Paleoecology of a Miocene flora from the Shanwang formation, Shandong province, northern East China

Abstract

The Shanwang Formation, which is late Early to early Middle Miocene based on radiometric dates and vertebrate fossils, was deposited in a small intermontane lake basin (N. Lat. 36.5°) and contains a rich assemblage of plant and animal fossils. The chief plant families represented by pollen taxa are Fagaceae, Juglandaceae, Betulaceae, Ulmaceae, Hamamelidaceae and Pinaceae. The combined pollen and leaf data indicate that the Miocene vegetation of the Shanwang area was mixed deciduous and evergreen broad-leaved forest with a humid warm-temperate to subtropical climate. In contrast, the modern vegetation is a deciduous broadleaved forest, that contains very few subtropical elements. The average annual temperature at Shanwang was similar to that of today. The main difference between the modern and Miocene climates is that the annual temperature range has increased (colder winters), and precipitation which was evenly distributed is now highly seasonal (winter dry). A comparison between the fossil pollen and leaf evidence reveals that the chief families of both assemblages are almost identical. Various evidence implies the fossil leaf assemblages are derived chiefly from a local or an autochthonous community; however, the pollen assemblage reflects a more regional character of vegetation and climate. The leaf fossil assemblage, which includes more insect-pollinated plant taxa, affords a better picture of the local ancient flora.

Climatic reconstruction at the Miocene Shanwang basin, China, using leaf margin analysis, CLAMP, coexistence approach, and overlapping distribution analysis

“…topographic diversity. The Miocene Shanwang flora is very similar to the montane floras of the middle reaches of the Yangtze River (Hu and Chaney, 1940;Liu and Leopold, 1992;Yang et al, 2002). About 80% of the genera in Shanwang Miocene now live in Shennongjia (Hubei Province) (31821 0 20 00 -31836 0 20 00 N, 110803 0 05 00 -110833 0 50 00 E).…”

Spatial and temporal characteristics of Neogene palynoflora in China and its implication for the spread of steppe vegetation

“…Presumably, the East-Asian summer monsoon during the late Early to early Middle Miocene was generally strong and supplied plenty of moisture to East Asia such that major woodland vegetation could bloom in East China and relatively humid steppe could develop in West China . In East China, the early Middle-Miocene Shanwang biota contained exceptionally well-preserved plant fossils and palynomorphs, which provided an ideal opportunity to undertake detailed quantitative palaeoclimate reconstruction (e.g., Liu and Leopold, 1992). The palaeoclimatic conditions predicted by coexistence analysis of leaf floras and palynofloras from Shanwang suggested that, the mean annual temperature ranged from 15.3 to 17.2 C, the mean temperature of the coldest month from 5.0 to 7.0 C, the mean temperature of the warmest month from 24.7 to 27.8 C and the mean annual precipitation from 996 to 1281 mm (Liang et al, 2003).…”

Fruits and Leaflets ofWisteria(Leguminosae, Papilionoideae) from the Miocene of Shandong Province, Eastern China

“…; for a detailed setting and stratigraphy, see Liu and Leopold 1992). This formation has provided exquisitely preserved insects, ostracodes, spiders, fish, amphibians, reptiles, birds, mammals, and plants since the 1930s (Hu and Chaney 1940;Li 1981;Liu and Leopold 1992;Yang and Yang 1994;Sun 1999). This site has yielded plant megafossils that have been assigned to 50 families, 104 genera, and 155 species, from which the leaflets Wisteria fallax (Nathorst) Tanai et Onoe have been reported (WGCPC 1978;Sun 1999).…”

“…This site has yielded plant megafossils that have been assigned to 50 families, 104 genera, and 155 species, from which the leaflets Wisteria fallax (Nathorst) Tanai et Onoe have been reported (WGCPC 1978;Sun 1999). Based on paleontologic and radiometric evidence, the Shanwang fossil biota is considered to be middle Miocene in age (Li 1981;Yang and Yang 1994;Sun 1999) or slightly earlier (late Early to early Middle Miocene; Liu and Leopold 1992). Most paleontologists and geologists accept a middle Miocene age for the Shanwang Formation (Sun et al 2002;Liang et al 2003;.…”