Robin Whatley (1936-2016)

Robin Charles Ignatius Whatley was born in England (Hawkhurst) on December 2nd 1936 and, being 79 years old, died in Wales on June 4th 2016. He attended the Sir Norton Knatchbull Grammar School in Ashford, Kent, and then took various jobs in farming, fishing and the National Service in the fifties. He received his higher education at the University of Hull, where he graduated with a First-class honours degree in both Geology and Zoology (1962). There, he subsequently earned a Ph.D. with an excellent Thesis on the Callovian and Oxfordian Ostracoda of England and Scotland (1965).Facultad de Ciencias Naturales y Muse

Constructional morphology of the shell/ligament system in opisthogyrate rostrate bivalves

The bivalve ligament provides the thrust for shell opening, acting as the resistance in a lever system against which adductor muscle effort is applied. Usually, its outer lamellar layer is subjected to tensile stress, while the inner fibrous layer is compressed, with the pivotal axis located between them. However, opisthogyrate rostrate bivalves display a concave dorsal margin, and both the umbo and the postero-dorsal angle of the shell project dorsally to the ligament, which then fails to act as pivotal axis. Three opisthogyrate rostrate genera of unrelated lineages show somewhat different solutions to this morpho-functional challenge. In Cuspidaria (Anomalodesmata), the ligament is internal, subjected only to compression and ventral to the pivotal axis, a thickened periostracum develops, forcing the dorsal margins of the valves to act as pivotal axis, and the posterior parts of the shell’s dorsal margins gape dorsally. In Nuculana (Palaeotaxodonta), the inner layer of the ligament is internal, the outer layer is external but reduced, and some species develop a dorsal ridge parallel to the commissural plane, on a level with the rostrum and acting as pivotal axis. In Pterotrigonia (Palaeoheterodonta) and other rostrate trigoniides, the ligament is external opisthodetic, but is allometrically reduced. Trigoniides may also develop a dorsal ridge.Facultad de Ciencias Naturales y Muse

Analisis paleodemecológico de signos de actividad de bivalvos infaunales de la Formación Mulichinco, Cretácico Inferior, Cuenca Neuquina, Argentina

El estudio de rasgos paleodemecológicos requiere de ciertas condiciones tafonómicas particulares. En la Formación Mulichinco (Valanginiano) se cumplen dichas condiciones, siendo frecuentes los signos de actividad de bivalvos excavadores que aparecen en sección transversal sobre las superficies de estratificación. Dos grupos de tales superficies fueron analizados, midiendo densidad poblacional, disposición espacial, distribución de tamaños y orientación en planta de las excavaciones. El paleoambiente se determinó por medio de un análisis sedimentológico detallado, y se registró la fauna de bivalvos presente con la intención de identificar a los potenciales productores. Se encontraron altas densidades poblacionales para ambos grupos, lo que indica condiciones físicas favorables y buen suministro de alimento, en tanto que la disposición espacial y la distribución de tamaños difiere entre dichos grupos; no se advirtió orientación preferencial en la mayoría de las superficies. El primer grupo (grupo A) muestra un patrón uniforme de disposición espacial y trazas de mayor tamaño; llama la atención la ausencia de pequeños tamaños. En el segundo grupo (grupo B), el patrón de disposición es indistinguible de uno al azar (salvo en un caso donde parece haber un patrón agregado). Se interpreta al grupo A como un conjunto de rastros de escape realizados por excavadores profundos en respuesta a depósitos de tormenta, en tanto que el grupo B es considerado como un conjunto de rastros de reposo/escape hechos por excavadores superficiales en ambientes dominados por mareas. Estudios paleodemecológicos de este tipo representan herramientas potencialmente útiles para los análisis sedimentológicos y de cuencas.The study of palaeodemecological features requires some particular taphonomic conditions. These conditions were met in the Mulichinco Formation (Valanginian), where burrowing bivalve trace fossils are widespread and often appear in cross section on bedding surfaces. Two groups of such beds were analyzed, measuring population density, spatial distribution, size distribution and horizontal orientation of the burrows. The palaeoenvironment was established by means of a detailed sedimentological analysis, and the bivalve fauna present was checked, in order to attempt identifying their potential producers. High population densities were found for both groups, indicating favourable physical conditions and good food supply, while differences in both spatial and size distributions were noticed between them; on most surfaces there was no preferred orientation. The first group (group A) showed a uniform pattern of spatial distribution and larger traces, with a remarkable absence of small sizes. In the second group (group B), the spatial distribution pattern is indistinguishable from a random distribution (except one case in which the pattern appears to be aggregated). Group A is interpreted as a set of escape traces made by deep burrowers in response to storm deposition, while group B is considered as resting/escape traces made by shallow burrowers in tide-dominated environments. Palaeodemecological studies of this kind are potentially useful tools for sedimentary and basin analyses.Fil: Echevarría, Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleozoología Invertebrados; ArgentinaFil: Damborenea, Susana Ester. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleozoología Invertebrados; ArgentinaFil: Manceñido, Miguel Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleozoología Invertebrados; Argentin

