Luis Alcalá

The upper Miocene mammal record from the Teruel–Alfambra region (Spain). The MN system and continental stage/age concepts discussed

Abstract An extended and revised mammal succession of 99 fossil localities from the Upper Miocene sediments of the Teruel–Alfambra region (NE Spain) is presented. An updated biozonation is proposed. The biostratigraphic justification for the correlation of the magnetic polarity patterns of the La Gloria, El Bunker, Masada Ruea, Masada del Valle and Masía de la Roma sections to the Geomagnetic Polarity Time Scale (GPTS) is discussed. A comparison with Late Miocene faunas from elsewhere in Europe demonstrates that faunal resemblance across the continent is very low. As illustrated by an analysis of the “Progonomys event,” local appearances of genera may be strongly diachronous and even species should not a priori be assumed to be isochronous at resolutions higher than several hundred thousands of years. These observations have implications for European continental stratigraphy and chronology: (1) The usefulness of the European mammal-based Stages/Ages can be doubted because their biostratigraphic significance is mainly local, and because more and more direct calibrations of mammal faunas to the numerical time scale are becoming established; (2) The European Mammal Neogene (MN) system, currently defined as a series of 16 time-ordered faunas, should not be divided into sub-units, because this weakens its power for cross-continental faunal correlation. In addition, the use of MN “boundaries” is erroneous and misleading, both from a philosophic and technical point of view.

A Giant European Dinosaur and a New Sauropod Clade

Fossils of a giant sauropod dinosaur, Turiasaurus riodevensis, have been recovered from terrestrial deposits of the Villar del Arzobispo Formation (Jurassic-Cretaceous boundary) of Riodeva (Teruel Province, Spain). Its humerus length (1790 millimeters) and estimated mass (40 to 48 metric tons) indicate that it may have been the most massive terrestrial animal in Europe and one of the largest in the world. Phylogenetic analysis indicates that the fossil represents a member of a hitherto unrecognized group of primitive European eusauropods that evolved in the Jurassic.

The Oldowan industry of Peninj and its bearing on the reconstruction of the technological skills of Lower Pleistocene hominids

The Oldowan technology has traditionally been assumed to reflect technical simplicity and limited planning by Plio-Pleistocene hominids. The analysis of the Oldowan technology from a set of 1.6-1.4 Ma sites (ST Site Complex) in Peninj adds new information regarding the curated behavior of early hominids. The present work introduces new data to the few published monographic works on East African Oldowan technology. Its relevance lies in its conclusions, since the Peninj Oldowan assemblages show complex technological skills for Lower Pleistocene hominids, which are more complex than has been previously inferred for the Oldowan stone tool industry. Reduced variability of tool types and complex use of cores for flaking are some of the most remarkable features that identify the Oldowan assemblages from Peninj. Hominids during this period seem to have already been experimenting with pre-determination of the flaked products from cores, a feature presently assumed to appear later in time. Planning and template structuring of flaked products are integral parts of the Oldowan at Peninj.

Soft-tissue preservation in Miocene frogs from Libros, Spain: Insights into the genesis of decay microenvironments

Abstract The Late Miocene Libros biota is a lacustrine-hosted, Konservat-Lagerstätte from Libros, near Teruel in northeast Spain. Adult frogs are characterized by the preservation of their soft tissues, some in histological detail. The soft tissues of the body outline are preserved as a layered structure, which comprises a central carbonaceous bacterial biofilm enveloped by the phosphatized remains of the mid-dermal Eberth-Katschenko layer, external to which is a second, thinner, carbonaceous bacterial biofilm. Bacterial autolithification is restricted to limited phosphatization of the cell margins of bacteria adjacent to phosphatized dermis. Phosphatization occurred during the late stages of decay; phosphate was sourced primarily from the dermis itself. Other tissues and organs are also defined in authigenic minerals: nervous tissue (aragonite), the stomach (calcium phosphate), and collagen fibers of the dermal stratum compactum (calcium sulphate); bone marrow is organically preserved. The disparate modes of soft-tissue preservation within individual specimens reflects development of several highly localized, chemically distinct microenvironments within the frog carcasses during decay. These microenvironments correspond to individual organs and tissues, were established at different times during decay, and varied in their duration. The preservation of soft tissues via multiple taphonomic pathways was controlled ultimately by anatomical and physiological factors.

High-fidelity organic preservation of bone marrow in ca. 10 Ma amphibians

Bone marrow in ca. 10 Ma frogs and salamanders from the Miocene of Libros, Spain, represents the first fossilized example of this extremely decay-prone tissue. The bone marrow, preserved in three dimensions as an organic residue, retains the original texture and red and yellow color of hematopoietic and fatty marrow, respectively; moldic osteoclasts and vascular structures are also present. We attribute exceptional preservation of the fossilized bone marrow to cryptic preservation: the bones of the amphibians formed protective microenvironments, and inhibited microbial infiltration. Specimens in which bone marrow is preserved vary in their completeness and articulation and in the extent to which the body outline is preserved as a thin film of organically preserved bacteria. Cryptic preservation of these labile tissues is thus to a large extent independent of, and cannot be predicted by, the taphonomic history of the remainder of the specimen.

