Distribution, evolution and extinction of global early Carboniferous flora

Abstract

The uniform Lepidodendropsis flora of the Early Carboniferous is uniformly and widely distributed in the Cathaysia, Laurasia, Kazakhstania and Gondwana continents. This is characterized by Lepidodendropsis, Sublepidodendron, Archaeosigillaria, Archaeocalamites, Sphenopteridium, Cardiopteridium, Rhodeopteridium, Rhacopteris, Triphyllopteris and Adiantites, etc. the global climatic differentiation was not very obvious during the Early Carboniferous, therefore, all Early Carboniferous plant assemblages belonged to the same phytogeographic province. It is known that some typical genera of the Lepidodendropsis flora of the Early Carboniferous, such as Lepidodendropsis, Lepidosigillaria and Archaeosigillaria are recorded from the Lower Devonian in Libya, Africa (Lejal-Nicol, 1975) and some elements of this flora are also recorded from the Late Devonian in China and other parts of the world. It is considered that this Lepidodendropsis flora gradually started appearing in the Early Devonian, began to diversify in the Late Devonian and reached its maximum development in the Early Carboniferous. The flora tended to decline in the Late Early Carboniferous and resulted in its extinction in the end of the Early Carboniferous.

Although some plant elements in Cathaysia, Euramerica, Angara and Gondwana had already appeared in the Early Carboniferous, especially in the late Early Carboniferous, the occurrence of the new taxa was regarded as a result of gradually increasing climatic differentiation and plant evolution. During the transition period from the Early Carboniferous to the Late Carboniferous, the differentiations of climatic conditions, tectonic movements, continental positions, oceanic currents and glaciation were quite obvious, resulting in the extinction of numerous typical elements of the Early Carboniferous flora and the appearance of some forerunners of the Late Carboniferous floras in the world. The Cathaysia, Euramerica, Angara and Gondwana floras derived from the identical Lepidodendropsis flora of the Early Carboniferous, but developed and flourished in different environmental conditions.