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Most upper Homerian and Ludfordian retiolitines have a tubarium with hexagonal meshes and azigzag pattern in the middle part of their lateral walls, a shallow ancora umbrella, and a free nema. Hoffmanigraptus varsoviensis n. gen., n. sp. is described from isolated, three-dimensional material, from the upper part of the Colonograptus praedeubeli Biozone (upper Homerian, Silurian) of Poland, Baltica, and represents one of the earliest forms with this construction. This type of tubarium is represented by the upper Homerian Doliograptus Lenz& Kozłowska-Dawidziuk, 2002 and Spinograptus Bouček& Münch, 1952, differing from Hoffmanigraptus n. gen. mainly in larger proximal lateral orifices, pattern of clathrial lists on lateral walls, as well as size and shape of tubaria. Hoffmanigraptus n. gen. has a tubarium widening medially, tapering towards the distal end and forming a finite tubarium, with a possible three-vaned nematularium. Flattened specimens Plectograptus? ovatus Kozłowska, Lenz & Štorch, 2001 and Plectograptus? karlsteinensis Kozłowska, Lenz & Štorch, 2001, preserved on a rock surface from the Barrandian area are assigned to the new genus. They are of the same upper Homerian age, and show the main features of the new form. Hoffmanigraptus n. gen. is regarded as an early member of the Plectograptus clade.

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., Published as part of 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, pp. 435-469 in Zootaxa 4568 (3) on pages 446-447, DOI: 10.11646/zootaxa.4568.3.2, http://zenodo.org/record/2601607, {"references":["Frech, F. (1897) Lethaea Geognostica 1. Lethaea Palaeozoica. E Schweizerbart'sche Verlagshandlung, Stuttgart, 690 pp.","Holm, G. (1890) Gotlands graptoliter. Svenska Vetenskap-Akademiens handlingar, 16, 1 - 34.","Eisenack, A. (1951) Retioliten aus dem Graptolithengestein. Palaeontographica, 100, 129 - 163.","Kozlowska-Dawidziuk, A. (1990) The genus Gothograptus (Graptolithina) from the Wenlock of Poland. Acta Palaeontologica Polonica, 35, 191 - 209.","Lenz, A. C. & Kozlowska, A. (2006) Graptolites from the lundgreni Biozone (Lower Homerian, Silurian), Arctic Islands, Canada: new species and supplementary material. Journal of Paleontology, 80, 616 - 637. https: // doi. org / 10.1666 / 0022 - 3360 (2006) 80 [616: GFTLBL] 2.0. CO; 2","Maletz, J. (2008) Retiolitid graptolites from the collection of Hermann Jaeger in the Museum fur Naturkunde, Berlin (Germany). I. Neogothograptus and Holoretiolites. Palaontologische Zeitschrift, 82, 285 - 307. https: // doi. org / 10.1007 / BF 02988896","Rickards, R. B. & Palmer, D. C. (2002) Gothograptus? meganassa sp. nov., an unusually large retiolitid graptoloid from the Late Wenlock ludensis Biozone of Long Mountain, Shropshire, UK. Special Papers in Palaeontology, 67, 225 - 232.","Kozlowska, A. (2016) A new generic name, Semigothograptus, for Gothograptus? meganassa Rickards & Palmer, 2002, from the Silurian post- lundgreni Biozone recovery phase, and comparative morphology of retiolitids from the lowermost upper Homerian (upper Wenlock). Zootaxa, 4208, 534 - 546. https: // doi. org / 10.11646 / zootaxa. 4208.6.2","Jaeger, H. (1991) Neue Standard-Graptolithenzonenfolge nach der \" Grossen Krise \" und der Wenlock / Ludlow-Grenze (Silur). Neues Jahrbuch fur Geologie und Palaontologie-Abhandlungen, 182, 303 - 354. [in German with English abstract] https: // doi. org / 10.1127 / njgpa / 182 / 1991 / 303"]}

Gothograptus nassa (Holm, 1890) Figs 10–12 1890 Retiolites nassa Holm, p. 25, pl. 2, figs 12–14. 1891 Gothograptus nassa Holm, Frech, pp. 670–671, fig. 223, 5–6. ?1900 Retiolites nassa Holm (Gothograptus, Frech), Wood, p. 486, fig. 27. 1908 Retiolites (Gothograptus) nassa (Holm), Ellis & Wood, pp. 343–344, fig. 225, pl. 34, figs 15a,d. ?1952 Gothograptus nassa (Holm, 1890), Bouček & Münch, pp. 11–15, fig. 2, a–i. 1952 Gothograptus intermedius Bouček & Münch, pp. 15–16, fig. 3 e–f. 1956 Gothograptus nassa (Holm, 1890), Tomczyk, pp. 42–44, fig. 8. 1979 Gothograptus nassa (Holm, 1890), Obut & Zaslavskaya, pp. 30–33, figs 1–4. 1999 Gothograptus nassa (Holm, 1890), Kozłowska-Dawidziuk, fig. 3. Material. The specimens of Gothograptus nassa studied come from Lithuania, Poland and Gotland. Material from Lithuania comes from the Šiupyliai-69 core, nassa Biozone (above parvus), at depths from 998.4 m to 997.0 m yielding 130 specimens and the Kybartai-14 core, depth 1087.8 m, a few specimens. The material from Poland, Bartoszyce IG-1 well, comes from the interval 1661.0 m to 1643.9 m, representing the parvus / nassa, dubius / nassa, and lower part of the praedeubeli biozones (see range chart in Porębska et al. 2006, fig. 2). The material is rich, containing about 2,000 specimens, representing different stages of growth of colonies. The Swedish material comes from Gotland, Blåhäll, locality 813–832, Blåhäll 1 (Spjeldnaes 1984), Dapps and Tegelbruk. Description. The tubaria represent mostly fragments of colonies at different stages of growth. The longest tubarium of 18 pairs of thecae is 2.8 cm long. It is an immature colony as it has not developed an appendix, and the distal part is not densely reticulated (Fig. 10A). The tubarium of Gothograptus nassa is almost parallel-sided. It widens from a proximal width of about 1.0 mm below the orifice of the first theca and reaches its maximum width (~ 1.2–1.4 mm) in the middle part of the tubarium, following which it tapers distally. The sicula length is about 1.4–1.5 mm. The mature tubaria have thick reticulum surrounding proximal lateral and ventral orifices (Fig. 4 H). There is a strong metasicular rim and reticulum around the sicula, which may represent the walls of th1 