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Article: Ferrari, M, Little, CTS orcid.org/0000-0002-1917-4460 and Atkinson, JW (2021) Upper Toarcian (Lower Jurassic) marine gastropods from the Cleveland Basin, England: systematics, palaeobiogeography and contribution to biotic recovery from the early Toarcian extinction event. Papers in Palaeontology, 7 (2). pp. 885-912. ISSN 2056-2799 https://doi.org/10.1002/spp2.1322

© The Palaeontological Association. This is the peer reviewed version of the following article: Ferrari, M., Little, C.T.S. and Atkinson, J.W. (2020), Upper Toarcian (Lower Jurassic) marine gastropods from the Cleveland Basin, England: systematics, palaeobiogeography and contribution to biotic recovery from the early Toarcian extinction event. Pap Palaeontol. doi:10.1002/spp2.1322, which has been published in final form at https://doi.org/10.1002/spp2.1322. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.

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LATE TOARCIAN (LOWER JURASSIC) MARINE GASTROPODS FROM THE CLEVELAND BASIN, ENGLAND: SYSTEMATICS, PALAEOBIOGEOGRAPHY AND CONTRIBUTION TO BIOTIC RECOVERY FROM THE EARLY TOARCIAN EXTINCTION EVENT

Journal: Palaeontology

Manuscript ID PALA-09-18-4325-OA.R3

Manuscript Type: Original Article

Date Submitted by the n/a Author:

Complete List of Authors: Ferrari, Mariel; Instituto Patagónico de Geología y Paleontología (IPGP, CCT CONICET-CENPAT) Little, Crispin; University of Leeds, School of Earth and Environment Atkinson, Jed; University of Leeds, School of Earth and Environment

Gastropods, taxonomy, Late Toarcian, Cleveland Basin, faunal recovery, Key words: Evolution

Palaeontology Page 1 of 64 Palaeontology

1 2 3 LATE TOARCIAN (LOWER JURASSIC) MARINE GASTROPODS FROM THE 4 5 CLEVELAND BASIN, ENGLAND: SYSTEMATICS, PALAEOBIOGEOGRAPHY 6 7 AND CONTRIBUTION TO BIOTIC RECOVERY FROM THE EARLY 8 TOARCIAN EXTINCTION EVENT 9 10 11 12 13 1* 2 2 14 by MARIEL FERRARI, , CRISPIN T.S. LITTLE and JED W. ATKINSON 15 16 17 18 1 19 Instituto Patagónico de Geología y Paleontología (IPGP CCT CONICET−CENPAT), Bvd. 20 Brown 2915, U9120CD, Puerto Madryn, Chubut, Argentina; e-mail; mferrari@cenpat- 21 22 conicet.gob.ar. 23 24 2School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, UK; e-mails: 25 26 [email protected], [email protected]. 27 28 29 30 31 Abstract. Here we describe a new late Toarcian (Lower Jurassic) marine gastropod fauna 32 from rocks of the Cleveland Basin exposed on the North Yorkshire coast of England. The 33 34 fossil assemblage comprises sixteen species, of which three are new: Katosira? bicarinata 35 36 sp. nov., Turritelloidea stepheni sp. nov. and Striactaenonina elegans sp. nov. Four species 37 38 are described in open nomenclature as Tricarilda? sp., Jurilda sp., Cylindrobullina sp. and 39 Cossmannina sp. The other species have previously been described: Coelodiscus minutus 40 41 (Schübler in Zieten), Procerithium quadrilineatum (Römer), Pseudokatosira undulata 42 43 (Benz in von Zieten), Palaeorissoina aff. acuminata (Gründel, 1999b), Pietteia unicarinata 44 (Hudleston), Globularia cf. canina (Hudleston), Striactaeonina cf. richterorum Schulbert 45 46 & Nützel, Striactaenonina aff. tenuistriata (Hudleston) and Sulcoactaeon sedgvici 47 48 (Phillips). Most of these species are the earliest records of their respective genera and show 49 50 palaeobiogeographical connections with contemporary gastropod associations from other 51 regions of Europe and South America. The taxonomic composition of the late Toarcian 52 53 Cleveland Basin gastropod assemblage differs substantially from the faunas of the late 54 55 Pliensbachian and early Toarcian Tenuicostatum Zone, showing the strong effect of the 56 57 58 59 60 Palaeontology Palaeontology Page 2 of 64

