Gothograptus Frech, 1897

Kozłowska, Anna, Bates, Denis, Zalasiewicz, Jan & Radzevičius, Sigitas, 2019, Evolutionary significance of the retiolitine Gothograptus (Graptolithina) with four new species from the Silurian of the East European Platform (Baltica), Poland and Lithuania, Zootaxa 4568 (3), pp. 435-469 : 446-447

Genus Gothograptus Frech, 1897

Type species. Retiolites nassa Holm, 1890 , pl. 2, fig. 12, 13; NRM-PZ Cn0025546

Type locality. Gotland, Sweden, Wenlock , upper Homerian, Gothograptus nassa Biozone ( Holm, 1890) .

Emended diagnosis. Streamlined shape of tubarium ended by appendix. Ancora umbrella with undulating rim. Sicula about 1.2–1.5 mm long. Proximal lateral and ventral orifices small, kidney-shaped on lateral side and triangular on ventral sides of tubarium. Lateral wall on reverse sides of tubarium built of stronger oblique lists, whereas obverse wall is composed of the nema and connecting rods. Semigothograptus and Neogothograptus differ from Gothograptus in having a free nema. Ventral wall composed of distinctive lips, genicular lists, pleural lists and mid-ventral lists. Singular genicular processes forming solid or reticulated hoods or veils, which may cover the thecal orifice and ventral wall of thecae. In mature specimens a dense and thick reticulum, very thick ancora lists, a thick sicular rim, and reticular structures surrounding the metasicula may occur.

Species included. Gothograptus nassa ( Holm, 1890) ; Gothograptus pseudospinosus ( Eisenack, 1951) , Gothograptus kozlowskii Kozłowska-Dawidziuk, 1990 ; Gothograptus obtectus Kozłowska-Dawidziuk, 1990 ; Gothograptus storchi Lenz & Kozłowska, 2006 ; Gothograptus auriculatus n. sp.; Gothograptus domeyki n. sp.; Gothograptus velo n. sp., Gothograptus diminutus n. sp.

Remarks. There are some problems with the designation of some Gothograptus species illustrated or described in the past. Jaeger illustrated and temporarily named, on an unpublished range chart for retiolitids, several species from North German glacial erratic boulders ( Maletz 2008, fig. 1). These species were never described or published by Jaeger. Based on Jaeger‘s data Maletz (2008) regarded most of the species as nomina nuda or not identified. One of them, G. eximinassa was included in the genus Neogothograptus ( Maletz 2008) .

The species G. praenassa was not identified. Later on Jaeger‘s G. gigantonassa was included in Semigothograptus meganassa ( Rickards & Palmer, 2002) ( Kozłowska 2016) . According to Jaeger‘s drawing, the material that he referred to G. osgaleae may be included in G. obtectus , whereas the specimens described as G. nassa and G. pseudospinosus are properly designated (Kozłowska personal observation).

G. pseudospinosus Eisenack, 1951 was described from a Baltic erratic boulder with no detailed stratigraphical designation ( Eisenack 1951). On his range chart of graptolites from the Wenlock of Germany, Jaeger (1991) placed this species in the lundgreni/testis Biozone, but did not describe the material. Thus G. pseudospinosus needs more detailed study.