1 and th1 2. In some specimens a part of the membrane of the sicula is preserved. An outer ancora is rarely developed in mature specimens (Figs 4F, 12D). Genicular hoods of nassa type are developed successively during astogeny. The new, rich material illustrates hood development through the successive stages of the astogeny of colonies. Hoods are well developed in all thecae in mature colonies (Fig. 12). The appearance of the first genicular hood in young G. nassa colonies may be on different thecae (Fig. 10). Young tubaria of up to six pairs of thecae usually do not have hoods developed. The first genicular hood may appear on the proximal or medial part of the tubarium. Thus some tubaria do not have hoods on several pairs of thecae but tubaria with e.g. eight pairs of thecae may already have well-developed hoods on six proximal thecae. The longest sub-mature tubarium with eighteen pairs of thecae represents the intermediate stage of colony growth. It has larger hoods in the middle part of the tubarium (Fig. 12A, C, I). The size of hoods increases during astogeny; in mature colonies the larger hoods, especially in the distal part of the tubarium, cover the thecal orifices for some distance below. The largest hoods are usually located in the medial part of colonies (Fig. 12A, I). The distal thecae are shorter and their genicular hoods are irregular. The rich material of different stages of astogenetic growth of G. nassa colonies also shows a marked variability in the shape of hoods from almost rectangular to ovate (Fig. 12A, C). In mature colonies the clathrial and reticular lists have similar thicknesses. The proximal orifices, both ventral and lateral in old colonies, are partly overgrown by some reticular lists. The nema is thicker at the distal end, and extends about 0.5–0.7 mm out of the tubarium. The appendix is well developed, about 1.5 mm long. Remarks. The thickened sicular rim and sicular reticulum, as well as an outer ancora umbrella, were first described by Bates & Kirk (1978, p. 431, pls. 2, 6–7). Obut and Zaslavskaya (1979) described the astogeny of Gothograptus nassa based on material from the deep 1-R core of from the Kaliningrad District of the Peribaltic Syncline, from the nassa Biozone. Based on the specimens illustrated by Bouček & Münch (1952, figs. 3e, f) at various stages of growth, co-occurring with G. nassa, the authors established that Gothograptus intermedius Bouček & Münch, 1952 represents young stages of growth of G. nassa. The observations presented herein, based on material from the cores of Lithuania and Poland, support this judgement., Published as part of 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, pp. 435-469 in Zootaxa 4568 (3) on pages 447-451, DOI: 10.11646/zootaxa.4568.3.2, http://zenodo.org/record/2601607, {"references":["Holm, G. (1890) Gotlands graptoliter. Svenska Vetenskap-Akademiens handlingar, 16, 1 - 34.","Spjeldnaes, N. (1984) Epifauna as a tool in autecological analysis of Silurian brachiopods. Special Papers in Palaeontology, 32, 225 - 235.","Bates, D. E. B. & Kirk, N. H. (1978) Contrasting modes of construction of retiolite-type rhabdosomes. Acta Palaeontologica Polonica, 23, 427 - 465.","Obut, A. M. & Zaslavskaya, N. M. (1979) Razvitie rabdosom i ekologiya Gothograptus nassa (Holm). In: Betekhtina A. O. & Zhuravleva, T. I. (Eds.), Sreda i Zhihn v Geologicheskom Proshlom. Vol. 43, Vaprosy Ekostratigrfii. Nauka, Siberian Branch, Novosibirsk, pp. 30 - 33. [in Russian]","Boucek, B. & Munch, A. (1952) Retioliti stredoevropskeho svrchniho wenloku a ludlowu. Sbornik Ustredniho Ustavu geologickeho 19, oddil paleontologicky, 1 - 151."]}

Gothograptus domeyki n. sp. Figs 15���16 ?1952 Gothograptus nassa, Bouček & M��nch, pp. 11���15, fig. 2, a���i. Type material. Holotype number VU RET-13, mature specimen with seven pairs of thecae and appendix (Fig. 16 A���B), ��iupyliai-69 core, 1009,1 m, lundgreni Biozone, paratype number VU RET-14, finite tubarium (Fig. 16 C���E), ��iupyliai-69 core, depth 1010.0 m, lundgreni Biozone, Lithuania. Etymology. Ignacy Domeyko (1802���1889) was a Polish geologist, mineralogist and educator; most of his life was spent in Chile. Diagnosis. Gothograptus with genicular hoods of nassa type developed on the first pair of thecae; second pair of thecae may have paired spines with seams or remnants of reticulum between them; subsequent thecae lacking genicular processes except for the last theca with a reticulated hood. Distinctively thicker thecal lips than pleural and genicular lists. G othograptus domeyki differs from other Gothograptus species in the lack of genicular structures in the medial and distal thecae. Remarks. Gothograptus domeyki n. sp. differs from other Gothograptus species in the lack of any genicular processes in most thecae as well as in having thick lips. G. domeyki n. sp. is similar to G. kozlowskii in having nassa type hoods on the first pair of thecae and reticulated hoods on the last pair of thecae. Similar reticulated hoods on the last thecae are also found in G. storchi. G. domeyki n. sp. is so far known only from Lithuania. Bouček & M��nch (1952) described some retiolitines as Gothograptus nassa, from the Czech Republic, lundgreni Biozone. Their drawings show some tubaria with thick lips, and without genicular nassa hoods, similar to those described herein for the first time in G. domeyki n. sp. Proper recognition of this form needs some detailed study. Material. Two cores from Lithuania: ��iupyliai-69 core, depths: 1009.7 m 30 young, 12 mature; 1009.1 m 50 young, 31 mature; Vilkavi��kis-131 core, depth 1095.8 m four fragments of mature specimens. Upper part of lundgreni Biozone. Description. Mature tubaria usually have seven or eight pairs of thecae