Machalski M.,Instytut Paleobiologii |
Jagt J.W.M.,Natuurhistorisch Museum Maastricht |
Alekseev A.S.,Russian Academy of Sciences |
Jagt-Yazykova E.A.,University of Opole
Acta Palaeontologica Polonica | Year: 2012
A complete uppermost Maastrichtian-Danian succession in the Sumbar River section, western Kopet Dagh (southwest Turkmenistan, Central Asia), constitutes one of the few instances in the world where the fossil record of the last ammonites can be directly positioned with respect to the iridium-rich, impact-related clay layer, which defines the Cretaceous-Paleogene (K-Pg) boundary. Two ammonite taxa, Baculites cf. vertebralis and Hoploscaphites constrictus johnjagti, range up to a level directly beneath the K-Pg boundary clay in the Sumbar River section. Thus, these two forms probably survived until the very end of the Maastrichtian in the western Kopet Dagh area. The terminal Maastrichtian ammonite records from the Sumbar River area represent the southeasternmost occurrences of these essentially Boreal taxa. Copyright © 2012.
Landman N.H.,American Museum of Natural History |
Goolaerts S.,Royal Belgian Institute Of Natural Sciences |
Jagt J.W.,Natuurhistorisch Museum Maastricht |
Jagt-Yazykova E.A.,University of Opole |
And 3 more authors.
Geology | Year: 2014
One of the puzzles about the end-Cretaceous extinctions is why some organisms disappeared and others survived. A notable example is the differential extinction of ammonites and survival of nautilids, the two groups of co-occurring, externally shelled cephalopods at the end of the Cretaceous. To investigate the role of geographic distribution in explaining this outcome, we compiled a database of all the occurrences of ammonites and the nautilid genus Eutrephoceras in the last 0.5 m.y. of the Maastrichtian. We also included recently published data on ammonite genera that appear to have briefly survived into the Paleocene. Using two metrics to evaluate the geographic range of each genus (first, a convex hull encompassing all of the occurrences of each genus, and second, the maximum distance between occurrences for each genus), we documented that most ammonite genera at the end of the Maastrichtian were restricted in their geographic distribution, possibly making them more vulnerable to extinction. The geographic distribution of those genera that may have briefly survived into the Paleocene is significantly greater than that of non-surviving genera, implying that more broadly distributed genera were more resistant to extinction. This pattern is further emphasized by the broad distribution of Eutrephoceras, which matches that of the most widely distributed ammonites at the end of the Maastrichtian. However, even the most widely distributed ammonites eventually succumbed to extinction, whereas Eutrephoceras survived. Evidently, a broad geographic distribution may have initially protected some ammonites against extinction, but it did not guarantee their survival. © 2014 Geological Society of America.
Lamolda M.A.,University of Granada |
Paul C.R.C.,University of Bristol |
Peryt D.,Instytut Paleobiologii |
Pons J.M.,University of Barcelona
Episodes | Year: 2014
The GSSP for the base of the Santonian Stage is defined at 94.4 m in the eastern border of the "Cantera de Margas" quarry, Olazagutia (Navarra, N. Spain: 42° 52′ 05.3" N, 2° 11′ 40" W) and marked by the first occurrence (FO) of the inoceramid bivalve Platyceramus undulatoplicatus. This first occurrence is located about 9 m below the contact between a lower marly unit and an upper more calcareous unit. The FO of the planktonic foraminifer Sigalia carpatica is the secondary marker of the GSSP and first occurs 7 m below the primary marker, but it becomes consistently present about 4.2 m above the boundary. In addition, six peaks in the carbon stable isotope curve can be recognized between the Kingsdown Event 17.2 m below and the Bedwell Event 12.35 m above the GSSP. The basal Santonian GSSP was approved by the International Subcommission on Cretaceous Stratigraphy in September 2010, by the International Commision of Stratigraphy in April 2012, and ratified by the International Union of Geological Sciences in January 2013.
Desojo J.B.,Museo Argentino de Ciencias Naturales Bernardino Rivadavia |
Heckert A.B.,Appalachian State University |
Martz J.W.,Denver Museum of Nature and Science |
Parker W.G.,Petrified Forest National Park |
And 4 more authors.
