scholarly journals A problematic animal fossil from the early Cambrian Hetang Formation, South China

2019 ◽  
Vol 93 (06) ◽  
pp. 1047-1057 ◽  
Author(s):  
Qing Tang ◽  
Jie Hu ◽  
Guwei Xie ◽  
Xunlai Yuan ◽  
Bin Wan ◽  
...  
Keyword(s):  
New Species ◽  
South China ◽  
Cambrian Explosion ◽  
Early Cambrian ◽  
Micro Ct ◽  
Early Life Stages ◽  
Reflected Light ◽  
Show Evidence ◽  
Incomplete Picture ◽  
Animal Taxon

AbstractThe lower-middle Hetang Formation (Cambrian Stage 2–3) deposited in slope-basinal facies in South China is well known for its preservation of the earliest articulated sponge fossils, providing an important taphonomic window into the Cambrian Explosion. However, the Hetang Formation also hosts a number of problematic animal fossils that have not been systematically described. This omission results in an incomplete picture of the Hetang biota and limits its contribution to the understanding of the early evolution of animals. Here we describe a new animal taxon, Cambrowania ovata Tang and Xiao, new genus new species, from the middle Hetang Formation in the Lantian area of southern Anhui Province, South China. Specimens are preserved as carbonaceous compressions, although some are secondarily mineralized. A comprehensive analysis using reflected light microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and micro-CT reveals that the new species is characterized by a spheroidal to fusoidal truss-like structure consisting of rafter-like crossbars, some of which are secondarily baritized and may have been internally hollow. Some specimens have aperture-like structures that are broadly similar to oscula of sponges, whereas others show evidence of a medial split reminiscent of gaping carapaces. While the phylogenetic affinity of Cambrowania ovata Tang and Xiao, n. gen. n. sp. remains problematic, we propose that it may represent carapaces of bivalved arthropods or more likely sponges in early life stages. Along with other problematic metazoan fossils such as hyolithids and sphenothallids, Cambrowania ovata Tang and Xiao, n. gen. n. sp. adds to the diversity of the sponge-dominated Hetang biota in an early Cambrian deepwater slope-basinal environment.UUID: http://zoobank.org/44de9472-7e3f-42d1-9554-7b3434df91d9

scholarly journals A superarmored lobopodian from the Cambrian of China and early disparity in the evolution of Onychophora

2015 ◽  
Vol 112 (28) ◽  
pp. 8678-8683 ◽  
Author(s):  
Jie Yang ◽  
Javier Ortega-Hernández ◽  
Sylvain Gerber ◽  
Nicholas J. Butterfield ◽  
Jin-bo Hou ◽  
...  
Keyword(s):  
South China ◽  
Cambrian Explosion ◽  
Suspension Feeding ◽  
Early Cambrian ◽  
Early Paleozoic ◽  
Crown Group ◽  
Morphological Disparity ◽  
Stem Group ◽  
Velvet Worms ◽  
Mode Of Life

We describe Collinsium ciliosum from the early Cambrian Xiaoshiba Lagerstätte in South China, an armored lobopodian with a remarkable degree of limb differentiation including a pair of antenna-like appendages, six pairs of elongate setiferous limbs for suspension feeding, and nine pairs of clawed annulated legs with an anchoring function. Collinsium belongs to a highly derived clade of lobopodians within stem group Onychophora, distinguished by a substantial dorsal armature of supernumerary and biomineralized spines (Family Luolishaniidae). As demonstrated here, luolishaniids display the highest degree of limb specialization among Paleozoic lobopodians, constitute more than one-third of the overall morphological disparity of stem group Onychophora, and are substantially more disparate than crown group representatives. Despite having higher disparity and appendage complexity than other lobopodians and extant velvet worms, the specialized mode of life embodied by luolishaniids became extinct during the Early Paleozoic. Collinsium and other superarmored lobopodians exploited a unique paleoecological niche during the Cambrian explosion.

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.