and appendix. The total length of the tubarium is about 7.0 mm, together with the appendix. The tubarium is almost parallel-sided, widest at 0.83 mm at the level of the first thecal pair, and then it slowly narrows to 0.4 mm just below the appendix. In some mature specimens the prongs of the ancora, as well as the sicular rim and lists above the proximal lateral orifices, are extremely thick ((Fig. 16A, B, E, H, I). An outer ancora is well developed in mature specimens. The proximal ventral orifices are overgrown by reticulum in mature colonies. Mid-ventral lists are 0.5 mm long in the first and last thecae, the rest are about 0.7 mm long. Genicular structures start to develop when the colony reaches about five thecal pairs. There are three types of genicular structures in mature tubaria of G. domeyki n. sp. The first pair of thecae have nassa hoods; usually they are small and do not cover the orifices of thecae or they are slightly larger than the thecal orifice. The second and third thecal pairs have a pair of curved spines grown on the pleural lists, extending horizontally. Seams on the inner sides of the spines indicate that there was a thin membrane between them, so that the spines form the sides of a hood. The bases of the spines in the mature tubaria are of triangular shape (Fig. 16G). Similar spines forming hoods are also found in Gothograptus kozlowskii (see below). The next thecae have no hoods; their lips are thick, about twice as thick as the geniculum list. The genicular lists became significantly thinner in the last thecae. The last pair of thecae have reticulated hoods covering orifices; the genicular list is not developed. The reticulum of these hoods is connected with the appendix (Fig. 16A). umbrella, outside view. Some young tubaria with five pairs of thecae have reticulum up to the third pair of thecae, small nassa hoods on the first thecae, the two next pairs of thecae having thin genicular spines. A specimen with seven pairs of thecae has a well-developed reticulum, except on the two last thecae. The lists of young colonies are thin; the thickest is the nema (Fig. 15A, D). During astogeny the next thicker lists are the lateral apertural rods. The lips and genicular lists are so thick that the thecal orifice is very narrow (Fig. 15E, 16E). The thecal orifices vary in shape from nearly rectangular to pyramidal with rounded corners (Fig. 7A, 16C, E). Mature colonies have a dense reticulum of similar thickness to the clathrial lists, thus the structures formed by clathrial lists are difficult to distinguish., Published as part of Koz��owska, Anna, Bates, Denis, Zalasiewicz, Jan & Radzevi��ius, 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, pp. 435-469 in Zootaxa 4568 (3) on pages 454-457, DOI: 10.11646/zootaxa.4568.3.2, http://zenodo.org/record/2601607, {"references":["Boucek, B. & Munch, A. (1952) Retioliti stredoevropskeho svrchniho wenloku a ludlowu. Sbornik Ustredniho Ustavu geologickeho 19, oddil paleontologicky, 1 - 151."]}

Gothograptus velo n. sp. Fig. 22 1990. Gothograptus (Gothograptus) sp. A. Kozłowska-Dawidziuk, pp. 202–203, pl. 24: 2; fig. 6A–E. Type material. Mature tubarium, holotype ZPAL G.XIII/35, Zawada 1 core, depth 1533.3–1540 m, Poland, upper part of lundgreni Biozone. Material. One finite tubarium with nine pairs of thecae. Diagnosis. Proximal thecae with no genicular structures, successive medial and distal thecae have genicular veils. The veils are built of thin reticular lists; there are no thicker lists at the end of the veil as in G. obtectus. Reticulum below thecal lip undergoes reduction in distal thecae. Description. The mature tubarium has nine pairs of thecae. The distal end is slightly damaged, together with the appendix (Fig. 22). The tubarium length is 10.1 mm, together with the extending nema. The width of the tubarium at the level of the first pair of thecae is 0.8 mm. The widest part of the tubarium is 1.2 mm at the level of the fifth thecal pair. The tubarium tapers distally to a width of 0.6 mm at the level of the ninth pair of thecae. The sicula length is 1.5 mm; the prosicula apex is connected to the lateral wall of the tubarium at the level of the lip of th1 2. The thecal lips are thick whereas the genicular lists are thinner in distal thecae but well developed and easy to distinguish (Fig. 22B). The two first pairs of thecae do not have genicular structures. The first well-developed veil is on the fifth pair of thecae. Some reticular lists of the veil of th6 1 are connected to the geniculum of th5 1, and to the reticulum of the th5 1 veil (Figs 9C, 22B). The reticulum of the ventral thecal wall is well-developed up to the fifth pair of thecae, but distally, below the long veils, it become poorly developed, eventually disappearing under the veils of the last thecal pairs. The genicular and mid-ventral lists below the veils exhibit a similar decrease in thickness, becoming as thin as some lists of the veil (Figs 9C, 22B). The outer ancora is well-developed in the mature tubarium, and built of thick reticulum (Fig. 22D). Some membrane of the metasicular wall is connected to the virgella (Fig. 22C). Proximal internal structures typical of the genus Gothograptus are present, but they are difficult to distinguish in the flattened material to hand. The nema is distinctively thicker than other lists of the tubarium, and the thickest part starts at the level of th5 1. Remarks. G. velo n. sp. differs from Gothograptus obtectus in the development of veils. The veils of G. velo are built of a delicate reticulum with no thick transverse lists as in G. obtectus. Some of the veils are connected to the veil of the previous theca, forming an external layer above the thecal orifices and thecae (Fig. 9C).

