PALEONTOLOGY OF VERTEBRATES

Author: BADIOLA KORTABITARTE AINARA.
Year: 2004.
University: PAÍS VASCO [www.ehu.es].
Place of defense: FACULTAD DE CIENCIA Y TECNOLOGÍA.
Place of preparation: FACULTAD DE CIENCIAS, UPV.

Summary: The site of paleontological Eocene Senior Zambrana part of one of the oldest lake systems of southern flank of Sinclinal of Miranda-Treviño (Region Vasco-Cantábrica). The study indicates sedimentológico palustres conditions typical of areas outside Lake, in an atmosphere c enagoso. Tafonómicas The characteristics of the association suggests that the fossils are Indians and discard the existence of reprocessing. Levels dug Zambrana have provided for 25 taxa of fossil vertebrates, for amphibians (Anura), reptile (scaly, qulonios, crocodiles) and mammals. The systematic study has focused on the recording of the latter (marsupials, rodents, carnivores, artiodáctilos and perisodáctilos), proposed cino new taxa perisodáctilos ecuoideos, including two new genres Plagiolophinae and three new species, the latter belonging to the genera Palaeotherium (palaeotheriidae) Leptolophus and Pachynolophus (Pachynolophidae). The site has also provided invertebrate fossils, carofítas and plant seeds. The study paleoecológico suggests half with masses tree, perhaps around the lake, and more open habitats and / or dry in the rest of the area. From a standpoint paleobiogeográfico, Zambrna observed ecuoideos endemic Iberian, related to those of Mazaterón (Cuenca del Duero, MP 15-16) and Llamaquique (Basin of Oviedo, MP 16-17). However, the association of artiodáctilos of Zambrana is typically European, which suggests the existence of contacts with the rest of Western Europe during the Headoniense higher. Zambrana is so far the only enclave of the Iberian Peninsula which has provided an association físol mammal's benchmark MP 18. His study contributes to a better understanding paleobiológico of todavías poorly known mammalian faunas of the Iberian Upper Eocene, pre-biotic and global environmental changes occurring around the limit Eoceno-Oligoceno.

Author: MARTÍNEZ ALBA DAVID.
Year: 2004.
University: BARCELONA [www.ub.es].
Place of defense: FACULTAT DE BIOLOGÍA.
Place of preparation: INSTITUT DE PALEONTOLOGIA M. CRUSAFONT.