Geological Society Special Publication | Year: 2013
Aetosauria is a clade of obligately quadrupedal, heavily armoured pseudosuchians known from Upper Triassic (late Carnian-Rhaetian) strata on every modern continent except Australia and Antarctica. As many as 22 genera and 26 species ranging from 1 to 6 m in ength, and with a body mass ranging from less than 10 to more than 500 kg, are known. Aetosauroides scagliai was recently recovered as the most basal aetosaur, placed outside of Stagonolepididae(the last common ancestor of Desmatosuchus and Aetosaurus). Interrelationships among the basal aetosaurs are not well understood but two clades with relatively apomorphic armour-the spinose Desmatosuchinae and the generally wide-bodied Typothoracisinae-are consistently ecognized. Paramedian and lateral osteoderms are often distinctive at the generic level but variation within the carapace is not well understood in many taxa, warranting caution in assigning isolated osteoderms to specific taxa. The aetosaur skull and dentition varies across taxa, and there is increasing evidence that at least some aetosaurs relied on invertebrates and/or small vertebrates s a food source. Histological evidence indicates that, after an initial period of rapid growth, lines of arrested growth (LAGs) are common and later growth was relatively slow. The common and widespread Late Triassic ichnogenus Brachychirotherium probably represents the track of an aetosaur. © The Geological Society of London 2013.
Fraaije R.H.B.,Oertijdmuseum de Groene Poort |
Van Bakel B.W.M.,Oertijdmuseum de Groene Poort |
Van Bakel B.W.M.,Naturalis Biodiversity Center |
Jagt J.W.M.,Natuurhistorisch Museum Maastricht |
Machalski M.,Instytut Paleobiologii
Zootaxa | Year: 2015
A new diogenid paguroid, Paguristes liwinskii sp. nov., is described from upper Albian phosphorite-bearing deposits near Annopol, along the east bank of the River Vistula (Wisła), east-central Poland. This new species constitutes an additional example of Early-Mid-Cretaceous macrofaunal shift, from marine reefal limestone to siliciclastic facies, triggered by the worldwide radiation of planktonic organisms. The species described here is the earliest known member of the genus Paguristes, previously recorded from the upper Santonian/lower Campanian to the Recent. Copyright © 2015 Magnolia Press.
Harasimiuk M.,University Marii Curie Sklodowskiej |
Domonik A.,University of Warsaw |
Machaiski M.,Instytut Paleobiologii |
Pininska J.,University of Warsaw |
And 2 more authors.
Przeglad Geologiczny | Year: 2011
At the beginning of 2010, works have been launched to establish Geopark- Małopolski Przełom Wisły (MPW). The main aimt of the works is a detailed identification and full inventory of abiotic conditions concerning: geology, relief, mining tradition and history of regions economic development, which descends from natural factors aud its valorization from the point of view of protection and possibilities ofgeoturistic use. One of the most important elements of scientific, didactic and geoturistic use of planned geopark is a series of formations from the Upper Jurassic to Danian, which are exposed along the banks of Vistula in the section between Zawichost and Puławy. Particularly important is the series of deposits from the Middle A lbian to Upper Maastrichtian, which constitutes unique in the European scale record of the evolution of sea basin which began withthe Middle Cretaceous transgression to continue till the regression at the end of the Cretaceous. Equally significant are landscape and geomorphological values. Another favorable circumstance for establishment of that geopark is the fact that on the area covered by the project, landscape parks, reserves, natural monuments and areas of Nature 2000, as well as highly ranked cultural objects, already exist. Project works on geopark will be concluded in the year 2012.
Currie P.J.,University of Alberta |
Funston G.F.,University of Alberta |
Osmolska H.,Instytut Paleobiologii
Acta Palaeontologica Polonica | Year: 2016
New specimens of Elmisaurus rarus from the Upper Cretaceous of Mongolia (Nemegt Formation) preserve bones not previously found in "elmisaurids" that help elucidate their relationships to Leptorhynchos elegans and other oviraptorosaurs. Elmisaurus rarus and the North American Leptorhynchos elegans are known from numerous but incomplete specimens that are closely related to, but nevertheless clearly distinguished from, Chirostenotes pergracilis and Epichirostenotes curriei. These specimens include the first known cranial bone attributed to Elmisaurus, the frontal, which clearly shows this animal had a cranial crest (most of which would have been formed by the nasal bones). The first vertebrae, scapula, femora, and tibiae from Elmisaurus are also described. The Elmisaurinae can be distinguished from the Caenagnathinae by the coossification of the tarsometatarsus and smaller size at maturity. Examination of oviraptorosaur hindlimbs reveals four distinct morphotypes, possibly attributable to paleoecological differences. Copyright © 2016 P.J. Currie et al.
