Abstract Stomata characteristics of two extinct conifer Cheirolepidiaceae species, Pseudofrenelopsis gansuensis and Pseudofrenelopsis dalatzensis , were used to reconstruct the atmospheric carbon dioxide concentration levels during the late Albian of the Cretaceous. A sequence of fossil samples was collected from five beds in the Dalazi Formation in the Zhixin and Luozigou basins of Jilin Province, northeastern China. The stomatal index was used to estimate the palaeo- p CO 2. The average stomatal index value of the two species was 4.1 and the atmospheric CO 2 content was c. 1200 ppmv by the average of Recent standardization and Carboniferous standardization. During the short interval from 104.8 ± 0.5 Ma to 104.0 ± 0.4 Ma in the late Albian, the atmospheric CO 2 content presents a decreasing tendency, with the highest value being c. 1300 ppmv in the Luozigou Basin. In addition, the higher atmospheric CO 2 values of the late Albian are likely linked to a ‘greenhouse climate’ during the time of Oceanic Anoxic Event 1c (OAE1c).

Abstract Non-pollen palynomorphs (NPPs) are ‘extra’ microfossils often found in palynology slides. These include remains of organisms within the size range of pollen grains ( c. 10–250 µm), resistant to laboratory treatments used for the preparation of palynological samples. NPPs are a large and taxonomically heterogeneous group of remains of organisms living in diverse environments. Taxonomically, they belong to a wide variety of groups such as cyanobacteria, algae, vascular plants, invertebrates and fungi. The aim of this chapter is to provide a general overview of NPP groups observed in palynology slides. It includes more than 40 of the most common groups starting with acritarcha, cyanobacteria and algae, moving through transitional groups to animals and fungi and finishing with human-made objects such as textile fibres. Although far from complete, it provides an updated overview of taxonomical diversity of NPPs and their indicator values. Further works on NPP identifications are of great importance to improve our current knowledge. Since NPPs occur in all kinds of sediments, their analysis is a powerful tool for reconstructing environmental changes over time. Further detailed studies of specific NPP groups and their indicator values will open the way for new fields of study.