abstract: The Zingiberales, including the gingers (Zingiber), bananas (Musa) and ornamental flowers (Strelitzia, Canna, and Heliconia) are a diverse group of monocots that occupy the tropics and subtropics worldwide. The monophyly of the order is well supported, although relationships between families are not well resolved. A rapid divergence of the Zingiberales has been proposed to explain the poor resolution of paraphyletic families in the order, and direct fossil evidence shows members of both of these lineages of Zingiberaceae and Musaceae were present by the Late Cretaceous. Comparisons of the fossils with extant relatives and their systematic placement have been limited because variation within modern taxa is not completely known. The current study focuses on describing zingiberalean fossil material from North Dakota that includes seeds, leaves, buds, adventitious roots and rhizomes. A survey of extant zingiberalean seeds was conducted, including descriptions of those for which data were previously unknown, in order to resolve the taxonomic placement of the fossil material. Upon careful examination, anatomical characters of the seed coat in fossil and extant seeds provide the basis for a more accurate taxonomic placement of the fossils and a better understanding of character evolution within the order. / Dissertation/Thesis / Ph.D. Plant Biology 2012

A new species of Cucubalus is described based on two fossil seeds recovered from the upper Pliocene Sanying Formation in northwestern Yunnan Province, southwestern China. The seeds are characterized by a reniform to circular outline in shape, and sinuous and discontinuous rugulae made of rod-like elements radiating from the hilum region to the dorsal margin. The combination of these characteristics shows their close resemblance to the extant genus Cucubalus in the Caryophyllaceae. A morphological principal coordinates (PCO) analysis further supports the assignment to this genus. Cucubalus is a monotypic genus today, but the late Pliocene fossil seeds have been described as a new species, Cucubalus prebaccifer Huang, Liu et Zhou, sp. nov. This newly documented Cucubalus fossil, representing the first fossil record of this genus, implies that the genus has existed in northwestern Yunnan, southwestern China, at least since the late Pliocene. It provides important information on the past biodiversity and biogeography of both the genus Cucubalus and the fossil-scant family Caryophyllaceae.

A new species of Cucubalus is described based on two fossil seeds recovered from the upper Pliocene Sanying Formation in northwestern Yunnan Province, southwestern China. The seeds are characterized by a reniform to circular outline in shape, and sinuous and discontinuous rugulae made of rod-like elements radiating from the hilum region to the dorsal margin. The combination of these characteristics shows their close resemblance to the extant genus Cucubalus in the Caryophyllaceae. A morphological principal coordinates (PCO) analysis further supports the assignment to this genus. Cucubalus is a monotypic genus today, but the late Pliocene fossil seeds have been described as a new species, Cucubalus prebaccifer Huang, Liu et Zhou, sp. nov. This newly documented Cucubalus fossil, representing the first fossil record of this genus, implies that the genus has existed in northwestern Yunnan, southwestern China, at least since the late Pliocene. It provides important information on the past biodiversity and biogeography of both the genus Cucubalus and the fossil-scant family Caryophyllaceae.

The occurrences of Staphylea L. (Staphyleaceae) fossils have been abundantly documented from the Cenozoic of Eurasia, but none has been confirmed from North America to date. In this study, we describe Staphylealevisemia sp. nov. on the basis of seed remains from the latest Miocene to earliest Pliocene of northeastern Tennessee, southeastern USA. The seeds are characterized by a smoothly inflated body, a large hilar scar perforated by several vascular traces and bordered by a distinctive lip-like rim, a cuticle coating the seed coat interior, and seed coat section containing weakly developed tiny lumina. According to the paleogeographic distribution of the genus, it is hypothesized that Staphylea originated from western Eurasia no later than the late Oligocene, and arrived in eastern North America no later than the late Neogene, most possibly through the North Atlantic land bridges like many other seed plants.