scholarly journals Symbiotic fouling of Vetulicola, an early Cambrian nektonic animal

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Yujing Li ◽  
Mark Williams ◽  
Thomas H. P. Harvey ◽  
Fan Wei ◽  
Yang Zhao ◽  
...  
Keyword(s):  
Fossil Record ◽  
Yunnan Province ◽  
Southwest China ◽  
Early Cambrian ◽  
Chengjiang Biota ◽  
Marine Deposit

Abstract Here, we report the earliest fossil record to our knowledge of surface fouling by aggregates of small vermiform, encrusting and annulated tubular organisms associated with a mobile, nektonic host, the enigmatic Cambrian animal Vetulicola. Our material is from the exceptionally preserved early Cambrian (Epoch 2, Age 3), Chengjiang biota of Yunnan Province, southwest China, a circa 518 million-year old marine deposit. Our data show that symbiotic fouling relationships between species formed a component of the diversification of animal-rich ecosystems near the beginning of the Phanerozoic Eon, suggesting an early escalation of intimate ecologies as part of the Cambrian animal radiation.

A New Helmetiid Arthropod from the Early Cambrian Chengjiang Lagerstätte, Southwest China

2014 ◽  
Vol 88 (2) ◽  
pp. 367-370 ◽  
Author(s):  
Fangchen Zhao ◽  
Shixue Hu ◽  
Han Zeng ◽  
Maoyan Zhu
Keyword(s):  
Yunnan Province ◽  
Anterior Margin ◽  
New Genus ◽  
Southwest China ◽  
Posterolateral Corner ◽  
Early Cambrian ◽  
Body Width ◽  
Total Body ◽  
Chengjiang Lagerstätte ◽  
Cephalic Shield

A new arthropod, Haifengella corona new genus new species is described from the early Cambrian Chengjiang Lagerstätte (Series 2, Stage 3), Yunnan Province, southwest China. It is readily assignable to helmetiida based on gross morphology of the tergum. The new helmetiid is unique in having the marginal spines extending over one-third of the total body width. The weakly sclerotized tergum consists of six thoracic tergites with edge-to-edge tergite articulations. The sub-trapezoidal cephalic shield has a pair of long spines projecting from each posterolateral corner. A prehypostomal sclerite (anterior sclerite) recesses in the anterior margin of the cephalic shield, and a pair of bulges that are close to the prehypostomal sclerite in the cephalic shield are presumed to be the position of ventral eyes. Each of the thoracic tergites exhibits a pair of long spines projecting from the posterolateral corners. The semicircular pygidium carries one terminal spine and two pairs of lateral spines.

scholarly journals An early Cambrian polyp reveals an anemone-like ancestor for medusozoan cnidarians

2021 ◽  
Author(s):  
Yang Zhao ◽  
Luke Parry ◽  
Jakob Vinther ◽  
Frances S. Dunn ◽  
Yujing Li ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Fossil Record ◽  
Soft Tissues ◽  
Common Ancestor ◽  
Last Common Ancestor ◽  
Early Cambrian ◽  
Crown Group ◽  
Sessile Polyp ◽  
Animal Evolution ◽  
Chengjiang Biota

Extant cnidarians are a disparate phylum of non-bilaterians and their diploblastic body plan represents a key step in animal evolution. Anthozoans (anemones, corals) are benthic polyps, while adult medusozoans (jellyfishes) are dominantly pelagic medusae. A sessile polyp is present in both groups and is widely conceived as the ancestral form of their last common ancestor. However, the nature and anatomy of this ancestral polyp, particularly of medusozoans, are controversial, owing to the divergent body plans of both groups in the extant lineages and the rarity of medusozoan soft tissues in the fossil record. Here we redescribe the enigmatic Conicula striata Luo et Hu from the early Cambrian Chengjiang biota, south China, which has previously been interpreted as a polyp, lophophorate or deuterostome. We show that C. striata possessed features of both anthozoans and medusozoans. Its stalked polyp and fully encasing conical, annulated organic skeleton (periderm) are features of medusozoans. However, the gut is partitioned by ~28 mesenteries, and has a tubular pharynx, resembling anthozoans. Our phylogenetic analysis recovers C. striata as a stem medusozoan, indicating that the enormously diverse medusozoans were derived from an anemone-like ancestor, with the pharynx lost and number of mesenteries reduced prior to the origin of crown group Medusozoa.

