Abstract Detail

Paleobotany

Wu, Xinkai [1], Liu, Xiaoyan [1], Kodrul, Tatiana [1], Quan, Cheng [2], Jin, Jianhua [1].

The First Northern Hemisphere Macrofossil Record of Dacrycarpus (Podocarpaceae) from Miocene of Guiping Basin, Guangxi, South China.

Dacrycarpus (Bennett) de Laubenfels (Podocarpaceae) has nine living species, mainly distributed in tropical montane from southernmost China to Fiji and New Zealand, including Vanuatu and New Caledonia, with the highest diversity in New Guinea. Only one species, D. imbricatus (Blume) de Laubenfels, occurred in South China. However, the fossil record of Dacrycarpus is well known from the Cenozoic of the Southern Hemisphere. The earliest Dacrycarpus was found from Eocene of Chile, Argentina and Tasmania. By the Oligocene, the records are mainly limited in southeastern Australia and New Zealand. The latest records are in the Miocene of New Zealand. Until now no macrofossil record has been reported from the Northern Hemisphere. In this study, we described a new species of the genus recovered from the Miocene Erzitang Formation of Guiping Basin, Guangxi, South China. The speciments consist of various forms foliage and three-dimensional preserved female cones, with well-preserved cuticles. The new materials have dimorphic foliage, composed of bifacially flattened “adult” leaves on long shoots and bilaterally flattened “juvenile” leaves on feather-like short shoots. All foliage have a single midvein and incurved mucro, as well as resin ducts. Bifacially flattened leaves are small, awl-shape, spirally arranged, imbricate, appressed, strongly keeled. Bilaterally flattened leaves are distichous, falcate, straight to slightly apically curved, decurrent, stongly keeled with a single prominently raised vein. Leaves are amphistomatic and stomatal complex is paratetracytic. Seed cones are terminal, obovate, deployed singly on a warty receptacle. Based on the architectural and cuticular features, the present fossils are assigned to the genus of Dacrycarpus, showing the most resemblance to D. imbricatus. This is the first macrofossil record of Dacrycarpus in the Northern Hemisphere, providing new evidence for the study of the origin and migration route of this genus. The distribution and living habitat of extant Dacrycarpus indicate that the fossil locality might have a very wet climate during the Miocene, representing a mountain rainforest climate.

1 - Sun Yat-sen University, School of Life Sciences, 135 Xingangxi Road, Guangzhou, China, Guangzhou, Guangdong, 510275, China
2 - Jilin University, Changchun, China, Research Center of Paleontology & Stratigraphy, 938, Xi-minzhu Str., Changchun, 130026 China, Changchun, Jilin, 130026, China

Keywords:
Dacrycarpus 
Northern Hemisphere
Macrofossil
 Miocene 
Guiping Basin
South China
Podocarpaceae.

Presentation Type: Oral Paper
Session: 1, Cookson/Moseley award presentations
Location: Sundance 4/Omni Hotel
Date: Monday, June 26th, 2017
Time: 8:45 AM
Number: 1004
Abstract ID:159
Candidate for Awards:Isabel Cookson Award