Leafy shoots of the cheirolepidiaceous conifer Pseudofrenelopsis parceramosa are a common and widespread component of many Lower Cretaceous floras in North America and Europe. Based on material from Great Britain, Alvin and colleagues have reconstructed the source plant of these shoots as a large tree with whorled lower order branches and spirally arranged ultimate shoots and leaves. Although such phyllotactic shifts are otherwise unknown among extant and fossil conifers, this reconstruction is, nevertheless, based on convincing association and anatomical evidence. We have undertaken an alternative reconstruction of the Pseudofrenelopsis parceramosa source plant based on new material from a locality in southwestern Arkansas originally described by Stanley and Delevoryas. Unfortunately, much of the earlier collection has been lost. The new fossils were recovered by screening clay collected along a stream bank exposure of the Holly Creek Formation. Although the gross morphological and cuticular features of the ultimate leafy shoots examined to date essentially conform to the British specimens, all of the branches, including the largest specimens representing lower branch orders, exhibit a spiral arrangement. Furthermore, the pollen cones, which are known from specimens attached to the leafy shoots, differ from those associated with the British specimens in several aspects of microsporophyll morphology, including the shape and the presence of long hairs on the microsporophyll lamina margin. It is becoming increasing likely that the fossils from Arkansas and the British material represent two distinct species of conifer with generally similar ultimate shoots. This finding may, at least in part, explain the persistent controversies surrounding the paleoecology of “P. parceramosa,” and underscores the importance of accurate reconstructions in elucidating the structure, diversity, paleoecology, and paleobiogeography of fossil plants. Preliminary information on the associated, intact ovulate cones and newly discovered fusainized wood will also be presented.

Key words: Cheirolepidiaceae, conifer, Cretaceous, Mesozoic, Pseudofrenelopsis