Summary: It explores the origin and evolution of the clade of large anthropomorphic humans (family Hominidae) from a paleontological and neontológica. The investigations were carried out under the leadership of Salvador Moyá-Solá, at the Institut de Paleontologia M. Crusafont (1998-2004) and PALAEOTHERIA, SCP (2003-2004). The objectives of this study were better extinct members of the group, making inferences paleonbiológicas and evolutionary based living and fossil taxa, and assessing the importance of heterocronía and exaptación in the evolution of hominids. Five taxa deserved special attention: Dryopithecus and Pierolapithecus (with emphasis on the phylogeny and locomotion), which has led to evaluate the prevalence of homoplasia: Oreopithecus and Pan (with the emphasis on heterocronía skull), to investigate the role of the constrictions evolutionary and Australopithecus (with emphasis on the proportions of the hands), with the aim of illustrating the importance of the principle of co-optation. The research included field work (co-manager of the intervention palaeontological to Nova Stage Dipósit Controlat Can Kill); laboratory work (description and measurement of specimens, both fossil and present members of the group), and analytical work (usually through computer-aided statistical methods). The major findings are summarized as follows: A-Taxonomy and phylogeny: erected a new genus and species of hominid basal (Pierolapithecus catalaunicus), close to the last common ancestor of Ponginae and Homininae. The Hylobatidae are considered the sister group of hominidae. All major anthropomorphic Eurasian included in Ponginae; Dryopithecus are considered a pongino primitive Oreopithecus a descendant of an ancestor island similar to Dryopithecus and Sivapithecus the taxon brother Pongo. It is not therefore require esencenarios biogeographic complex suggesting an origin of the European anthropomorphic Africans. B-Homoplasia: Pierolapithecus and Dryopithecus suggest that the last common ancestor of the most primitive Hominidae is what suggests the current forms with behavior suspensores having evolved independently several times. La homoplasia (debida tanto a convergencia como a paralelismo) es muy frecuente, como se ejemplifica no sólo por la adquisición independiente de la suspensión, sino también del bipedismo y de la presión de precisión de tipo humano, entre otros. This has serious implications for the methods cladista of phylogenetic reconstruction, which ruled out a weighting of the characters in advance. C-Heterochronia: It proposes a new model heterocrónico, characterized by a double standardization through development. Eight types can be distinguished from heterocronía, including two new ones: the postformación and pre. The bonobo and Oreopithecus show a similar pattern of pedomorfosis skull, and is characterized by a reduced prognatismo, reducing the size of the brain, and microdoncia. In both cases, the downsizing of the canines could, in conjunction with the microdoncia postcanina, a readjustment adaptive secondary to the reduction of prognatismo, instead of reflecting changes in behavior sociosexual. Changes in the size and shape of the skull and jaw of the bonobo, along with changes in the size and shape of the skull and jaw of the bonobo, along with the changes in brain size, are documented in the stadiums postnatal development earliest. Reducing the size of the brain is proposed as the most likely d natural selection in bonobos reasons metabolic, behavioral and morphological changes have been dragged as not adaptive products, which leads to the paradox of the form (the possibility the morphology evol 8 ucione c 4b3 sa result of the selection on morphological characters). D-Paleobiología: Given the principle of co-optation, it is necessary to distinguish between the function and evolutionary origin when hypotheses are proposed to adapt. This is exemplified by the proportions of gracious human hand (which are considered an adjustment to handling, but a exaptación the manufacture of stone tools), as well as the plan body ortógorado (which is considered an adjustment to trepación, but a exaptación regarding the suspension). The high prevalence of homoplasia in the evolution of hominids, along with the paradox of the form and the principle of co-optation, indicate that we must understand the morphology before attempting to make inferences paleobiológicas or phylogenetic.

Author: CAMBRA MOO OSCAR.
Year: 2005.
University: AUTÓNOMA DE MADRID [www.uam.es].
Place of defense: FACULTAD DE CIENCIAS.
Place of preparation: FACULTAD DE CIENCIAS.

Summary: The Tafonomía, scientific sub-disciplina still in formation, part of the growing scientific forefront multidisciplinary, and thanks to its development in recent years, it provides a very important platform for the inference of dynamic paleocológicas, integrating it sedimentológicas inputs, stratigraphic, geochemical, tectonic, paleoclimatológicas, ecological, iconológicas, geomorphological, and statistics. To a large extent, the development of modern Tafonomía, can be linked to three events simultaneously, increased information fossil record: increase in the detection of soft tissue preserved, the use of experimental updated at the time of pose any study involving the reconstruction of natural processes. Our main scenario work has raised recognize what are the extrinsic and intrinsic factors that regulate and modulate the process tafonómico in arcosaurios and recognize common patterns that cause the dispersal of copies. Particularly we have been interested to know what is the role of biological factors as size, age, or morphology in the process bioestratinómico. Large contributions of this research to the development of the vertebrate tafonomía can be summarized as follows: 1-Analysis of dispersion: recognition of a pattern of dismantling characteristic of arcosaurios quadrupeds, opening the potential to characterize and predict positions of the elements in accumulations of skeletal remains. 2-Actuotafonomía: to characterize the influence of the means of production (external factors) in the early stages of fossilization, calculating and quantifying the distortion it produces will aquatic environment, as opposed to land, thus the possibility of rebuilding and where how long it took an individual buried. 3-Paleohistología: to characterize the diversity of birds mesozoicas histological and how this has influenced their evolutionary process. 4-Preservation: confirm the important role that had the microbial mats in the conservation and fosildiagénesis of fossils of deposit The Hoyas the Lower Cretaceous.