The analysis of the hyoid apparatus of fossil xenarthrans provides insight on the form of the tongue and its function in food intake and intraoral processing. The hyoid apparatus of xenarthrans is notable for fusion among its elements. The presence of a V-bone, a complex consisting of fused basihyal and thyrohyal bones, is a consistent and probably synapomorphic feature of xenarthrans. Fusion of other elements is variable in fossil xenarthrans. Most fossil sloths retain independent elements, as in living dasypodids and mammals generally. Among nothrotheriids, the elements are slender and their articular surfaces indicate considerable mobility, and the relatively long and horizontal orientation of the geniohyoid muscle suggests considerable tongue protrusion. Among mylodontines, such as Paramylodon and Glossotherium, the elements indicate relatively mobile articulations, except between the stylo- and epihyals. The relatively posterior placement of the apparatus and the length and alignment of the geniohyoid muscle indicate considerable capacity for tongue protrusion. Scelidotherium, however, had rigidly articulated stylohyal and epihyal, and the apparatus lies farther anteriorly, which together with the elongated, steeply inclined mandibular symphysis, indicates a relatively shorter geniohyoid muscle and thus more limited capacity for tongue protrusion. A similar situation is indicated for Megatherium, casting doubt on the classical reconstruction of this sloth as having a long prehensile tongue. Among cingulates Prozaedyus resembles living dasypodids, indicating considerable tongue protrusion important in food acquisition and intake. More extensive fusion of hyoid elements occurs in the cingulates Glyptodon and Proeutatus, in which the stylohyal and epihyal at least, are fused into a single element termed the sigmohyal. The presence of this element supports recent proposals of a sister-group relationship between glyptodonts and eutatines. The rigidity of the apparatus suggests limited tongue protrusion, but the tongue, in glyptodonts at least, was a powerful structure important for intraoral manipulation of food.

A Miocene Sr-isotope chronostratigraphy of the sedimentites deposited by the "Paranense" Sea along a NE-SW transect stretching for 1200 km along the southwestern Atlantic coast is performed herein. Determined numerical ages are presented and discussed for shells of Aequipecten paranensis from the Argentinean Puerto Madryn Formation, Facies Balneario La Lobería, "Entrerriense Beds" of the Salado Basin, and Paraná Formation, and from the Camacho Formation (Uruguay). The 87 Sr/ 86 Sr ages fall into five age-groups that embrace the "Paranense" flooding in the latest Serravalian-Messinian interval. For the Puerto Madryn Formation, the ages span the latest Serravalian to the Tortonian and are stratigraphically coherent with the Transgressive Phase (11.90-10.37 Ma) and the Regressive Phases (10.22-9.82 Ma and 9.40-9.05 Ma) of that unit. Ages of 8.85-7.95 Ma for the "Entrerriense Beds" show them to be Tortonian and the Facies Balneario La Lobería, and the Paraná and Camacho formations span the age-range 7.50-6.0 Ma, comprising the Tortonian-Messinian interval. These ages allow correlation of the base of the Barranca Formation with the Regressive Phase of the Puerto Madryn Formation and its middle horizons with the Facies Balneario La Lobería. The "Entrerriense Beds" are correlated with the "Beds of Cabo Buentiempo". Dating the "Paranense" marine incursion permits a reappraisal of its paleogeography and to differentiate their deposits from those of the "Patagoniense" Sea. The flooding surface was more reduced than previously thought being its northwesternmost limit in the surroundings of the Santa Fe Province and its southernmost boundary in southern Santa Cruz Province. Moreover, our results proved that the Paranaian Molluscan Bioprovince was coeval with the Valdesian Molluscan Bioprovince for 2.35 Ma and that the species that constituted the Aequipecten paranensis Zone lived for at least 5.9 Ma .

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2012): Changes in vertebral laminae across the cervicodorsal transition of a well-preserved rebbachisaurid (Dinosauria, Sauropoda) from the Cenomanian of Patagonia, Argentina, Journal of Vertebrate Paleontology, 32:1, 219-224 To link to this article: http://dx.

Abstract. Traditionally, the use of good techniques to improve software modularity, such as advanced separation of concerns, has no impact in the user experience, for example while navigating Web software. While the intent of these techniques is to simplify evolution and maintenance, navigation design quality is often seen as an unrelated concern. In this paper we present a novel approach for improving navigation in Web applications by using some of the core application's concerns (called navigational concerns) to derive their navigational structure. Using some realistic examples we show that, by carefully using these concerns, we can improve the user experience. Some implementation issues are discussed and a thorough comparison with related ideas in the Web Engineering field is presented.

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The top of the Querales Formation is well exposed at the Quebrada Corralito section, 17 m thick, in northern Venezuela. The section, dominated by siliciclastic accumulations of fine-grained sediments, preserves one cycle of transgressive-regressive phases of the deltaic environments facing the marine platform. An X-ray analysis revealed kaolinite as the main clay mineral. The age ranges from late Early Miocene to early Middle Miocenezones N8 to N9, Late Burdigalian to Langhian. The section shows low biodiversity, including eleven macroinvertebrate taxa and two ichnotaxa; at its base, it contains mostly plant debris and amber from the continent, thus revealing a continental source near the littoral zone. Its middle portion preserves macroinvertebrates from the littoral zone, but also including the cephalopod Aturia sp., transported by a hydraulic flow to an area of greater depth; these macroinvertebrates are absent from overlying sections, at a time in which the basin was flooded most. The X-ray diffraction on six rock samples revealed mainly the presence of quartz with calcite, subordinated plagioclase and traces of potassium feldspar. Other minerals that compose this stratigraphic section are pyrite, dolomite and siderite, but they are disseminated in a siltstone. The section is dominated by mudstone sediments. The succession is kaolinite in the most pure fraction, and in lesser proportion smectite and illite; the stratified illite-smectite, chlorite and chlorite-smectite are present in low quantity. The mineralogical components of a molluscan valve were also examined, showing abundant pyrite, and moderate amounts of siderite and dolomite. In a part of the section, we recorded a rich assemblage of calcareous microfossils with foraminifers, nannofossils and marine ostracods. In the