scholarly journals The genus Eryma Meyer, 1840 (Crustacea: Decapoda: Erymidae): new synonyms, systematic and stratigraphic implications

2017 ◽  
Vol 188 (3) ◽  
pp. 15 ◽  
Author(s):  
Julien Devillez ◽  
Sylvain Charbonnier
Keyword(s):  
Nauk Sssr ◽  
Upper Jurassic ◽  
Late Permian ◽  
Akademii Nauk Sssr ◽  
Triassic Boundary ◽  
Doklady Akademii Nauk Sssr ◽  
New Synonyms ◽  
The Family ◽  
Permian Triassic Boundary ◽  
Groove Pattern

Among Erymidae Van Straelen, 1925 (Van Straelen V. 1925. Contribution à l'étude des crustacés décapodes de la période jurassique. Mémoires de la Classe des Sciences de l'Académie royale de Belgique 7: 1–462), typical Mesozoic crustaceans, the genus Eryma Meyer, 1840 (Meyer H. von. 1840a. Briefliche Mittheilungen. Neues Jahrbuch für Mineralogie, Geognosie, Geologie und Petrefactenkunde 576–587) includes the largest number of species, mainly from Jurassic deposits. However, the lack of clear diagnoses for erymid genera has led to mistakes in generic assignments and to the establishment of redundant genera. The review of the concept of Eryma herein presents an attempt to clarify its diagnosis, mainly supported by the carapace groove pattern and the morphology of chelae of the first pair of pereiopods, and to emphasize its systematic implications. Thus, we maintain the synonymy of Klytia Meyer, 1840, Bolina Münster, 1839 (Münster G. 1839. Decapoda Macrura. Abbildung und Beschreibung der Fossilen Langschwänzigen Krebse in den Kalkschiefern von Bayern. Beiträge zur Petrefaktenkunde 2: 1–88) (sensu Étallon [Étallon A. 1859. Description des crustacés fossiles de la Haute-Saône et du Haut-Jura. Bulletin de la Société géologique de France 16: 169–205]), and Erymastacus Beurlen, 1928 (Beurlen K. 1928. Die Decapoden des Schwäbischen Jura mit Ausnahme der aus den oberjurassischen Plattenkalken stammenden. Palaeontographica 70: 115–278) with Eryma. Moreover, a review of the genera Protoclytiopsis Birshtein, 1958 (Birshtein JA. 1958. Ein Vertreter der ältesten Ordo der Crustacea Decapoda Protoclitiopsis antiqua gen. nov. sp. nov. aus dem Permo West-Sibiriens. Doklady Akademii Nauk, SSSR 122: 477–480), and Galicia Garassino and Krobicki, 2002 (Garassino A, Krobicki M. 2002. Galicia marianae n. gen., n. sp. (Crustacea, Decapoda, Astacidea) from the Oxfordian (Upper Jurassic) of the Southern Polish Uplands. Bulletin of the Mizunami Fossil Museum 29: 51–59), reveals the presence of a junction between the postcervical and branchiocardiac grooves. This feature is diagnostic of Eryma and supports the integration of these genera into the synonymy of Eryma. The addition of Protoclytiopsis to the synonymy of Eryma makes Eryma antiquum (Birshtein, 1958) nov. comb. the oldest representative of the genus and of the family, extending its stratigraphic range to the Late Permian (Changhsingian). Thus, this work also emphasizes that Erymidae crossed the Permian-Triassic boundary.

