Cambrian explosion: Birth of tree of animals

Lower Cambrian Burgess Shale-type fossil associations of South China

Deuterostomes are a remarkably diverse super-phylum, including not only the chordates (to which we belong) but groups as disparate as the echinoderms and the hemichordates. The phylogeny of deuterostomes is now achieving some degree of stability, especially on account of new molecular data, but this leaves as conjectural the appearance of extinct intermediate forms that would throw light on the sequence of evolutionary events leading to the extant groups. Such data can be supplied from the fossil record, notably those deposits with exceptional soft-part preservation. Excavations near Kunming in southwestern China have revealed a variety of remarkable early deuterostomes, including the vetulicolians and yunnanozoans. Here we describe a new group, the vetulocystids. They appear to have similarities not only to the vetulicolians but also to the homalozoans, a bizarre group of primitive echinoderms whose phylogenetic position has been highly controversial.

Ancestral echinoderms from the Chengjiang deposits of China

Vetulicolians have variously been considered to be unusual arthropods, stem-group deuterostomes or relatives of the tunicates. They are known from a number of Cambrian Lagerstatten, and are particularly diverse in the Chengjiang biota of Yunnan Province, China. We recognize two classes, Vetulicolida and Banffozoa, which together form a monophyletic group. Within the Chinese collections we also identify two new species and recognize one new genus: Vetulicola monile sp. nov. and Bullivetula variola gen. et sp. nov. The evidence from new and previously described specimens is used to undertake a phylogenetic analysis and to evaluate a range of hypotheses for the affinities of vetulicolians. Given the difficulties of interpreting features in enigmatic fossils and the apparently contradictory set of characters possessed by vetulicolians, it is not possible on current evidence to reach an unequivocal conclusion regarding the phylogenetic position of the group. One possibility is that they are a sister group of arthropods that lost limbs but gained gill structures analogous to those of deuterostomes, but several features remain unexplained by this model. If they are protostomes, a more generally parsimonious position is close to the kinorhynchs. An alternative is that they are deuterostomes, although a placement at the base of the clade is not supported by the evidence. If they are deuterostomes, it is more likely that they are close to the tunicates.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1475-4983.2006.00606.x

The Systematics and phylogenetic relationships of vetulicolians

A Burgess Shale-type biota is, in part, characterized by a wide diversity of taxa and soft-part preservation. Each provides unique historical insights into early metazoan evolution. Among the more than 40 globally distributed biotas, the early Cambrian Chengjiang and Middle Cambrian Burgess-type biotas are the largest. The Kaili Biota, from the earliest Middle Cambrian of Guizhou, China, contains representatives of 110 metazoan genera belonging to 10 phyla. It contains many well-persevered soft-bodied specimens. This Chinese biota has become the third most taxonomically diverse Burgess Shale-type fauna. Because the Kaili Biota formed in an outer-shelf environment, its main faunal character is large numbers of eocrinoids and planktoic trilobites. The Kaili is younger than the Chengjiang Biota but older than the Canadian Burgess Shale Biota; it shares 30 genera with the Chengjiang and 38 genera with the Burgess Biota. The Kaili Biota displays a taphonomic window to the diversification and evolution of marine offshore organisms covering 5.13 million years between the Early and Middle Cambrian.

Kaili Biota: A Taphonomic Window on Diversification of Metazoans from the Basal Middle Cambrian: Guizhou, China

The genus and species Yuyuanozoon magnificissimi gen. et sp. nov., a new fossil vetulicolian, is reported from the Early Cambrian Chengjiang Fauna in Yunnan of China. It has a bipartite body plan and five pairs of chain-formed gill sacs, showing the general characteristics of Ventulicolia. However, the exclusive "atrial cavity" and external gill observed indicate that the new form is different from those previously described as vetulicolians, probably representing a lineage developed within deuterostomes and more primitive than urochordates.

A New Vetulicolian from the Early Cambrian Chengjiang Fauna in Yunnan of China

Based on the classified result of Landsat ETM+remote sensing images of 2006 and 2009,the paper simulated and forecasted land cover types of Qinhuai River Basin in the future by using the CA- Markov model. In the model- building process,the transition probability matrix and the transition area matrix were obtained through the Markov model,which determined the conversion rules and iterative times of the CA model. The land cover pattern of the study area in 2012 and 2018 was simulated and forecasted with the CA- Markov model. Then the forecast result was compared with the actual classified data of 2012 to verify the forecast accuracy. The raster number forecast error of each land cover type is not higher than 6. 5 %,and the spatial location accuracy is 76. 5 %.The forecast results show that the paddy field decreased to 33. 3 % and the impervious surface reached 31. 1 % of Qinhuai River Basin in 2018. Most of the paddy field converted into impervious surface. The impervious surface of urban areas expands obviously in such urban areas as Nanjing,Lukou,Jurong and Lishui. The methods can provide a basis for dynamic monitoring as well as sustainable development of Qinhuai River Basin.

Simulation and forecast of land cover pattern in Qinhuai River Basin based on the CA-Markov model

Aiming at the problems of multi-party interaction and data trust in load dispatching, this paper explores the credentialization technology of dispatching instruction in load dispatch and control scenarios. This paper designs a voucher storage mechanism of load dispatch instructions based on Blockchain, and analyzes the storage content and on-chain storage mode. It provides a solution for future massive load resource participation dispatch.

Research on Dispatch Instruction Voucher Storage Mechanism for Load Dispatch Based on Blockchain

Virtual power plant collects all kinds of decentralized and callable power and load, and uses digital means to do unified scheduling and management through virtual power plant. Virtual power plants have a huge variety of resources. This paper proposes to use blockchain technology to support the scheduling and trading of virtual power plants. The introduction of blockchain technology into the scheduling and trading of virtual power plants can not only ensure the security of virtual power plant data information, but also reduce the credit cost of virtual power plant trading center, so that virtual power plants can obtain a greater degree of security, so as to solve the current difficulties and challenges faced by virtual power plants.

Application Research of Blockchain Technology in Virtual Power Plant Dispatching and Trading

Research on the Operation Mode of Virtual Power Plants Participating in Day-ahead market

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