1 2 3 early Toarcian mass extinction event on the marine gastropod communities in the basin. 4 5 Only a few gastropod species are shared between the late Toarcian faunas and the much 6 7 more diverse Aalenian gastropod faunas in the Cleveland Basin, suggesting there was a 8 facies control on gastropod occurrences at that time. This is also a potential explanation for 9 10 the taxonomic differences between the late Toarcian gastropod faunas in the Cleveland 11 12 Basin and those in France, and Northern and Southern Germany. 13 14 15 16 Key words: Gastropods, taxonomy, late Toarcian, Cleveland Basin, faunal recovery, 17 18 evolution. 19 20 21 22 23 MASS extinction events have had major effects on the pattern of biotic evolution on Earth, 24 25 both by reducing standing diversity and by opening ecospace for subsequent radiations of 26 surviving organisms. While much palaeontological research effort has been expended over 27 28 the past 40 years elucidating patterns of extinction and identifying cause-and-effect 29 30 mechanisms for the major mass extinction events, much less is known about biotic recovery 31 32 patterns, including rates and the structure of post-extinction communities. One of the mass 33 extinction events identified in the 1980s in the Sepkoski Phanerozoic diversity curves was 34 35 in the Lower Jurassic at the Pliensbachian-Toarcian stage boundary, resulting in the loss of 36 37 15-20% of marine families and genera (Sepkoski 1996). This event has been studied 38 extensively and is now regarded to have occurred mainly in the early Toarcian, co-incident 39 40 with the deposition of laminated black shale facies across the NW European area, a 41 42 negative carbon isotope excursion and progressive global warming, probably due to 43 44 volcanogenic CO2 released from the Karoo-Ferrar Volcanic Province (see Thibault et al. 45 2018 and Xu et al. 2018 for recent reviews). Although the early Toarcian extinction event 46 47 is best known from the European record, it has been also identified in Canada, Chile, 48 49 Siberia and Tibet (Aberhan & Fürsich 2000; Wignall et al. 2006; Zakharov et al. 2006; Al 50 51 Suwaidi et al. 2016, Martindale & Aberhan 2017). The early Toarcian laminated black 52 shale facies in NW Europe (referred to often as the Toarcian Oceanic Anoxic Event) 53 54 represents periods of time when oxygen levels in the sediments and probably periodically 55 56 much of the contemporary water column fell to levels below which animals could not live, 57 58 59 60 Palaeontology Page 3 of 64 Palaeontology

