Article: Systematics of the Late Carboniferous medullosalean pteridosperm Laveineopteris and its associated Cyclopteris leaves
C. J. Cleal and C. H. Shute
Laveineopteris is emended to become a morphogenus for the vegetative parts of certain medullosalean pteridosperms that grew in the Westphalian (Late Carboniferous) tropical rainforests. The plant bore pinnate foliage as sun leaves and entire orbicular leaves (cyclopterids) as shade leaves. The cyclopterids were attached to the axis of the saplings and epiphyllously to the lower parts of the pinnate fronds. Species recognition is mainly by the macro-morphology of the pinnate fronds. However, species can also be distinguished based on the epidermal anatomy of both pinnate fronds and cyclopterids, in particular the distribution and detailed structure of the stomata and hydathodes. Laveineopteris first appeared in the lowland swamp forests of Europe during the early Langsettian (Westphalian A), and there were two principal species: L. loshii and L. tenuifolia. During the early Bolsovian (early Westphalian C), a variety of L. tenuifolia appeared that was adapted to both the lowland swamps, and the upland swamps of the intramontane basins (central Bohemia and Saar-Lorraine). The smaller-pinnuled L. rarinervis also first appeared in the Bolsovian and seems to have been restricted to the lowland swamps. The morphogenus Cyclopteris should be used only for cyclopterid fossils, where they cannot be related to the species of Laveineopteris, Callipteridium or Margaritopteris that originally bore them.