Abstract Detail

Paleobotanical Section

Jin, Jianhua [1].

Eocene Podocarpium (Leguminosae) from South China and its phytogeographic implications.

The previous fossil records indicate that the extinct genus Podocarpium A. Braun ex Stizenberger 1851 of the Leguminosae was extensively distributed in Eurasian sediments from Early Oligocene to Pliocene. A new fossil species of this genus collected from Eocene Changchang Formation of Changchang Basin and Youganwo Formation of Maoming Basin of South China is described in this paper, and it is the oldest megafossil record up to the present. Although the speculated extant similar groups of Podocarpium, such as Gilletiodendron, Tessmannia, Brachystegia, Cryptosepalum and some species of the pantropical genus Cynometra, are distributed only in tropical and subtropical Africa, certain record of this genus has not been reported there yet by far. The ancestral population of this genus is supposed to originate in East Asia, most probably in South China, in view of the distribution of megafossil records and related palynological data. Combining the paleoclimate changes and its occurrences, the paleobiogeography pattern of Podocarpium through Cenozoic of Eurasia is discussed. Podocarpium may have been originated in the Eocene of South China. During the Oligocene, it was able to enter Europe. The existence of a wide spread arid band between North and South China from the Paleocene to the Oligocene made it difficult for Podocarpium, a thermophilous and moisture-loving plant, to disperse northward. In the Miocene it spread extensively across subtropical to warm temperate areas in Eurasia and reached its peak after the arid band disappeared. Due to the influence of the Tibetan plateau uplift and climatic deterioration, distribution of Podocarpium rapidly shrank and it finally became extinct in Eurasia during the Pliocene.

1 - Sun Yat-sen University, School of Life Sciences, 135 Xingangxi Road, Guangzhou, Guangdong, 510275, China

Keywords:
Eocene
Podocarpium
Leguminosae
phytogeography
South China.

Presentation Type: Poster:Posters for Sections
Session: P
Location: Hall D/The Shaw Conference Centre
Date: Monday, July 27th, 2015
Time: 5:30 PM
Number: PPB004
Abstract ID:389
Candidate for Awards:None