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

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.

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 Tabelliscolex (Cricocosmiidae: Palaeoscolecidomorpha) from the early Cambrian Chengjiang Biota, and the evolution of seriation in Ecdysozoa

2021 ◽  
pp. jgs2021-060
Author(s):  
Xiaomei Shi ◽  
Richard J. Howard ◽  
Gregory D. Edgecombe ◽  
Xianguang Hou ◽  
Xiaoya Ma
Keyword(s):  
Phylogenetic Analyses ◽  
Sensu Stricto ◽  
Cambrian Explosion ◽  
Early Cambrian ◽  
Content Type ◽  
Link Type ◽  
Stem Group ◽  
New Material ◽  
Supplementary Material ◽  
Chengjiang Biota

Cricocosmiidae is a clade of palaeoscolecid-like worms from the Chengjiang Biota, China (Cambrian Stage 3). In contrast to palaeoscolecids sensu stricto, which exhibit tessellating micro-plate trunk ornamentation, cricocosmiids possess larger, serially repeated sets of trunk sclerites bearing resemblance to lobopodian trunk sclerites (e.g., Microdictyon spp.). Cricocosmiidae were therefore proposed as stem-group Panarthropoda in some studies but are recovered as stem-group Priapulida in most phylogenetic analyses. The affinity of cricoscosmiids within Ecdysozoa is therefore of much interest, as is testing the homology of these seriated structures. We report four new specimens of the rare cricocosmiid Tabelliscolex hexagonus, yielding new details of the ventral trunk projections, sclerites and proboscis. New data confirm T. hexagonus possessed paired ventral trunk projections in a consistent seriated pattern, which is also reported from new material of Cricocosmia jinningensis (Cricocosmiidae) and Mafangscolex yunnanensis (Palaeoscolecida sensu stricto). Even when the seriated sclerites and ventral projections of cricocosmiids are coded as homologous with the seriated trunk sclerites and paired appendages, respectively, of lobopodian panarthropods, our tree searches indicate they are convergent. Cricocosmiidae is nested within a monophyletic “Palaeoscolecida sensu lato” clade (Palaeoscolecidomorpha nov.) in stem-group Priapulida. Our study indicates that morphological seriation has independent origins in Scalidophora and Panarthropoda.Thematic collection: This article is part of the Advances in the Cambrian Explosion collection available at: https://www.lyellcollection.org/cc/advances-cambrian-explosionSupplementary material:https://doi.org/10.6084/m9.figshare.c.5551565

scholarly journals Brachiopod-dominated communities and depositional environment of the Guanshan Konservat-Lagerstätte, eastern Yunnan, China

2020 ◽  
Vol 178 (1) ◽  
pp. jgs2020-043 ◽  
Author(s):  
Feiyang Chen ◽  
Glenn A. Brock ◽  
Zhiliang Zhang ◽  
Brittany Laing ◽  
Xinyi Ren ◽  
...  
Keyword(s):  
Depositional Environment ◽  
Sedimentary Environment ◽  
Low Energy ◽  
Cambrian Explosion ◽  
Early Cambrian ◽  
Tissue Preservation ◽  
Content Type ◽  
Guanshan Biota ◽  
Supplementary Material ◽  
Later Phase

The Guanshan Biota is an unusual early Cambrian Konservat-Lagerstätte from China and is distinguished from all other exceptionally preserved Cambrian biotas by the dominance of brachiopods and a relatively shallow depositional environment. However, the faunal composition, overturn and sedimentology associated with the Guanshan Biota are poorly understood. This study, based on collections through the best-exposed succession of the basal Wulongqing Formation at the Shijiangjun section, Wuding County, eastern Yunnan, China recovered six major animal groups with soft tissue preservation; brachiopods vastly outnumbered all other groups. Brachiopods quickly replace arthropods as the dominant fauna following a transgression at the base of the Wulongqing Formation. A transition from a botsfordiid-, eoobolid- and acrotretid- to an acrotheloid-dominated brachiopod assemblage occurs up-section. Four episodically repeated lithofacies reveal a relatively low-energy, offshore to lower shoreface sedimentary environment at the Shijiangjun section, which is very different from the Wulongqing Formation in the Malong and Kunming areas. Multiple event flows and rapid obrution are responsible for faunal overturn and fluctuation through the section. A detailed lithofacies and palaeontological investigation of this section provides a better understanding of the processes and drivers of faunal overturn during the later phase of the Cambrian Explosion.Supplementary material: Composition and comparison of the Malong Fauna and the Guanshan Biota is are available at: https://doi.org/10.6084/m9.figshare.c.5080799

