Early Cambrian Lingulellotreta (Lingulata, Brachiopoda) from South Kazakhstan (Malyi Karatau Range) and South China (Eastern Yunnan)

1997 ◽  
Vol 71 (4) ◽  
pp. 577-584 ◽  
Author(s):  
Lars E. Holmer ◽  
Leonid E. Popov ◽  
Svetlana P. Koneva ◽  
Rong Jia-Yu
Keyword(s):  
South China ◽  
Lower Cambrian ◽  
Early Cambrian ◽  
Younger Age ◽  
New Material ◽  
Lowermost Part

“Lingulepis’ malongensis Rong from the upper part of the Lower Cambrian Chiungchussu Formation of Yunnan is referred to Lingulellotreta Koneva; L. malongensis (=Lingulellotreta ergalievi Koneva) is redescribed on the basis of new material from the Lower Cambrian of south Kazakhstan. It is the earliest known taxon of the Lingulellotretidae, which is unique within the Linguloidea in having an elongate pedicle foramen and internal pedicle tube. The occurrence of Lingulellotreta malongensis in south China is considered usually to be of Atdabanian age, but brachiopod based correlation with south Kazakhstan suggests that a possible Botomian or younger age, for both the upper part of Chiungchussu Formation in Yunnan and the lowermost part of Shabakty Group in the Malyi Karatau Range, is equally plausible.

scholarly journals Ontogeny of the articulated yiliangellinine trilobite Zhangshania typica from the lower Cambrian (Series 2, Stage 3) of southern China

2016 ◽  
Vol 91 (1) ◽  
pp. 86-99 ◽  
Author(s):  
Jin-bo Hou ◽  
Nigel C. Hughes ◽  
Jie Yang ◽  
Tian Lan ◽  
Xi-guang Zhang ◽  
...  
Keyword(s):  
South China ◽  
Lower Cambrian ◽  
Southern China ◽  
Junior Synonym ◽  
Early Cambrian ◽  
South China Block ◽  
The South ◽  
Positive Allometry ◽  
Regional Correlation ◽  
Almost All

AbstractNew discoveries of the early Cambrian yiliangellinine trilobite Zhangshania typica Li and Zhang in Kunming preserve almost all instars from early postembryonic (protaspid) to mature (holaspid) phases in articulated state, in addition to mature specimens with antennae bearing paired spines on the basal articles. The ontogenetic series shows protarthrous development with some, but likely not all, early holaspid instars expressing additional pygidial segments, gradual rearward migration of the location of the longest pleural spines on the trunk segments, and striking positive allometry of the genal spines. It also reveals Parazhangshania sichuanensis Li and Zhang, 1990 to be the holaspid stage 3 of Z. typica, and therefore its junior synonym. This new find in the Hongjingshao Formation provides species-based regional correlation across the South China block and Z. typica may provide an important biostratigraphic marker for the base of the traditional Tsanglangpuan Stage.

New material of three-dimensionally phosphatized and microscopic cycloneuralians from the Cambrian Paibian Stage of South China

2017 ◽  
Vol 92 (1) ◽  
pp. 87-98 ◽  
Author(s):  
Yunhuan Liu ◽  
Qi Wang ◽  
Tiequan Shao ◽  
Huaqiao Zhang ◽  
Jiachen Qin ◽  
...  
Keyword(s):  
New Species ◽  
South China ◽  
Early Cambrian ◽  
Late Cambrian ◽  
New Material ◽  
Western Hunan ◽  
Fossil Embryos

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.

Ontogeny of the redlichiid trilobite Metaredlichia cylindrica from the lower Cambrian (Stage 3) of South China

2012 ◽  
Vol 86 (4) ◽  
pp. 646-651 ◽  
Author(s):  
Tao Dai ◽  
Xingliang Zhang
Keyword(s):  
Black Shale ◽  
South China ◽  
Lower Cambrian ◽  
Morphological Changes ◽  
Hubei Province ◽  
Early Cambrian ◽  
Developmental Trends ◽  
Ontogenetic Stages ◽  
Two Stages ◽  
Fourth Pair

A number of immature and mature exoskeletons allow the first detailed description of the ontogeny of the early Cambrian redlichiid trilobite Metaredlichia cylindrica, from black shale of the Shuijingtuo Formation in Hubei Province, South China. The material includes numerous complete protaspides, within which two stages can be differentiated according to the appearance of a shallow furrow that separates the protopygidial area from the protocranidium. Also, identification of the subsequent ontogenetic stages, including meraspides and holaspides, depends on isolated cranidia that display prominent morphological changes such as the contraction of frontal glabellar lobe, appearance of the fourth pair of glabellar furrows, and modification of the facial suture from proparian to opisthoparian. Incorporating the whole ontogenetic sequence allows us not only to trace the developmental trends of various structures with growth, but also to assign the protaspides to their adults correctly, particularly with the help of meraspid specimens.

