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A new kogaionid multituberculate mammal from the Maastrichtian of the Transylvanian Basin, Romania
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Abstract: The Latest Cretaceous (Maastrichtian) terrestrial sedimentary sequences of the Hateg Basin in Transylvania are well known for the so-called “Hateg Island” vertebrate faunas, which evolved in endemic (insular?) conditions. In addition to frogs, lizards, turtles, crocodilians, birds and dinosaurs, peculiar multituberculate mammals have been recorded, all belonging to the family Kogaionidae. Here, a new species of the genus Barbatodon is reported from the Maastrichtian S¸ ard Formation in the Transylvanian Basin (Alba County, Romania). Barbatodon oardaensis n. sp. is characterized by M1 cusp formula 3:4:2 and is much smaller than the two other Maastrichtian kogaionids from Transylvania, Barbatodon transylvanicus and Kogaionon ungureanui. The origin and paleobiogeography of kogaionids are discussed. Résumé: Les séquences continentales du Crétacé terminal (Maastrichtien) du bassin de Hateg en Transylvanie sont réputées pour leurs faunes de vertébrés originaires de « l’île de Hateg », qui ont évolué dans des conditions endémiques (insulaires ?). Hormis des grenouilles, lézards, tortues, crocodiles, oiseaux et dinosaures, des mammifères multituberculés particuliers ont également été mentionnés, tous appartenant à la famille des Kogaionidae. Une nouvelle espèce du genre Barbatodon est décrite dans le Maastrichtien de la Formation de S¸ ard, dans le bassin de Transylvanie (district d’Alba, Roumanie). Barbatodon oardaensis n. sp. est caractérisée par une formule dentaire de M1 3:4:2 et est plus petite que les deux autres kogaionidés de Transylvanie, Barbatodon transylvanicus et Kogaionon ungureanui. L’origine et la paléobiogéographie des kogaionidés sont discutées.
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Paleobiogeography of the lotus plant (Nelumbonaceae: Nelumbo) and its bearing on the paleoclimatic changes
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The historical reconstruction of the origin and dispersal of plant taxa in space and time facilitates a better understanding of theirmodern distribution patterns. However,most studies of paleobiogeography have focused on terrestrial plants, and the distribution changes of aquatic plants are less well understood. Here we study the lotus plant Nelumbo (Nelumbonaceae), an aquatic perennial herb, with a disjunctive distribution across East, South and Southeast Asia-North Australia and North America. The reproductive organs of Nelumbo changchangensis He et Jin from the Eocene of Hainan, China are supplementarily described. Analysis of the spatial and temporal distributions of Nelumbo in the geologic past indicates that the genus first occurs in mid-latitude area of Laurasia in the Early Cretaceous, then becomeswidespread in North America and Eurasia and expands into SouthAmerica during the Late Cretaceous, and reaches its maximum northern limit during the Eocene. The genus persists and thrives in North America and Eurasia until the Pliocene. The Pleistocene ice age causes the extinction of Nelumbo in Europe and central Asia, and its populations in North American and Asia are also restricted to refuges of lower latitude. Like the terrestrial plants Metasequoia (Cupressaceae) and Nordenskioeldia (Trochodendraceae), the fluctuations of Nelumbo distribution ranges are also linked to climatic changes in the Cenozoic. The cooling climate and increasing seasonality in the Eocene of East Asia may favor the origin of tubers and the differentiating of the ecotypes in lotus, which allow the deciduous type to survive in cold winters.
