Article: Charophytes from the Lower Cretaceous of the Iberian Ranges (Spain)
In the Upper Barremian of the Iberian Ranges (Las Hoyas, Cuenca, Spain) an association of exceptionally well preserved charophyte thalli comprises four new form-species: Palaeonitella vermicularis sp. nov., Charaxis spicatus sp. nov., Clavatoraxis robustus gen. et sp. nov., and Clavatoraxis diaz-romerali sp. nov. This is the youngest fossil record of the genus Palaeonitella. The new form-genus Clavatoraxis is erected to include charophyte vegetative remains bearing spine-cell rosettes, a character attributed to the family Clavatoraceae. This is the first time an assemblage of charophyte vegetative remains has been described and related to assemblages of fructifications. This gives a good correlation at family level between the frequency of taxa found as vegetative remains and calcified fructifications. Two biocoenoses are represented: Clavatoraxis robustus displays adaptations found in extant charophytes living in permanent shallow water lakes whereas Clavatoraxis diaz-romerali was adapted to light-limited, probably deeper, environments. Palaeonitella vermicularis grew twisted round thalli of Clavatoraxis. Early Cretaceous freshwater communities appear to have been dominated by charophytes, and not by aquatic ferns as believed previously.