Comprehensive database on Induan (Lower Triassic) to Sinemurian (Lower Jurassic) marine bivalve genera and their paleobiogeographic record
Marine bivalve genera that were described or mentioned for Triassic and Lower Jurassic deposits worldwide are reviewed in terms of their validity, stratigraphic range, paleogeographic distribution, paleoautoecology and shell mineralogy. Data were originally compiled at species level and are arranged systematically. A brief discussion for each genus includes synonymy, taxonomic status and included subgenera, as well as current uncertainties about their validity and range. The distribution of each genus is also shown on paleogeographic maps. Type species and first and last appearances of each genus are also mentioned. We recognize as valid 280 genera and their included subgenera, and we furth…
Nomenclatural revision concerning some genera of the Order Trigoniida (Bivalvia)
The authors have become aware of a couple of nomenclatural conflicts involving Mesozoic trigoniid genera, which are in need of clarification and proposal of replacement names: The case of Protrigonia. The subgenus Trigonia (Protrigonia) Guo, 1985 (p. 204, 269; type species Trigonia (Protrigonia) yunnanensis Guo, 1985), was proposed to encompass those species referred to the genus Trigonia which, according to that author, have small and nearly smooth shells and relatively weak teeth. Guo (1985) also included other Triassic species: Trigonia gaytani (von Klipstein, 1843) and Trigonia zlambachiensis Haas, 1909. According to Fang et al. (2009, p. 55) there was a wrong translation from the Chine…
Biotic recovery after the end-Triassic extinction event: Evidence from marine bivalves of the Neuquén Basin, Argentina
We analyze the Late Triassic extinction and Early Jurassic recovery of bivalve faunas within marine environments in the Atuel River area of the Neuquén Basin, Argentina. Data were collected from a hundred samples with invertebrates in a well-exposed uppermost Triassic to lower Jurassic section in the Neuquén Basin (southern Mendoza Province, Argentina) and allow a high-resolution reconstruction of the local diversity dynamics. The nearly continuous presence of marine stenohaline major taxa such as cnidarians, rhynchonelliform brachiopods, echinoderms and cephalopods indicates normal salinity throughout. All bivalve species were identified, and each occurrence was recorded in meters above th…
De extinción en extinción: la vida se reinventa una y otra vez
Episodios de extinción y recuperación que afectaron el desarrollo de la vida en la Tierra, cada uno extendido por lapsos de millones de años, más largos que la historia completa de la especie humana. Se ilustran mediante ejemplos del registro fósil marino del Mesozoico temprano, centrándonos en los invertebrados marinos del tiempo que transcurrió entre el fin del Pérmico y el del Jurásico temprano, es decir, entre hace unos 252 y 174 Ma. Los fósiles encontrados en el actual territorio argentino, en sitios que entonces estuvieron bajo el mar, aportan información útil para analizar este lapso de tiempo que contiene dos de las grandes extinciones señaladas y también una menor.
Population response during an Oceanic Anoxic Event: The case of Posidonotis (Bivalvia) from the Lower Jurassic of the Neuquén Basin, Argentina
Benthonic marine species show a wide range of biological reactions to seawater chemical changes through time, from subtle adjustments to extinction. The Early Toarcian Oceanic Anoxic Event (T-OAE) was recently recognized in the Neuquén Basin, Argentina, confirming its global scope. The event was identified chemostratigraphically on the basis of a relative increase in marine organic carbon and a characteristic negative carbon-isotope excursion (δ13Corg) in bulk rock and fossil wood in the upper Pliensbachian–lower Toarcian interval in the Arroyo Lapa section (Neuquén). Simultaneously with collection of lithological samples, a high-resolution biostratigraphical survey was carried out, and the…
Dinámica de la paleodiversidad de los Bivalvos del Triásico y Jurásico Inferior.
Los bivalvos son un grupo de invertebrados muy utilizado para el estudio de dinámicas evolutivas, dado que su concha los hace buenos candidatos para la fosilización y son abundantes en el registro fósil. El objetivo de esta tesis es el estudio de la paleodiversidad genérica de los bivalvos marinos en el intervalo Induense (Triásico Inferior) - Sinemuriense (Jurásico Inferior) [In-Sin], que comienza con la recuperación de la extinción del límite Pérmico - Triásico (P/T) y termina con la recuperación de la extinción del Triásico - Jurásico (T/J).En primer lugar, se han eliminado, en la medida de lo posible, los errores de la práctica taxonómica mediante la elaboración crítica de una base de d…
Parainoceramyan. gen. forParainoceramusCox, 1954 (exVoronetz, 1936)partim(Bivalvia, Jurassic)
Several Jurassic pterioid bivalve species have been referred to Parainoceramus Cox by different authors, yet this has proved inadequate because the meaning of such genus has been compounded by nomenclatural and idiomatic problems, as well as misinterpretations. Hence, the new genus Parainoceramya is here proposed to accommodate several species previously referred to Parainoceramus, with Crenatula ventricosa J. de C. Sowerby as its type. Permian species originally assigned to Parainoceramus, including the type species, are referred to the genus Kolymia Likharev. All species attributed to Parainoceramus s.l. are reviewed and the new genus is compared with related genera. As here understood, t…