![]() ![]() ![]() These materials are stored at the collection of Invertebrate Paleontology of the Miguel Lillo Institute (PIL). Two fossilized specimens have been studied attributed to burrowing anemones, in which details of its external and internal morphology and its respective structures of bioturbation can be observed. An actualized condensed version about the bioestratigraphic aspects can be found in detail in Césari et al. The paleontological and geological aspects of the Leoncito Formation have been studied mainly by Keidel and Harrington (1938), Baldis (1964), Lech (1986a-b, 1989), López Gamundi and Alonso (1982), and López Gamundi and Rosello (1995). Intercalation of sandstone and lutyte, 6. Geological map of the Leoncito Formation in the hamlet of Leoncito Encima: 1. Location of the outcrop of the Leoncito Formation with fossils, Leoncito Encima, San Juan, Argentina. Throughout this work, the knowledge about this group of organisms is enlarged by identifying the internal morphological characteristics of the fossilized specimens found in the Leoncito Formation (late Lower Carboniferous early Upper Carboniferous) appearing on the southeast of the city of Barreal, San Juan province, Argentina ( Figure 1.A).įigure 1. The latter, unlike the sea anemones, present various complete mesenteries and only one siphonoglyph they have a stretched body and are adapted to living in tubes produced by them either on the sand or on the mud. Other anthozoans similar to the actiniarians are the ceriantharians. Internally, they show even mesenteries, either complete or incomplete, in hexamerous cycles and normally two siphonoglyphs. The body of the burrowing anemones can be divided in three sections (capitulum, scapus and physa). The tentacles can be organized in different rings around the mouth or they can round off the oral surface completely. They own a pedal disc with which they fix to hard objects, or their base is modified to drill the soft substrate of the sea floor. They are solitary organisms that lack hard parts, which present only the poly phase in their life cycle. These belong to the actiniarians group, anthozoan cnidaria commonly called sea anemone. The fossil specimens here studied are similar in its external and internal morphology to burrowing anemones. Palaeoanemone belongs to a rare case of fossilization of a solitary polyp of anthozoan cnidaria, in which it was possible to identify numerous anatomical features, as well as traces of its activity in the sediment. Palabras clave: Cnidaria Actiniaria Morfología Interna Carbonífero Argentina.Ī review of the actiniarian: Palaeoanemona marcusi, previously described by Lech (1986b) for carboniferous marine rocks of San Juan, Argentina, allowed for the recognition of part of the internal morphological characters, not observed before. El conocimiento anatómico que se tiene de la morfología de este género es ampliado al describirse detalles de las paredes de su cuerpo, peristoma y faringe, así como mesenterio y tentáculos. Palaeoanemone es un caso excepcional de fosilización de estos organismos en el que se preservo parte de su morfología tanto externa como interna. Las rocas del Carbonífero marino de Argentina presentes numerosas asociaciones de invertebrados entre los que se puede encontrar anémonas cavadoras como así también rastros de su actividad biológica. ![]() Resumen: Morfología interna de Palaeoanemone (Cnidaria: Actinaria): anémona cavadora del Carbonífero de la Argentina. Key words: Cnidaria Actiniaria Inner Morphology Carboniferous Argentina. The anatomical knowledge that is known about the morphology of this genus is enlarged by observing details of the walls of their body, peristome and pharynx, as well as mesenteries and tentacles. Palaeoanemone is an exceptional case of fossilization of these organisms, preserving its morphology both external and internal. E-mail: The rocks of marine carboniferous of Argentina present numerous associations of invertebrates, among which can be found burrowing anemones and also traces of its biological activity. Inner morphology of Palaeoanemone (Cnidaria: Actiniaria): a burrowing anemone of the Carboniferous of ArgentinaġCentro Nacional Patagónico-CONICET, Brown 2915, (9120) Puerto Madryn, Chubut, Argentina.
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