Francisco Ortega

National Distance Education University | UNED · Departamento de Física Matemática y de Fluidos

Turtle shells frequently exhibit anomalous osseous modifications on their surface which can sometimes compromise the survival of the organism. Nowadays, despite the large number of anomalies identified in both extant and extinct turtle shells, the etiology, as well as the pathogenesis, of the various osseous modifications remains unknown in most do...

Hylaeochelys is the only thalassochelydian turtle identified in the Cretaceous record. A single Lower Cretaceous species is known, Hylaeochelys belli, identified in United Kingdom and Germany and defined in the first half of the 19th century. Less than a decade ago, the presence of Hylaeochelys in the Upper Jurassic was recognized through the find...

The Lo Hueco fossil site (Cuenca, Spain) is one of the most relevant localities for the study of Late Cretaceous continental vertebrate faunas from Europe. The fossil record of theropod dinosaurs from this locality is represented by scarce isolated postcranial materials that were preliminarily attributed to abelisaurids and to a possible giant bird...

The osteology of Pilmatueia faundezi Coria, Windholz, Ortega & Currie, 2019, a dicraeosaurid sauropod from the Lower Cretaceous of Patagonia, is reassessed from the perspective of a new specimen (MLL-Pv-010) that provides additional information on the axial skeleton and the pectoral girdle. The specimen MLL-Pv-010 is composed of three articulated a...

La aparente similitud entre las técnicas de extracción, así como el estudio de materiales pretéritos, parece que es lo que ha marcado la unidad del Patrimonio Paleontológico y Arqueológico en la normativa cultural. Sin embargo, debemos tener en cuenta las diferencias entre ellos y que su unidad en la legislación puede provocar una indefensión legal...

Species occurrence data, although an important cornerstone for palaeobiodiversity analyses, is usually spread across publications. To solve this, researchers have started building databases, but these are permanent works-in-progress. The systematic information present in database varies, and they present different types of biases. Here we present a...

Malafaia E., Escaso F., Rauhut O.W.M., Ortega F. 2022. Isolated theropod teeth from the Tendaguru Formation (Upper Jurassic, Tanzania). In: Belvedere M., Mecozzi B., Amore O., Sardella R. (eds.). Abstract book of the XIX Annual Conference of the European Association of Vertebrate Palaeontologists, Benevento/Pietraroja, Italy, 27th-2nd July 2022. Pa...

Ortega F., Malafaia E., Escaso F., Coria R.A. 2022. New material of theropods (Abelisauroidea?) from Lo Hueco (Late Cretaceous. Cuenca, Central Spain). In: Belvedere M., Mecozzi B., Amore O., Sardella R. (eds.). Abstract book of the XIX Annual Conference of the European Association of Vertebrate Palaeontologists, Benevento/Pietraroja, Italy, 27th-2...

Ortega F., de Celis A., Malafaia E., Narváez I., Serrano-Martínez, A., Arcucci A. 2022. On the diagnosis of Iberosuchus macrodon (Crocodyliformes, Notosuchia) from the Eocene of Portugal. In: Belvedere M., Mecozzi B., Amore O., Sardella R. (eds.). Abstract book of the XIX Annual Conference of the European Association of Vertebrate Palaeontologists,...

The hindlimb of Ibero-Armorican lithostrotian sauropods exhibits morphological similarities between the different proposed clades present in the Campanian-Maastrichtian. Comparison with other Late Cretaceous titanosaurs revealed that these similarities can be found between groups that are recovered apart in the phylogeny, with possible convergences...

Excellent outcrops of the upper part of the “Continental Intercalaire” deposits occur in the Gara Samani area, southern Algeria. These strata are recognised herein as belonging to the Gara Samani Formation, which is composed of the Samani Vertebrate-rich Sand Member, the Samani Sandstone Member and the Méguidène Stratified Sand Member. The first two...