New vauxiid sponges from the Chengjiang Biota and their evolutionary significance

2021 ◽  
pp. jgs2020-162
Author(s):  
Fan Wei ◽  
Yang Zhao ◽  
Ailin Chen ◽  
Xianguang Hou ◽  
Peiyun Cong
Keyword(s):  
South China ◽  
Vertical Surface ◽  
Cambrian Explosion ◽  
Evolutionary Significance ◽  
Early Cambrian ◽  
Geological History ◽  
Burgess Shale ◽  
Content Type ◽  
Dermal Layer ◽  
Chengjiang Biota

Aspiculate demosponges are rarely described in geological history on account of the absence of spicules that are stable and resistant to degradation. One exception is the exquisite preservation of sponges without any mineralised skeletons discovered in Lagerstätten (e.g. the Burgess Shale). The Chengjiang Biota, an early example of a Burgess Shale-type Biota in South China (Cambrian Series 2, Stage 3), is one of the only examples of convincing aspiculate sponges until now. Here, we describe Vauxia pregracilenta sp. nov. and V. paraleioia sp. nov., as well as two poorly preserved vauxiid specimens (Vauxia sp.) in open nomenclature, from the Chengjiang Biota. V. pregracilenta has a fan-like holdfast and branches in various sizes, as well as a typical two-layered net-like skeleton, without spicules. The endosomal layer is hexagonal, while the dermal layer is sub-rectangular. V. paraleioia is characterised by a two-layered subconical skeleton, with the dermal layer ornamented with vertical surface grooves. The openings of the dermal and endosomal layers of V. paraleioia are both hexagonal but of different sizes. These newly discovered Vauxia species indicate that the aspiculate sponges were diversified in the early Cambrian period. Partial silicification of the fibres of aspiculate Vauxia are confirmed from the Chengjiang Biota.Thematic collection: This article is part of the Advances in the Cambrian Explosion collection available at: https://www.lyellcollection.org/cc/advances-cambrian-explosion

Oceanic chemistry recorded by cherts during the early Cambrian Explosion, South China

2020 ◽  
Vol 558 ◽  
pp. 109961 ◽  
Author(s):  
Hongjie Zhang ◽  
Haifeng Fan ◽  
Hanjie Wen ◽  
Xiangkun Zhu ◽  
Shihong Tian
Keyword(s):  
South China ◽  
Cambrian Explosion ◽  
Early Cambrian

scholarly journals A xandarellid artiopodan from Morocco – a middle Cambrian link between soft-bodied euarthropod communities in North Africa and South China

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Javier Ortega-Hernández ◽  
Abdelfattah Azizi ◽  
Thomas W. Hearing ◽  
Thomas H. P. Harvey ◽  
Gregory D. Edgecombe ◽  
...  
Keyword(s):  
New Species ◽  
North Africa ◽  
South China ◽  
Early Cambrian ◽  
Burgess Shale ◽  
Middle Cambrian ◽  
West Gondwana ◽  
Lower Palaeozoic ◽  
Chengjiang Biota ◽  
Stratigraphic Range

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.

Occurrence of the eudemersal radiodont Cambroraster in the early Cambrian Chengjiang Lagerstätte and the diversity of hurdiid ecomorphotypes

2020 ◽  
Vol 157 (7) ◽  
pp. 1200-1206 ◽  
Author(s):  
Yu Liu ◽  
Rudy Lerosey-Aubril ◽  
Denis Audo ◽  
Dayou Zhai ◽  
Huijuan Mai ◽  
...  
Keyword(s):  
New Species ◽  
South China ◽  
Early Cambrian ◽  
Burgess Shale ◽  
Stem Group ◽  
Lower Palaeozoic ◽  
Trophic Webs ◽  
Chengjiang Lagerstätte ◽  
A New Species

AbstractRadiodonts are a diverse clade of Lower Palaeozoic stem-group euarthropods that played a key role in the emergence of complex marine trophic webs. The latest addition to the group, Cambroraster falcatus, was recently described from the Wuliuan Burgess Shale, and is characterized by a unique horseshoe-shaped central carapace element. Here we report the discovery of Cambroraster sp. nov. A, a new species from the Cambrian Stage 3 Chengjiang Lagerstätte of South China. The new occurrence of Cambroraster demonstrates that some of the earliest known radiodonts had already evolved a highly derived carapace morphology adapted to an essentially eudemersal life as sediment foragers.