A stratigraphical framework for Miocene (MN4-MN13) continental sediments of Central Spain

New bio- and magnetostratigraphic data from the Miocene continental sediments of Central Spain are used to update the existing stratigraphical framework. Our revised record is based on the study of more than two hundred mammal faunas, ranging from the Late Ramblian (ca 18 Ma) to the Late Turolian (ca 6 Ma).

The basal nodosaurid ankylosaur Europelta carbonensis n. gen., n. sp. from the Lower Cretaceous (lower Albian) Escucha Formation of northeastern Spain.

Nodosaurids are poorly known from the Lower Cretaceous of Europe. Two associated ankylosaur skeletons excavated from the lower Albian carbonaceous member of the Escucha Formation near Ariño in northeastern Teruel, Spain reveal nearly all the diagnostic recognized character that define nodosaurid ankylosaurs. These new specimens comprise a new genus and species of nodosaurid ankylosaur and represent the single most complete taxon of ankylosaur from the Cretaceous of Europe. These two specimens were examined and compared to all other known ankylosaurs. Comparisons of these specimens document that Europelta carbonensis n. gen., n. sp. is a nodosaur and is the sister taxon to the Late Cretaceous nodosaurids Anoplosaurus, Hungarosaurus, and Struthiosaurus, defining a monophyletic clade of European nodosaurids– the Struthiosaurinae.

Organic preservation of fossil musculature with ultracellular detail

The very labile (decay-prone), non-biomineralized, tissues of organisms are rarely fossilized. Occurrences thereof are invaluable supplements to a body fossil record dominated by biomineralized tissues, which alone are extremely unrepresentative of diversity in modern and ancient ecosystems. Fossil examples of extremely labile tissues (e.g. muscle) that exhibit a high degree of morphological fidelity are almost invariably replicated by inorganic compounds such as calcium phosphate. There is no consensus as to whether such tissues can be preserved with similar morphological fidelity as organic remains, except when enclosed inside amber. Here, we report fossilized musculature from an approximately 18 Myr old salamander from lacustrine sediments of Ribesalbes, Spain. The muscle is preserved organically, in three dimensions, and with the highest fidelity of morphological preservation yet documented from the fossil record. Preserved ultrastructural details include myofilaments, endomysium, layering within the sarcolemma, and endomysial circulatory vessels infilled with blood. Slight differences between the fossil tissues and their counterparts in extant amphibians reflect limited degradation during fossilization. Our results provide unequivocal evidence that high-fidelity organic preservation of extremely labile tissues is not only feasible, but likely to be common. This is supported by the discovery of similarly preserved tissues in the Eocene Grube Messel biota.

A new archaic Homo sapiens fossil from Lake Eyasi, Tanzania.

a Department of Prehistory, Complutense University, Prof. Aranguren s/n, 28040 Madrid, Spain b Archaeology Unit, University of Dar es Salaam, Dar es Salaam, Tanzania c Fundación Conjunto Paleontológico de Teruel, Edificio Dinópolis, Avda. Sagunto s/n, 44002 Teruel, Spain d Department of Medical Physics and Applied Radiation Sciences, McMaster University, Ontario, Canada e School of Geography and Earth Sciences, McMaster University, Ontario, Canada f Department of Prehistory and Archaeology, University of Valladolid, Plaza del Campus s/n, 47011 Valladolid, Spain

NEW SPECIES OF HIPPARION FROM LA ROMA 2 (LATE VALLESIAN; TERUEL, SPAIN): A STUDY OF THE MORPHOLOGICAL AND BIOMETRIC VARIABILITY OF HIPPARION PRIMIGENIUM

Abstract Morphological and biometrical variability is analyzed in Hipparion primigenium (V. Meyer) from four Vallesian and Turolian locations in Spain (Masía de Barbo, Puente Minero, Nombrevilla, and Los Valles de Fuentidueña). Previously unstudied remains of Hipparion from La Roma 2 (Teruel Province, Spain) are described and tested by multivariate analysis. This form is compared with: 1) Hipparion primigenium (or Hippotherium primigenium) from the above-mentioned Spanish localities; 2) large-sized specimens from Çalta (Turkey) and Pavlodar (Kazakhstan); 3) forms from the locality type of Eppelsheim, Höwenegg, and Dürkheim (Germany), and Nikiti 1 (Greek); and 4) specimens from two other Spanish localities, Concud and Venta del Moro. Hipparion remains from La Roma 2 are identified as Hipparion laromae n. sp. by body mass and morphological characteristics, and confirmed by bivariate and multivariate analyses. The faunal assemblages indicate a late Vallesian age (MN10) for La Roma 2 locality and an early Turolian age (MN11) for the Puente Minero locality.