Fishes from the marine and continental miocene in Entre Ríos, central eastern Argentina

La diversa fauna neógena que se registra en los acantilados orientales del río Paraná cerca de la ciudad de Paraná, Entre Ríos es conocida desde la mitad del siglo XIX. Muchos vertebrados de agua dulce, marinos y terrestres se han colectado allí. La mayoría de los fósiles miocenos viene de la parte superior de la Formación Paraná (taxones marinos y dulceacuícolas) y de la base de la suprayacente y continental Formación Ituzaingó (“Conglomerado osífero”) (taxones dulceacuícolas, terrestres y marinos retrabajados). De acuerdo a los vertebrados, las temperaturas marinas durante la depositación de la Formación Paraná eran similares a aquéllas presentes actualmente en la costa atlántica a la latitud de Paraná. La fauna de agua dulce del “Conglomerado osífero” sugiere un clima más cálido que el presente e importantes conexiones biogeográficas con cuencas norteñas de América del Sur. Durante los últimos años, los afloramientos fueron intensamente explorados. Algunos de los nuevos reportes incluyen el primer registro de caraciformes cinodóntidos para el área, el descubrimiento del grupo hermano de las pirañas (Megapiranha paranensis), el primer registro en el área del tiburón escielorrínido Megascyliorhinus, el registro más antiguo de especies con dientes aserrados del género de tiburón lámnido Carcharodon y una ballena balenoptérida atacada por el tiburón lámnido Carcharodon plicatilis. Finalmente, enfatizamos en que varios de los géneros miocenos de peces de agua dulce y marinos se han extinguido y que varias pseudoextinciones no pueden explicarse por causas climáticas o tectónicas.Fishes of the marine and continental Miocene of Entre Ríos, eastern central Argentina. The diverse Neogene fauna collected in the cliffs exposed along the left bank of the Paraná River near the city of Paraná, Entre Ríos Province, Argentina, has been scientifically known since the middle of the 19th century. Many freshwater, marine, and terrestrial vertebrates were recorded therein. Most of the Miocene fossils come from the upper part of the Paraná Formation (marine and some freshwater taxa) and the base of the overlying continental Ituzaingó Formation (“Conglomerado osífero”) (freshwater, terrestrial, and reworked marine taxa). According to fish and cetacean evidence marine temperatures during the deposition of the upper part of the Paraná Formation were similar to those recorded in the Atlantic coast at the same latitude today. The freshwater fauna of the “Conglomerado osífero” suggests a climate warmer than present and important basin connections with northern South American basins. Recent intense survey of the outcrops has given new information about the icthtyofauna that occupied the Paranian Sea and the subsequent freshwater basins in the area. Some new reports include the first occurrence of cynodontid characifoms and the scyliorhinid shark Megascyliorhinus in the area, the discovery of the sister group of piranhas (Megapiranha paranensis), the oldest occurrence in the Atlantic of serrated species of the lamnid shark genus Carcharodon, and a balaenopterid whale attacked by the shark Carcharodon plicatilis. We found that there are several extinctions of the freshwater and marine Miocene genera and pseudoextinctions that cannot be explained by climatic or tectonic causes.Fil: Cione, Alberto Luis. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Departamento Científico de Paleontología de Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cabrera, Daniel Alfredo. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Departamento Científico de Paleontología de Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Azpelicueta, Maria de Las M.. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Zoología de Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Casciotta, Jorge R.. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Zoología de Vertebrados; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; ArgentinaFil: Barla, María Julia. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; Argentin

