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Abstract Detail



Paleobotanical Section

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

Whole-plant reconstruction and phylogenetic relationships of a new species of Elatides (Cupressaceae) from the Early Cretaceous of Mongolia.

Exceptionally well-preserved lignified fossils from the Early Cretaceous of Mongolia include abundant conifer shoots with attached leaves, pollen cones, and seed cones. Based on these fossils, we describe a new whole-plant reconstruction of an Elatides species that enables a critical evaluation of the relationship of this extinct taxon to extant conifers. This species is based on bulk lignite samples collected from the Tugrug mine in central Mongolia, which were then disaggregated in water, cleaned with hydrochloric and hydrofluoric acids, washed, and dried in air. The new species produced helically arranged leaves 6-11 mm long with two narrow lateral stomatal bands predominantly on the adaxial leaf surface. Pollen cones are small, up to 3 mm in length, and typically borne laterally on shoots in pseudo-whorls. Each microsporophyll has three pollen sacs, which produce small non-saccate pollen with circular apertures. Seed cones are up to 25 mm long and primarily borne terminally, although they occur laterally on leafy shoots as well. They consist of numerous bract-scale complexes, each with a relatively small ovuliferous scale composed of a membranous, occasionally lobed, pad of tissue that is tightly adpressed but not fused to the bract. Bract-scale complexes typically bear four to six seeds. The new species of Elatides is the most completely described Elatides species currently known, and the major features of its seed cone and pollen cone morphology, particularly its ovuliferous scale, suggest it is most closely related to extant Cunninghamia in the Cupressaceae. Morphological cladistic analyses using parsimony, both with and without molecular constraints, placed the new species in an expanded Cunninghamioideae clade that includes extant other Elatides species, a number of Cunninghamia-like fossils, and extant Cunninghamia. These analyses also place this clade as sister to other extant Cupressaceae.  


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1 - Nanjing Institute of Geology and Palaeontology, State Key Laboratory of Palaeobiology and Stratigraphy, 39 East Beijing Road, Nanjing, 210008, China
2 - Brown University, Box G-W, 80 Waterman Street, Providence, RI, 02912, USA
3 - Chicago Botanic Garden, Senior Scientist, 1000 Lake Cook Road, Glencoe, IL, 60022, USA
4 - Mongolian Academy of Sciences, Paleontological Center, Ulaanbaatar-51, P.O. Box 260, Ulaanbaatar, Mongolia
5 - Niigata University, Department of Environmental Sciences, 8050, 2-cho, Ikarashi, Nishi-ku, Niigata, 950-2181, Japan
6 - Ruhr-University Bochum, Institute for Evolution and Biodiversity of Plants, Universitaetsstrasse 150, Bochum, 44801, Germany
7 - Yale University, School of Forestry and Environmental Studies, 195 Prospect Street, New Haven, CT, USA

Keywords:
Cretaceous
Mongolia
conifer evolution
Cupressaceae
Cunninghamia.

Presentation Type: Oral Paper:Papers for Sections
Session: 37
Location: Pines North/Boise Centre
Date: Wednesday, July 30th, 2014
Time: 8:45 AM
Number: 37002
Abstract ID:228
Candidate for Awards:None


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