Shell pitting is relatively abundant but with unclear character and etiology in extinct turtles, since reports on extant turtles with similar condition do not usually include morphological descriptions, illustrations, or data concerning etiology or pathogenesis. Therefore, the available interpretations on shell pitting in the fossil record of turtl...

Los Modelos de Distribución de Especies (SDM por sus siglas en inglés), son modelos o algoritmos que intentan explicar porqué, cómo y de qué manera se distribuyen las especies en distintas áreas, en base al concepto del nicho ecológico. A pesar de que esta metodología se desarrolló en el campo de la Biología de la Conservación, actualmente se está...

The Palaeogene sedimentary successions of the Duero Basin host an important record of fossil vertebrates, especially mammals and reptiles. The main fossil sites are placed at the west margin (Salamanca and Zamora areas) spanning from the Lutetian to the late Priabonian; and at the southeast tip (Almazán Basin) mainly Bartonian in age. The continued...

The Campanian–Maastrichtian Konzentrat-Lagerstätte at Lo Hueco (Spain) has yielded a large sample of appendicular elements referable to sauropod titanosaurs that exhibit considerable morphological variability. The taxonomic assessment of these elements is difficult, they display various degrees of preservation (including fragmentary preservation an...

Iguanodon bernissartensis is the most frequently and widely cited styracosternan ornithopod in Western Europe during the Early Cretaceous, although some of these assignments likely need to be revised to establish the true distribution of the taxon. Here, we describe a new specimen of I. bernissartensis from the upper Barremian of the Iberian Penins...

Ortega, F.; Malafaia, E.; Narvaéz, I.; Serrano-Martínez, A.; Arcucci, A. 2022. Internal anatomy of the Iberosuchus macrodon holotype (middle eocene of portugal) revealed by CATscan. In: Fialho, P.; Pereira, S. (Eds) Newsletter da SPdP, Sociedade Portuguesa de Paleontologia, 1, p. 28

The Poyos site (Villalba de la Sierra Fm., Guadalajara, Central Spain) has provided numerous isolated eggshell fragments and complete eggs often grouped as clutches across several stratigraphic levels which outcrop over more than 10 km. Although these remains are not currently assigned to a specific ootaxon, it is clearly distinct to those found on...

Campanian-Maastrichtian outcrops from the Villalba de la Sierra Formation along the Cuenca and Guadalajara provinces (Spain) have yielded abundant oological remains. The Portilla and Zafra de Záncara localities (Cuenca) have provided isolated eggshell fragments, while the Poyos site (Guadalajara) has provided a large amount of remains ranging from...

Duerosuchus piscator is a middle Eocene eusuchian known only from Corrales del Vino (Zamora, Spain). The species was defined based on an incomplete skull, partial lower jaws and two vertebrae from a single individual, and several osteoderms referred to other specimens. A detailed study of these remains allows us to question the attribution of all t...

The Upper Cretaceous (Campanian-Maastrichtian) outcrops of the Margas, Arcillas y Yesos de Villalba de la Sierra Fm. have provided abundant fossils of fishes, amphibians, squamates, turtles, crocodylomorphs and dinosaurs. Among them, dinosaur eggshells found in Portilla (Cuenca) were preliminarily assigned to Megaloolithus siruguei. In recent years...

This study presents new palynological and sedimentological data concerning the Upper Triassic outcrop El Atance (Guadalajara province, Spain). This fossil site has provided a unique and unprecedented concentration of reptile skeletons from the Late Triassic in the Iberian Peninsula, which are almost complete, articulated and preserved in three dime...

Ortega F., Escaso F., Malafaia E., Coria R.A. 2021. Aves gigantes en el Cretácico Superior de Lo Hueco (Fuentes, Cuenca). Lucas Mallada 23. XXXVI Jornadas de la SEP. 207-208. http://revistas.iea.es/index.php/LUMALL

The sedimentary sequence of the Villalba de la Sierra Formation is located at the southwestern branch of the Iberian Ranges, being early Campanian to middle? Eocene in age. The titanosaurian fossil record from the upper Campanian-lower Maastrichtian levels is abundant and diverse. In recent years, two important fossil localities have been discovere...

