Pristiograptus dubius labiatus Urbanek, 1997

Urbanek, Adam, Radzevičius, Sigitas, Kozłowska, Anna & Teller, Lech, 2012, Phyletic evolution and iterative speciation in the persistent Pristiograptus dubius lineage, Acta Palaeontologica Polonica 57 (3), pp. 589-611 : 608

Pristiograptus dubius labiatus Urbanek, 1997

Figs. 5R, 6T, 13D–F .

1997 Pristiograptus dubius labiatus subsp. nov.; Urbanek 1997: 160– 161, pl. 16: 1–11, text−fig. 44A–D.

Material.—20 rhabdosomes and many from Mielnik borehole (761.75– 727.7 m), Poland.

Remarks.—The ss angle is acute and the thecal apertural lip is at a right angle to rhabdosomal axis. The thecal lip is distinct with an incision in its ventral side, similar to P. lodenicensis ( Fig. 5H). The sicula has three rings.

Stratigraphic and geographic range.— Monograptus (Slovinograptus) balticus – M. (Uncinatograptus) spineus Biozone , Upper Ludlow, Poland.

Figures

Fig. 13. SEM micrographs of Ludfordian graptolites Pristiograptus dubius postmagnus subsp. nov. and Pristiograptus dubius labiatus Urbanek, 1997. A–C. Pristiograptus dubius postmagnus subsp. nov., Mielnik−1 borehole, Poland, depth 780.5 m; Monograptus (Uncinatograptus) acer Biozone. A. ZPAL G.44/48, lateral view of rhabdosome (A1), the thecal lip with connection to the succeeding theca (A2), and proximal end of rhabdosome (A3). B. ZPAL G.44/49, lateral view of rhabdosome sicula with rings (B1) and proximal end of rhabdosome (B2). C. ZPAL G.44/50, medial part of rhabdosome (C2), enlargements showing connections to the succeeding thecae (C1, C3). D–F. Pristiograptus dubius labiatus Urbanek, 1997, Mielnik−1 borehole, Poland, depth 753.3 m; Monograptus (Uncinatograptus) spineus–Neocolonograptus parultimus Interzone. D. ZPAL G.44/51, general view of rhabdosome (D1), sicula with two first thecae and depression on th1 lip (D). E. ZPAL G.44/52, lateral view of rhabdosome (E) and proximal end of rhabdosome (E). F. ZPAL 2 1 2 G.44/53, lateral view of rhabdosome (F1) enlargement of proximal end (F2).