Three New Brachiopod Species from the Middle Permian (Wordian) of the South Kitakami Belt, Northeastern Japan

2016 ◽  
Vol 20 (2) ◽  
pp. 80-89
Author(s):  
Jun-Ichi Tazawa
Keyword(s):  
Middle Permian ◽  
The South ◽  
Northeastern Japan

Subduction polarity of the Ailaoshan Ocean (eastern Paleotethys): Constraints from detrital zircon U-Pb and Hf-O isotopes for the Longtan Formation

2019 ◽  
Vol 132 (5-6) ◽  
pp. 987-996
Author(s):  
Xiao-Ping Xia ◽  
Jian Xu ◽  
Chao Huang ◽  
Xiaoping Long ◽  
Meiling Zhou
Keyword(s):  
South China ◽  
Detrital Zircon ◽  
South China Block ◽  
The South ◽  
Forearc Basin ◽  
Isotopic Signatures ◽  
Northeastern Japan ◽  
O Isotopes ◽  
A Minor ◽  
Back Arc

Abstract The Paleotethys Ailaoshan Ocean separated the South China and Indochina blocks during the late Paleozoic. Uncertainty remains regarding subduction of this ocean—whether it was subducted eastward beneath the South China block or westward beneath the Indochina block. In this study, we present new detrital zircon U-Pb age, and Hf and O isotope data from the Longtan Formation, which was recognized to be deposited before the ocean closed. Our results show that the formation can be divided into three units: Unit 1 is distributed west of the suture and dominates the area; it contains major age peaks at 290–250 Ma and minor multiple old age peaks. Unit 2 consists of a minor distribution west of the suture, and it shows a dominant 250 Ma age peak; old zircons are very few or not present. Their Hf and O isotopic signatures are similar to those of unit 1. Unit 3 is distributed east of the suture and is characterized by a single distinct ca. 240 Ma age peak with almost no Precambrian zircons. We interpret that units 1 and 2 were likely deposited in a back-arc and forearc basin, respectively, and a volcanic arc developed on the eastern margin of the Indochina block, similar to the present-day northeastern Japan arc. Meanwhile, unit 3 was likely deposited in a forearc basin on the western margin of the South China block. Therefore, the Ailaoshan Ocean may undergone bipolar subduction both westward and eastward beneath the Indochina and South China blocks, respectively.

SMALL FOOTPRINTS EXPAND MIDDLE PERMIAN AMPHIBIAN DIVERSITY IN THE SOUTH AFRICAN KAROO

Palaios ◽  
2020 ◽  
Vol 35 (1) ◽  
pp. 1-11 ◽  
Author(s):  
JUAN CARLOS CISNEROS ◽  
MICHAEL O. DAY ◽  
JACO GROENEWALD ◽  
BRUCE S. RUBIDGE
Keyword(s):  
South African ◽  
Middle Permian ◽  
Aquatic Biota ◽  
The South ◽  
Adult Form ◽  
Karoo Basin ◽  
Assemblage Zone

ABSTRACT Two new tetrapod trackways are described from the Tapinocephalus Assemblage Zone of the South African Karoo Basin. We interpret both to be traces attributable to small anamniote tetrapods. The larger footprints are tentatively referred to aff. Batrachichnus salamandroides. These imprints are distinguished from other records of Batrachichnus by a pentadactyl pes that produces only impressions of digits III–V. Digits I and II are recognized only by their drag marks. This trace occurs in association with a second set of footprints of uncertain affinities. However, these smaller imprints are not sufficiently well preserved and could represent undertracks or partially eroded footprints. None of the footprints can be attributed to the adult forms of the two temnospondyl taxa known from the Guadalupian part of the Karoo Basin: Rhinesuchus whaitsi or Rhinesuchoides tenuiceps. We interpret the aff. Batrachichnus trackway to have been produced by a small, adult temnospondyl or microsaur (Recumbirostrae), whereas the smaller set of footprints was likely made by a juvenile rhinesuchid or an unknown amphibian, either a paedomorphic form or a tiny adult form. The discovery shows that a more diverse aquatic biota existed at this time in the Karoo than osteological records currently suggest.

Brachiopods of the order Chonetida from the Lower and Middle Permian of the South Kitakami Mountains, Northeast Japan

2015 ◽  
Vol 49 (1) ◽  
pp. 19-25
Author(s):  
G. A. Afanasjeva ◽  
Tazawa Jun-ichi ◽  
Shintani Tomohiko
Keyword(s):  
Middle Permian ◽  
The South

A new Permagrionidae from the Middle Permian of the South of France (Odonatoptera: Protozygoptera)

Zootaxa ◽  
2013 ◽  
Vol 3702 (4) ◽  
pp. 397
Author(s):  
CAITLIN FATE ◽  
JEAN LAPEYRIE ◽  
ANDRE NEL
Keyword(s):  
Middle Permian ◽  
The South
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