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Early Eocene cambaytheres from Indo-Pakistan are the sister group of Perissodactyls
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Cambaytherium, Nakusia, and Kalitherium are closely related early Eocene mammals from the Indo-Pakistan region that have been assigned to Perissodactyla (Laurasiatheria)or Anthracobunidae. The latter have been variously considered artiodactyls or perissodactyls, but more recently are usually placed at the base of the order Proboscidea or of the more inclusive Tethytheria (Afrotheria). We present new evidence from the dentition, skull, and postcranial skeleton of Cambaytherium, from Gujarat, India (ca. 54.5 Ma), that cambaytheres occupy a pivotal position as the sister taxon of Perissodactyla. Cambaytherium was more robust than basal perissodactyls such as ″Hyracotherium″ and Homogalax, and had a body mass of ~25-27 kg based on humeral, radial, and dental regressions. Perissodactyl synapomorphies include a transverse nasal-frontal suture, twinned molar metaconids, and an astragalus with deeply grooved trochlea and a saddleshaped navicular facet. Like perissodactyls, cambaytheres are mesaxonic and have hooflike unguals and a cursorially-adapted skeleton. Plesiomorphic traits compared to basal perissodactyls include bunodont molars with large conules and almost no hint of bilophodonty, unmolarized premolars, sacrum with four vertebrae, humerus with distally extensive pectoral crest and distal articulation lacking a capitular tail, distal radius without discrete scaphoid and lunate fossae, femur with low greater trochanter, calcaneus robust and wide with rounded ectal facet, astragalus wide with moderately long neck and vestigial astragalar foramen, navicular and cuboid short and wide, metapodials short and robust, and Mc I and Mt V present. In most or all of these traits cambaytheres are intermediate between phenacodontid condylarths and perissodactyls but closer to the latter. Our phylogenetic analyses place cambaytheres just outside perissodactyls, and place anthracobunids among primitive perissodactyls. However, similarities between cambaytheres and anthracobunids suggest that they are closely related, and future discovery of skeletal material of anthracobunids will provide a test of this hypothesis. Our results indicate that Anthracobunidae are not Proboscidea or tethytheres, and suggest that the origin of Perissodactyla may have taken place on the drifting Indian plate. How the progenitors of perissodactyls reached India is more problematic but might have involved land connections with Afro-Arabia during the Paleocene. Field work and research supported by the National Geographic Society.
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Focus stacking: Comparing commercial top-end set-ups with a semi-automatic low budget approach. A possible solution for mass digitization of type specimens
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Eocene stratigraphy of the Wadi Al-Hitan World Heritage Site and adjacent areas (Fayum, Egypt).
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Early Eocene environmental development in the northern Peri-Tethys (Aktulagay, Kazakhstan) based on benthic foraminiferal assemblages and stable isotopes (O, C).
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The Aktulagay section in Kazakhstan provides an expanded northern Tethyan record of the middle Ypresian (calcareous nannoplankton zones NP11-13, ~ 54-50 Ma), including the Early Eocene Climatic Optimum (EECO). The marl sequence features a series of sapropel beds, observed throughout the Peri-Tethys, indicative of the basin-wide occurrence of episodic hypoxic events. In order to unravel the paleoenvironmental evolution at Aktulagay during this period of global warming, we investigated the benthic foraminiferal record by means of a detailed multivariate analysis of the > 63 μm fraction, as well as through stable isotopic (C, O) investigations on excellently preserved benthic foraminiferal specimens. The Alashen Formation (NP11 to lower NP12; ~ 54 to 52.5 Ma), in the lower part of the sequence, contains a diverse assemblage of deep outer neritic (~ 200-250 m) benthic foraminifera, with common Pulsiphonina prima and Paralabamina lunata. The sea-floor conditions are interpreted as initially (54 Ma) well-ventilated and oligo- to mesotrophic, gradually changing to more eutrophic and oxygen-limited, culminating in more permanent low-oxygen conditions and eutrophy in the sapropel-bearing Aktulagay B1 unit (middle NP12; ~ 52.5-52 Ma). The latter conclusion is corroborated by the dominance of Anomalinoides acutus and Bulimina aksuatica and the lower diversity. Also the upward migration of endobenthic species to the sediment-water interface, as suggested by rising δ13Cendobenthic values, supports this interpretation. A transgression, which flooded lowlands, might have caused this development. In the Aktulagay B2 unit (top NP12-NP13; ~ 52-50 Ma), benthic foraminiferal assemblages dominated by Epistominella minuta suggest an oligotrophic environment, with transient pulses of phytodetritus and moderate ventilation. The Aktulagay B2 unit coincides with the peak temperature interval of the EECO, as indicated by its position close to the base of NP13 and rising δ13Cepibenthic values. Large river plumes, episodically reaching the area, in a monsoonal climatic context, might explain this basin development. Although it is not unlikely that some of the observed patterns are related to long-term climate change, it can currently not be excluded that changing paleogeography and variable connections to the Tethys, Atlantic and the Arctic Ocean were responsible for the long-term period with dysoxia and anoxia during deposition of the sapropel beds at the Peri-Tethyan seafloor. The evolution of the basin as observed in Aktulagay shows similarities to the evolution of the North Sea Basin as observed in Denmark, suggesting that these basins were connected during the Early Eocene.
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Distribution patterns of subsurface copepods and the impact of environmental parameters
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Apalachocyclops gen. nov. (Copepoda, Cyclopoida, Cyclopidae): A Nearctic "Doppelgänger" of the European speocyclopines.
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Diversity patterns of fauna in dripping water of caves from Transylvania.
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Assessing copepod (Crustacea: Copepoda) species richness at different spatial scales in northwestern Romanian caves.
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