Nature and origin of the volcanic ash beds near the Permian–Triassic boundary in South China: new data and their geological implications

2019 ◽  
Vol 157 (4) ◽  
pp. 677-689 ◽  
Author(s):  
Binsong Zheng ◽  
Chuanlong Mou ◽  
Renjie Zhou ◽  
Xiuping Wang ◽  
Zhaohui Xiao ◽  
...  
Keyword(s):  
Trace Element ◽  
Continental Margin ◽  
South China ◽  
Volcanic Ash ◽  
Active Continental Margin ◽  
Main Body ◽  
Early Triassic ◽  
Late Permian ◽  
Triassic Boundary ◽  
Permian Triassic Boundary

AbstractPermian–Triassic boundary (PTB) volcanic ash beds are widely distributed in South China and were proposed to have a connection with the PTB mass extinction and the assemblage of Pangea. However, their source and tectonic affinity have been highly debated. We present zircon U–Pb ages, trace-element and Hf isotopic data on three new-found PTB volcanic ash beds in the western Hubei area, South China. Laser ablation inductively coupled plasma mass spectrometry U–Pb dating of zircons yields ages of 252.2 ± 3.6 Ma, 251.6 ± 4.9 Ma and 250.4 ± 2.4 Ma for these three volcanic ash beds. Zircons of age c. 240–270 Ma zircons have negative εHf(t) values (–18.17 to –3.91) and Mesoproterozoic–Palaeoproterozoic two-stage Hf model ages (THf2) (1.33–2.23 Ga). Integrated with other PTB ash beds in South China, zircon trace-element signatures and Hf isotopes indicate that they were likely sourced from intermediate to felsic volcanic centres along the Simao–Indochina convergent continental margin. The Qinling convergent continental margin might be another possible source but needs further investigation. Our data support the model that strong convergent margin volcanism took place around South China during late Permian – Early Triassic time, especially in the Simao–Indochina active continental margin and possibly the Qinling active continental margin. These volcanisms overlap temporally with the PTB biocrisis triggered by the Siberian Large Igneous Province. In addition, our data argue that the South China Craton and the Simao–Indochina block had not been amalgamated with the main body of Pangea by late Permian – Early Triassic time.

Are Late Permian carbon isotope excursions of local or of global significance?

2019 ◽  
Vol 132 (3-4) ◽  
pp. 521-544 ◽  
Author(s):  
Borhan Bagherpour ◽  
Hugo Bucher ◽  
Torsten Vennemann ◽  
Elke Schneebeli-Hermann ◽  
Dong-xun Yuan ◽  
...  
Keyword(s):  
Carbon Isotope ◽  
South China ◽  
Sea Water ◽  
Equatorial Position ◽  
Late Permian ◽  
Terrestrial Organic Matter ◽  
Triassic Boundary ◽  
Atmospheric Propagation ◽  
Isotope Record ◽  
Permian Triassic Boundary

Abstract We present a new, biostratigraphically calibrated organic and inorganic C-isotope record spanning the basal Late Permian to earliest Triassic from southern Guizhou (Nanpanjiang basin, South China). After fluctuations of a likely diagenetic overprint are removed, three negative carbon isotope excursions (CIEs) persist. These include a short-lived CIE during the early Wuchiapingian, a protracted CIE ending shortly after the Wuchiapingian–Changhsingian Boundary, and a third CIE straddling the Permian–Triassic boundary. Comparison of our new C-isotope record with others from the same basin suggests that influences of local bathymetry and of the amount of buried terrestrial organic matter are of importance. Comparison with other coeval time series outside of South China also highlights that only the negative CIE at the Permian–Triassic boundary is a global signal. These differences can be explained by the different volumes of erupted basalts between the Late Permian Emeishan and the younger Siberian large igneous provinces and their distinct eruptive modalities. Emeishan volcanism was largely submarine, implying that sea water was an efficient buffer against atmospheric propagation of volatiles. The equatorial position of Emeishan was also an additional obstacle for volatiles to reach the stratosphere and benefit from an efficient global distribution. Consequently, the local significance of these CIEs calls into question global correlations based on C-isotope chemostratigraphy during the Late Permian. The timing of the Late Permian Chinese CIEs is also not reflected in changes in species diversity or ecology, unlike the sudden and global Permian–Triassic boundary crisis and subsequent Early Triassic upheavals.

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