The Triassic-Jurassic boundary in the Andes of Argentina

The Arroyo Malo Formation at Alumbre Creek, on the northern bank of the Atuel River, west central Argentina, comprises a c. 300 m thick continuous marine succession across the Triassic-Jurassic System boundary, consisting of massive and laminated pelites indicative of a slope depositional environment. Late Triassic invertebrates, including ammonoids, nautiloids, bivalves, gastropods, brachiopods and corals are restricted to the lower 150 m. Beds between 125-135 m from the bottom yield Choristoceras cf. marshi Hauer, a species found in the Marshi/Crickmayi Zone of Europe and North America, together with loose fragments of Psiloceras cf. pressum Hillebrandt, coeval with the lower to middle part of the Hettangian Planorbis Zone. About 80 m higher are beds yielding Psiloceras cf. rectocostatum Hillebrandt, a species that gives name to an Andean biozone partially coeval with the Johnstoni and Plicatulum Subzones, upper Planorbis Zone. Other fossils recorded in the Rhaetian strata of this section are foraminifers, ostracods and plant remains identified as Zuberia cf. zuberi (Szaj.) Freng. and Clathropteris sp. The section was also sampled for conodonts and radiolarians, thus far with negative results. A palaeomagnetic study is underway.La Formazione Arroyo Malo ad Alumbre creek, sulla sponda settentrionale del fiume Atuel, Argentina centro-occidentale, comprende una successione marina continua spessa circa 300 m attraverso i! limite Triassico-Giurassico, ed e costituita da peliti massive e laminate indicative di un ambiente deposizionale di scarpata. Gli inverttfjrati del Ttiassico superiore, che includono ammonoidi, nautiloidi, bivalvi, gasteropodi, brachiopodi e coralli sono limitati ai primi 150 m. Gli strati fra i 125-135 m dalla base hanno dato Choristoceras cf. marshi Hauer, una specie trovata nella Zona a Marshi/Crickmayi di Europa e Nord America, insieme con frammenti sparsi di Psiloceras cf. pressum Hillebrandt, coeva con la parte mediana della Zona a Planorbis dell'Hettangiano. Circa. 80 m piu in alto ci sono strati contenenti Psiloceras cf. rectocostatum Hlllebrandt, una specie che da i! no me ad una biozona andina parzialmente coeva con le Sottózone a Johnstoni e Plicatulum, Zona a Planorbis superiore. Altri fossili documentati negli strati del Retico di questa sezione sono foraminiferi, ostracodi e resti di piante identificati come Zuberia cf. zuberi (Szaj.) Freng. e Clathropteris sp. La sezione e stata anche campionata per quanto riguarda conodonti e radiolari, finora con risultati negativi. Uno studio paleomagnetico e in corso.Fil: Riccardi, Alberto Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Departamento de Paleontología Invertebrados; ArgentinaFil: Damborenea, Susana Ester. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Departamento de Paleontología Invertebrados; ArgentinaFil: Manceñido, Miguel Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Departamento de Paleontología Invertebrados; ArgentinaFil: Iglesia Llanos, Maria Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Geología. Instituto de Geofísica "Daniel Valencio"; Argentin

Martínez Chacón, M. L. y Rivas, P. (Eds.) 2009. <i>Paleontología de Invertebrados</i> : Sociedad Española de Paleontología–Universidad de Oviedo–Universidad de Granada–Instituto Geológico y Minero de España, 524 pp.

