Leaf waxes (i.e., n-alkyl lipids or n-alkanes) are land-plant biomarkers widely used to reconstruct changes in climate and the carbon isotopic composition of the atmosphere. There is little information available, however, on how the production of leaf waxes by different kinds of plants might influence the abundance and isotopic composition of n-alkanes in sedimentary archives. This lack of info...

The phrase “Darwin’s abominable mystery” is frequently used with reference to a range of outstanding questions about the evolution plant group today known as angiosperms. Here, I seek more fully understand what prompted Darwin coin in 1879, and meaning he attached it, by surveying systematics, paleobotanical records, phylogenetic hypotheses his time. In light this historical research, argue tha...

Insects possess a surprisingly extensive fossil record. Compilation of the geochronologic ranges of insect families demonstrates that their diversity exceeds that of preserved vertebrate tetrapods through 91 percent of their evolutionary history. The great diversity of insects was achieved not by high origination rates but rather by low extinction rates comparable to the low rates of slowly e...

Summary A recurring motif of Carlquist’s work is the identification traits typical for primary xylem angiosperms as a whole, but found in secondary certain species. These together make up ‘Carlquistian syndrome’. Convergent occurrence syndrome plants with similar habits suggests its adaptive value. One components — raylessness has received most attention and been regarded result selection favou...

The extraordinary contemporary species richness and ecological predominance of flowering plants (angiosperms) are even more remarkable when considering the relatively recent onset of their evolutionary diversification. We examine the evolutionary diversification of angiosperms and the observed differential distribution of species in angiosperm clades by estimating the rate of diversification fo...

The continuing study of early angiosperms from the Yixian Formation (approximately 125 Ma) of northeastern China has yielded a second early angiosperm genus. This report is a detailed account of this early flowering plant and recognizes earlier reports of similar fossils from Russia and China. Entire plants, including roots, stems, and branches terminating in fruits are presented and reconstruc...

Cycads are an important relic from the past and represent the oldest living seed plants. Cycads have been instrumental in our understanding the evolution of angiosperms and gymnosperms because they have recognizable morphological characteristics intermediate between less-recently evolved plants such as ferns and more-derived (advanced) plants including the angiosperms. Cycads also produce sever...