Abstract Detail



Paleobotany

Manchester, Steven [1].

Hidden gems in the Cretaceous Dakota Sandstone of Kansas.

X-ray investigation of Dakota Sandstone specimens collected near Fort Harker, Kansas, in the late 19th century have revealed a surprising diversity of fruits, seeds and flowers faithfully preserved as molds and casts hidden within the sandstone pieces. These plant remains accompany the fossil leaves for which the Dakota Formation is best known, representing coastal vegetation growing along the eastern flank of the Epicontinental Seaway during the latest Albian and/or early Cenomania, ca 100 Ma. Unlike the previously described rare fossil fruits and seeds discovered by fortuitous fracture in the field, these fossils are not visible at the sediment surface but are preserved intact, without the fragmentation that occurs with traditional mechanical methods of exposure. Micro-CT scans at the resolution of 30 microns are sufficient to reveal diagnostic features of flower and fruit morphology preserved within the sediment, even for very small flowers in the range of 1 to 3 mm in diameter. Reproductive structures encountered to date include gymnosperm seed and pollen cones plus three kinds of flowers with intact perianth, stamens and gynoecium, and various fruits and seeds, some even with delicate wings preserved. The new information facilitates more complete descriptions of previously recognized taxa, and has allowed for the recognition of several new taxa. The angiosperm remains include Magnoliids and Eudicots. Although the Dakota Sandstone is known mainly for its well preserved leaf impressions, the taxonomic resolution available from leaves is limited compared to that available from reproductive organs. Broader application of this method, employing a variety of visualization algorithms for microCT scan data sets, can be expected to provide new insights into the floristic composition of the Dakota formation, and the status of  floral and fruit morphology relatively early in the evolutionary radiation of angiosperms.


1 - Florida Museum Of Natural History, Po Box 117800, Gainesville, FL, 32611, United States

Keywords:
fruits
paleobotany
Cretaceous.

Presentation Type: Oral Paper
Number: 0004
Abstract ID:539
Candidate for Awards:None


Copyright © 2000-2018, Botanical Society of America. All rights reserved