Devonian to Triassic paleobotanical record from Chile: An overview of the micro- and macrofossil record and fossil localities

Abstract

Late Paleozoic to early Mesozoic floras are well represented in Chile by several continental fossiliferous outcrops across the country. The oldest floras are Late Devonian in age, and they are mostly located in northern Chile (e.g., El Toco, Arrayán, Las Placetas formations) and are dominated by herbaceous lycopsids. In turn, Middle to Late Triassic floras are widely distributed throughout Chile (e.g., Mamiña, La Ternera, San Felix, Las Breas, El Puquén, Santa Juana, and Panguipulli formations), and are characterized by typical Triassic Gondwanan taxa, such as the ferns Asterotheca, Cladophlebis and Dictyophyllum; the sphenophyte Neocalamites; the corystosperm Dicroidium; the cycadophytes Pterophyllum, and Pseudoctenis; the ginkgophytes Baiera, Sphenobaiera and Ginkgoites; the conifer Heidiphyllum, and gymnosperms of uncertain affinities (i.e., Linguifolium and Taeniopteris). Lycophytes are hitherto unknown in the Chilean Triassic macrofloras. A single fossil locality has been regarded tentatively as Early Triassic in age based on palynomorphs. Most of the Devonian to Triassic plants found in Chile are preserved as impressions, lacking organic matter. However, some adpression plant fossils and palynomorphs have also been found. Fossil woods have been reported from several Triassic sediments of Chile, especially in the northern part of the country. The plant fossil record from Chile is relevant for understanding the dynamics and evolution of the late Paleozoic to early Mesozoic vegetation in the southwestern edge of Gondwana. This contribution provides a general framework that will support future and more detailed paleobotanical studies in Chile. Lastly, this work intents to motivate new generations of paleobotanists in Chile.