Resumen de Dactyloidites ottoi en depósitos marinos someros de la Formación Coris, Mioceno, Costa Rica
- español
Las trazas de Dactyloidites ottoi, asociadas a facies de areniscas silíceas, de grano medio, limpias, con laminaciones paralelas planas y curvas y laminación inclinada HCS se desarrollaron en ambientes someros (upper shoreface), de la Formación Coris (Mioceno). Fueron condiciones de alta energía generadas por olas, tormentas, corrientes y mareas. Sedimentación episódica con eventos erosivos de alta energía por tormentas y depositación de baja energía con aporte de materia orgánica favorecieron el retrabajo del sedimento. Estos icnofósiles no son frecuentes en el registro sedimentario y no habían sido reportados en Costa Rica. Están constituidos por varios elementos elongados que salen radialmente de un conducto central y conforman series de galerías superpuestas en forma de abanico o roseta. Aunque no se conoce el productor, diferentes estudios coinciden en que es una traza de alimentación tipo fodicnia producida por un organismo vermiforme que forma parte de la icnofacies Cruziana.
- English
Dactyloidites ottoi traces associated with medium grained, mature, siliceous sandstone facies, with planar and curved parallel lamination and HCS cross laminations were developed in shallow marine environments (upper shoreface) of the Coris For-mation (Miocene). High-energy environmental conditions were caused by waves, storms, tides and currents. Episodic sedimentation with high-energy erosive events caused by storms alternating with low-energy deposition with organic matter input favored sediment rework by organisms. These ichnofossils are infrequent in the sedimentary record and they had not previously been reported in Costa Rica. They are constituted by elongated elements which radiate from a central shaft and create a series of rosetted or fan-shaped tiered galleries. The organism that created these structures is yet unknown, however, several studies coincide that it must have been a feeding fodichnia trace produced by a worm-like organism which is part of the Cruziana Icnofacies.
