Astroniumxylon, Schinopsixylon, andParametopioxylonn. gen. fossil woods from upper Cenozoic of Argentina: taxonomic revision, new taxon and new records

Abstract

This paper presents new descriptions of Anacardiaceae fossil woods from the Ituzaingó Formation (late Cenozoic) at the Toma Vieja, Curtiembre, and Arroyo El Espinillo localities, Argentina. We describe eight silicified woods assigned to four different species in three genera, one of which, Parametopioxylon crystalliferum n. gen. n. sp., is new. Similarities between these three genera and the six Anacardiaceae species previously recorded from the late Cenozoic in northeastern Argentina are investigated using multivariate analysis techniques (correspondence and cluster analysis). Our study is based on 33 characters scored for 17 fossil specimens (10 Astroniumxylon Brea, Aceñolaza, and Zucol 2001; five Schinopsixylon Lutz, 1979; and two Parametopioxylon n. gen.) and four extant species (Astronium balansae Engl., Astronium urundeuva Engl., Schinopsis balansae Engl., and Metopium sp.). Our main goal is to determine the wood anatomical features useful for distinguishing among these species. Results of the multivariate analyses support the previous classification where Schinopsixylon is distinguished from Astroniumxylon by having exclusively paratracheal axial parenchyma, ≥30% multiseriate rays, and multiseriate rays that are ≥5 cells wide and commonly 301–400 μm in height. Additionally, we propose that Schinopsixylon heckii Lutz, 1979 is synonymous with S. herbstii Lutz, 1979. A diagnostic key for the fossil species studied is given. Wood anatomy of Anacardiaceae fossil woods from Argentina (late Cenozoic) suggests a warm, dry to semi-humid climate for this region, supporting previous studies.

Tyloses in fossil plants: New data from a Mississippian tree, with a review of previous records

“…Tyloses have been documented in fossil lignophytes from the Carboniferous to the present. There are innumerable reports of tyloses in angiosperm and gymnosperm woods from the Mesozoic and Cenozoic, based on both permineralized (e.g., Medlyn and Tidwell 1975;Wheeler and Manchester 2002;Wei et al 2019;Franco et al 2020;Oh et al 2020) and anthracological specimens, including subfossils from archaeological sites (e.g., Dufraisse et al 2018). Here, we will focus on the oldest documented evidence of tyloses in extant groups and their occurrence in key extinct groups.…”

Fossil woods from Argentina (1884–2021)

“…The records are distributed through all the periods/epochs, but most of them are from the Cenozoic (57 %). Particularly, Pliocene and Pleistocene have more records per Ma, a consequence of the numerous studies of the Entre Ríos Province (e.g., Franco et al 2020).…”

Registro Paleobotánico Del Plio–pleistoceno Inferior en El Valle Del Río Uruguay. Caracterización Fitolítica De La Formación San Salvador, Este De La Provincia De Entre Ríos, Argentina.

“…Los conocimientos paleobotánicos del Cenozoico tardío de Entre Ríos abarcan estudios de maderas fósiles y fitolitos de la región litoral Argentina, en diversas localidades y diferentes unidades formacionales; los cuales se han realizado en sedimentos desde el Mioceno tardío hasta el Holoceno, con contribuciones en la cuenca del río Paraná para el Mioceno tardío (Formación Paraná;Zucol y Brea, 2000;Brea et al, 2001Brea et al, , 2012Franco y Brea, 2008), el Mioceno-Pleistoceno (Formación Ituzaingó;Brea y Zucol, 2007;Franco, 2009Franco, , 2010Franco, , 2011Franco, , 2012Franco, , 2014Franco, , 2017Franco y Brea, 2010, 2015Brea et al, 2013;Franco et al, 2019) y el Pleistoceno Tardío (Formación Salto Ander Egg; Patterer, 2017). Mientras que para la cuenca del río Gualeguay, el Pleistoceno Superior ha sido estudiado en la Formación Arroyo Feliciano , 2018Zucol et al, 2016) y en la del río Uruguay los registros abarcan el Plioceno-Pleistoceno Inferior (con la Formación San Salvador; Patterer et al, 2012;Patterer, 2015), el Pleistoceno Tardío (Formación El Palmar; Brea, 1998Brea, , 1999Zucol et al, 2005;Brea et al, 2010;Brea y Zucol, 2011;Patterer, 2012;Patterer et al, 2012Patterer et al, , 2014Patterer et al, , 2020Ramos et al, 2012Ramos et al, , 2014Ramos et al, , 2015Ramos et al, , 2017a…”