The Pliocene Tartaro Formation in Central Luzon Basin is described as a fossiliferous shallow marine sedimentary unit in the eastern portion of the basin, coeval with the Cataguintingan Formation on the west (MGB, 2010). In the study of Kase and Aguilar (2006), the formation is described to represent an intertidal and subtidal, shallow marine setting, based on its sedimentary features and fossil content. It is composed of gently dipping beds of clayey sandstones and sandy siltstones, with high abundance of mollusks, corals, and benthic foraminifera. The fossil specimens collected in a locality in the middle section of the Madlum River succession were described as not only abundant, but also highly diverse with exquisite preservation. A recent palaeoichthyological study conducted by Mediodia et al. (2024) identified fossilized fish remains such as otoliths, vertebrae, and teeth. These fossilized fish remains are the subject of ongoing studies in Tartaro Formation. One of the microfossils commonly observed in Tartaro Formation are ostracods. Ostracods, similar to benthic foraminifera, are proven to be useful bioindicators for environmental studies by understanding their community structure (Paphavasit & Karnchana, 1979). Ostracods are bivalved microcrustaceans from the Phylum Arthropoda, Subphylum Crustacea, and Class Ostracoda (Moore, Lalicker, and Fischer, 1952), with the marine exclusive taxa from the Subclass Myodocopa (Rodriguez-Lazaro and Ruiz-Muñoz, 2012). They are abundant even in small amount of sediment sample, and provide precise species-level determination due to their unique morphology and carapace (shell) surface ornamentations. Because of their calcified carapace, ostracods are well-represented in the fossil record. Described as the most complex metazoans used in the field of micropaleontology (University College London [UCL], 2020), the scarcity in the studies of ostracods opens an avenue for further paleontological research in the country. This research aims to describe, for the first time, the fossil ostracods of the Pliocene Tartaro Formation, and the implication/s of their assemblage and distribution.
This research addresses the UN Sustainable Goals for Life Below Water (SDG 14).
Cover photo: Schudack U.& Schudack, M., 2009. Ostracod biostratigraphy on the Lower Cretaceous of the Iberian chain (eastern Spain). Journal of Iberian Geology 35 (2) 2009: 141 – 168.
