Dimorphism of Bivalved ArthropodBranchiocaris? Yunnanensisfrom the Early Cambrian Chengjiang Biota, South China

A new arthropod Jugatacaris agilis n. gen. n. sp. with excellent soft anatomy is reported from the Early Cambrian Chengjiang biota. Its “bivalved” carapace with a dorsal fin-like fusion is distinct from those of other Cambrian arthropods. A pair of stalked eyes and a prominent median eye protrudes the carapace anteriorly. The cephalon, attaching to the carapace through the lateral adductor muscles at maxillary segment, bears an antennule, antenna and mandible. The trunk is comprised of a large number of segments (varying from 55 to 65), two-thirds of which is covered by the carapace. Each segment, except for the posterior three to five, carries a pair of uniform biramous appendages. The endopodite is composed of 30 podomeres and a terminal claw. The oar-shaped exopododite is fringed with filaments and distally bears a broad setiferous lobe. Trunk terminates with a conical telson and a pair of broad furcal rami serving as steering devices. Internal features like gonad and gut have also been found. The presence of the food groove combined with other morphological features indicates that Jugatacaris was a filter feeder. The appendages design associated with the overall body-plan supports the view that Jugatacaris is a crustaceanomorph. The accurate phylogenic assessment will remain the subject of debate until more information becomes available.

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New vauxiid sponges from the Chengjiang Biota and their evolutionary significance

Journal of the Geological Society ◽

10.1144/jgs2020-162 ◽

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

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

Scientific Reports ◽

10.1038/srep42616 ◽

2017 ◽

Vol 7 (1) ◽

Cited By ~ 4

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.

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New tubicolous problematic fossil with some “lophophorate” affinities from the Early Cambrian Chengjiang biota in south China

GFF ◽

10.1080/11035897.2013.801035 ◽

2013 ◽

Vol 135 (2) ◽

pp. 184-190 ◽

Cited By ~ 2

Author(s):

Xianfeng Yang ◽

Olev Vinn ◽

Xianguang Hou ◽

Xinglei Tian

Keyword(s):

South China ◽

Early Cambrian ◽

Chengjiang Biota

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The enigmatic metazoan Yuyuanozoon magnificissimi from the early Cambrian Chengjiang Biota, Yunnan Province, South China

Journal of Paleontology ◽

10.1017/jpa.2018.18 ◽

2018 ◽

Vol 92 (6) ◽

pp. 1081-1091 ◽

Cited By ~ 3

Author(s):

Yujing Li ◽

Mark Williams ◽

Sarah E. Gabbott ◽

Ailin Chen ◽

Peiyun Cong ◽

...

Keyword(s):

South China ◽

Yunnan Province ◽

Early Cambrian ◽

Circular Opening ◽

Single Specimen ◽

Anatomical Features ◽

Anterior Section ◽

Phylogenetic Affinity ◽

The Family ◽

Chengjiang Biota

AbstractVetulicolians are a group of exclusively Cambrian animals characterized by an anterior section with lateral pouches and a posterior section that appears segmented. The precise phylogenetic affinity of vetulicolians is debated because there is a lack of consensus regarding the interpretation of their anatomical features. Their disparate morphology might even cause one to question whether this is a monophyletic taxon. In total, there are 15 species grouped into three families included in vetulicolians. Here we focus on new specimens of Yuyuanozoon magnificissimi Chen, Feng, and Zhu in Chen et al., 2003, a species that was first described from only a single specimen from the Chengjiang Biota (Cambrian Series 2, Stage 3, Eoredlichia-Wutingaspis trilobite Biozone), Yunnan Province, China. The species is notable in being exceptionally large (up to 20 cm long). Morphological observations on the new specimens clarify the nature of the wide circular opening at the presumed anterior end of the animal and the cowl-shaped lateral openings within this anterior section. Taphonomic observations identify wrinkles in the anterior section and twists in the posterior segmented section. In particular, the shape of the anterior opening of Yuyuanozoon magnificissimi suggests significant differences from other vetulicolians. Taxonomic reappraisal of Y. magnificissimi indicates that it belongs within the family Didazoonidae, as that is presently defined.