Gothograptus velo n. sp. Fig. 22 1990. Gothograptus (Gothograptus) sp. A. Kozłowska-Dawidziuk, pp. 202���203, pl. 24: 2; fig. 6A���E. Type material. Mature tubarium, holotype ZPAL G.XIII/35, Zawada 1 core, depth 1533.3���1540 m, Poland, upper part of lundgreni Biozone. Material. One finite tubarium with nine pairs of thecae. Diagnosis. Proximal thecae with no genicular structures, successive medial and distal thecae have genicular veils. The veils are built of thin reticular lists; there are no thicker lists at the end of the veil as in G. obtectus. Reticulum below thecal lip undergoes reduction in distal thecae. Description. The mature tubarium has nine pairs of thecae. The distal end is slightly damaged, together with the appendix (Fig. 22). The tubarium length is 10.1 mm, together with the extending nema. The width of the tubarium at the level of the first pair of thecae is 0.8 mm. The widest part of the tubarium is 1.2 mm at the level of the fifth thecal pair. The tubarium tapers distally to a width of 0.6 mm at the level of the ninth pair of thecae. The sicula length is 1.5 mm; the prosicula apex is connected to the lateral wall of the tubarium at the level of the lip of th1 2. The thecal lips are thick whereas the genicular lists are thinner in distal thecae but well developed and easy to distinguish (Fig. 22B). The two first pairs of thecae do not have genicular structures. The first well-developed veil is on the fifth pair of thecae. Some reticular lists of the veil of th6 1 are connected to the geniculum of th5 1, and to the reticulum of the th5 1 veil (Figs 9C, 22B). The reticulum of the ventral thecal wall is well-developed up to the fifth pair of thecae, but distally, below the long veils, it become poorly developed, eventually disappearing under the veils of the last thecal pairs. The genicular and mid-ventral lists below the veils exhibit a similar decrease in thickness, becoming as thin as some lists of the veil (Figs 9C, 22B). The outer ancora is well-developed in the mature tubarium, and built of thick reticulum (Fig. 22D). Some membrane of the metasicular wall is connected to the virgella (Fig. 22C). Proximal internal structures typical of the genus Gothograptus are present, but they are difficult to distinguish in the flattened material to hand. The nema is distinctively thicker than other lists of the tubarium, and the thickest part starts at the level of th5 1. Remarks. G. velo n. sp. differs from Gothograptus obtectus in the development of veils. The veils of G. velo are built of a delicate reticulum with no thick transverse lists as in G. obtectus. Some of the veils are connected to the veil of the previous theca, forming an external layer above the thecal orifices and thecae (Fig. 9C)., Published as part of Koz��owska, Anna, Bates, Denis, Zalasiewicz, Jan & Radzevi��ius, 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, pp. 435-469 in Zootaxa 4568 (3) on pages 462-466, DOI: 10.11646/zootaxa.4568.3.2, http://zenodo.org/record/2601607

Gothograptus kozlowskii Kozłowska-Dawidziuk, 1990 Figs 17���18 1990. Gothograptus (Gothograptus) kozlowskii, Kozłowska-Dawidziuk; pp. 197���200; pl. 23: 1���4; pl. 24: 3; fig. 4A���E. 2010. Gothograptus kozlowskii, Loydell, Nestor & M��nnik; p. 5, fig. 4h. Material. New material of G. kozlowskii comes from Poland, Bartoszyce IG-1 core, from the upper part of the lundgreni Biozone, depths from 1677.5 to 1672.8 m, and from the testis Biozone, depth 1668.8 m. These are mostly young and fragments of mature specimens, about 30 in all. Specimens from Lithuania, ��iupyliai-69 core, occur in the upper part of the lundgreni Biozone, depths: 1010.0 m to 1008.1 m. They represent mostly fragments of about 40 mature and young tubaria. Description. The best, completely preserved mature tubarium has fifteen thecae and a fragment of appendix. Tubarium without appendix is 6.5 mm long, 0.6 mm wide above the ancora umbrella rim. The widest part of the tubarium is at the level of the fourth thecal pair��� 0.8 mm; the width then decreases slowly towards the distal thecae and at the level of seventh thecal pair it is 0.5 mm. The virgella is very thin in mature specimens. The prosicular apex is located at the level of the lip of the second theca. The nema is thicker distally. In mature specimens the connecting rods, going from nema to lips, are poorly distinguishable from other lists of the lateral wall. The nassa type of genicular hoods of the first thecae are small, and do not cover the thecal orifices. The third pair of thecae has lateral spines with seams extending horizontally; the next thecae have hoods with a few lists of reticulum surrounded by a thick looping list. The structure extends below the lip with thicker lists bordering the structure. From the fourth thecal pair the genicular lists are very thin, and in the last thecae are difficult to define, whereas the lips are distinctive. As with the genicular lists, the mid-ventral lists become thinner distally; they are extremely thin in the three last pairs of thecae. In flattened mature specimens, only the genicular spines on proximal thecae distinctively protrude out of the tubarium (Fig. 17A, C���D). The most distal thecae have thick lips and very thin mid-ventral lists. The most mature specimen has extremely thick lists, the reticulum and clathrium being of similar widths, the widest about 50 ��m. In these specimens the thick outer ancora umbrella covers a large part of the ancora (Fig. 18C). Remarks. The new collections of Gothograptus kozlowskii from Lithuania and Poland come from the upper part of the lundgreni Biozone and from the testis Biozone. These data gave a more precise stratigraphical position of the species than the first described forms from an erratic boulder (Kozłowska-Dawidziuk 1990). Colonies of this species also occur in Latvia in the upper part of the lundgreni Biozone (Loydell et al. 2010). Radzevičius (2006, fig. 4G, H, I) illustrated juvenile Gothograptus specimens from the lundgreni Biozone of the ��iupyliai-69 borehole (Lithuania) and identified them as Gothograptus cf. kozlowskii. There are not enough features to identify them to the proper species., Published as part of Koz��owska, Anna, Bates, Denis, Zalasiewicz, Jan & Radzevi��ius, 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, pp. 435-469 in Zootaxa 4568 (3) on page 457, DOI: 10.11646/zootaxa.4568.3.2, http://zenodo.org/record/2601607, {"references":["Kozlowska-Dawidziuk, A. (1990) The genus Gothograptus (Graptolithina) from the Wenlock of Poland. Acta Palaeontologica Polonica, 35, 191 - 209.","Loydell, D. K., Nestor, V. & Mannik, P. (2010) Integrated biostratigraphy of the lower Silurian of the Kolka- 54 core, Latvia. Geological Magazine, 147, 253 - 280.","Radzevicius, S. (2006) Late Wenlock biostratigraphy and the Pristiograptus virbalensis group (Graptolithina) in Lithuania and the Holy Cross Mountains. Geological Quarterly, 50, 333 - 344."]}

