Article: The epidermal structure of the Carboniferous gymnosperm frond Reticulopteris
The epidermal structure of Upper Carboniferous Reticulopteris fronds is documented for the first time. It is shown to be very similar to that of Neuropteris obliqua, confirming earlier stratigraphical and gross-morphological evidence of a phylogenetic link between the two frond-types. The evolution of Reticulopteris fronds with their anastomosed venation from typical open-veined Neuropteris probably reflects the drier climate in the middle Westphalian. Barthelopteris gen. nov. is proposed for the Stephanian and Autunian species 'Reticulopteris' germarii, which has a very different epidermal structure from type Reticulopteris.