José J. Moratalla

Multivariate analysis on Lower Cretaceous dinosaur footprints: Discrimination between ornithopods and theropods

Abstract The discrimination of ornithopod from theropoddinosaur footprints can sometimes be problematical. In order to obtain discriminatory criteria, an analysis BMDP (4M, 7M) on a sample of 66 Lower Cretaceous tridactyl footprints of diverse geographical origins has been carried out. The more significant ichnological parameters explaining sample variability are related with the digital widths and with the whole dimensions of the footprints. Some other parameters, such as digital angulation (often used as an important discriminatory criterion), seem to be of limited significance. Based on the more significant ichnological parameters, some indices have been proposed. These indices are used in bivariate analyses which allow to discriminate ornithopod from theropod footprints with a different degree of confidence.

A new crested pterosaur from the early cretaceous of Spain: the first European tapejarid (Pterodactyloidea: Azhdarchoidea)

Background The Tapejaridae is a group of unusual toothless pterosaurs characterized by bizarre cranial crests. From a paleoecological point of view, frugivorous feeding habits have often been suggested for one of its included clades, the Tapejarinae. So far, the presence of these intriguing flying reptiles has been unambiguously documented from Early Cretaceous sites in China and Brazil, where pterosaur fossils are less rare and fragmentary than in similarly-aged European strata. Methodology/Principal Findings Europejara olcadesorum gen. et sp. nov. is diagnosed by a unique combination of characters including an unusual caudally recurved dentary crest. It represents the oldest known member of Tapejaridae and the oldest known toothless pterosaur. The new taxon documents the earliest stage of the acquisition of this anatomical feature during the evolutionary history of the Pterodactyloidea. This innovation may have been linked to the development of new feeding strategies. Conclusion/Significance The discovery of Europejara in the Barremian of the Iberian Peninsula reveals an earlier and broader global distribution of tapejarids, suggesting a Eurasian origin of this group. It adds to the poorly known pterosaur fauna of the Las Hoyas locality and contributes to a better understanding of the paleoecology of this Konservat-Lagerstätte. Finally, the significance of a probable contribution of tapejarine tapejarids to the early angiosperm dispersal is discussed.

A preliminary note on the first tetrapod trackways from the lithographic limestones of Las Hoyas (Lower Cretaceous, Cuenca, Spain)

Although famous as a fossil lagerstatte that has produced numerous well-preserved vertebrates, recent discoveries indicate that the lithographic limestones of Las Hoyas (Calizas de la Huerguina Formation) also contain vertebrate trackways. We herein report on at least two distinctive tetrapod track types tentatively assigned to crocodilians and to turtles. Turtle tracks are isolated while the crocodile ones are forming a trackway showing an animal walking with a very regular step and stride length on an emergent surface. It is interesting to note the similarity between the inferred turtle tracks from Las Hoyas and those from the Late Jurassic lithographic limestones of Cerin, France. The occurrence of tracks in both environments suggests that the ichnofaunas are similar.

Dinosaur tracks from the Lower Cretaceous of Regumiel de la Sierra (province of Burgos, Spain): Inferences on a new quadrupedal ornithopod trackway

A dinosaur tracksite has been discovered comprising three types of tridactyl footprints at Regumiel de la Sierra (province of Burgos, north‐central Spain). The rocks belong to Lower Cretaceous Wealden deposits of the Western Cameros Basin and two ichnological levels comprising 8 trackways and several isolated tracks were noted. All the footprints are tridactyl, although there are three types. Level 1 holds a trackway of which the footprints belong to a big iguanodontid dinosaur. Level 2 has yielded 6 trackways and several isolated tracks of Iguanodon‐like morphology, and also a theropod trackway. One iguanodontid trackway of level 2 has manus impressions suggesting that the dinosaur used a quadrupedal gait. The degree of inward rotation of footprints (similar to that of the other ones) suggests that this did not significantly modify the slight rotation of the pelvic girdle or the role of the tail during progression. The shape of manus prints suggests that the digit II was almost free and the III and TV on...

