Bryozoan fauna from the Permian (Artinskian-Kungurian) Zhongba Formation of southwestern Tibet

Abstract

The bryozoan assemblage from the Zhongba Formation of southwestern Tibet includes 30 species of 25 genera. Seven species are new: Fistulipora sakagamii n. sp., Dybowskiella hupehensiformis n. sp., Etherella tibetensis n. sp., Dyscritella lii n. sp., Streblotrypa (Streblotrypa) parviformis n. sp., Timanotrypa australis n. sp., and Protoretepora irregularis n. sp. One genus with one species is also new: Tibetiporella ornata n. gen. n. sp. The described fauna implies a Cisuralian (Artinskian-Kungurian) age of the Zhongba Formation and shows relationships to the Cisuralian faunas of Thailand, Western Australia, Oman, Timor, central Pamir, Iran, Urals, and other Tibetan localities. The bryozoan fauna from the Zhongba Formation shows an intermixture of both Boreal and Gondwana elements, and implies stronger faunal migrations into the tropical region from both the north and south. Palaeoecological analysis suggests that the Zhongba Formation was deposited in a middle shelf setting some distance from shoreline, probably influenced by local currents.

Faunal similarity in Madagascan and South Indian Late Cretaceous vertebrate faunas

“…11), contain the most prolific and diverse, although rare with few species, conodont assemblages known from the Australian Cisuralian (Nicoll and Metcalfe, 1998). According to Nicoll and Metcalfe (2001, p. 65 Timanotrypa australis (see Ernst et al, 2008;Ernst, 2016). These suggest a warm-water influence in the Noonkanbah fauna.…”