RUI: Cheirolepidiaceous Conifer Fossils from North America: New Data on the Structure and Diversity of the Dominant Mesozoic Vegetation

University Of South Alabama, Mobile AL

Investigators

Abstract

ABSTRACT Cheirolepidiaceous Conifer Fossils from North America: New Data on the Structure and Diversity of the Dominant Mesozoic Vegetation Brian J. Axsmith EAR-0105476 Members of the extinct conifer family Cheirolepidiaceae evolved high levels of morphological diversity and reproductive sophistication, and were among the dominant land plants of the Mesozoic Era. Nevertheless, many aspects of the structure and evolution of these plants remain poorly understood. This situation represents a significant gap in our understanding of the Mesozoic world and the evolutionary history of seed plants. The proposed research involves the collection and/or description of new cheirolepidiaceous conifers from sites in Arkansas, Connecticut, Massachusetts and New Jersey that will elucidate the structure, diversity and evolution of this intriguing family. In addition to the first description of the important genus Hirmeriella from North America, at least three new taxa, as well as the only intact seed cones of the cosmopolitan species Pseudofrenelopsis parceramosa, will be described. In addition, a preliminary phylogenetic analysis of the Cheirolepidiaceae will be undertaken. Although much of the current state of knowledge regarding these plants is based on European collections, the proposed research will demonstrate that North America was a major locus of cheirolepidiacean diversity and evolution