First pterosaur remains from the Early Cretaceous Lagerstätte of Las Hoyas, Spain: palaeoecological significance

Pterosaur teeth from the Early Cretaceous Lagerstatte of Las Hoyas (Spain) are described. We reassess the track from this site previously ascribed to a pterosaur, concluding that it is a theropod footprint. The teeth belong to two pterodactyloid taxa: a basal Istiodactylidae similar to Haopterus and an indeterminate Ornithocheiridae. From a palaeoecological point of view, the occurrence of such pterosaurs in the freshwater wetland palaeobiota of Las Hoyas strengthens the evidence of the similarity of this Spanish locality to the famous Early Cretaceous Lagerstatten of Liaoning in China.

Los Cayos Dinosaur Tracksite: An Overview on the Lower Cretaceous Ichno-Diversity of the Cameros Basin (Cornago, La Rioja Province, Spain)

The Los Cayos dinosaur tracksite is located at the eastern sector of the Cameros Basin (Cornago Township, La Rioja province), NE Spain. The sediments consist of interbedded terrigenous siliciclastics and carbonates belonging to the Enciso Group (Early Cretaceous, Aptian in age). The sedimentological and faunal evidence suggests that these sediments were deposited in a low gradient lacustrine environment. Los Cayos constitutes a relatively wide area with at least 6 localities that have yielded dinosaur tracks. More than 2,000 dinosaur tracks have been discovered to date. Medium to large theropod dinosaurs constitute about 95% of the ichnofauna. Ornithopod dinosaur tracks have been reported from only one of the outcrops (Los Cayos D). Los Cayos S has yielded theropod and sauropod tracks. One sauropod trackway shows a narrow-gauge locomotion pattern and a manus print morphology suggesting that the trackmaker was a titanosaurid, or at least a titanosauriform sauropod. Some pterosaur manus impressions, avian-like footprints of small size and possible turtle tracks complete the assemblage of one of the most impressive and best-preserved dinosaur tracksites of the European Lower Cretaceous.

Didactic and Divulgative Resources of the Middle Triassic Vertebrate Tracksite of Los Arroturos (Province of Guadalajara, Spain)

The Middle Triassic reptile tracksite of Los Arroturos (Guadalajara, Spain) provides a high scientific and didactic interest. In this site, numerous tracks and trackways of rauisuchian archosaurs are preserved, being an especially characteristic site in the Triassic of Spain. The tracksite is very useful for developing educational goals, such as fieldtrips and teaching activities. In this work, some fieldtrips have been carried out for students of primary and secondary school levels. These type of activities offer a great opportunity to promote interest in geosciences and improve awareness about the importance of palaeontological heritage. Nevertheless, this tracksite is extremely vulnerable, and suffers from continuous degradation caused by weathering. The plan to develop it as an educational site relies on its survival; however, if no adequate protection is provided, the tracks will quickly be completely deteriorated. It is necessary to take urgent measures to protect this site. The surrounding area offers an outstanding cultural heritage and it would be interesting to publicise this tracksite as well as using this publicity to promote its protection.

Exceptional coprolite association from the Early Cretaceous continental Lagerstätte of Las Hoyas, Cuenca, Spain

Coprolites are some of the most abundant fossils at the Las Hoyas site, a well-known Early Cretaceous Konservat-Lagerstätte located in Cuenca, central Spain. The coprolite association is described, introducing taphonomic features and sedimentological properties. This study is based on a subsample of 433 fossils selected from some 2000 specimens collected. The taphonomic features of the coprolites show that their integrity, absence of desiccation marks, and volume are congruent with faeces produced and deposited in an aquatic ecosystem, which were immediately covered by microbial mats. The highest abundance of coprolites, 96%, occurs in layers linked to the presence of microbial mats. Consequently, it is likely that coprolites are taphonomically autochthonous. A dichotomous key has been made in order to delimit the morphotypes. The key is based on (1) presence/absence of spiral marks, (2) morphology of coprolite ends, including polarity, expansion, and surface, and (3) overall shape, outline, diameter, and constrictions. Twelve different morphotypes are distinguished: spiral, circular, irregular, elongated, rosary, ellipsoidal, cylinder, bump-headed lace, fir-tree, cone, straight lace, and thin lace. The association is dominated by thin-lace and cylinder morphotypes. The sizes, inclusions, and EDX analyses indicate that the Las Hoyas coprolites correspond mostly to carnivorous producers with ichthyophagous diets, as crocodiles, urodelans and different kind of fishes.