Gothograptus domeyki n. sp. Figs 15–16 ?1952 Gothograptus nassa, Bouček & Münch, pp. 11–15, fig. 2, a–i. Type material. Holotype number VU RET-13, mature specimen with seven pairs of thecae and appendix (Fig. 16 A–B), Šiupyliai-69 core, 1009,1 m, lundgreni Biozone, paratype number VU RET-14, finite tubarium (Fig. 16 C–E), Šiupyliai-69 core, depth 1010.0 m, lundgreni Biozone, Lithuania. Etymology. Ignacy Domeyko (1802–1889) was a Polish geologist, mineralogist and educator; most of his life was spent in Chile. Diagnosis. Gothograptus with genicular hoods of nassa type developed on the first pair of thecae; second pair of thecae may have paired spines with seams or remnants of reticulum between them; subsequent thecae lacking genicular processes except for the last theca with a reticulated hood. Distinctively thicker thecal lips than pleural and genicular lists. G othograptus domeyki differs from other Gothograptus species in the lack of genicular structures in the medial and distal thecae. Remarks. Gothograptus domeyki n. sp. differs from other Gothograptus species in the lack of any genicular processes in most thecae as well as in having thick lips. G. domeyki n. sp. is similar to G. kozlowskii in having nassa type hoods on the first pair of thecae and reticulated hoods on the last pair of thecae. Similar reticulated hoods on the last thecae are also found in G. storchi. G. domeyki n. sp. is so far known only from Lithuania. Bouček & Münch (1952) described some retiolitines as Gothograptus nassa, from the Czech Republic, lundgreni Biozone. Their drawings show some tubaria with thick lips, and without genicular nassa hoods, similar to those described herein for the first time in G. domeyki n. sp. Proper recognition of this form needs some detailed study. Material. Two cores from Lithuania: Šiupyliai-69 core, depths: 1009.7 m 30 young, 12 mature; 1009.1 m 50 young, 31 mature; Vilkaviškis-131 core, depth 1095.8 m four fragments of mature specimens. Upper part of lundgreni Biozone. Description. Mature tubaria usually have seven or eight pairs of thecae and appendix. The total length of the tubarium is about 7.0 mm, together with the appendix. The tubarium is almost parallel-sided, widest at 0.83 mm at the level of the first thecal pair, and then it slowly narrows to 0.4 mm just below the appendix. In some mature specimens the prongs of the ancora, as well as the sicular rim and lists above the proximal lateral orifices, are extremely thick ((Fig. 16A, B, E, H, I). An outer ancora is well developed in mature specimens. The proximal ventral orifices are overgrown by reticulum in mature colonies. Mid-ventral lists are 0.5 mm long in the first and last thecae, the rest are about 0.7 mm long. Genicular structures start to develop when the colony reaches about five thecal pairs. There are three types of genicular structures in mature tubaria of G. domeyki n. sp. The first pair of thecae have nassa hoods; usually they are small and do not cover the orifices of thecae or they are slightly larger than the thecal orifice. The second and third thecal pairs have a pair of curved spines grown on the pleural lists, extending horizontally. Seams on the inner sides of the spines indicate that there was a thin membrane between them, so that the spines form the sides of a hood. The bases of the spines in the mature tubaria are of triangular shape (Fig. 16G). Similar spines forming hoods are also found in Gothograptus kozlowskii (see below). The next thecae have no hoods; their lips are thick, about twice as thick as the geniculum list. The genicular lists became significantly thinner in the last thecae. The last pair of thecae have reticulated hoods covering orifices; the genicular list is not developed. The reticulum of these hoods is connected with the appendix (Fig. 16A). umbrella, outside view. Some young tubaria with five pairs of thecae have reticulum up to the third pair of thecae, small nassa hoods on the first thecae, the two next pairs of thecae having thin genicular spines. A specimen with seven pairs of thecae has a well-developed reticulum, except on the two last thecae. The lists of young colonies are thin; the thickest is the nema (Fig. 15A, D). During astogeny the next thicker lists are the lateral apertural rods. The lips and genicular lists are so thick that the thecal orifice is very narrow (Fig. 15E, 16E). The thecal orifices vary in shape from nearly rectangular to pyramidal with rounded corners (Fig. 7A, 16C, E). Mature colonies have a dense reticulum of similar thickness to the clathrial lists, thus the structures formed by clathrial lists are difficult to distinguish.

Gothograptus auriculatus n. sp. Figs 13���14 2006 Gothograptus nassa, Calner, Kozłowska, Masiak & Schmitz, p. 80, fig. 1E. Type material. Holotype ZPAL G.55/23, mature specimen with six pairs of thecae and distal end broken off (Fig. 13 B); paratype ZPAL G.55/24, distal end of mature tubarium with five pairs of thecae and appendix (Fig. 13 C, F). Bartoszyce IG-1well, depth 1645.2 m, Poland, lower part of praedeubeli Biozone. Etymology. Latin auriculatus ���relating to the earlobe shape of the genicular structures. Diagnosis. Tubarium with genicular structures formed by the nassa type of hood, and paired vertical auriclelike structures bordering both sides of the thecal orifices. Auricle structures are characteristic only of Gothograptus auriculatus n. sp. In mature colonies the auricles bend towards the mid-ventral list below the thecal lip and nassa hood. Remarks. G. auriculatus n. sp. differs from G. nassa in having two lateral auricles, as additional elements located on the lateral sides of the thecal orifices and below the lips. Young colonies of the new species have nassa hoods; the auricles appear later in astogeny. Material. The material studied comes from Poland, Lithuania and Germany. The most abundant material comes from the Bartoszyce IG- well, ranges from 1649.0 to 1645.2 m, praedeubeli Biozone, yielding about 1300, mostly young, specimens. Two fragments of G. auriculatus come from Lithuania, Pilviskiai-141 core, depth 842.2 m, nassa / praedeubeli Biozone. Description. Tubaria