Es innegable el rol crucial que el registro paleontologico de los invertebrados ha venido demostrando a lo largo del tiempo como herramienta fundamental para biozonaciones y correlaciones estratigraficas, para aplicaciones tafonomica, paleoecologicas y paleoambientales, asi como para otras facetas de la geologia regional), para interpretaciones paleogeograficas y biogeograficas, para elaborar esquemas filogeneticos o contrastar hipotesis macroevolutivas, sin dejar de lado el interes cultural y recreativo para el publico en general. No menos indudable es que la solidez de tales emprendimientos cientificos, academicos y/o aplicados se sustenta en el conocimiento sistematico de diversos grupos de invertebrados fosiles. En dicho contexto, encarar el proyecto de publicar un manual que proporcione una puesta al dia sobre la materia, como lo ha efectuado la Sociedad Espanola de Paleontologia, constituye una apuesta ambiciosa, especialmente frente a la mayor repercusion mediatica de ciertos vertebrados (como los dinosaurios) en el imaginario popular. El resultado de tal desafio es esta obra didactica gestada y editada esmeradamente por cuatro instituciones seneras de la paleontologia espanola. La misma se inscribe en la tradicion del clasico tratado de Paleontologia del catedratico Bermudo Melendez y viene destinada a servir de consulta obligada tanto para alumnos como para quienes se dedican a la docencia e investigacion.Facultad de Ciencias Naturales y Muse

Taxa dedicated to Alberto C. Riccardi

Dr. Alberto Riccardi has greatly impacted in the advance of palaeontological and geological knowledge in several areas of the world, particularly in LatinAmerica. As a token of appreciation to his outstanding career, contributions, and positive influence, he has been recognized in several instances with the dedication of taxa bearing his name. His former mentor, several of his former students, and colleagues are among the people that have dedicated scientific names to him. This brief contribution summarizes the taxa and the circumstances related to each genus and species dedicated to Dr. Riccardi of which the authors are aware.Fil: Macellari, Carlos E.. Repsol Exploración; EspañaFil: Damborenea, Susana Ester. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleozoología Invertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Manceñido, Miguel Oscar. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleozoología Invertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Taxa dedicated to Alberto C. Riccardi

Dr. Alberto Riccardi has greatly impacted in the advance of palaeontological and geological knowledge in several areas of the world, particularly in LatinAmerica. As a token of appreciation to his outstanding career, contributions, and positive influence, he has been recognized in several instances with the dedication of taxa bearing his name. His former mentor, several of his former students, and colleagues are among the people that have dedicated scientific names to him. This brief contribution summarizes the taxa and the circumstances related to each genus and species dedicated to Dr. Riccardi of which the authors are aware.Facultad de Ciencias Naturales y Muse

Robin Whatley (1936-2016)

Robin Charles Ignatius Whatley was born in England (Hawkhurst) on December 2nd 1936 and, being 79 years old, died in Wales on June 4th 2016. He attended the Sir Norton Knatchbull Grammar School in Ashford, Kent, and then took various jobs in farming, fishing and the National Service in the fifties. He received his higher education at the University of Hull, where he graduated with a First-class honours degree in both Geology and Zoology (1962). There, he subsequently earned a Ph.D. with an excellent Thesis on the Callovian and Oxfordian Ostracoda of England and Scotland (1965).Facultad de Ciencias Naturales y Muse

Early Jurassic trigoniides from southern South America: their recovery after extinction and its bearing on the evolution of the group

