scholarly journals Middle Cambrian through lowermost Ordovician conodonts from Hunan, South China

2017 ◽  
Vol 91 (S73) ◽  
pp. 1-89 ◽  
Author(s):  
Xi-ping Dong ◽  
Huaqiao Zhang

AbstractSince 1986, samples with a total mass of more than 14,000 kg, mainly from three key sections in western Hunan, South China, have been processed for conodonts. Previous work mainly focused on biostratigraphy, but the taxonomy has been performed only on the faunas of the middle Cambrian. Described herein are conodonts of the upper Cambrian (Furongian Series) through lowermost Ordovician from Hunan, South China. Conodonts of the middle Cambrian are redescribed, based on material that has been recovered for more than three decades. The fauna consists of 82 species belonging to 36 genera. Newly established genera areLugnathusn. gen.,Miaognathusn. gen.,Millerodontusn. gen.,Tujiagnathusn. gen.,Wangcunellan. gen. andWangcunognathusn. gen. New species areCoelocerodontus hunanensisn. sp.,Furnishina wangcunensisn. sp.,Laiwugnathus hunanensisn. sp.,Laiwugnathus transitansn. sp.,Lugnathus hunanensisn. gen. n. sp.,Miaognathus multicostatusn. gen. n. sp.,Millerodontus intermediusn. gen. n. sp.,Prosagittodontus compressusn. sp.,Tujiagnathus gracilisn. gen. n. sp.,Wangcunella conicusn. gen. n. sp.,Wangcunognathus elegansn. gen. n. sp.,Westergaardodina dimorphan. sp.,Westergaardodina gigantean. sp., andWestergaardodina solan. sp. The taxonomy of some conodont genera is revised. In the light of histological investigation, genera are assigned to euconodonts, paraconodonts, or protoconodonts. The 13 conodont zones previously proposed in the middle Cambrian through lowermost Ordovician remain the same, but taxa within these conodont zones are documented more clearly because of the revised taxonomy proposed herein.

2001 ◽  
Vol 75 (2) ◽  
pp. 241-260 ◽  
Author(s):  
Sean P. Robson ◽  
Brian R. Pratt

Linguliform brachiopods were recovered from the Upper Cambrian Downes Point Member (lower Sunwaptan) and from the Middle Ordovician Factory Cove Member (Arenig) of the Shallow Bay Formation, Cow Head Group, of western Newfoundland. These rocks are a series of Middle Cambrian to Middle Ordovician conglomerates, lime mudstones, and shales that formed a sediment apron at the base of the lower Paleozoic continental slope of Laurentia. The linguliform brachiopod fauna consists of sixteen species assigned to twelve genera. Three new species are described: Picnotreta lophocracenta, Neotreta humberensis, and Siphonotretella parvaducta.


2017 ◽  
Vol 92 (1) ◽  
pp. 87-98 ◽  
Author(s):  
Yunhuan Liu ◽  
Qi Wang ◽  
Tiequan Shao ◽  
Huaqiao Zhang ◽  
Jiachen Qin ◽  
...  

AbstractSome rare microscopic cycloneuralians are present in the Cambrian of South China, represented by Eopriapulites and Eokinorhynchus (both early Cambrian), fossil embryos of Markuelia (middle to late Cambrian), and palaeoscolecids (early to late Cambrian). Among them, palaeoscolecids are relatively diverse and abundant. Here, we describe new material of three-dimensionally phosphatized and microscopic cycloneuralians from the Paibian Stage of Wangcun Lagerstätte, western Hunan, South China. New material includes fossil embryos assignable to Markuelia sp., two other types of fossil embryos, and three species of palaeoscolecids, including Dispinoscolex decorus Duan, Dong, and Donoghue, 2012, Schistoscolex hunanensis Duan, Dong, and Donoghue, 2012, and Austroscolex sinensis new species. The palaeoscolecid fragments differ mainly in size and armor of the trunk annuli. Since Eokinorhynchus and Eopriapulites occurred the earliest among the Cambrian cycloneuralians, it is proposed here that: (1) cycloneuralians originated in the Cambrian Fortunian small shelly faunas rather than in the early Cambrian macrobenthos, (2) ancestral cycloneuralians may have simple trunk armor, and (3) Eopriapulites represents an ancestral cycloneuralian.


1972 ◽  
Vol 9 (3) ◽  
pp. 266-279 ◽  
Author(s):  
W. T. Dean

Holasaphus centropyge Matthew, 1895, the type species of the genus, is redescribed using known and new material from the Middle Cambrian of Nova Scotia. A new species, Holasaphus mesopotamicus, described from the Derik–Mardin district of southeastern Turkey, marks the only other known occurrence of the genus. The presence there of Holasaphus and the agnostid Peronopsis in the middle portion of the Sosink Formation suggests that the latter may be no younger than Middle Cambrian and lends additional support to evidence for the probable regional absence of Upper Cambrian strata.


2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Javier Ortega-Hernández ◽  
Abdelfattah Azizi ◽  
Thomas W. Hearing ◽  
Thomas H. P. Harvey ◽  
Gregory D. Edgecombe ◽  
...  

Abstract Xandarellida is a well-defined clade of Lower Palaeozoic non-biomineralized artiopodans that is exclusively known from the early Cambrian (Stage 3) Chengjiang biota of South China. Here we describe a new member of this group, Xandarella mauretanica sp. nov., from the middle Cambrian (Stage 5) Tatelt Formation of Morocco, making this the first non-trilobite Cambrian euarthropod known from North Africa. X. mauretanica sp. nov. represents the youngest occurrence of Xandarellida – extending its stratigraphic range by approximately 10 million years – and expands the palaeobiogeographic distribution of the group to the high southern palaeolatitudes of West Gondwana. The new species provides insights into the lightly sclerotized ventral anatomy of Xandarellida, and offers stratigraphically older evidence for a palaeobiogeographic connection between Burgess Shale-type euarthropod communities in North Africa and South China, relative to the (Tremadocian) Fezouata biota.


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