A Cheirolepidiaceae Frenelopsis teixeirae from the Lower Cretaceous of the Santa Susana Formation, near Torres Vedras locality (Estremadura region, western Portugal), is analyzed by means of Fourier Transform Infrared (FTIR) spectroscopy in Attenuated Total Reflection (ATR) mode at both micro and macro scales. This analytical technique (ATR-FTIR spectroscopy), which requires minimal sample preparation and a small amount of material, is used to evaluate the chemical composition of the F. teixeirae cuticles. For this, functional groups (i.e., specific groupings of atoms within molecules), that compose the complex chemical structure making up the F. teixeirae cuticles, are detected, analyzed, and interpreted from the resulting spectra. The Frenelopsis material comprises compressions of eighteen leafy axes with very well-preserved cuticles. Previously reported chemical information derived from transmission FTIR spectra of the foliar cuticle of the podocarp Squamastrobus tigrensis from the Lower Cretaceous of Argentina is used for comparison in order to assess the existence of a distinctive spectroscopic pattern for this Portuguese taxon. Semi-quantitative data derived from FTIR spectra of both fossil taxa were statistically analyzed using principal component analysis (PCA). The F. teixeirae cuticles have a lower contribution of C = O stretch and a lower degree of biopolymeric matrix cross-linking (higher CHal/C = O ratio) than those of S. tigrensis. Despite the existing differences between both conifers, spectroscopic patterns characterizing each fossil taxon are not fully distinctive from a chemotaxonomic perspective. This is mainly related to the relatively variable morphological cuticular features (e.g., trichomes) and to the biomacropolymeric chemistry among the leaves of each fossil taxon.

采用衰减全反射 (ATR) 模式下的傅里叶变换红外 (FTIR) 光谱仪，在微光和微光下，对来自托雷斯韦德拉斯地区（葡萄牙西部埃斯特雷马杜拉地区）附近白垩纪圣苏珊娜组的 Cheirolepidiaceae Frenelopsis teixeirae 进行了分析。宏观尺度。这种分析技术（ATR-FTIR 光谱）需要最少的样品制备和少量的材料，用于评估F. teixeirae角质层的化学成分。为此，从所得光谱中检测、分析和解释构成F. teixeirae角质层的复杂化学结构的官能团（即分子内原子的特定分组）。这Frenelopsis材料由十八个叶轴压缩而成，角质层保存完好。之前报道的来自阿根廷白垩纪下部罗汉松Squamastrobus tigrensis叶角质层透射 FTIR 光谱的化学信息被用于比较，以评估该葡萄牙分类群是否存在独特的光谱模式。使用主成分分析 (PCA) 对两种化石类群的 FTIR 光谱得出的半定量数据进行统计分析。与S. tigrensis相比，F . teixeirae 角质层的 C = O 拉伸贡献较低 ，生物聚合物基质交联程度较低（CHal/C  = O 比率较高） 。尽管两种针叶树之间存在差异，但从化学分类学的角度来看，表征每个化石分类群的光谱模式并不完全独特。这主要与相对可变的形态角质层特征（例如，毛状体）以及每个化石分类单元的叶子之间的生物大分子化学有关。