Thylacosmilids are a clade of metatherian predators known from lower Miocene to upper Pliocene strata of South America. They had highly specialized skulls with enlarged canines. Here, we describe remains of a new thylacosmilid taxon from the Argentine Pampas. This specimen comprises a partial postcranial skeleton from the upper Pliocene-Lower Pleistocene Vorohu & eacute; Formation near Miramar in Buenos Aires Province. It shares several features supporting referral to Thylacosmilidae including a strong neck, robust forelimbs, and a shortened tibia. However, it shows notable differences from more derived thylacosmilids, especially Thylacosmilus atrox, the only thylacosmilid represented by relatively complete postcranium. The Vorohu & eacute; Formation taxon differs by having a robust atlas, simpler ventral crest in the fifth cervical vertebra, enlarged medial epicondyle of the humerus, less distally projected capitulum, a more developed process on top of the lateral epicondylar crest, an enlarged radial fossa, deep coronoid fossa bordered by a marked ridge, smaller medial epicondyle on the femur, and a straight tibial shaft. These character states support establishment of a new genus and species. Phylogenetic analysis places the Vorohu & eacute; Formation taxon as the sister of Thylacosmilus atrox. Functional comparisons suggest powerful neck musculature and forelimbs, coupled with low cursoriality-traits typical of ambush predators. The Vorohu & eacute; Formation taxon is one of the geologically youngest sparassodonts, and shows that thylacosmilids coexisted not only with early North American placental carnivores (e.g., procyonids), but also probably mustelids and foxes.Eric del Campo* [eric.delcampo.93@gmail.com], Laboratorio de Anatom & iacute;a Comparada y Evoluci & oacute;n de los Vertebrados, Museo Argentino de Ciencias Naturales "Bernardino Rivadavia", Av. & Aacute;ngel Gallardo 470, C1405DJR, Ciudad Aut & oacute;noma de Buenos Aires, Argentina and Consejo Nacional de Investigaciones Cient & iacute;ficas y T & eacute;cnicas (CONICET); Federico L. Agnol & iacute;n [fedeagnolin@yahoo.com.ar], Laboratorio de Anatom & iacute;a Comparada y Evoluci & oacute;n de los Vertebrados, Museo Argentino de Ciencias Naturales "Bernardino Rivadavia", Av. & Aacute;ngel Gallardo 470, C1405DJR, Ciudad Aut & oacute;noma de Buenos Aires, Argentina; Consejo Nacional de Investigaciones Cient & iacute;ficas y T & eacute;cnicas (CONICET) and Fundaci & oacute;n de Historia Natural "F & eacute;lix de Azara", Departamento de Ciencias Naturales y Antropolog & iacute;a, Universidad Maimonides, Hidalgo 775, Buenos Aires, Argentina; Nicol & aacute;s R. Chimento [nicochimento@hotmail.com], Laboratorio de Anatom & iacute;a Comparada y Evoluci & oacute;n de los Vertebrados, Museo Argentino de Ciencias Naturales "Bernardino Rivadavia", Av. & Aacute;ngel Gallardo 470, C1405DJR, Ciudad Aut & oacute;noma de Buenos Aires, Argentina; Consejo Nacional de Investigaciones Cient & iacute;ficas y T & eacute;cnicas (CONICET) and Fundaci & oacute;n de Historia Natural "F & eacute;lix de Azara", Museo de Ciencias Naturales y Arqueolog & iacute;a "Prof. Manuel Almeida", 25 de Mayo 533 (2820), Gualeguaych & uacute;, Entre R & iacute;os, Argentina; Daniel Boh [dannyboh@gmail.com], Museo Municipal Punta Hermengo, Vivero Dun & iacute;cola Municipal "Florentino Ameghino", Partido de General Alvarado, Miramar, Provincia de Buenos Aires, Argentina; Mariano Magnussen [marianomagnussen@yahoo.com.ar], Laboratorio de Anatom & iacute;a Comparada y Evoluci & oacute;n d & Aacute;ngel Gallardo 470, C1405DJR, Ciudad Aut & oacute;noma de Buenos Aires, Argentina; Francisco De Cianni [deciannifrancisco@gmail.com], Consejo Nacional de Investigaciones Cient & iacute;ficas y T & eacute;cnicas (CONICET) and Museo Argentino de Ciencias Naturales "Bernardino Rivadavia", Av. & Aacute;ngel Gallardo 470, C1405DJR, Ciudad Aut & oacute;noma de Buenos Aires, Argentina.