slightly widening up to th1 2, then parallel-sided and gently tapering distally, ended by an appendix. Most of the specimens are represented by fragments of tubaria up to the 11th thecal pair. Tubarium width at the level of the first thecal pair is about 1.5 mm, and in the middle part of the tubarium 1.2 mm. The longest fragment of tubarium, comprising 11 pairs of thecae, is 10 mm long. The lists of the young stages of colony are very thin, about 15 ��m across, while the lists of the mature tubarium are about five times thicker, at 75 ��m. The thickening of lists starts from the proximal end. The looping meshes of the ancora umbrella are overgrown by a reticulum in the mature colonies. The ancora prongs below the lateral proximal orifices and the lists surrounding the proximal lateral orifices are extremely wide in mature specimens (Fig. 14 C���F).The reticular lists also become very wide in mature colonies, making the reticulum meshes very small. In the most mature specimens the reticulum lists reach similar thicknesses to those of the main lists of the tubaria (Fig. 13D). Based on well-preserved specimens representing the young tubaria, the sicula length is estimated at 1.4 mm, the length of the prosicula at 400 ��m (Fig. 2). The nema starts at the level of the th1 2 geniculum and is connected to the obverse lateral wall of the tubarium. The typical genicular structures are well developed in mature specimens. During astogeny the auricles, typical of this species, are first developed in more distal thecae (Fig. 13 A���C). The longest hoods in mature specimens are about 370 ��m long, and extend below the lips. As a consequence the thecal orifices are not visible. The hoods of astogenetically old tubaria may be elongated in the centre of their lower parts (Fig. 13E). The distal thecae are shorter and their genicular structures are usually irregular and shorter horizontally (Fig. 13E). In mature specimens, the nema widens distally to about 67 ��m across at the most distal end of the tubarium and in the appendix (Figs 3, 13C). A nematularium was not identified. Remarks. Gothograptus auriculatus n. sp. has been described from the praedeubeli Biozone of Sweden, and published as G. nassa (Calner et al. 2006, fig. 1E). This taxon, also found in erratic boulders from Germany, has been illustrated and identified by Jaeger as Gothograptus nassa late form (Maletz 2010, figs 1, 2). The specimens, stored in the Museum f��r Naturkunde, Berlin, come from a fauna containing the type material of Colonograptus praedeubeli., Published as part of Koz��owska, Anna, Bates, Denis, Zalasiewicz, Jan & Radzevi��ius, 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, pp. 435-469 in Zootaxa 4568 (3) on pages 451-454, DOI: 10.11646/zootaxa.4568.3.2, http://zenodo.org/record/2601607, {"references":["Calner, M., Kozlowska, A., Masiak, M. & Schmitz, B. (2006) A shoreline to deep basin correlation chart for the middle Silurian coupled extinction-stable isotopic event. GFF, 128, 79 - 84. https: // doi. org / 10.1080 / 11035890601282079","Maletz, J. (2010) Retiolitid graptolites from the collection of Hermann Jaeger II: Cometograptus, Spinograptus and Plectograptus. Palaontologische Zeitschrift, 84, 501 - 522. https: // doi. org / 10.1007 / s 12542 - 010 - 0065 - x"]}

Gothograptid retiolitines were distinctive in being one of the very few graptolite groups to thrive through the late Wenlock extinction event that killed off most graptoloid species, and their distinctive construction may have been a factor in this success amid environmental adversity. New and rich material from two localities in Poland and five localities in Lithuania contains Gothograptus nassa, Gothograptus obtectus and four new species. The detailed morphology and reconstruction of the tubarium shows its specific features, different from other lundgreni Biozone retiolitines. The tubarium is narrow, elongated, finite, massive and compact. The thecal orifices are hidden by simple hoods or by extraordinary reticulated veils, which may cover the ventral walls. The colonies of Gothograptus species from the lundgreni Biozone are short, usually having eight pairs of thecae, whereas species from the post-lundgreni interval may reach more than 20 pairs of thecae. A common feature of Gothograptus species is the presence of singular genicular structures tightly covering thecal orifices. Reticulated hoods and veils are characteristic of species from the lundgreni Biozone. The most common such structures are nassa hoods, located on the proximal thecae in some species from the lundgreni Biozone, and on every theca of post-lundgreni species. Only Gothograptus domeyki n. sp. has no genicular processes on most thecae. Within a total of four species from the lundgreni Biozone and three species from the nassa and praedeubeli Biozones, we describe here the new species Gothograptus domeyki and Gothograptus velo from the lundgreni Biozone, Gothograptus diminutus from the parvus/nassa Biozone, and Gothograptus auriculatus from the dubius/nassa and praedeubeli biozones; G. auriculatus n. sp. is the youngest form of the genus Gothograptus. Variation within the genus Gothograptus during the post-lundgreni interval period is shown for the first time.

Genus Semigothograptus new genus Etymology. The generic name Semigothograptus is derived from semi (half in Latin) and Gothograptus Frech, 1897 indicating some similarity to the genus Gothograptus. Type and only species. Gothograptus? meganassa (Rickards & Palmer, 2002) Type locality. Aston Piggot, Long Mountain, Shropshire, UK; material deposited in the Sedgwick Museum, Cambridge (Rickards & Palmer 2002). Diagnosis. Tubarium widening gradually from proximal end, nema free. Ancora umbrella simple, a pair of large looping meshes on each side of tubarium. Proximal ventral orifices of triangular shape; lateral orifices kidney-shaped. Ventral wall represented by mid-ventral lists, lips, genicular list, and long lateral apertural rods convex towards the centre of lateral wall, which become distinctly sigmoidal the more distal they are. Oblique clathrial lists on lateral walls. Remarks. The new genus Semigothograptus has a free nema, which therefore does not affect the pattern of the lateral wall, whereas Gothograptus, to which the described species was tentatively designated by Rickards and Palmer, has the nema connected to the lateral (obverse) side of the tubarium (Fig. 1 A). The long lateral apertural rods, convex towards the centre of lateral wall, are unique to Semigothograptus.