Olempska E.,Instytut Paleobiologii |
Wacey D.,University of Bristol |
Wacey D.,University of Western Australia
Palaeogeography, Palaeoclimatology, Palaeoecology | Year: 2016
Hollow microtubular structures with pyrite grains at their termini have been found in phosphatocopines ( Hesslandona toreborgensis and Hesslandona cf. angustata) from the late Cambrian of northern Poland, and in the metacopine ostracod Cytherellina submagna from the Early Devonian of Podolia, Ukraine.The Cambrian phosphatocopines are secondarily phosphatised and microtubes (5-20. μm in diameter) are preserved inside the phosphatized bivalved shield, visible on the shield surface as half-open microstructures with pyrite grains at their terminal end. They are visible only where an external coating layer has peeled off. In the Devonian ostracod C. submagna, microtubes ( c. 1-8. μm in diameter) occur within the phosphatized internal mould/steinkern and are visible on the surface of the mould due to the dissolution of the calcite carapace during extraction of the limestone samples.These microtubular structures are here interpreted as ambient inclusion trails (AITs) due to the presence of terminal pyrite crystals of equivalent diameter to the microtube, polygonal microtube cross-sections, plus longitudinal striations on the microtube walls that record the movement of the migrating angular pyrite crystal. AITs are thought to form when mineral crystals, typically pyrite, are impelled to migrate through a fine-grained mineral matrix under increased fluid/gas pressure.Our new materials provide the first record of exceptionally preserved AITs occurring in crustaceans and only the third reported occurrence of AITs in the Palaeozoic. The intimate occurrence of AITs with phosphatized crustacean body fossils supports the hypothesis that AITs are likely driven by increases in gas pressure due the decomposition of soft tissue. In the case of Cytherellina submagna, our calculations suggest that as little as 20μg of organic matter decaying within a volume of 0.06mm3, encased by an impermeable outer carapace, may have been sufficient to produce a large number (>100) of AITs. © 2015 Elsevier B.V.
Uchman A.,Jagiellonian University |
Gazdzicki A.,Instytut Paleobiologii
Polish Polar Research | Year: 2010
Trace fossils Phymatoderma melvillensis isp. nov., Thalassinoides isp., ?Nereites isp. and Planolites isp. are reported from the glacimarine sediments of the Cape Melville Formation (Lower Miocene) of King George Island, West Antarctica. Their occurrence and strong bioturbation of sediments point to an offshore or deeper (outer shelf or upper slope) environment. Deep marine crab Antarctidromia inflata Förster, 1985, has been found in Thalassinoides isp. The tracemaker (?crustacean) of Phymatoderma melvillensis rereworked pelletal sediments probably during times of food deficiency.
Sulej T.,Instytut Paleobiologii
Zoological Journal of the Linnean Society | Year: 2010
Disarticulated bones of several individuals recovered from the Late Triassic fluvial and lacustrine deposits at Krasiejów, Poland, are here described, allowing the restoration of the skull structure of a new aetosaurian archosaur: Stagonolepis olenkae sp. nov. The Krasiejów deposits probably correspond in age to the Lehrberg Beds (late Carnian) of Baden-Württemberg, Germany. The stratigraphical position of the new taxon combined with other available evidence is used to propose a model of aetosaurian evolution. The proposed phylogenetic position of Aetosaurus ferratus (Norian, Germany) as the basal aetosaurid is refuted and this species is instead proposed to be the most derived member of the Stagonolepis-Aetosaurus evolutionary lineage. Gradual change in several morphological characters can be observed from Stagonolepis robertsoni, through the new species from Krasiejów, to the stratigraphically youngest Aetosaurus ferratus. These changes include a decrease in the number of teeth and a decrease in the convexity of the ventral profile of the maxilla. The anterior elongation of the maxilla is associated with the expansion of the anterior tip of the maxilla towards the naris. In S. robertsoni and S. olenkae, the maxilla extends to middle of the naris, whereas in Aetosaurus, it reaches the anterior half of the naris. © 2010 The Linnean Society of London.