Pristiograptus sp.

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 : 604

Pristiograptus sp. sensu Radzevičius, 2003

Figs. 5D, 7B.

2003 Pristiograptus sp. ; Radzevičius 2003: 8–9, fig. 10.

Material.— One specimen, VU−9−219, from the Parovėja−9 borehole (595.4 m), Lithuania; rhabdosome with first 8 thecae and sicula .

Remarks.—The thecal lip is distinct, extending over the free part of the succeeding theca and additionally its ends are connected ( Fig. 5D). This connection is clearly visible in the medial and distal parts of the rhabdosome. Th 1 and th 2 either do not have such thecal apertural lip connections or they are covered by cortical tissue. The lips of the distal thecae are bifurcated. An intergrowth arch is well developed especially in the proximal part of the rhabdosome. The distance between the thecal apertural lip connection on the succeeding theca and the origin of its bifurcation is 0.25 mm for th 1 and th 2, and 0.35 mm for th 3 to th 5. There are no sicular rings.

Stratigraphic and geographic range.—Wenlock, C. perneri Biozone , Lithuania.