The Qingjiang biota—A Burgess Shale–type fossil Lagerstätte from the early Cambrian of South China

Science ◽  
2019 ◽  
Vol 363 (6433) ◽  
pp. 1338-1342 ◽  
Author(s):  
Dongjing Fu ◽  
Guanghui Tong ◽  
Tao Dai ◽  
Wei Liu ◽  
Yuning Yang ◽  
...  
Keyword(s):  
New Taxa ◽  
South China ◽  
Environmental Gradients ◽  
Taxonomic Diversity ◽  
High Abundance ◽  
Cambrian Explosion ◽  
Early Cambrian ◽  
Burgess Shale ◽  
Very High

Burgess Shale–type fossil Lagerstätten provide the best evidence for deciphering the biotic patterns and magnitude of the Cambrian explosion. Here, we report a Lagerstätte from South China, the Qingjiang biota (~518 million years old), which is dominated by soft-bodied taxa from a distal shelf setting. The Qingjiang biota is distinguished by pristine carbonaceous preservation of labile organic features, a very high proportion of new taxa (~53%), and preliminary taxonomic diversity that suggests it could rival the Chengjiang and Burgess Shale biotas. Defining aspects of the Qingjiang biota include a high abundance of cnidarians, including both medusoid and polypoid forms; new taxa resembling extant kinorhynchs; and abundant larval or juvenile forms. This distinctive composition holds promise for providing insights into the evolution of Cambrian ecosystems across environmental gradients.

scholarly journals Latest Permian deep-water ostracods from southwestern Guangxi, South China

2007 ◽  
Vol 26 (2) ◽  
pp. 169-191 ◽  
Author(s):  
Aihua Yuan ◽  
Sylvie Crasquin-Soleau ◽  
Qinglai Feng ◽  
Songzhu Gu
Keyword(s):  
New Species ◽  
South China ◽  
Deep Water ◽  
World Wide ◽  
Pelagic Species ◽  
Two New Species ◽  
First World

Abstract. A very diverse ostracod fauna was discovered in the latest Permian strata of the Dongpan section, southwestern Guangxi, South China. Fifty-one species belonging to twenty-eight genera were identified and described, including two new species (Bairdia dongpanensis n. sp. and Spinomicrocheilinella anterocompressa n. sp). This type of assemblage, with nineteen palaeopsychrospheric species and four pelagic species, is the first world-wide deep-water ostracod fauna reported from the latest Permian strata and the first one recorded in the Permian of China. The palaeoenvironmental analysis allows one to propose an evaluation of the bathymetry variation along the Dongpan section.

scholarly journals Current understanding on the Cambrian Explosion: questions and answers

PalZ ◽  
2021 ◽  
Author(s):  
Xingliang Zhang ◽  
Degan Shu
Keyword(s):  
Environmental Changes ◽  
Size Variation ◽  
Progressive Increase ◽  
Cambrian Explosion ◽  
Time Interval ◽  
Early Cambrian ◽  
Ecological Processes ◽  
Questions And Answers ◽  
Evolutionary Event ◽  
History Of

AbstractThe Cambrian Explosion by nature is a three-phased explosion of animal body plans alongside episodic biomineralization, pulsed change of generic diversity, body size variation, and progressive increase of ecosystem complexity. The Cambrian was a time of crown groups nested by numbers of stem groups with a high-rank taxonomy of Linnaean system (classes and above). Some stem groups temporarily succeeded while others were ephemeral and underrepresented by few taxa. The high number of stem groups in the early history of animals is a major reason for morphological gaps across phyla that we see today. Most phylum-level clades achieved their maximal disparity (or morphological breadth) during the time interval close to their first appearance in the fossil record during the early Cambrian, whereas others, principally arthropods and chordates, exhibit a progressive exploration of morphospace in subsequent Phanerozoic. The overall envelope of metazoan morphospace occupation was already broad in the early Cambrian though it did not reach maximal disparity nor has diminished significantly as a consequence of extinction since the Cambrian. Intrinsic and extrinsic causes were extensively discussed but they are merely prerequisites for the Cambrian Explosion. Without the molecular evolution, there could be no Cambrian Explosion. However, the developmental system is alone insufficient to explain Cambrian Explosion. Time-equivalent environmental changes were often considered as extrinsic causes, but the time coincidence is also insufficient to establish causality. Like any other evolutionary event, it is the ecology that make the Cambrian Explosion possible though ecological processes failed to cause a burst of new body plans in the subsequent evolutionary radiations. The Cambrian Explosion is a polythetic event in natural history and manifested in many aspects. No simple, single cause can explain the entire phenomenon.

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