The Gothograptus nassa type of genicular hoods Genicular processes are typical of many retiolitids, mostly in post- lundgreni Biozone species. One of them is the genicular hood, typical of Gothograptus nassa Holm, 1890, named here the nassa type. In the evolutionary history of the retiolitines, nassa type genicular hoods are present in four species, all of them within the Gothograptus lineage, which started during the lundgreni Biozone, and ranges into to the lower Ludfordian leintwardinensis Biozone (Kozłowska 2015). The species are Gothograptus kozlowskii Kozłowska-Dawidziuk, 1990 from the lundgreni Biozone, Gothograptus nassa from the dubius / nassa Biozone and lower part of the praedeubeli Biozone, Semigothograptus meganassa (Rickards & Palmer, 2002) from the uppermost part of the dubius / nassa Biozone and ludensis Biozone, and Neogothograptus eximinassa Maletz, 2008 from the ludensis/gerhardi Biozone. The nassa type of genicular hoods are developed only on the first thecal pair in the oldest species, Gothograptus kozlowskii, whereas the rest of the genicular processes are largely of reticulated construction. In mature tubaria of Gothograptus nassa, Semigothograptus meganassa and Neogothograptus eximinassa genicular hoods of the nassa type are well-developed on every theca (Kozłowska et al. 2009). The detailed structure of the hood is shown herein in two well-preserved specimens of Semigothograptus meganassa and G. nassa (Fig. 7). The hood is built from many, very thin and densely packed parallel subjacent bandages as shown in detail on Fig. 7 B, F, G. The bandages grow proximally from the genicular list forming a structure of high density. Irregular bandages, growing also proximally and started above the geniculum, are secreted on the outer surface of the hood, strengthening it during astogeny (Fig. 7 A, E���H). The hoods of thecae within mature tubaria may occlude the whole thecal aperture leaving very little space for the zooids. There are some differences in the density of the parallel bandages forming the nassa type of hoods. The irregular bandages forming the outer layer of the hood may be weakly developed. The most dense and solid hoods are those of Gothograptus kozlowskii and G. nassa, whereas the hoods of Semigothograptus meganassa (Fig. 7 A��� D), and hoods of Neogothograptus eximinassa (Maletz 2008, fig. 9H, K) have some space between the parallel bandages. However, in the mature specimens of Semigothograptus meganassa described by Rickards & Palmer (2002), the hoods form solid structures as in the G. nassa hoods (Rickards & Palmer 2002, text-fig. 4A���F). In the diagnosis of the Gothograptus ? meganassa, Rickards & Palmer (2002, p. 229) note that the hoods are ���heavily pigmented but with clear microfusellar tissue���. SEM examination of the present material reveals that these hoods have distinctive pustules on the parallel bandages as well as on the typical irregular bandages covering the hoods (Fig. 7). The pustules are a unique structure known only on the bandage surfaces of some retiolitids (Bates et al. 2005). Thus the pustules identified under SEM, clearly indicate the bandages. The morphology of the Neogothograptus eximinassa hoods is shown by Maletz (2008, fig. 9H, K) on SEM pictures. They are similar to the Semigothograptus meganassa hoods but the enlargement is too small to see the details. The pustules are very weakly visible on the parallel structures building the genicular hoods (Maletz, personal communication). Maletz (2008) regarded the hoods as composed of microfusellar structure., Published as part of Koz��owska, Anna, 2016, A new generic name, Semigothograptus, for Gothograptus? meganassa Rickards & Palmer, 2002, from the Silurian post- lundgreni Biozone recovery phase, and comparative morphology of retiolitids from the lowermost upper Homerian (upper Wenlock), pp. 534-546 in Zootaxa 4208 (6) on pages 542-543, DOI: 10.11646/zootaxa.4208.6.2, http://zenodo.org/record/215001, {"references":["Holm, G. (1890) Gotlands graptoliter. Svenska Vetenskap-Akademiens handlingar, 16, 1 - 34.","Kozlowska, A. (2015) Evolutionary history of the Gothograptus lineage of the Retiolitidae (Graptolithina). Estonian Journal of Earth Sciences, 64, 56 - 61.","Kozlowska-Dawidziuk, A. (1990) The genus Gothograptus (Graptolithina) from the Wenlock of Poland. Acta Palaeontologica Polonica, 35, 191 - 209.","Rickards, R. B. & Palmer, D. C. (2002) Gothograptus? meganassa sp. nov., an unusually large retiolitid graptoloid from the Late Wenlock ludensis Biozone of Long Mountain, Shropshire, UK. Special Papers in Palaeontology, 67, 225 - 232.","Maletz, J. (2008) Retiolitid graptolites from the collection of Hermann Jaeger in the Museum fur Naturkunde, Berlin (Germany). I. Neogothograptus and Holoretiolites. Palaontologische Zeitschrift, 82, 285 - 307. https: // doi. org / 10.1007 / BF 02988896","Kozlowska A., Lenz, A. C. & Melchin, M. (2009) Evolution of the retiolitid Neogothograptus (Graptolithina) and its new species from the upper Wenlock of Poland, Baltica. Acta Palaeontologica Polonica, 54, 423 - 434. https: // doi. org / 10.4202 / app. 2008.0022","Bates, D. E. B., Kozlowska, A. & Lenz, A. C. (2005) Silurian retiolitid graptolites: Morphology and evolution. Acta Palaeontologica Polonica, 50, 705 - 720."]}

Kozłowska, Anna (2016): A new generic name, Semigothograptus, for Gothograptus? meganassa Rickards & Palmer, 2002, from the Silurian post- lundgreni Biozone recovery phase, and comparative morphology of retiolitids from the lowermost upper Homerian (upper Wenlock). Zootaxa 4208 (6): 534-546, DOI: http://doi.org/10.11646/zootaxa.4208.6.2

