Neogene Myrtaceae fossil woods from the Ituzaingó Formation, Paraná Basin, northeastern Argentina: Anatomical, systematic and palaeoenvironmental insights

Summary The Myrtaceae family is predominantly distributed in the Southern Hemisphere, in particular in Australia and South America. This study describes two fossil woods with distinctive Myrtaceae anatomy from the Late Miocene of South America. The specimens were preserved by siliceous cellular permineralization. The anatomic features of Uruguayanoxylon ragoneseae sp. nov. and U ruguayanoxylon aff. striata Bolzon & Cardoso Marchiori 2002, were described in detail. Uruguaianoxylon ragoneseae sp. nov. shows strong similarities to Myrcia DC. ex Guill., while Uruguaianoxylon aff. striata is more closely related to Blepharocalyx salicifolius (Kunth) O. Ber. The presence of Myrtaceae fossil woods in the Miocene sediments of Entre Ríos, Argentina, expands our understanding of their evolutionary history and palaeobiogeography, indicating wider historical distributions potentially linked to humid or seasonally dry tropical and subtropical forests. These results underline the significant climatic and environmental changes that have occurred since the Miocene and have influenced the distribution and diversity of Myrtaceae species. Also, their remarkable ability to adapt to different humid conditions. This study provides new insights into the taxonomic composition of the palaeoflora in the Ituzaingó Formation from Entre Ríos Province, Argentina.