Recently, Mexico has become a significant area for research on Cretaceous Crossognathiformes. Despite this, most Mexican crossognathiforms remain undescribed, and their relationships have not been evaluated within a comprehensive phylogenetic framework. In this study we describe a new species, Nusaviichthys antigonae sp. nov., which exhibits the diagnostic features of the genus, including the mesoparietal condition of the skull and numerous small, conical teeth on the vomer and both jaws. The new species is distinguished from Nusaviichthys nerivelai by the nearly smooth external surfaces of the jaw and dermal skull bones, which lack the conspicuous ornamentation present in the latter species. The discovery of N. antigonae expands the known taxonomic diversity of Crossognathiformes during the Cretaceous and further highlights the importance of the Mexican fossil record for understanding the evolutionary history of this group.Nayeli Lupercio Espericueta* [nayelupercio@comunidad.unam.mx], Posgrado en Ciencias de la Tierra, Instituto de Geolog & iacute;a, Universidad Nacional Aut & oacute;noma de M & eacute;xico, Ciudad de M & eacute;xico, 04510, M & eacute;xico; Jes & uacute;s Alvarado-Ortega [alvarado@geologia.unam.mx], Instituto de Geolog & iacute;a, Universidad Nacional Aut & oacute;noma de M & eacute;xico, Circuito de la Investigaci & oacute;n S/N, Ciudad Universitaria, Alcald & iacute;a Coyoac & aacute;n, Ciudad de M & eacute;xico 04510, M & eacute;xico.
A new palynological assemblage is documented from the Vaca Muerta Formation in the Quebrada del Sapo area of the Neuqu & eacute;n Basin in Argentina. One hundred and three palynomorph species are recognized. Systematic treatments are provided for sporomorphs (Cyathidites, Cyclusphaera, Nevesisporites, Shanbeipollenites), algae (Cymatiosphaera and Tetrastrum), acritarchs (Leiosphaeridia) and dinoflagellate cysts (Cribroperidinium, Dingodinium, ?Lithodinia, cf. Sirmiodinium). Tetrastrum multifilorum is identified for the first time from Argentina, while Cyathidites asper and Dingodinium tuberosum represent new occurrences from the Neuqu & eacute;n Basin; Cribroperidinium granulatum var. 1 is recorded for the second time globally. The dinoflagellate cyst composition indicates that the lower part of the Vaca Muerta Formation cannot be younger than early-late Tithonian; upper Tithonian deposits likely extend to near the top of the unit. The top of the Vaca Muerta Formation may lie within the lower part of the upper Tithonian. Our new evidence suggests that the basal range of Cyclusphaera radiata in Argentina extends into at least the ?lower Berriasian. Shanbeipollenites proxireticulatus extends into the upper Tithonian, and reveals its first Upper Jurassic occurrence outside of Tanzania. Scenedesmus ranges into the upper Tithonian and is thus the first Jurassic example in Argentina and the second oldest globally. Palaeobiogeographically, the Vaca Muerta Formation assemblage is comparable to those from the Upper Jurassic of southeast Africa, and could reflect a marine connection between the Neuqu & eacute;n Basin and the Mandawa and Lamu basins via the Mozambique Corridor.Luis S Ag & uuml;ero* [luisaguero@ingeosur-conicet.gob.ar], Instituto Geol & oacute;gico del Sur (INGEOSUR), Universidad Nacional del Sur- Consejo Nacional de Investigaciones Cient & iacute;ficas y T & eacute;cnicas (CONICET), Av. Alem 1253, cuerpo B ', 1 degrees Piso, B8000CPB Bah & iacute;a Blanca, Buenos Aires, Argentina; Departamento de Geolog & iacute;a, Universidad Nacional del