Zhongbei Block, Lhaze County (Permian of China)

Where: Xizang, China (29.1° N, 88.0° E: paleocoordinates 22.1° S, 67.7° E)

• coordinate stated in text

• outcrop-level geographic resolution

When: Quxia Formation, Wuchiapingian (259.9 - 254.2 Ma)

• Fossils come from a Permian exotic block within undifferentiated Triassic rocks. It is one of a group of isolated blocks in the so-called Zhongbei melange of the North Yarlungzangbo melange subbelt (Wang et al, 1996).

• group of beds-level stratigraphic resolution

Environment/lithology: lithified, shelly/skeletal limestone

• This is interpreted as an isolated block most likely representing an isolated seamount or a Permian carbonate platform located on the outer shelf of the southern margin in the Neotethys. It probably collided with and became sandwiched into younger marine deposits during the collision of the Indian and Eurasian plates during the early Cenozoic.
• Mainly reddish densely-fissured crinoidal limestone; the uppermost part of the carbonate sequence of Sheng (1984). No internal stratigraphy was observed.

Size class: macrofossils

Reposited in the NIGPAS

Collection methods: mechanical,

Primary reference: S. Z. Shen, G. R. Shi, and N. W. Archbold. 2003. A Wuchiapingian (Late Permian) brachiopod fauna from an exotic block in the Indus-Tsangpo Suture Zone, southern Tibet, and its palaeobiogeographical and tectonic implications. Palaeontology 46(2):225-256 [T. Olszewski/T. Olszewski/M. Clapham]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 24590: authorized by Tom Olszewski, entered by Tom Olszewski on 11.08.2002

Creative Commons license: CC BY (attribution)

Taxonomic list

Rhynchonellata
 Athyridida - Neoretziidae
Hustedia remota Eichwald 1860
2 incomplete ventral valves
 Athyridida - Athyrididae
? Spirigerella media Waagen 1883
incomplete conjoined shell
 Spiriferida - Martiniidae
Martinia elegans Diener 1897
20 conjoined shells
Martinia orbicularis Gemmellaro 1899
9 conjoined shells
 Spiriferida - Spiriferellidae
Elivina tibetana Diener 1897
nearly complete conjoined shell and an incomplete ventral valve
 Spiriferida - Choristitidae
Zhejiangospirifer giganteus n. sp. Shen et al. 2003
type specimens: incomplete conjoined shell, incomplete ventral valve, and incomplete dorsal valve; seven other specimens
 Spiriferida - Elythidae
"? Squamularia squamularioides" = Permophricodothyris squamularioides
"? Squamularia squamularioides" = Permophricodothyris squamularioides Huang 1933
incomplete ventral valve
 Rhynchonellida - Psilocamaridae
Cyrolexis superstes, "Stenoscisma timorense" = Bicamella timorensis
Cyrolexis superstes de Verneuil 1845
six conjoined shells
"Stenoscisma timorense" = Bicamella timorensis Hayasaka and Gan 1940
three ventral valves
 Rhynchonellida - Stenoscismatidae
Stenoscisma purdoni Davidson 1862
four incomplete conjoined shells
 Rhynchonellida - Wellerellidae
Uncinunellina timorensis Beyrich 1865
two conjoined shells and an ventral valve
Strophomenata
 Productida -
Incisius sp. Grant 1976
incomplete ventral valve
"Marginifera ornata" = Marginifera (Marginifera) ornata Waagen 1884
1 ventral valve
Spinomarginifera alpha Huang 1932
1 complete decorticated conjoined shell
 Productida - Paucispiniferidae
Jinomarginifera lhazeensis n. gen. n. sp. Shen et al. 2003
6 conjoined shells and an external mould of a dorsal valve
 Productida - Linoproductidae
Linoproductus sp. Chao 1927
ventral valve
 Productida - Productidae
? Stereochia sp. Grant 1976
incomplete conjoined shell
 Productida - Productellidae
Chonetella nasuta Waagen 1884
2 ventral valves
Echinauris sp. Muir-Wood and Cooper 1960
ventral valve
Anthozoa
 Stauriida - Plerophyllidae
Paracaninia indet. Chi 1937 horn coral
 Stauriida - Hapsiphyllidae
Allophyllum sp. Schouppe 1957 horn coral