Carinachitiids, hexangulaconulariids, and Punctatus: problematic metazoans from the Early Cambrian of South China

1992 ◽  
Vol 66 (3) ◽  
pp. 384-406 ◽  
Author(s):  
Simon Conway Morris ◽  
Chen Menge
Keyword(s):  
South China ◽  
Lower Cambrian ◽  
Morphological Variability ◽  
The Other ◽  
Early Cambrian ◽  
Additional Support ◽  
Alternative Suggestion

Carinachitiids, hexangulaconulariids, and Punctatus are distinctive and abundant components of early skeletal faunas from the Lower Cambrian of South China. Carinachitiids are redescribed on the basis of Carinachites spinatus from Kuanchuanpu, Shaanxi, and C. tetrasulcatus and C. curvatornatus from Emei, Sichuan. Tubes of all species are characterized by pronounced quadriradial symmetry, but whereas C. spinatus and C. curvatornatus generally have prominent ornamentation consisting of transverse ribbing, that of C. tetrasulcatus is much more subdued. Neither apex nor well-defined aperture is evident in any of the carinachitiids. Hexangulaconulariids are redescribed on the basis of Arthrochites emeishanensis from Emei and Hexaconularia sichuanensis from Kuanchuanpu. In common with the carinachitiids, the former species shows wide morphological variability. The tubes expand rapidly from a blunt apex, bear prominent ribbing, and possess variably developed lateral grooves that impose a quasi-hexaradial symmetry. Hexaconularia sichuanensis is described from fragmentary material with prominent ribbing and well-defined lateral grooves. Punctatus emeiensis has a tapering ribbed cone, with a stellate ornamentation adapically that is replaced by longitudinal ribbing towards the aperture. Carinachitiids and hexangulaconulariids are widely regarded as related to conularids, and this proposal receives additional support here. An external abortive ?borehole in a specimen of Carinachites also supports the tubicolous interpretation of these fossils. An alternative suggestion that carinachitiids and hexangulaconulariids represent the internal rachis of a sea-pen is also considered. The affinities of Punctatus are more speculative, but the genus may be related to the other two groups. The ecology of Punctatus, however, remains problematic.

scholarly journals An Early Cambrian problematic fossil: Vetustovermis and its possible affinities

2005 ◽  
Vol 272 (1576) ◽  
pp. 2003-2007 ◽  
Author(s):  
Jun-yuan Chen ◽  
Di-ying Huang ◽  
David J Bottjer
Keyword(s):  
South China ◽  
Lower Cambrian ◽  
Early Cambrian ◽  
Animal Group ◽  
Middle Cambrian ◽  
Animal Groups ◽  
Anatomical Features ◽  
Anatomical Analysis ◽  
Evolutionary Level ◽  
Well Differentiated

The Early Cambrian problematic fossil Vetustovermis (Glaessner 1979 Alcheringa 3 , 21–31) was described as an annelid or arthropod. Anatomical analysis of 17 new specimens from the Lower Cambrian Maotianshan Shale at Anning, Kunming (South China) does not support its affinities with annelids or arthropods. Anatomical features instead resemble other animal groups including modern flatworms, nemertines and molluscs. The presence of a pelagic slug-like form and ventral foot, as well as a head with eyes and tentacles indicates a possible affinity with molluscs, but these characters are not present only in molluscs; some of them are shared with other animal groups, including flatworms and nemertines. For example, a ventral foot-like structure is found in nemertines, ‘turbellarians’, and some polychaete groups. The well differentiated head is seen in separate bilaterian groups, but among molluscs it did not occur before the evolutionary level of the Conchifera. Unlike the ctenia-gills in molluscs, the gills in Vetustovermis are bar-like. All the characters displayed in this 525 million-year old soft-bodied animal fail to demonstrate clear affinity with molluscs or any other known extant or extinct animal groups, but argue for representing an independently evolved animal group, which flourished in Early Cambrian and possibly in Middle Cambrian time.

scholarly journals Malongitubus: a possible pterobranch hemichordate from the early Cambrian of South China

2017 ◽  
Vol 92 (1) ◽  
pp. 26-32 ◽  
Author(s):  
Shixue Hu ◽  
Bernd-D. Erdtmann ◽  
Michael Steiner ◽  
Yuandong Zhang ◽  
Fangchen Zhao ◽  
...  
Keyword(s):  
South China ◽  
Organic Material ◽  
Early Cambrian ◽  
Burgess Shale ◽  
Shallow Marine ◽  
Marine Communities ◽  
Mass Occurrence ◽  
Branching Points ◽  
New Material ◽  
Chengjiang Lagerstätte

