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Lejeunea palaeomexicana was described in 1984 based on an inclusion of a sterile leafy liverwort in a piece of Miocene Mexican amber. A reinvestigation of the type specimen provided evidence for a basal group of ocelli in the leaf lobes. Ocelli are unknown among extant representatives of Lejeunea but occur in several other genera of Lejeuneaceae. Based on the brown colour of the cell walls, the asymmetrical leaf lobes, the two cells wide ventral merophyte and the position of the ocelli, we propose a transfer of Lejeunea palaeomexicana to Ceratolejeunea.

The Baltic amber fossil Jungermannia berendtii is transferred to Solenostoma based on the presence of numerous long rhizoids, distinct trigones, and subquadrate-rotund to elongate-elliptical leaves.

A sterile liverwort inclusion in a piece of Miocene amber from the Dominican Republic is described and assigned to the extant genus Lejeunea. The inclusion resembles a complex of extant American Lejeunea species (L. angusta, L. aphanes, L. cladogyna, L. urbanii) that share autoecy, a small size, and ovate to obovate leaf lobes with rounded apices. A definite assignment to one of these species is impossible due to inacessibility of several diagnostically relevant characters such as perianths and oil bodies. The inclusion is clearly different from the extinct Lejeunea palaeomexicana; hence at least two different Lejeunea species occured in the Miocene of Middle America.

Thermal properties of French Cretaceous ambers were investigated and compared with other ambers from various sites of the world. The amber samples came from 10 different localities in southern France, in the Charentes, Languedoc, and Provence regions, ranging from Late Albian to Santonian in age. Thermogravimetric (TG) and Differential Thermogravimetric (DTG) profiles were obtained at heating rate of 10 K/min in air, starting from room temperature (20 degrees C) and reaching a maximum temperature of 700 degrees C. Elemental Analysis for total Carbon, Hydrogen, Nitrogen and Sulphur was also carried Out. The TG combustion profile of the resins started after 200 degrees C and complete combustion took place near 600 degrees C. The DTG behaviour is characterized by a main exothermal peak situated between 394 and 420 degrees C, accompanied by minor peaks and shoulders. The increasing value of the main exothermal peak correlates well to the increase of the age of the specimens, with a significant correlation coefficient (r = 0.7721, p = 0.0089). A significant correlation (r = 0.6728, p = 0.0004) is also found with other samples of different age and origin. By considering the whole pattern of DTG peaks, a possible fingerprinting model of the French ambers is evaluated by multivariate analysis. Cluster Analysis and Principal Component Analysis show the presence of several clusters, according to the geological age and possibly to the palaeobotanical origin. The elemental analysis is consistent with that of other Cretaceous samples from different sites of the world. Carbon and hydrogen are the main constituents (range 73-80% and 9.5-11.5% respectively). Sulphur is detected in small amounts (0.8-2.4%). Nitrogen is absent or appears as traces only (0-0.008%). Oxygen and other elements range from 4.6 to 16.8%. No successful Clustering was possible according to the elemental composition. Thermal analysis, completed with multivariate statistics, is a useful Source of information also for French ambers, as a help for identification of the age, diagenetic processes and palaeobotanical origin.