Genus Semigothograptus new genus Etymology. The generic name Semigothograptus is derived from semi (half in Latin) and Gothograptus Frech, 1897 indicating some similarity to the genus Gothograptus. Type and only species. Gothograptus? meganassa (Rickards & Palmer, 2002) Type locality. Aston Piggot, Long Mountain, Shropshire, UK; material deposited in the Sedgwick Museum, Cambridge (Rickards & Palmer 2002). Diagnosis. Tubarium widening gradually from proximal end, nema free. Ancora umbrella simple, a pair of large looping meshes on each side of tubarium. Proximal ventral orifices of triangular shape; lateral orifices kidney-shaped. Ventral wall represented by mid-ventral lists, lips, genicular list, and long lateral apertural rods convex towards the centre of lateral wall, which become distinctly sigmoidal the more distal they are. Oblique clathrial lists on lateral walls. Remarks. The new genus Semigothograptus has a free nema, which therefore does not affect the pattern of the lateral wall, whereas Gothograptus, to which the described species was tentatively designated by Rickards and Palmer, has the nema connected to the lateral (obverse) side of the tubarium (Fig. 1 A). The long lateral apertural rods, convex towards the centre of lateral wall, are unique to Semigothograptus., Published as part of Koz��owska, Anna, 2016, A new generic name, Semigothograptus, for Gothograptus? meganassa Rickards & Palmer, 2002, from the Silurian post- lundgreni Biozone recovery phase, and comparative morphology of retiolitids from the lowermost upper Homerian (upper Wenlock), pp. 534-546 in Zootaxa 4208 (6) on page 536, DOI: 10.11646/zootaxa.4208.6.2, http://zenodo.org/record/215001, {"references":["Frech, F. (1897) Lethaea geognostica, 1 Lethaea palaeozoica, II. Graptolithiden, Stuttgart, 544 - 684.","Rickards, R. B. & Palmer, D. C. (2002) Gothograptus? meganassa sp. nov., an unusually large retiolitid graptoloid from the Late Wenlock ludensis Biozone of Long Mountain, Shropshire, UK. Special Papers in Palaeontology, 67, 225 - 232."]}

Semigothograptus meganassa (Rickards & Palmer, 2002) (Figs 1 D, 2B, 3, 4B, 7A���D) 2001 Gothograptus nassa Holm, 1890 (wide form)���Kozłowska-Dawidziuk, Lenz & ��torch, pp. 151���152, fig. 4: 11���12. 2002 Gothograptus ? meganassa Rickards & Palmer, pp. 228���231, text-fig. 4. Diagnosis. Genicular hoods of nassa type, reticulum dense in mature colonies. Material. Four fragments of isolated tubaria with up to six pairs of thecae, from laminated marls, Bartoszyce IG-1 drill core, depth 1649.2 m and 1649.0 m, geographical coordinates 54˚14��� N, 20˚57���S, Poland, eastern part of Baltica, East European Platform. Based on flattened graptolites Tomczyk (1974) assigned the interval 1636.5��� 1650.0 m to the dubius / nassa Biozone, upper Homerian, Wenlock. The material comes from the uppermost part of the dubius / nassa Biozone. The studied material was isolated from the rock though slow dissolution in 10���30% hydrochloric acid (HCl), for cleaning specimens with sediment attached 10% hydrofluoric acid (HF) was used. Specimens are stored in glycerine in plastic containers, and on SEM stubs in the Institute of Paleobiology, Polish Academy of Sciences in Warsaw. Description. Length of immature tubarium with proximal end, ZPAL G.54/1, consisting of four pairs of thecae is 5.4 mm (Fig. 1 D). The distance from the ancora umbrella rim to the lip of th1 1 is 1 mm. Length of lateral apertural rods increases gradually from 0.94 mm in the first theca up to 1.1 mm in the fourth. Width of tubarium measured between thecal lip and lateral apertural rod also increases distally. Width of tubarium on the th1 1 level is 0.7 mm, on th2 1 is 0.8 mm, on th3 1 is 1.1 mm, and th4 1 level is 1.2 mm. Specimen ZPAL G.54/2, representing possibly a more distal part of tubarium, is parallel-sided, about 1 mm wide. The proximal ventral orifices are of triangular shape (Fig. 1 D, 4B). The proximal lateral orifices are located centrally, between looping meshes of the ancora umbrella. The looping meshes are developed on both sides of tubarium forming a wavy shape of the ancora umbrella rim (Figs 2, 4 B). They are smaller on the th1 1 side of tubarium (Fig. 2 B). Within the looping meshes are some thin additional lists (Fig. 2 B). Inside specimen ZPAL G. 54/2 there is a free list, which may represent a fragment of the free virgella or nema (Fig. 3 B). Lateral apertural rods (pleural lists of Rickards & Palmer 2002) are long, and distinctly convex towards the longitudinal axis of the lateral walls. Clathrial lists of the lateral walls of tubarium are relatively thin, oblique, going from lateral apertural rod to lateral apertural rod of tubarium (Fig. 4 B). Thecal apertures are almost rectangular. Genicular hoods are of nassa type. On the immature specimen the hoods are present on the first thecae, becoming larger in the medial part of tubarium and absent in the two distal growing thecae (Figs 1 D, 4B). In some thecae there are some narrow open spaces between bandages, possibly due to taphonomic changes (Fig. 7 A���D). Some irregular bandages are secreted on the outer surface of the upper part of the hoods (Fig. 7 A, D). The largest specimen, of six pairs of thecae, is preserved in two fragments with no proximal end (Fig. 3). The specimen possibly represents the medial part of the tubarium. The reticulum of the tubarium is composed of thin lists, dense in the proximal and medial part of the growing colony, becoming weaker distally, and not developed in the most distal immature part of the tubarium., Published as part of Koz��owska, Anna, 2016, A new generic name, Semigothograptus, for Gothograptus? meganassa Rickards & Palmer, 2002, from the Silurian post- lundgreni Biozone recovery phase, and comparative morphology of retiolitids from the lowermost upper Homerian (upper Wenlock), pp. 534-546 in Zootaxa 4208 (6) on pages 536-538, DOI: 10.11646/zootaxa.4208.6.2, http://zenodo.org/record/215001, {"references":["Rickards, R. B. & Palmer, D. C. (2002) Gothograptus? meganassa sp. nov., an unusually large retiolitid graptoloid from the Late Wenlock ludensis Biozone of Long Mountain, Shropshire, UK. Special Papers in Palaeontology, 67, 225 - 232.","Holm, G. (1890) Gotlands graptoliter. Svenska Vetenskap-Akademiens handlingar, 16, 1 - 34.","Tomczyk, H. (1974) Bartoszyce IG- 1, Goldap IG- 1. In: Modlinski, Z. (Ed.), Profile glebokich otworow wiertniczych Instytutu Geologicznego, 14, pp. 1 - 362."]}