AbstractMalongitubus kuangshanensis Hu, 2005 from the early Cambrian Chengjiang Lagerstätte of China is redescribed as a pterobranch and provides the best evidence to demonstrate that hemichordates were present as early as Cambrian Stage 3. Interpretation of this taxon as a hemichordate is based on the morphology of the branched colony and the presence of resistant inner threads consistent with the remains of an internal stolon system. The presence of fusellar rings in the colonial tubes cannot be unambiguously proven for Malongitubus, probably due to early decay and later diagenetic replacement of the thin organic material of the tubarium, although weak annulations are still discernible in parts of the tubes. The description of M. kuangshanensis is revised according to new observations of previously reported specimens and recently collected additional new material. Malongitubus appears similar in most features to Dalyia racemata Walcott, 1919 from the Cambrian Stage 5 Burgess Shale, but can be distinguished by the existence of disc-like thickenings at the bases of tubarium branching points in the latter species. Both species occur in rare mass-occurrence layers with preserved fragmentary individuals of different decay stages, with stolon remains preserved as the most durable structures. Benthic pterobranchs may have occurred in some early Cambrian shallow marine communities in dense accumulations and provided firm substrates and shelter for other benthic metazoans as secondary tierers.

Characteristics and formation processes of (Ba, K, NH4)-feldspar and cymrite from a lower Cambrian black shale sequence in Anhui Province, South China

2018 ◽  
Vol 82 (1) ◽  
pp. 1-21 ◽  
Author(s):  
Chao Chang ◽  
Wen-Xuan Hu ◽  
Qi Fu ◽  
Jian Cao ◽  
Xiao-Lin Wang ◽  
...  
Keyword(s):  
Black Shale ◽  
South China ◽  
Lower Cambrian ◽  
Tectonic Setting ◽  
Anhui Province ◽  
Hydrothermal Fluids ◽  
Early Cambrian ◽  
Formation Processes ◽  
Multi Stage ◽  
Extensional Tectonic

ABSTRACTBarium-rich silicates were recently found in the lower Cambrian black shale sequence of Anhui Province, South China. The Ba silicates can be divided into Ba-poor K-feldspar, Ba-rich K-feldspar and cymrite, on the basis of occurrence and composition. The Ba-poor K-feldspar have low BaO contents (<1.00 wt.%) and occur as sporadic grains in mudstone. In contrast, the Ba-rich K-feldspar have higher BaO contents (1.36–20.51 wt.%) and occur mainly as rims around grains of Ba-poor K-feldspar in mudstone, as void fillings in dolostone, and as grains dispersed in chert. The cymrite is observed only in chert and occurs as dispersed euhedral tabular crystals. Analyses of the Ba-poor K-feldspar and Ba-rich K-feldspar provide compositions that total <100 wt.% and show non-stoichiometry characterized by (Na + K + Ba + Ca)apfu less than 1.00 and (Al + Si)apfu slightly higher than 4.00. Raman and infrared (IR) spectroscopy has revealed the presence of ${\rm NH}_{\rm 4}^{\rm +} $ and H2O in the Ba-rich K-feldspar, which accounts for the unusual composition of these feldspars. We suggest that the formation processes of the Ba-poor K-feldspar, Ba-rich K-feldspar and cymrite were closely associated with multi-stage hydrothermal fluids enriched in Ba and NH4, consistent with an extensional tectonic setting during the early Cambrian. The Ba-poor K-feldspars might have formed through interactions between pre-existing K-feldspars and hydrothermal fluids. The Ba-rich K-feldspars in mudstone and dolostone formed mainly by precipitation from hydrothermal fluids that infiltrated the sediments, and we suggest the Ba-rich K-feldspars and cymrite in the chert are of exhalative hydrothermal origin.

scholarly journals Development of the early Cambrian oryctocephalid trilobite Oryctocarella duyunensis from western Hunan, China

2021 ◽  
pp. 1-16
Author(s):  
Tao Dai ◽  
Nigel C. Hughes ◽  
Xingliang Zhang ◽  
Shanchi Peng
Keyword(s):  
South China ◽  
Growth Pattern ◽  
Lower Cambrian ◽  
Hunan Province ◽  
Early Cambrian ◽  
Gradual Change ◽  
Stage 4 ◽  
Western Hunan ◽  
Trunk Segments

Abstract Abundant articulated specimens of the oryctocarine trilobite Oryctocarella duyunensis from the lower Cambrian (Stage 4, Series 2) Balang Formation at the Bulin section in western Hunan Province, South China, permit the description of all meraspid degrees. The maximum number of thoracic segments observed in this collection is 11. Meraspid growth was accompanied by progressive and gradual change in overall form, and this animal showed an homonymously segmented trunk with variation in the number of pygidial segments during ontogeny. Such variation permits a variety of plausible explanations, but a model of successive instars defined by the number of thoracic segments, and in suborder by the number of pygidial segments, is highly unlikely to explain the growth pattern because it would result in the loss of trunk segments between some instars. Degree-based ontogenetic staging is compatible with the variation observed.

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