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A new species of the taeniolabidid multituberculate Catopsalis is described from the Simpson Quarry fauna of the Puercan age Bear Formation of the Crazy Mountains Basin, south-central Montana. The molars retain a conservative cusp formula, yet are distinct from those of other early members of the genus in their extremely large size, which is approximately the same as that of C. calgariensis from the late Torrejonian to early Tiffanian. The combination of apomorphic and plesiomorphic features in the new species indicates a greater degree of complexity in the evolution of the genus than previously recognized.
An abundant early Silurian brachiopod assemblage of 14 species, with strong affinities to the early Rhuddanian faunas of Britain and Baltoscandia, was recovered from the Akkerme Peninsula, on the western side of Lake Balkhash, southern Central Kazakstan. The occurrence of Stricklandia lens mullochensis, which is ttre earliest member of the Stricklandia-Costistricklandia lineage, dates this brachiopod assemblage as early Rhuddanian, within a stratigraphic interval from the Akidograptus acuminatus to the lower part of the Monagraptus cyphus graptolite biozones. This is the first well documented record of early Rhuddanian brachiopods in Kazakhstan. The assemblage also includes Meifodia tulkulensis sp. nov. and Eospirifer cinghizicus with well preserved spiralia. The co-occurrence of Stricklandia lens mullochensis and Eospirifer cinghizicus has not been recorded previously and is regarded here as the most signiffcant difference between the early Rhuddanan brachiopod faunas of the Baltic (East-European) Plate and Britain; in contrast Eospirifer first appears in the two latter areas in the late Llandovery.
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Yunnanozoon and the ancestry of chordates

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The oldest known chordate, Yunnanozoon lividum Hou et al. 1991, from the Chengjiang Lagerstätte of Yunnan shows several features in its anatomy that had not been expected to occur at this stage of evolution. Its metameric dorsal myomeres were separated by straight myosepta. The notochord was located ventrad of the muscular blocks instead of being bordered by them. The pharynx did not contain any filtratory basket but had only seven pairs of branchial arches. These were composed of rows of minute scleritic segments that connected the notochord with a rigid ventral trough. The head region was rather complex in organization and bore a specialized ring-like mouth apparatus. The presence of sensory organs, perhaps large eyes with sclerotic rings, is probable. Only in the remarkable elongation of the notochord and metameric arrangement of oval gonads this early chordate is similar to Branchiostoma. The anterior part of the muscular blocks of Yunnanozoon resembles a little the proboscis and collar of the enteropneusts and may perhaps be homologous with these structures, although in Yunnanozoon they are displaced much behind the mouth. The whole metameric muscular unit is proposed to correspond to the 'quilted pneu structure' of the Ediacaran problematic fossil Dickinsonia. Monotypic Yunnanozoa classis n., Yunnanozoida ordo n., and Yunnanozoidae fam n. are proposed for this early chordate.
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