Cretaceous spreite-dominated ichnoassemblages in Antarctica.
Daniel Sedorko1,2, Carolina Gutiérrez3, Pablo J Pazos3
1Universidade Federal do Rio de Janeiro, Museu Nacional, Departamento de Geologia e Paleontologia, Campus de Pesquisa e Ensino, Avenida Bartolomeu de Gusmão, 875, São Cristóvão, 20941-160 Rio de Janeiro, RJ, Brazil.
Anais Da Academia Brasileira De Ciencias
|December 19, 2024
Summary
This study analyzes trace fossils from Antarctica
Area of Science:
- Paleontology
- Sedimentology
- Stratigraphy
Background:
- Trace fossils provide insights into ancient environments and organism behavior.
- Spreite trace fossils indicate specific feeding strategies and depositional conditions.
Purpose of the Study:
- To investigate ichnoassemblages dominated by spreite trace fossils.
- To determine the depositional setting and paleoenvironmental conditions of the Upper Cretaceous Snow Hill Island Formation.
- To interpret the ichnofacies and the ecological significance of the trace fossils.
Main Methods:
- Systematic description and analysis of ichnoassemblages.
- Stratigraphic logging of sedimentary successions.
- Ichnofacies analysis and interpretation of depositional environments.
Main Results:
- Dominance of spreite structures (Paradictyodora antarctica, Euflabella) suggests deposit-feeding activity.
- Euflabella's prevalence in upper levels indicates adaptation to variable food resources and a trophic generalist role.
- Ichnofauna characteristics challenge clear assignment to Phycosiphon or Rosselia ichnofacies, with evidence suggesting some freshwater influence in upper levels.
- High ichnodisparity and spreite burrows support attribution to the Cruziana ichnofacies.
Conclusions:
- The ichnoassemblages are attributed to the Cruziana ichnofacies.
- The depositional setting is interpreted as deltaic with fluctuating energy conditions.
- Trace fossil distribution provides evidence for adaptive strategies and paleoenvironmental changes.
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