First record of the fossil bee nest Elipsoideichnus meyeri from Argentina (Colón, Entre Ríos province)

CÓNSOLLE-GONELLA, C.; VERDE, M.; DE VALAIS, S. ; APESTEGUÍA, S.; DÍAZ-MARTÍNEZ, I.; GALLINA, P.A.; GIANECHINI, F.A.; CITTON, P.; ACEÑOLAZA, F.G.

Serie Correlación Geológica INSUGEO

INSUGEO - Universidad Nacional de Tucumán

Año: 2023 vol. 38 p. 5 - 17

1514-4186

We present the first record of the trace fossil Elipsoideichnus meyeri Roselli, 1987, from outcrops of the Prefectura Naval Argentina quarry, Parque Nacional El Palmar, Colón (Entre Ríos province), Argentina. E. meyeri consists of a singular helicoidal fossil bee nest, to date only recorded from the Asencio Formation (Norte Basin) of southwestern Uruguay. The new specimen came from rocks traditionally assigned to the Puerto Yeruá Formation (Chaco Paraná Basin), considered Upper Cretaceous in age based on paleontological content of correlative strata in the area, composed of dinosaur and plant remains. However, the most reliable stratigraphic framework for the studied locality should keep the lithostratigraphic names of the Norte Basin of Uruguay, being the main argument for the presence of a regional unconformity between Guichón and Mercedes formations, which precludes the assignment of this new record to the Puerto Yeruá Formation. Observed facies and this new record itself allowed the preliminary assignation of Prefectura Naval Argentina E. meyeri-hosting strata to the Asencio Formation, which is reinforced by the record presented here itself due to there are no taphonomic evidence supporting significant transport horizontally or vertically. About the chronostratigraphic assignment of this record, there are no concluding elements to locate it within the Upper Cretaceous or Eocene, being a matter of fact and still in flux. This record expands the geographical distribution of this ichnotaxon, allowing the development of further research in this area and, re-opening questions related to the palaeobiology and chronostratigraphy of ancient bees in this area of southern South America.