Latest Carboniferous (Late Gzhelian) Fusulinids from Timor Leste and their Paleobiogeographic Affinities

Abstract

An uppermost Gzhelian bioherm discovered in the central highlands of Timor Leste contains abundant foraminifera belonging to 17 genera. Representatives of the families Biseriamminidae, Biwaellidae, Bradyinidae, Cornuspiridae, Lasiodiscidae, Palaeotextulariidae, Pseudotaxidae, Ozawainellidae, Schubertellidae, Schwagerinidae, Staffellidae and Textrataxidae are present, including 21 species referred to known types and 12 species left in open nomenclature. Two newSchwagerinaspecies are described:Schwagerina timorensisnew species, andSchwagerina maubissensisnew species. The assemblage belongs to the uppermost GzhelianSchwagerina robusta–Ultradaixina bosbytauensisZone although a possible lowest Asselian correlation cannot be excluded (the nameUltradaixinais controversial and sometimes synonymized asBosbytauella. The case to resolve this issue has been submitted to the Bulletin of Zoological Nomenclature). The bioherm is the oldest carbonate unit so far recorded from the Maubisse Formation and the oldest sedimentary unit biostratigraphically dated in Timor. This discovery has implications for the latest Carboniferous–earliest Permian climate history of Timor that lay in the northern part of the north-south East Gondwana rift system along which the western margin of Australia later developed. The highest peak in fusulinid diversity within the Pennsylvanian–Cisuralian interval and a major marine transgression documented in many regions in Northern Pangaea took place during the latest Gzhelian to earliest Asselian and evidence for this is now extended to southern Pangaea. Cluster analysis, using the Jaccard similarity index at species level, of late Gzhelian fusulinids from 16 regions has been performed. This shows that the Timor fauna is most closely related to faunas from South China and the Changning-Menlian region of Yunnan (China). The assemblages here are distinct from those of three biogeographic regions (Arctic, Uralo-Asian and Irano-Taurids) recognized within the Tropical belt.

Australia going down under: Quantifying continental subduction during arc-continent accretion in Timor-Leste

“…The Maubisse Formation was described by AudleyCharles (1968) as a 900mthick unit of massive fossiliferous limestones weathering dark red, as well as thick successions of mafic extrusive rocks. The Maubisse Formation is mainly Permian in age , with a few sections dated as Latest Carboniferous (Davydov et al, 2013(Davydov et al, , 2014. We find the Maubisse For mation to consist of massive gray limestone weathering dark red, containing plentiful ammonites, crinoids, and other fossils and interbedded with thick basalts and mafic volcaniclastics (Fig.…”

Cisuralian and Guadalupian global paleobiogeography of fusulinids in response to tectonics, ocean circulation and climate change

“…turgida and Ch. rotundaalso occurred in the western U.S. (Dunbar and Skinner, 1937;Skinner and Wilde, 1966;Davydov et al, 1997;Stevens and Stone, 2009), indicating some connections between Tethys and eastern Panthalassa. This genus originated in the Tethys realm in the middle Artinskian (Davydov et al, 2014) but had a delayed appearance in the western U.S. about 2-2.5…”

Reconciling regional continuity with local variability in structure, uplift and exhumation of the Timor orogen

“…The Permian Maubisse Formation primarily consists of crinoidal carbonates, lavas and volcaniclastic units, interpreted as deposits on higher platforms coeval with basin deposition of the Atahoc and Cribas Formations (Bird and Cook, 1991). Additionally, some lower sections of the Maubisse Formation in Timor-Leste have been dated as latest Carboniferous in age (Davydov et al, 2013(Davydov et al, , 2014.…”