The study of abundant permineralized fern remains collected in the Oligocene Rancahue Formation (Neuquen Province, Argentina) allowed the identification of two different taxa. The name Cuyenopteris patagoniensis nov. gen., nov. sp. is proposed for several stems and fronds characterized by the presence of caulinar dictyosteles with root gaps, producing C-shaped leaf traces composed by two hippocampiform bundles flanked by eight to ten small round bundles, half of them diverging from cauline meristeles and the rest from the hippocampiform bundles. The presence of these features, along with frond bases with adaxial grooves and a pair of pneumatophores, suggest affinities with the Blechnaceae or Dryopteridaceae. The second identified taxon is Alsophilocaulis calveloi Menendez. Based on features observed in these new materials, including characteristics of the mantle of adventitious roots and anatomy of the petiole bases, an emended diagnosis for this latter species is proposed.

中文翻译：

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来自 Rancahué 地层的渐新世蕨类植物（Aluminé，Neuquén，阿根廷）：Cuyenopteris patagoniensis nov. 将军，十一月 sp. （Polypodiales：Blechnaceae/Dryopteridaceae）和Alsophilocaulis calveloi Menéndez。维拉（Cyatheales：Cyatheaceae）

对在渐新世 Rancahue 组（阿根廷内乌肯省）中收集的大量透矿化蕨类植物遗骸的研究允许鉴定两种不同的分类群。Cuyenopteris patagoniensis nov。将军，十一月 sp. 建议用于几种茎和叶，其特征在于存在具有根间隙的茎状叶状茎，产生由两个海马状束组成的 C 形叶迹，两侧是 8 到 10 个小圆束，其中一半从茎状分生组织分出，其余的从茎分生组织分生出来海马束。这些特征的存在，连同带有正面凹槽的叶状基部和一对气孔，表明与 Blechnaceae 或 Dryopteridaceae 有亲缘关系。第二个确定的分类单元是Alsophilocaulis calveloi Menendez。基于在这些新材料中观察到的特征，