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Ontogeny and dimorphism of Isoxys auritus (Arthropoda) from the Early Cambrian Chengjiang biota, South China

Gondwana Research ◽

10.1016/j.gr.2013.06.007 ◽

2014 ◽

Vol 25 (3) ◽

pp. 975-982 ◽

Cited By ~ 16

Author(s):

Dongjing Fu ◽

Xingliang Zhang ◽

Graham E. Budd ◽

Wei Liu ◽

Xiaoyun Pan

Keyword(s):

South China ◽

Early Cambrian ◽

Chengjiang Biota

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A New Platy-armored Worm from the Early Cambrian Chengjiang Lagerstätte, South China

Acta Geologica Sinica - English Edition ◽

10.1111/j.1755-6724.2003.tb00103.x ◽

2010 ◽

Vol 77 (1) ◽

pp. 1-6 ◽

Cited By ~ 4

Author(s):

HAN Jian ◽

ZHANG Xingliang ◽

ZHANG Zhifei ◽

SHU Degan

Keyword(s):

South China ◽

Early Cambrian ◽

Chengjiang Lagerstätte

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Sedimentary geochemistry of the Early Cambrian Niutitang Formation to reconstruct the palaeo‐depositional environments and to evaluate the organic matter enrichment mechanism from the Yangtze Block, South China

Geological Journal ◽

10.1002/gj.4304 ◽

2021 ◽

Author(s):

Rizwan Sarwar Awan ◽

Chenglin Liu ◽

Ashar Khan ◽

Qibiao Zang ◽

Yuping Wu ◽

...

Keyword(s):

Organic Matter ◽

South China ◽

Depositional Environments ◽

Early Cambrian ◽

Yangtze Block ◽

Sedimentary Geochemistry ◽

Niutitang Formation

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Ancestral morphology of Ecdysozoa constrained by an early Cambrian stem group ecdysozoan

BMC Evolutionary Biology ◽

10.1186/s12862-020-01720-6 ◽

2020 ◽

Vol 20 (1) ◽

Author(s):

Richard J. Howard ◽

Gregory D. Edgecombe ◽

Xiaomei Shi ◽

Xianguang Hou ◽

Xiaoya Ma

Keyword(s):

Feeding Strategy ◽

Phylogenetic Analyses ◽

Morphological Diversity ◽

Early Cambrian ◽

Ancestral State ◽

Crown Group ◽

Stem Group ◽

Chengjiang Biota ◽

Fossil Records ◽

Experimental Decay

Abstract Background Ecdysozoa are the moulting protostomes, including arthropods, tardigrades, and nematodes. Both the molecular and fossil records indicate that Ecdysozoa is an ancient group originating in the terminal Proterozoic, and exceptional fossil biotas show their dominance and diversity at the beginning of the Phanerozoic. However, the nature of the ecdysozoan common ancestor has been difficult to ascertain due to the extreme morphological diversity of extant Ecdysozoa, and the lack of early diverging taxa in ancient fossil biotas. Results Here we re-describe Acosmia maotiania from the early Cambrian Chengjiang Biota of Yunnan Province, China and assign it to stem group Ecdysozoa. Acosmia features a two-part body, with an anterior proboscis bearing a terminal mouth and muscular pharynx, and a posterior annulated trunk with a through gut. Morphological phylogenetic analyses of the protostomes using parsimony, maximum likelihood and Bayesian inference, with coding informed by published experimental decay studies, each placed Acosmia as sister taxon to Cycloneuralia + Panarthropoda—i.e. stem group Ecdysozoa. Ancestral state probabilities were calculated for key ecdysozoan nodes, in order to test characters inferred from fossils to be ancestral for Ecdysozoa. Results support an ancestor of crown group ecdysozoans sharing an annulated vermiform body with a terminal mouth like Acosmia, but also possessing the pharyngeal armature and circumoral structures characteristic of Cambrian cycloneuralians and lobopodians. Conclusions Acosmia is the first taxon placed in the ecdysozoan stem group and provides a constraint to test hypotheses on the early evolution of Ecdysozoa. Our study suggests acquisition of pharyngeal armature, and therefore a change in feeding strategy (e.g. predation), may have characterised the origin and radiation of crown group ecdysozoans from Acosmia-like ancestors.

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