Oldest Known Eucalyptus Macrofossils Are from South America

The evolutionary history of Eucalyptus and the eucalypts, the larger clade of seven genera including Eucalyptus that today have a natural distribution almost exclusively in Australasia, is poorly documented from the fossil record. Little physical evidence exists bearing on the ancient geographical distributions or morphologies of plants within the clade. Herein, we introduce fossil material of Eucalyptus from the early Eocene (ca. 51.9 Ma) Laguna del Hunco paleoflora of Chubut Province, Argentina; specimens include multiple leaves, infructescences, and dispersed capsules, several flower buds, and a single flower. Morphological similarities that relate the fossils to extant eucalypts include leaf shape, venation, and epidermal oil glands; infructescence structure; valvate capsulate fruits; and operculate flower buds. The presence of a staminophore scar on the fruits links them to Eucalyptus, and the presence of a transverse scar on the flower buds indicates a relationship to Eucalyptus subgenus Symphyomyrtus. Phylogenetic analyses of morphological data alone and combined with aligned sequence data from a prior study including 16 extant eucalypts, one outgroup, and a terminal representing the fossils indicate that the fossils are nested within Eucalyptus. These are the only illustrated Eucalyptus fossils that are definitively Eocene in age, and the only conclusively identified extant or fossil eucalypts naturally occurring outside of Australasia and adjacent Mindanao. Thus, these fossils indicate that the evolution of the eucalypt group is not constrained to a single region. Moreover, they strengthen the taxonomic connections between the Laguna del Hunco paleoflora and extant subtropical and tropical Australasia, one of the three major ecologic-geographic elements of the Laguna del Hunco paleoflora. The age and affinities of the fossils also indicate that Eucalyptus subgenus Symphyomyrtus is older than previously supposed. Paleoecological data indicate that the Patagonian Eucalyptus dominated volcanically disturbed areas adjacent to standing rainforest surrounding an Eocene caldera lake

Correction of the spelling of Trichomycterus eichhorniarum Miranda Ribeiro, 1912 (Siluriformes: Trichomycteridae)

Miranda Ribeiro (1912) described Trichomycterus eichorniarum based on specimens caught between the pseudo-rhizomes of the water hyacinth Eichhornia azurea and named the species referring to this circumstance. In the description he missed an ‘h’ in both, the specific name and the provided reference to ‘Eichornea’. The latter is an orthographical variant of this generic name that should be “corrected to the validly published form of that name” according to Article 61.4 of the International Code of Nomenclature for Algae, Fungi, and Plants (Melbourne Code) (McNeill 2012).Fil: Koerber, Stefan. Friesenstr. 11. 45476 Muelheim; AlemaniaFil: Azpelicueta, Maria de Las M.. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; Argentin

Hemigrammus tridens Eigenmann (Characiformes, Characidae): First records of a small tetra from the Paraná River basin

Hemigrammus tridens is a small characid described by Eigenmann (in Eigenmann & Ogle, 1907) from Paraguay River, in the country Paraguay. The species has a conspicuous trident-shaped caudal spot, few perforated lateral line scales, scales on the caudal fin, and two pentacuspidate teeth in the outer series of the premaxilla. Hemigrammus tridens is found in the Paraná River basin of both, Argentina and Paraguay. The records from Argentina are the first for this species in the country. Comments on the type series are added.Fil: Azpelicueta, Maria de Las M.. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Zoología de Vertebrados; ArgentinaFil: Koerber, Stefan. Universitat Dusseldorf; Alemani

First record of Pimelodella mucosa Eigenmann & Ward, 1907 (Siluriformes: Heptapteridae) in Formosa, Argentina and comments on the geographical distribution of P. howesi Fowler, 1940

The examination of the specimens re­cord­ed as Pimelodella howesi in Argentina reveals a misidentification that allow us to confirm the presence of Pimelodella mucosa for first time in the country.Fil: Aguilera, Gaston. Consejo Nacional de Investigaciones Científico y Técnicas. Centro Científico Tecnológico Tucumán. Unidad Ejecutora Lillo; Argentina. Fundación Miguel Lillo; ArgentinaFil: Azpelicueta, Maria de Las M.. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Zoología de Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

First record of the hypoptopomatine genus Eurycheilichthys Reis & Schaefer, 1993 (Siluriformes, Loricariidae) from Argentina

The hypoptopomatine genus Eurycheilichthys was so far considered to be endemic to the South of Brazil. One of its species, E. pantherinus, was described from the upper Uruguay river basin. We inform about the finding of this species within the Garibaldi creek, headwater of the arroyo Yabotí Guazú. This is the first record for Argentina which is found in a tributary of the middle Uruguay river.Fil: Azpelicueta, Maria de Las M.. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; ArgentinaFil: Koerber, Stefan. Friesenstraße 11.; Alemani