After a major reduction due to the end-Triassic extinction event (only three surviving genera according to Ros-Franch et al., 2014), the order Trigoniida (Mollusca, Bivalvia) experienced a strong diversification during the Early Jurassic. In southern basins from South America at least eleven genera were recognized between the Hettangian and the Toarcian (Leanza 1993, Pérez et al. 2008). Three of them (Trigonia, Prosogyrotrigonia and Frenguelliella) were Triassic survivors, while the other eight genera evolved during the Jurassic, with the respective oldest records for many of them occurring within these basins. The genera Groeberella, Neuquenitrigonia and Quadratojaworskiella are exclusive from South America. The possibility that Groeberella evolved from myophorid ancestors as suggested by Pérez et al. (1995) implies a fourth surviving lineage from the Triassic. Neuquenitrigonia is clearly related to the Trigonia lineage (Pérez et al. 2008). The genus Quadratojaworskiella contains only two species; certain differences between them, nevertheless, suggest relationships to different genera for each. The genus Jaworskiella includes a few species from South and North America (Poulton 1979, Leanza 1993, Pérez et al. 2008), though they might represent different offshoots from Frenguelliella, perhaps providing an example of parallel evolution. Myophorella, a widespread and conspicuous Jurassic genus, most likely evolved from some species of Jaworskiella within southern South America during the Pliensbachian. Scaphorella seems to be closely related to Myophorella. Psilotrigonia is a genus of uncertain affinities; its oldest record (the Late Sinemurian or Early Pliensbachian species P. vegaensis) is from northern Chile (Pérez et al. 2008) being found later on in North America (Poulton 1979). The list of genera is completed with Vaugonia, most likely originating in Japan during the Hettangian and subsequently arriving to South America in the late Sinemurian via North America (Poulton 1979), though a wide variety of species have been included within the genus, which deserves detailed phylogenetic revision.Facultad de Ciencias Naturales y Muse

Viviendo bajo una sombrilla: incrustantes en corales escleractinidos de fondo blando, Formación Agrio, Cretácico Inferior de la Cuenca Neuquina

En la Formación Agrio (Valanginiano˗Hauteriviano), los corales escleractínidos se encuentran circunscriptos a niveles discretos, formando comunidades generalmente de alta abundancia y baja diversidad. Una de ellas (hacia el tope de la unidad), está compuesta por colonias de Stylomaeandra Fromentel, 1877, de morfología meandroide pedunculada, correspondiente a habitantes de fondo blando. Estas colonias presentan esclerobiontes y aquí se resumen los resultados preliminares de su análisis. Se seleccionaron 22 colonias con muy buena preservación. Todas presentan esclerobiontes en la cara inferior (pared epitecal), donde se concentra el 94,33 % de los mismos, mientras que solo el 18,18 % presenta colonización de la cara superior (superficie calicinal). Asimismo, la riqueza es mayor para la cara inferior: 9 taxa vs. 4 también hallados en la cara superior, abarcando braquiópodos thecideidos, ostras, poliquetos tubícolas y briozoos ciclostomados. Sobre la cara inferior dominan tales braquiópodos. La desigual distribución y diversidad que muestran los esclerobiontes entre ambas caras de Stylomaeandra sugieren que la incrustación tuvo lugar principalmente in vivo (la cara superior portaba los pólipos). El predominio de dichos braquiópodos, contrastante con su ausencia en microhábitats similares sobre moluscosde la Formación Agrio, confirma su habitual preferencia a fijarse sobre corales modernos bajo condiciones ambientales crípticas y esciáfilas. El tamaño reducido de los corales sugiere estrés ambiental; la concentración de esclerobiontes en un microambiente críptico podría estar relacionada a esta circunstancia. Se continuará el análisis calculando otras métricas para evaluar parámetros paleoautoecológicos de Stylomaeandra (por ejemplo, capacidad de automovilidad) y elucidar posibles causas de estrés ambiental.Fil: Luci, Leticia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Garberoglio, Ricardo Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Lazo, Dario Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Manceñido, Miguel Oscar. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaReunion de Comunicaciones de la Asociacion Paleontologica ArgentinaLa PlataArgentinaAsociación Paleontológica ArgentinaFundación Mueso de La Plata "Francisco Pascasio Moreno" - Universidad Nacional de La PlataUniversidad Nacional de La Plata. Facultad de Ciencias Naturales y Muse