Swimming reptile prints from the Keuper facies (Carnian, Upper Triassic) of Los Gallegos new tracksite (Iberian Range, Valencia province, Spain)

A new locality of Carnian reptile tracks (Upper Triassic) is described from the Manuel Sandstone Formation (Keuper facies). The track-bearing layer is located in the Los Gallegos creek (municipality of Cortes de Pallás, Valencia province) and the prints are preserved as natural casts. The tracks are isolated and, although there are certain alignments, these do not constitute trackways. Most of the prints are made up of sub-parallel digital marks. The number of digits and their size is variable, being tetradactyl the most complete ones. In some cases, the heel area has been preserved, although the impression of the V toe has never been so. No handprints have been found either. This preservation does not allow precise identification, although general characters as well as age suggest that these tracks may be related to the chirotheroid group and therefore, with archosauriform or archosaur crurotarsal reptiles. The characteristics of sediment, footprints and the presence of structures such as digit reflectures, Z-traces, posterior overhangs and longitudinal striations suggest that the ichnites were produced by swimming, totally or partially buoyant reptiles in a context dominated by a fluvial system with restricted marine influence during the Carnian Humid Episode.ResumenSe describe un nuevo yacimiento de huellas de reptiles de edad Carniense (Triásico Superior), pertenecientes a la formación Areniscas de Manuel (Facies Keuper). Las capas que contienen las icnitas, preservadas como moldes, afloran en el margen de la rambla de Los Gallegos (municipio de Cortes de Pallás, provincia de Valencia). A pesar de apreciarse una vaga alineación entre algunas huellas, estas no se agrupan formando rastros. La mayoría de las icnitas consisten en marcas digitales subparalelas. El número de impresiones digitales registradas en cada huella y sus dimensiones son variables, si bien las más completas son tetradáctilas. En algunos casos se ha preservado la impresión del talón, aunque en estos casos no existe registro del dedo V. No se ha podido identificar ninguna marca de mano. El tipo de preservación observada no permite una identificación precisa, si bien los rasgos generales y la edad asignada a este yacimiento sugieren que los productores podrían estar relacionados con el grupo quiroteroide y, por tanto, con reptiles arcosauriformes o arcosaurios crurotarsales. Las características del sustrato, de las icnitas y la presencia de ciertos rasgos característicos como flexuras digitales, trazas digitales en Z, proyecciones digitales posteriores y estrías longitudinales sugieren que las huellas fueron producidas por reptiles que se desplazaban en un régimen de natación o semi-natación en un medio fluvial con cierta influencia marina durante el Episodio Húmedo del Carniense.

The Exceptional Fossil Site of Las Hoyas (SPAIN) from an Educational Perspective

The paleontological heritage of the fossil site of Las Hoyas (Early Cretaceous of Cuenca, Spain) is becoming a relevant part of the sociocultural identity of Castilla-La Mancha autonomous community in general, and of Cuenca province in particular. The most recent scientific advances, including several fossil findings that have had high scientific impact, have made Las Hoyas to regularly be the center of attention in the local, national, and international media, especially since the reinterpretation of the paleoecosystem represented by the locality published in 2010. These results have led to a renaissance of the interest of the society for this unique site. As a consequence, Las Hoyas has been declared Site of Cultural Interest by the regional government, in the form of paleontological zone. This recognition, which grants the locality with the highest level of protection, sets a legal framework for the educative initiatives developed at this locality, which can be categorized as non-formal education, formal education, and Social Paleontology.