The impact of plant functional group and depositional environment on preservation quality of Eurasian Cenozoic palaeofloras

Leaf traits describe the morphological, chemical and physiological properties of a plant's leaves. Some of these traits may be preserved in the fossil record, providing us with valuable information about the plant itself and the palaeoecosystem it lived in. Here, seven different palaeofloras from Eurasia were analysed, ranging from mid-Oligocene (ca 30 Ma) to upper Miocene (ca 7 Ma) to examine which traits are best preserved across these environments. The quality of preservation was assessed across the different palaeofloras and plant functional groups using the Taphonomic Completeness Score (sensu O'Rourke et al. 2026). Furthermore, ordination was conducted to illustrate the multivariate leaf trait space. Our results show that woody angiosperms were the dominant plant group in most sites, whereas ferns and gymnosperms were generally less common and herbaceous angiosperms were exceptionally rare. Preservation quality varied among both plant functional groups and palaeofloras. Multivariate analysis of leaf trait space revealed only minor differences between the palaeofloras, supporting the idea of a rather homogenous European flora in the mid-Cenozoic. On the contrary, leaf traits differed among plant functional groups with conifers, ferns and grasses occupying distinct trait spaces, showing little or no overlap with woody angiosperms. This study extends on the functionality of the Taphonomic Completeness Score for broad-scale application to palaeofloras of various times and taxonomic compositions.