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.

scholarly journals Discussion on ‘Tabelliscolex (Cricocosmiidae: Palaeoscolecidomorpha) from the early Cambrian Chengjiang Biota and the evolution of seriation in Ecdysozoa’ by Shi et al. 2021 (JGS, jgs2021-060)

2021 ◽  
pp. jgs2021-111
Author(s):  
Martin R. Smith ◽  
Alavya Dhungana
Keyword(s):  
Bayesian Approach ◽  
Early Cambrian ◽  
Content Type ◽  
Animal Body ◽  
Link Type ◽  
Stem Group ◽  
Cambrian Radiation ◽  
Supplementary Material ◽  
Chengjiang Biota

Exceptionally preserved fossils are key to reconstructing the origin of the modern animal body plans in the Cambrian radiation. The Panarthropod phyla Euarthropoda, Onychophora and Tardigrada have roots in a ‘lobopodian’ grade typified by broadly cylindrical organisms with sclerotized dorsal plates and paired ventral projections. A similar anatomical configuration has been taken to link certain palaeoscolecid worms with the earliest ecdysozoans. Shi et al. (2021) contend that these similarities evolved convergently, and that palaeoscolecids are priapulan relatives with little bearing on the panarthropod evolution.Here we show that this conclusion holds only under a particular treatment of inapplicable character states with known shortcomings. When inapplicable tokens are handled more rigorously, palaeoscolecids are most parsimoniously reconstructed as stem-group panarthropods with homologous dorsal plates and ventral projections – highlighting the degree to which the treatment of inapplicable data can influence fundamental evolutionary conclusions. As the position of palaeoscolecids depends so strongly on the underlying methodology, and is highly uncertain under a Bayesian approach, we consider it premature to exclude the possibility that panarthropods evolved from a grade of palaeoscolecids with dorsal plates and ventral projections.Supplementary material:https://doi.org/10.6084/m9.figshare.16419522

A new arthropod Pygmaclypeatus daziensis from the Early Cambrian Chengjiang Lagerstätte, South China

2000 ◽  
Vol 74 (5) ◽  
pp. 979-982 ◽  
Author(s):  
Xingliang Zhang ◽  
Jian Han ◽  
Degan Shu
Keyword(s):  
South China ◽  
Fossil Record ◽  
South Australia ◽  
Early Cambrian ◽  
Burgess Shale ◽  
Closely Related Species ◽  
Stratigraphic Position ◽  
Chengjiang Lagerstätte ◽  
Early Metazoan ◽  
North Greenland

The early Cambrian Chengjiang Lagerstatte, generally regarded as late Atdabanian (Qian and Bengtson, 1989; Bengtson et al., 1990), has become celebrated for perhaps the earliest biota of soft-bodied organisms known from the fossil record and has proven to be critical to our understanding of early metazoan evolution. The Sirius Passet fauna from Peary Land, North Greenland, another important repository of soft-bodied and poorly sclerotized fossils, was also claimed as Early Cambrian (Conway Morris et al., 1987; Budd, 1995). The exact stratigraphic position of the Sirius Passet fauna (Buen Formation) is still uncertain, although the possibility of late Atdabanian age was proposed (Vidal and Peel, 1993). Recent work dates it in the “Nevadella” Biozone (Budd and Peel, 1998). It therefore appears to be simultaneous with or perhaps slightly younger than Chengjiang Lagerstatte, Eoredlichia Biozone (Zhuravlev, 1995). The Emu Bay Shale of Kangaroo Island, South Australia, has long been famous as a source of magnificent specimens of the trilobites Redlichia takooensis and Hsunaspis bilobata. It is additionally important as the only site in Australia so far to yield a Burgess-Shale-type biota (Glaessner, 1979; Nedin, 1992). The Emu Bay Shale was considered late Early Cambrian in age (Daily, 1956; Öpik, 1975). But Zhang et al.(1980) reassessed its age based on data from the Chinese Early Cambrian. The occurrence of Redlichia takooensis and closely related species of Hsunaspis indicates an equivalence to the Tsanglangpuian in the Chinese sequence, and the contemporary South Australia fauna correlate with the Botomian of Siberia (Bengtson et al., 1990). Thus the Emu Bay Shale is younger than the upper Atdabanian Chengjiang Lagerstatte, Chiungchussuian.

