, dipnoans, titanosaur sauropod dinosaurs, and a variety of theropod dinosaurs (cf. Carcharodontosauridae, cf. Spinosauridae, cf. Abelisauria and Coelurosauria indet.) are reported. The Plottier Formation, in turn, has yielded remains of Chelidae turtles, crocodyliforms, titanosaur sauropods, theropods (cf. Carcharodontosauridae, Coelurosauria indet., cf. Unenlagiinae), and ornithopods. To date, the Portezuelo Formation has been the less prolific of all. Except for the record of a possible spinosaurid in the Cerro Lisandro Formation, the rest of the evidence obtained from El Anfiteatro is congruent with the record of other Patagonian sites where the Limayan and Neuquenian tetrapod associations were established.
Ichnos, Sep 6, 2016
ABSTRACT At least four parallel trackways of medium-sized and robust ornithopods are described fr... more ABSTRACT At least four parallel trackways of medium-sized and robust ornithopods are described from the Upper Jurassic Tereñes tracksite in Asturias (N. Spain). While the tracks and trackways of small and gracile ornithopods are common in the Jurassic record, large ornithopods are very rare in this period. Ornithopod gregarious behavior has been recorded from many Cretaceous ichnoassemblages, but there are few examples from the Jurassic, and these always relate to small individuals. The Asturian tracks are quite different from known ichnogenera, but they are not sufficiently well preserved to propose a new one. Medium-large Jurassic ornithopods with robust feet such as Draconyx or Cumnoria are the best candidates to be the trackmakers.
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Papers by Jose Ignacio Ruiz-Omeñaca