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Four new species of the jumping spider genus Synagelides Strand, 1906 from Guizhou and Yunnan, China are described: Synagelides angustus sp. nov. (♀), S. latus sp. nov. (♂♀), S. subagoriformis sp. nov. (♂♀), and S. triangulus sp. nov. (♀). Photographs of the habitus and copulatory organs and a distributional map are provided. [ABSTRACT FROM AUTHOR]

The morphology and ontogeny of the trilobite Changaspis elongata based on 216 specimens collected from the Lazizhai section of the Balang Formation (Stage 4, Series 2 of the Cambrian) in Guizhou Province, South China are described. The relatively continuous ontogenetic series reveals morphological changes, and shows that the species has seventeen thoracic segments in the holaspid period, instead of the sixteen as previously suggested. The development of the pygidial segments shows that their number gradually decreases during ontogeny. A new dataset of well-preserved specimens offers a unique opportunity to investigate developmental traits after segment addition is completed. The ontogenetic size progressions for the lengths of cephalon and trunk show overall compliance with Dyar's rule. As a result of different average growth rates for the lengths of cephalon, trunk and pygidium, the length of the thorax relative to the body shows a gradually increasing trend; however, the cephalon and pygidium follow the opposite trend. Morphometric analysis across fourteen post-embryonic stages reveals growth gradients with increasing values for each thoracic segment from anterior to posterior. The reconstruction of the development traits shows visualization of the changes in relative growth and segmentation for the different body parts. The new dataset and growth gradient of the trunk suggest that the thoracic segment growth dynamics of early Cambrian to Silurian trilobites follow the same general continuous, steady-state growth gradient decreasing from posterior to anterior. [ABSTRACT FROM AUTHOR]

The morphology and ontogeny of the trilobite Changaspis elongata based on 216 specimens collected from the Lazizhai section of the Balang Formation (Stage 4, Series 2 of the Cambrian) in Guizhou Province, South China are described. The relatively continuous ontogenetic series reveals morphological changes, and shows that the species has seventeen thoracic segments in the holaspid period, instead of the sixteen as previously suggested. The development of the pygidial segments shows that their number gradually decreases during ontogeny. A new dataset of well-preserved specimens offers a unique opportunity to investigate developmental traits after segment addition is completed. The ontogenetic size progressions for the lengths of cephalon and trunk show overall compliance with Dyar's rule. As a result of different average growth rates for the lengths of cephalon, trunk and pygidium, the length of the thorax relative to the body shows a gradually increasing trend; however, the cephalon and pygidium follow the opposite trend. Morphometric analysis across fourteen post-embryonic stages reveals growth gradients with increasing values for each thoracic segment from anterior to posterior. The reconstruction of the development traits shows visualization of the changes in relative growth and segmentation for the different body parts. The new dataset and growth gradient of the trunk suggest that the thoracic segment growth dynamics of early Cambrian to Silurian trilobites follow the same general continuous, steady-state growth gradient decreasing from posterior to anterior. [ABSTRACT FROM AUTHOR]

Naraoia is a taxon represented by commonly non-mineralized fossil found in lower-middle Cambrian strata and widely distributed in China, North America, and is an important component of Burgess Shale-type biotas. Well-preserved representatives of Naraoia are known from the Chengjiang and Kaili biotas of South China. Here, we report a new species of Naraoia, Naraoia taijiangensis sp. nov. from the Balang Fauna, Guizhou, South China. The new species clearly represents an intermediate morphology between Misszhouia longicadata and N. cf. N. compacta. It is obvious that there is a body-morphologic evolution for Naraoia from the Cambrian Series 2 to Cambrian Series 3 (lower Cambrian to the middle Cambrian). N. taijiangensis sp. nov. provides new data about evolution and geographical range of this genus. [ABSTRACT FROM AUTHOR]