La Cantera del Mas de la Parreta, localizada al sureste de la localidad de Morella (Castellón, España), es una de las áreas fosilíferas más ricas en restos de vertebrados continentales de la Formación Arcillas de Morella (Cretácico Inferior, Barremiense) y ha proporcionado una fauna diversa compuesta por condrictios, osteíctios, plesiosaurios, tort...

Bothremydidae is the most abundant clade of turtles in the Campanian and Maastrichtian (Upper Cretaceous) fossil record of southwestern Europe. Several members of Foxemydina Gaffney, Tong & Meylan, 2006 are known in an area that includes Southern France and the North-Eastern half of Spain. The problematic ‘Polysternon’ atlanticum is the worst chara...

Malafaia E., Escaso F., Coria RA. 2021. A velociraptorine tibia from Lo Hueco (Upper Cretaceous, Central Spain). In: Belvedere M., Díez Díaz V., Mecozzi B., Sardella R (eds.). Abstract book of the XVIII annual conference of the European Association of Vertebrate Palaeontologists, online, 5th-9th July 2021. Palaeovertebrata, 44, 111

Fossils from Konservat-Lagerstätten are usually exceptionally preserved, allowing to decipher key paleobiological aspects of the fossil record. An example is Pelecanimimus polyodon from the Early Cretaceous of Las Hoyas (Cuenca, Spain). The skull of the type specimen is almost complete and well preserved, and presents some characters like the prese...

Pelecanimimus polyodon was discovered in 1993 in the Spanish Barremian fossil site of Las Hoyas, being the first ornithomimosaur described from Europe. So far, there has been no detailed description of the holotype of Pelecanimimus, which is composed of the anterior-half of an articulated skeleton. Here we report a new, detailed, revised and more a...

Two unpublished shells of thalassochelydian turtles from Tithonian (Late Jurassic) outcrops of the Lusitanian Basin (west central Portugal) are studied here. They are recognised as attributable to the plesiochelyid littoral genus Plesiochelys. They show characters unknown for the so far available Portuguese record of Plesiochelys, exclusively based...

Changes in the ontogenetic trajectories are a potential evolutionary driving force. These changes have been recently characterized in the dorsum of the skull of crocodylians, but are still unknown in the palatal area, which is a key-structure for the interpretation of crocodylomorph evolutionary history. In order to understand the morphological div...

Parahenodus atancensis de Miguel Chaves, Ortega & Pérez-García, 2018 is a recently described bizarre cyamodontoid placodont, based on a partial but well-preserved Spanish Upper Triassic skull. It was identified as the sister taxon of the German highly specialized Henodus chelyops Huene, 1936. The use of micro-computed tomography has been able to si...

Notosuchians are a crocodyliform clade with a rich Gondwanan fossil record, especially in Cretaceous South American deposits. More than half of all described species come from South America and, around one quarter, have been discovered in the Adamantina Formation (Bauru Group, Brazil). The large amount of notosuchian remains from this formation, al...

In this .xls file you can find raw Paleobiology Database (PBDB) data, final dataset of notosuchian occurrences, and variables analyzed with generalised least squares (GLS) regressions.

In this .xls file you can find the complete results of raw species counts (TDEs), shareholder quorum subsampling estimates and generalised least squares (GLS).

Table S1 (countries composing each spatial region analyzed), Table S2 (time-bin schemes) and a note about new published notosuchian specimens.

In 2007, a paleontological site with vertebrate fossils from Late Cretaceous was discovered in Fuentes (Cuenca Province). During excavation, more than 8000 fossils were retrieved among which the most singular are a set of 20 partial skeletons of titanosaurian sauropods in anatomic connection. The fossils present conservation problems derived from t...