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

2018 ◽  
Vol 92 (6) ◽  
pp. 1081-1091 ◽  
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.

Bryozoans from the early Cambrian Chengjiang Biota

2021 ◽  
Author(s):  
Fan Wei ◽  
Xiangtong Lei ◽  
Gaorong Li ◽  
Yang Zhao ◽  
Xian-guang Hou ◽  
...  
Keyword(s):  
Digestive Tract ◽  
Molecular Clock ◽  
Southwest China ◽  
Growth Direction ◽  
Cambrian Explosion ◽  
Early Cambrian ◽  
Exterior Wall ◽  
Ecological Migration ◽  
Chengjiang Biota ◽  
Freshwater Environments

Abstract Bryozoa are colonial, aquatic, generally sessile coelomate metazoans, with a retractable lophophore and U-shaped digestive tract. They are widely distributed and highly diverse in extant marine and freshwater environments. Current confident fossils of the earliest bryozoan only occur in the Early Ordovician, although molecular estimation date their origin in or prior to the early Cambrian, rendering the origin and early evolution of bryozoans are intensely debated. Here, we describe two cyclostomes, Panpipora yunnanensis gen. et. sp. nov. and Corynotrypa sp., having been recovered from the Cambrian Chengjiang Biota (~ 518 m.y.) in Southwest China. The bryozoans represent the earliest fossils of Bryozoa, predating the record of the phylum by more than 30 million years. Our finding reveals that the Bryozoa, as all other skeletonised metazoans, first evolved during the Cambrian Explosion, and it is congruent with estimation of molecular clock that the cyclostomes is the earliest biomineralised clade. Corynotrypa might be derived from unmineralized ctenostomes by stolonal mineralization and change of growth direction of polypides from vertical to creeping. The unmineralised frontal exterior wall might be a share character existed in all ancestral clades. Encrusting specimens that inhabited in muddy environments have been confirmed here, further suggesting that encrusting bryozoans underwent a profound ecological migration from soft- to hard-bottom facies from Cambrian to Ordovician.

scholarly journals Intraspecific variation in the Cambrian: new observations on the morphology of the Chengjiang euarthropod Sinoburius lunaris

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Michel Schmidt ◽  
Yu Liu ◽  
Xianguang Hou ◽  
Joachim T. Haug ◽  
Carolin Haug ◽  
...  
Keyword(s):  
Intraspecific Variation ◽  
Southwest China ◽  
3D Models ◽  
Morphological Characters ◽  
Open Questions ◽  
New Findings ◽  
Unique Shape ◽  
Variable Species ◽  
Chengjiang Biota ◽  
3D Software

Abstract Background The Chengjiang biota from southwest China (518-million-years old, early Cambrian) has yielded nearly 300 species, of which more than 80 species represent early chelicerates, crustaceans and relatives. The application of µCT-techniques combined with 3D software (e.g., Drishti), has been shown to be a powerful tool in revealing and analyzing 3D features of the Chengjiang euarthropods. In order to address several open questions that remained from previous studies on the morphology of the xandarellid euarthropod Sinoburius lunaris, we reinvestigated the µCT data with Amira to obtain a different approach of visualization and to generate new volume-rendered models. Furthermore, we used Blender to design 3D models showing aspects of intraspecific variation. Results New findings are: (1) antennulae consist of additional proximal articles that have not been detected before; (2) compared to other appendages, the second post-antennular appendage has a unique shape, and its endopod is comprised of only five articles (instead of seven); (3) the pygidium bears four pairs of appendages which are observed in all specimens. On the other hand, differences between specimens also have been detected. These include the presence/absence of diplotergites resulting in different numbers of post-antennular appendages and tergites and different distances between the tip of the hypostome and the anterior margin of the head shield. Conclusions Those new observations reveal intraspecific variation among Chengjiang euarthropods not observed before and encourage considerations about possible sexual dimorphic pairs or ontogenetic stages. Sinoburius lunaris is a variable species with respect to its morphological characters, cautioning that taxon-specific variabilities need to be considered when exploring new species.