Sur (UNS), Av. Alem 1253, cuerpo B', 2.degrees Piso, B8000CPB Bah & iacute;a Blanca, Buenos Aires, Argentina; Marcelo A. Mart & iacute;nez [martinez@criba.edu.ar], Instituto Geol & oacute;gico del Sur (INGEOSUR), Universidad Nacional del Sur- Consejo Nacional de Investigaciones Cient & iacute;ficas y T & eacute;cnicas (CONICET), Av. Alem 1253, Cuerpo B ', B8000CPB Bah & iacute;a Blanca, Buenos Aires, Argentina; Departamento de Geolog & iacute;a, Universidad Nacional del Sur (UNS), Av. Alem 1253, cuerpo B', 2.degrees Piso, B8000CPB Bah & iacute;a Blanca, Buenos Aires, Argentina; Daniela E. Olivera [daniela.olivera@uns.edu.ar], Shandong Provincial Key Laboratory of Depositional Mineralization and Sedimentary Minerals, Shandong University of Science and Technology. Qianwangang Road 579, 266590 Qingdao, Shandong Province, PR China.
The camenellan tommotiid Kennardia (Family Kennardiidae) is a relatively rare, poorly known early Cambrian taxon endemic to East Gondwana, characterized by sclerites with an external ornament of strong concentric ribs, but generally lacking or having weakly expressed radial folds, plicae or ribs that occur in other kennardiid taxa. Here we describe distinctive sclerite types of two Kennardia species with mutually exclusive stratigraphic ranges recovered from carbonates in the Hawker Group (Arrowie Basin) and the biohermal Koolywurtie Limestone Member of the Parara Limestone (western Stansbury Basin), South Australia. Isolated sclerite types have distinctive morphology and micro-ornament that enable recognition of the type species Kennardia reticulata, which occurs in strata equivalent to the Kulparina rostrata to Micrina etheridgei biozones (Cambrian Series 2, Stage 3) in the Arrowie Basin of South Australia and the Amadeus Basin in the Northern Territory. Kennardia reticulata is characterized by three more or less coniform sclerite types including a symmetrical A-type sclerite and two asymmetrical B- and C-type sclerites each with two subtypes (B1, B2, C1, C2). All sclerites have a characteristic very fine, nearly equidimensional reticulate micro-ornament. A new species, Kennardia tepperi sp. nov., is restricted to the Dailyatia odyssei Zone (Cambrian Series 2, Stages 3-4) in the Arrowie and Stansbury basins, South Australia. Kennardia tepperi has two subtypes (A1, A2) of the symmetrical A-type sclerite, and two asymmetric types (B and C) sclerites with no subtypes. The new species is distinguished by a micro-ornament consisting of a reticulated ornament superimposed on small sharply pointed pustules on concentric ribs and inter-rib grooves.Glenn A. Brock* [glenn.brock@mq.edu.au], School of Natural Sciences, Macquarie University, New South Wales, Australia; Marissa J. Betts [marissa.betts@une.edu.au] Palaeoscience Research Centre, School of Environmental and Rural Science, University of New England, Armidale, New South Wales 2351, Australia; Timothy P. Topper [timothy.topper@nwu.edu.cn] State Key Laboratory of Continental Evolution and Early Life, Shaanxi Key Laboratory of Early Life and Environments Department of Geology, Northwest University, Xi'an 710069, PR China and Department of Palaeobiology, Swedish Museum of Natural History, Box 50007, SE-10405 Stockholm, Sweden; Sarah M. Jacquet [jacquets@missouri.edu], Department of Geological Sciences, University of Missouri, Columbia, MO 65211, USA; John R. Paterson [jpater20@une.edu.au] Palaeoscience Research Centre, School of Environmental and Rural Science, University of New England, Armidale, New South Wales 2351, Australia.