Terreneuvian bio- and chemostratigraphy of the South Sichuan Region (South China)

2021 ◽  
pp. jgs2020-167
Author(s):  
Ben Yang ◽  
Michael Steiner
Keyword(s):  
Carbon Isotope ◽  
South China ◽  
Cambrian Explosion ◽  
The South ◽  
Yangtze Craton ◽  
Content Type ◽  
Link Type ◽  
Small Shelly Fossils ◽  
Assemblage Zone ◽  
Supplementary Material

Classical sections, such as the Maidiping and Daqiao Mine sections of South Sichuan (China), expose early Cambrian deposits that are crucial for understanding the biological and environmental evolution of Yangtze Craton. These sequences are rich in Terreneuvian small shelly fossils, which can be assigned to assemblages I and III from South China. The Anabarites trisulcatus– Protohertzina anabarica Assemblage Zone (Assemblage I) is recognized at the lower Maidiping Formation. The second assemblage (Paragloborilus subglobosus – Purella squamulosa Assemblage Zone) cannot be verified in South Sichuan, although previous reports claimed its existence based on the occurrence of Paragloborilus subglobosus. The third assemblage (Watsonella crosbyi Assemblage Zone) is confirmed in the upper Maidiping Formation. The abundant bioclasts in this interval indicate abrasions and bioerosions by winnowing or starved sedimentation. Carbon isotope values from the Maidiping section present no negative excursion at the presumed Ediacaran–Cambrian transition. A positive carbon isotope excursion is observed in the upper Maidiping Formation (Assemblage III) which is correlated to the ZHUCE excursion in the Dahai Member of eastern Yunnan. The shallow water deposits of South Sichuan can be correlated with the South China, western Mongolia and Siberia successions based on biozonations and carbon isotope trends.Thematic collection: This article is part of the Advances in the Cambrian Explosion collection available at: https://www.lyellcollection.org/cc/advances-cambrian-explosionSupplementary material:https://doi.org/10.6084/m9.figshare.c.5326834

The Burgess Shale arthropod Mollisonia (M. sinica new species): new occurrence from the Middle Cambrian Kaili fauna of southwest China

2002 ◽  
Vol 76 (6) ◽  
pp. 1106-1108 ◽  
Author(s):  
Xingliang Zhang ◽  
Yuanlong Zhao ◽  
Ruidong Yang ◽  
Degan Shu
Keyword(s):  
Southwest China ◽  
Middle Part ◽  
Guizhou Province ◽  
Cambrian Explosion ◽  
Early Cambrian ◽  
Burgess Shale ◽  
Middle Cambrian ◽  
Lowermost Part ◽  
Dark Green ◽  
Chengjiang Lagerstätte

The Early Cambrian Chengjiang Lagerstätte, Yunnan Province, Southwest China, has become one of the most celebrated Cambrian fossil Lagerstatten not only for perhaps the earliest biota of soft-bodied organisms in the Phanerozoic (Yuan and Zhao, 1999; Zhang et aI., 2001; but see Budd and Jensen, 2000), but also for a number of significant discoveries (Shu et al., 1996a, 1996b, 1999a, 1999b, 2001), proven to be of particular importance for our understanding the Cambrian explosion. Also in Southwest China, Guizhou Province, there is a very significant, although less acclaimed, Middle Cambrian soft-bodied fauna as well, namely the Kaili fauna, which occurs in the Kaili Formation in Kaili area (Kuizhou). The age of the Kaili Formation ranges from late Early to early Middle Cambrian. Regionally, the Kaili Formation is about 222 m thick and consists of three parts. The lowermost part (late Early Cambrian, about 55 m thick) is dominated by thin, calcareous siltstone strata interbedded with limestone layers at the base. The middle part (early Middle Cambrian, ca. 123 m) consists of dark green mudstone and shale, while the uppermost part (ca. 44 m) is composed of interbedded limestone and silty shale. The Kaili fauna is derived from mudstones in the middle part of the formation (Zhao et aI., 1994; Zhu et aI., 2000).

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