Abstract Detail

Mesozoic and Cenozoic plant evolution and biotic change: A symposium in honor of Ruth Stockey

Herrera, Fabiany [1], Shi, Gongle [2], Leslie, Andrew B. [3], Knopf, Patrick [4], Ichinnorov, Niiden [5], Takahashi, Masamichi [6], Crane, Peter [2], Herendeen, Patrick [7].

A Swamp from the Early Cretaceous of Mongolia: Revealing a Conifer-Dominated Forest During the Rise of the Angiosperms.

Fossils and molecular evidence suggest that all extant and crown conifer families were established by the Early Cretaceous. However, recognition of the lineages that lead to extant groups (e.g., Cupressaceae s. l., Pinaceae) remains incomplete. Exquisitely preserved lignite fossils (seed and pollen cones, foliage, and wood) from the Aptian-Albian of central Mongolia (Tevshiin Govi and Tugrug localities) provide taxonomic diversity and morphological and anatomical data that contribute to a more complete understanding of the complex pattern of conifer evolution. New Mongolian fossils include at least six seed cones, three pollen cones, five leaf morphospecies, and at least four wood types. One of the seed cones bears multilobed ovuliferous scales that suggest an affinity with extinct members of the voltzian clade of the Voltziales (‘transitional conifers”); this fossil also shows that voltzian seed cones with complex bract-scale arrangement and morphology persisted into the later Mesozoic. Three other seed cones show affinity with stem and crown Pinaceae. Whole-plant reconstructions of two additional taxa show affinities with the subfamilies Cunninghamioideae and Taiwanioideae of the Cupressaceae s.l. Although other major plant groups (e.g., corystosperms, filmy ferns and other taxa of uncertain relationships) are also present in the lignite floras, the fossil localities were dominated by conifers. The deposition and taphonomic conditions of the lignite deposits suggest that these coniferous plants inhabited permanently flooded systems (e.g., forest-moor swamps), however, the presence of charcoal in the same sedimentary sequences suggest that fire events were also part of the Early Cretaceous landscape in Mongolia.

1 - Chicago Botanic Garden, Plant Science Center, 1000 Lake Cook Road, Uiversity Of Florida, Glencoe, Il, 60022, USA
2 - Yale University, Yale School of Forestry and Environmental Studies, 195 Prospect Street, New Haven, CT, 06511, USA
3 - Brown University, Department of Ecology and Evolutionary Biology, 80 Waterman Street, Providence, RI, 02921, USA
4 - Botanischer Garten Rombergpark, Am Rombergpark 49b, Dortmund, 44225, Germany
5 - Mongolian Academy of Sciences, Institute of Paleontology and Geology, Ulaanbaatar, 51, P.O. Box 260, Mongolia
6 - Niigata University , Department of Environmental Sciences, Faculty of Sciences, 8050, 2-cho, Ikarashi, Nishi-ku, Niigata, Japan
7 - Chicago Botanic Garden, Senior Scientist, 1000 Lake Cook Road, Glencoe, IL, 60022, USA

Keywords:
Early Cretaceous
Conifers
Voltziales
Cupressaceae
Pinaceae
Mongolia.

Presentation Type: Colloquium Presentations
Session: C6
Location: Salon 5/The Shaw Conference Centre
Date: Wednesday, July 29th, 2015
Time: 4:15 PM
Number: C6011
Abstract ID:218
Candidate for Awards:None