The fossil record of spinosaurid theropods from the Lower Cretaceous of the Iberian Peninsula is relatively abundant, but not very informative. This record, as generally occurs in other geographic areas, is mainly represented by isolated teeth, probably due to the distinctive features of the dentition of these theropods. However, cranial and postcr...

Members of the aquatic clade of reptiles Sauropterygia quickly evolved and diversified during the Triassic, acquiring different lifestyles and trophic roles with a cosmopolitan distribution. Although the first Triassic sauropterygian remains from the Iberian Peninsula were found more than a century ago, most of the relatively abundant recovered fos...

The titanosaurian appendicular skeleton exhibits morphological similarities among different clades and its osteological information is usually less taxonomically meaningful than those of other regions of the skeleton. There is a probable morphological convergence due to morphofunctional similarities between members of different titanosaurian groups...

Carcharodontosaurian allosauroids were temporally restricted to the Cretaceous, being known from all land masses with the exception of Antarctica. In addition to Veterupristisaurus from Tanzania, exceptions to this distribution have been reported recently, consisting on fragmentary materials from Upper Jurassic strata of China, Germany, and Portuga...

The palaeontological area of Algora (Guadalajara Province, central Spain) provides the largest concentration of vertebrate macroremains for the Cenomanian of south-western Europe. The available faunal list for Algora, based on the analysis of scarce remains collected in geological surveys carried out more than thirty years ago, was never updated. T...

Allodaposuchus precedens is a basal member of Eusuchia, which was established almost a century ago on a set of cranial and postcranial fragmentary remains from the lower Maastrichtian of Vălioara, Romania. It was the first described member and type species of Allodaposuchidae, a recently described European clade representing one of the nearest outg...

The conservation of paleontological heritage depends greatly on the diversity and complexity of the materials that compose both the fossils and the matrix that includes and fills them. A common practice in fossil preparation treatments consists in removing part of the surrounding matrix that, in some cases, prevents direct access to the specimens o...

Sauropods were among the most diverse lineages of dinosaurs, with an ample geographic distribution throughout the Mesozoic. This evolutionary success is largely attributed to neck elongation and its impact on feeding efficiency. However, how neck elongation influenced exactly on feeding strategies is subject of debate. The process of mounting a nea...

Dinosaurs are part of the palaeontological heritage of the Cuenca province. The social dimension and the attraction they exert on the public invite to think about if this palaeontological heritage is able to contribute to the creation of a brand of territory that would identify and differentiate a tourism destination. For this purpose, an approach...

Fossil skeletal mounts are more than popular attractions at paleontological exhibitions. Thorough History they have proven, when properly mounted, to be great devices for evaluating paleobiological hypotheses otherwise untestable. Nevertheless, mounting skeletons based on preconceived notions or looking for spectacularity has also contributed to sp...

RESUMEN Los tres yacimientos de vertebrados del Barremiense superior descubiertos recientemente en las "Hoces de Beteta" (Vadillos-1, Vadillos-2, El Tobar) se encuentran situados en facies "Weald" pertenecientes a la Formación Arenas y Arcillas de El Collado. En ellos, se han identificado distintos tipos de fósiles correspondientes a plantas (ABSTR...

‘Partanosaurus zitteli’ is an obscure and doubtful sauropterygian taxon from the Ladinian (Middle Triassic) of the Austrian Alps, described at the end of the 19th century and based on isolated axial and pectoral remains belonging to a single individual. For more than 20 years, it has been considered an invalid species, belonging to the much better...

Agaresuchus fontisensis is an allodaposuchid crocodile from the Campanian–Maastrichtian (Late Cretaceous) of Lo Hueco (Cuenca, Spain). Allodaposuchidae is a clade of European basal eusuchians, which is considered a part of the stem group of Crocodylia. The holotype and paratype skulls of Agaresuchus fontisensis were scanned on computed tomography a...