The Early Cambrian Balang Formation is comprised of mudrock and shale, which was deposited in a shelf environment in the eastern part of Guizhou, south China. The Balang Fauna, which consists of seven phyla, occurs in the middle and upper parts of the Balang Formation. Arthropods are important constituents of the Balang Fauna and include a great number of trilobites, large bivalved arthropods, and newly-discovered well-preserved bradoriid fossils. The bradoriids present include three genera and four species: Comptaluta inflate (Cheng, 1974) emend Hou et al., 2002; Comptaluta kailiensis sp. nov, and Alutella elongeta sp. nov, Aluta sp. This faunal assemblage in the Balang Formation is distinguished from the Tsunyiella Chang, 1964, Songlinella Yin, 1978 and Kunmingella Hou, 1956 assemblage which occurs in the Niutitang and Mingxinsi formations of the Yangtze Platform in middle region of Guizhou and which is earlier than the Balang Formation in age. However, this assemblage resembles the ComptalutaÖpik, 1968 assemblage from the Early Cambrian Heilinpu Formation in Wuding County, Yuanan Province and from the Ordian Stage of the Cambrian of Australia. The great abundance of ComptalutaÖpik, 1968 and overall taxonomic diversity of the ComptalutaÖpik, 1968 assemblage set it distinctly apart from the Alutella Kobayashi et Kato, 1951 and Aluta Hou, 1956 assemblages of the Balang Formation. Alutella Kobayashi et Kato, 1951 and Aluta Hou, 1956 also occur in the Early Cambrian Niutitang Formation of the Yangtze Platform of Guizhou. Individual Bradoriids from the Balang Formation are characterized by large size (>3 mm). The discovery of new Bradoriid assemblages not only expands the group's geographical range and assemblage affinities, but also indicates that Bradoriids migrated eastward from shallow-water to deeper-water environments during the Early Cambrian, indicating that they were capable of life in deeper-water, and adaptation to a new ecological setting. [ABSTRACT FROM AUTHOR]

Gogiid eocrinoids (Echinodermata) are the most abundant coelomate invertebrates in the Middle Cambrian (Taijiangian) Kaili Biota, Taijiang County, Guizhou Province, China. Both long- and short-stalked taxa are represented. The short-stalked Globoeocrinus globulus n. gen. and sp. has a globular theca, with well-developed sutural pores on all thecal plates in older mature specimens, short, thick stalk composed of small polygonal to rounded platelets, a large flattened attachment disc, and up to ten long, thin, helically coiled brachioles with tall, pointed cover plates. Some younger mature specimens have varying patches of non-pored plates that usually occur on the upper (probably) posterior portion of the theca. This species is over three times more abundant than the other co-occurring long-stalked gogiid Sinoeocrinus lui Zhao, Huang and Gong, 1994. Most specimens of G. globulus (ca. 80%) attach to acrotretid brachiopods, trilobite exuviae, or other skeletal remains. They are also capable of attaching directly to the seafloor. [ABSTRACT FROM AUTHOR]

A new genus and species of edrioasteroid grade echinoderm, Kailidiscus chinensis, is described from the Kaili Biota of the basal lower Middle Cambrian Kaili Formation from Guizhou Province, China. This echinoderm has a strong resemblance to isorophid edrioasteroids, bearing a well-developed peripheral rim, long curved ambulacra, and slightly imbricate interambulacral plating at maturity. However, the presence of pore-bearing, double biserial floor plates, tiered cover plates, lack of radially positioned oral frame plates, and unincorporated hydropore/gonopore are unknown in isorophids. Many of these features bear strong resemblance to eocrinoids and helicoplacoids, attesting to the plesiomorphic nature of this taxon. Despite the obvious anatomical differences, specimens of this species preserve a complete ontogeny that resembles that of isorophids. Juveniles show a discoidal theca with straight ambulacra that transitions to an inflated theca with strongly curved ambulacra with maturity. [ABSTRACT FROM AUTHOR]