naa a22 4500 510808581 CHVBK 20180411083430.0 cr unu---uuuuu 180411e20130301xx s 000 0 eng 10.1007/s12542-012-0150-4 doi (NATIONALLICENCE)springer-10.1007/s12542-012-0150-4 Dobrowolska Kinga Instytut Paleobiologii PAN, ul. Twarda 51/55, 00-818, Warszawa, Poland aut Reconstruction of the proximal ends of retiolitid rhabdosomes (Graptolithina) from the Upper Wenlock and the Lower Ludlow [Elektronische Daten] [Kinga Dobrowolska] Detailed study of the ultrastructures on the cortical lists of retiolitids occurring after the lundgreni event has been undertaken. The extremely well preserved material from the Gołdap borehole of Poland (Baltica) enables classification of clathrial lists into two types—with single and double seams. Significantly different seam development is observed between two groups of retiolitids occurring before and after the lundgreni event. The study of seams and increments on the lists enables reconstruction of the membrane arrangement of the rhabdosomes. Reconstruction of the proximal ends, the arrangement of the ancora umbrella, and the layout of the proximal ventral and lateral orifices of five genera, Neogothograptus, Holoretiolites, Plectograptus, Spinograptus, and Quattuorgraptus n. gen., is presented. The new genus Quattuorgraptus is separated from Spinograptus because of the different development of the ancora umbrella and the width of the lateral walls of the rhabdosome. The Author(s), 2012 Ancora umbrella nationallicence Membrane nationallicence Retiolitidae nationallicence Graptolites nationallicence Proximal end nationallicence Silurian nationallicence Ancore Umbrella nationallicence Membran nationallicence Retiolitidae nationallicence Graptolithen nationallicence Proximale Ende nationallicence Silur nationallicence Paläontologische Zeitschrift Springer-Verlag 87/1(2013-03-01), 1-17 0031-0220 87:1<1 2013 87 12542 https://doi.org/10.1007/s12542-012-0150-4 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s12542-012-0150-4 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Dobrowolska Kinga Instytut Paleobiologii PAN, ul. Twarda 51/55, 00-818, Warszawa, Poland aut NATIONALLICENCE 773 0- Paläontologische Zeitschrift Springer-Verlag 87/1(2013-03-01), 1-17 0031-0220 87:1<1 2013 87 12542 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer