The Himalayan connection of the Middle Triassic brachiopod fauna from Socotra (Yemen)

Abstract

The Socotra Island (Yemen) is located out of the coast of the East African corner of Somalia, and presents the main geological features of South Oman (Dofhar Mountains) as well as the sedimentary cover of southern Yemen. However, the sedimentary succession of Socotra is of particular interest for the Triassic, as it represents the only location in the southern Middle East with outcropping marine facies of this period. These sediments were described for the first time by Samuel et al. (1997), within an oil prospecting study, but no detailed litho-and biostratigraphic study has been presented so far.The general stratigraphy of the Triassic succession of Socotra was studied in the master thesis of Giorgioni The aim of this paper is twofold: (i) illustrate the Triassic brachiopod assemblages of the Socotra Island and constrain their time of occurrence on the base of conodont biostratigraphic dating and (ii) discuss the affinities of the Triassic brachiopods from Socotra with the time equivalent fauna from Himalaya (India, Nepal, and Tibet), as well as their paleobiogeographic implications.We show that the brachiopod assemblages found in Socotra have a strong affinity with those from Himalaya,

The Anisian (Middle Triassic) brachiopod fauna from Qingyan, Guizhou, south-western China

“…The other four genera Nudirostralina, Koeveskallina, Diholkorhynchia and Adygella are widely distributed. A similar fauna which contains only six species have been discovered from Socotra, Yemen by Gaetani et al (2018). Though most of the determinable species are known only from Himalayan region, these genera, Nudirostralina, Spirigerellina, Adygella, Koeveskallina and Lepismatina are cosmopolitan.…”

A new Early Triassic brachiopod fauna from southern Tibet, China: Implications on brachiopod recovery and the late Smithian extinction in southern Tethys

“…griesbachi and ?P. dieneri should be represented as different ontogenetic stages of the same species (Gaetani et al, 2018).…”

The Anisian (Middle Triassic) brachiopods from the southern Qilian Mountains, north‐western China

“…Spirigerellina stoliczkai (Bittner, 1899) described by Gaetani et al . (2018, fig. 7)), but these radial ridges are much finer and weaker than those of Crenulatomargus .…”

“…1976; Chen 1983; Siblík 1991; MacFarlan 1992; Gaetani 2016; Gaetani et al . 2018; Grădinaru & Gaetani 2019). Of these, the southern Qilian Mountains record the highest taxonomic diversity at species level, and the southern Qilian fauna, therefore, is one of the most important brachiopod assemblages in the Middle Triassic (Guo et al .…”