Query: classification: "38.22"
|Title||First record of fish microfossils from Ramsåsa, site C, Skåne, southern Sweden|
|Keywords||Osteostracan; thelodont; acanthodian fish scales; Whitcliffian; Sweden|
|Abstract||Within the thelodont dominated fauna of Ramsåsa, site C, Skåne, southern Sweden (Ludlow, Whitcliffian), the scales of the Thelodus parvidens group outnumber those of the combined T. sculptilis-T. admirabilis groups, some specimens of which are indistinguishable. Scale forms that might belong to one of several Thelodus taxa are designated as forma baltica (new form), forma T. radiosus Lehman, and forma T. ramosus Lehman, whereas forma T. querceus Lehman is introduced to cover a particular (heterogeneous?) group of monocuspid scales previously assigned to T. trilobatus Hoppe. Among the acanthodians, Nostolepis striata scales predominate. The checklist of N. striata trunk scales is extended to 62 characters. The smallest nostolepid teeth known so far are illustrated. The histology of Radioporacanthodes biblicus is shown in detail and the presence of wide arcade canals connecting the anterior grooves to the first pores of the radial pore rows is demonstrated. Problematical poracanthodid scales (formerly included in ‘Poracanthodes porosus’), chiefly from Estonia, are described as forma bifurcata (new form). The ontogeny and functioning of the porosiform pore system in some of these scales are discussed. New, small scales of an unnamed acanthodian taxon (morph 5) are described. The fauna is placed in the Upper Ludlow (Whitcliffian) within the T. sculptilis biozone.|
|Classification||42.81 ; 38.22|
|Download paper|| http://www.repository.naturalis.nl/document/46238 |