scholarly journals Genetic diversity and population structure of rice stripe virus in China

2009 ◽  
Vol 90 (4) ◽  
pp. 1025-1034 ◽  
Author(s):  
Tai-Yun Wei ◽  
Jin-Guang Yang ◽  
Fu-Long Liao ◽  
Fang-Luan Gao ◽  
Lian-Ming Lu ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Yunnan Province ◽  
Southwest China ◽  
Eastern China ◽  
Rice Stripe Virus ◽  
Genetic Distances ◽  
Geographical Regions ◽  
Strong Negative Selection ◽  
Recent Outbreak

Rice stripe virus (RSV) is one of the most economically important pathogens of rice and is repeatedly epidemic in China, Japan and Korea. The most recent outbreak of RSV in eastern China in 2000 caused significant losses and raised serious concerns. In this paper, we provide a genotyping profile of RSV field isolates and describe the population structure of RSV in China, based on the nucleotide sequences of isolates collected from different geographical regions during 1997–2004. RSV isolates could be divided into two or three subtypes, depending on which gene was analysed. The genetic distances between subtypes range from 0.050 to 0.067. The population from eastern China is composed only of subtype I/IB isolates. In contrast, the population from Yunnan province (southwest China) is composed mainly of subtype II isolates, but also contains a small proportion of subtype I/IB isolates and subtype IA isolates. However, subpopulations collected from different districts in eastern China or Yunnan province are not genetically differentiated and show frequent gene flow. RSV genes were found to be under strong negative selection. Our data suggest that the most recent outbreak of RSV in eastern China was not due to the invasion of new RSV subtype(s). The evolutionary processes contributing to the observed genetic diversity and population structure are discussed.

scholarly journals Acronema crassifolium sp. nov. (Apiaceae), a distinct new species from Yunnan, southwest China

Phytotaxa ◽  
2013 ◽  
Vol 87 (3) ◽  
pp. 39
Author(s):  
HUAN-CHONG WANG ◽  
XIN-MAO ZHOU ◽  
HANG SUN ◽  
YUE-HUA WANG
Keyword(s):  
New Species ◽  
Pollen Morphology ◽  
Yunnan Province ◽  
Southwest China

Acronema crassifolium, a distinct new species endemic to Yunnan province, China, is described and illustrated. It is characterized by its thickly papery, ternate, abaxially dark purple leaves, terminal umbels with 8–13 rays, and absent calyx teeth. The pollen morphology of the new species is also described in this study.

A review of the non-lyctine powder-post beetles of Yunnan (China) with a new genus and new species (Coleoptera: Bostrichidae)

Zootaxa ◽  
2022 ◽  
Vol 5091 (4) ◽  
pp. 501-545
Author(s):  
YI-FENG ZHANG ◽  
LING-ZENG MENG ◽  
ROGER A. BEAVER
Keyword(s):  
New Species ◽  
Southeast Asia ◽  
Yunnan Province ◽  
New Genus ◽  
Southwest China ◽  
Geological History ◽  
Yunnan Region ◽  
Palearctic Region ◽  
History Of ◽  
First Time

The powder post beetles (Coleoptera: Bostrichidae) (except Lyctinae) of Yunnan Province in Southwest China are reviewed for the first time. Keys to twenty-six genera and fifty-two species from the Yunnan region are provided. One new genus and seven new species are described: Dinoderus (Dinoderastes) hongheensis sp. nov., Dinoderus (Dinoderastes) nanxiheensis sp. nov., Gracilenta yingjiangensis gen. nov., sp. nov., Calonistes vittatus sp. nov., Calophagus colombiana sp. nov., Xylodrypta guochuanii sp. nov. and Xylodrypta zhenghei sp. nov.. Fourteen species are recorded in China for the first time. The bostrichid fauna of Yunnan is compared with those of the neighbouring bio-geographically related Southeast Asian and Himalayan regions. The fauna has a close affinity with that of tropical Southeast Asia and a much weaker relationship with the Palearctic region. The differences with the Himalayas may reflect the separate evolutionary and complex geological history of the two areas.

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