Search

The gigantopterids are a pan-palaeotropical Late Palaeozoic (to Early Mesozoic) plant group with unknown affiliations. Two gigantopterid species, both sole representatives of their respective genera, are known from the Early Permian Mengkarang Formation of Jambi (Sumatra, Indonesia). Through an emendation of the Jambi gigantopterids, based on the old and newly collected material, and a subsequent analysis of the leaf morphology of several gigantopterid genera, we conclude that the Jambi species are similar to the other gigantopterids, but do not appear to be related to them directly. We propose a possible scenario for the evolution of gigantopterid leaf morphology, based on marginal leaf growth, with implications for the validity of the gigantopterids as a natural group. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 161, 302–328. [ABSTRACT FROM AUTHOR]

Abstract: Recent expeditions to the Early Permian formations of Jambi, Sumatra, have produced material of a new species of peltasperm affinity, Comia variformis nov. sp., with a remarkably broad morphological range that touches on several other Permian taxonomic groups. It is found in association with material attributable to the callipterid genus Rhachiphyllum, in addition to Supaia-like material and an Autunia fructification, corroborating a peltasperm affinity. Palaeogeographic relationships of the morphologies found in C. variformis and the other material show strong relationships with North China and even the Angaran region, suggesting a migration zone running from the North China Block to the West Sumatra–West Myamar terrane. [Copyright &y& Elsevier]

Abstract: New material of the Early Permian alethopterid genus Macralethopteris is examined in detail. The material stems from different locations and statistical comparison of the morphological differences between collections suggests that the material is derived from several populations of a single species. Comparison is made with related Cathaysian and Euramerican species, showing the isolated occurrence of Macralethopteris in the Cathaysian region. Characteristics of the species and possible ecological implications suggest that Macralethopteris hallei grew in more mesic circumstances than usually associated with alethopterids. It is argued that M. hallei might have been a relatively small alethopterid with possible cormous growth. [Copyright &y& Elsevier]