Abstract The Chaco Region is the third biogeographic and morpho-structural territory of South America after the Amazon and Cerrado savannahs. This region is one of the few areas in the world where the transition from the tropics to temperate zones does not consist of a desert but of semi-arid woodlands and savannahs. The modern biodiversity patterns of the region were severely affected by the climatic and environmental changes that occurred during the Quaternary. Remains of an extinct megamammal Neosclerocalyptus sp. (Upper Pleistocene) and charred fossil woods inside of sedimentary nodules, was recently discovered in Chaco Argentina. The aim of paper is the paleoenvironmental reconstruction of quaternary sedimentation in the western Chaco through the taxonomic identification of charred woods and siliceous microfossils analysis. Twenty-three charcoal fragments related to Anacardiaceae, Apocynaceae, Fabaceae, Rhamnaceae and Malvaceae were identified. The phytolith analysis showed that Poaceae elements were the most abundant compared to the other herbaceous and non-herbaceous elements, along with algae and sponge microfossils. Eco-anatomic features of the charcoals and the microfossil remains suggest that environment and climate conditions existed in the area during the Upper Pleistocene were similar to the current one. Finally, the results reveal the presence of natural wildfires during the Quaternary in the region.

中文翻译：

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与 Neosclerocalyptus sp. 相关的烧焦的木材和植物微遗骸。(Cingulata, Chlamyphoriidae, Glyptodontinae) 来自阿根廷西查科上更新世

摘要 查科地区是南美洲继亚马逊和塞拉多大草原之后的第三个生物地理和形态结构领地。该地区是世界上为数不多的从热带过渡到温带的地区之一，不是沙漠，而是半干旱林地和大草原。该地区现代生物多样性格局受到第四纪气候和环境变化的严重影响。已灭绝的巨型哺乳动物 Neosclerocalyptus sp. 的遗骸。（上更新世）和沉积结核内的烧焦化石木材，最近在阿根廷查科发现。论文的目的是通过烧焦木材的分类学鉴定和硅质微化石分析，重建查科西部第四纪沉积的古环境。鉴定出与漆树科、夹竹桃科、豆科、鼠李科和锦葵科有关的二十三个木炭碎片。植硅体分析表明，与其他草本和非草本元素​​以及藻类和海绵微化石相比，禾本科元素最丰富。木炭和微化石遗骸的生态解剖特征表明，该地区在上更新世时期存在的环境和气候条件与当前相似。最后，结果揭示了该地区第四纪期间自然野火的存在。以及藻类和海绵微化石。木炭和微化石遗骸的生态解剖特征表明，该地区在上更新世时期存在的环境和气候条件与当前相似。最后，结果揭示了该地区第四纪期间自然野火的存在。以及藻类和海绵微化石。木炭和微化石遗骸的生态解剖特征表明，该地区在上更新世时期存在的环境和气候条件与当前相似。最后，结果揭示了该地区第四纪期间自然野火的存在。