1 2 3 punctuated with short duration oxygenation events (e.g. Röhl et al. 2001). This facies is 4 5 well represented as the ‘Jet Rock’ (Mulgrave Shale Member; Powell 2010) in the expanded 6 7 Toarcian sections in the Cleveland Basin, cropping out in superb coastal exposures of North 8 Yorkshire. Several very comprehensive palaeontological studies have been made of these 9 10 globally important rock sections, establishing both the pattern and rates of biotic extinction 11 12 during the early Toarcian event, using macrofossil range chart data (e.g. Little 1996; 13 14 Harries & Little 1999; Caswell et al. 2009; Danise et al. 2013). Up until recently very little 15 was known about the biotic recovery from the early Toarcian extinction event in the 16 17 Cleveland Basin, in part because of local sedimentary gap in the middle Toarcian. 18 19 Therefore, an extensive new collection of marine macrofossils was made from the 20 Ravenscar section on the North Yorkshire coast (Figure 1), which has a complete middle to 21 22 late Toarcian sequence, representing four ammonite zones and around 5.1 million years of 23 24 geological time (Knox 1984; Powell 2010; Boulila et al. 2014). After the bivalves, 25 26 gastropods form the second largest proportion of the benthic macrofossils in this collection 27 in terms of diversity, and this paper provides a systematic description of the gastropod taxa 28 29 represented. In addition, we compare the taxonomic affinities of this gastropod fauna with 30 31 pre-extinction and Aalenian gastropod faunas in the Cleveland Basin, and contemporary 32 33 gastropod occurences from other regions of Europe and South America, to assess post- 34 extinction recovery and Toarcian palaeobiogeographical connections, respectively. 35 36 37 38 39 GEOLOGICAL SETTING 40 41 The Cleveland Basin hosts one of the most expanded Toarcian rock sections in the UK, yet 42 43 across much of the basin the Lower Jurassic sequence is terminated by an erosive period 44 45 during the Middle Jurassic (Powell 2010). This resulted in the Aalenian-aged Dogger 46 Formation resting unconformably on the middle Toarcian Alum Shale Member of the 47 48 Whitby Mudstone Formation (Figure 1). However, within the Peak Trough, which was 49 50 actively subsiding during the Lower Jurassic, a middle to late Toarcian sequence was 51 preserved from erosion, and is exposed in the sea cliffs and foreshore between Ravenscar 52 53 and Blea Wyke, North Yorkshire (Figure 2). This sequence consists of the uppermost 54 55 members of the Whitby Mudstone Formation and the Blea Wyke Sandstone Formation 56 57 58 59 60 Palaeontology Palaeontology Page 4 of 64

1 2 3 (Figure 2), and represents a regressive sedimentary sequence, from mudstones to fine 4 5 sandstones (Knox 1984; Powell 2010). The late Toarcian rocks are capped by the oolitic 6 7 facies of the Dogger Formation, probably disconformably, as the last Toarcian sub-zone 8 appears to be missing from the sequence here (Knox 1984). Descriptions of the Ravenscar 9 10 section in the 19th and early 20th century tended to group the Blea Wyke Sandstone 11 12 Formation with the Dogger Formation (discussed in detail by Dean 1954), rather than the 13 14 underlying Lower Jurassic sequence. Partly for this reason, there have been relatively few 15 non-ammonite palaeontological studies from late Toarcian Ravenscar section. In the case of 16 17 the gastropods, Tate and Blake (1876) listed two species from the Peak Mudstone and Fox 18 19 Cliff Siltstone Members of the Whitby Mudstone Formation (their Ammonites jurensis 20 Zone), Hudleston (1884, 1887) described and figured two species from the Yellow 21 22 Sandstone Member of the Blea Wyke Sandstone Formation (his ‘Yellow Sandstones’) and 23 24 Dean (1954) listed a single species from the Peak Mudstone Member of the Whitby 25 26 Mudstone Formation (his ‘Striatulus Shales’). 27 28 29 30 31 MATERIAL AND METHODS 32 33 In the summer of 2013 and 2017 JWA and CTSL collected 24,006 macrofossil specimens 34 35 from 37 sample points covering 45 metres of the Ravenscar section from the top of the 36 37 Alum Shale Member of the Whitby Mudstone Formation to the top of the Blea Wyke 38 Sandstone Formation [Figure 2; Ferrari et al. (2020, table 1)]. Of the macrofossils 477 were 39 40 gastropods. An additional three gastropod specimens collected in 2017 from loose blocks of 41 42 the Grey Sandstone Member were donated by Rob Taylor. The gastropods were preserved 43 44 in two modes: 1) specimens preserved with recrystallized shells, mainly in the Whitby 45 Mudstone Formation, but also some in the Blea Wyke Sandstone Formation; 2) specimens 46 47 preserved as external moulds in mineralized patches of shells in the Yellow Sandstone 48 49 Member. Representative specimens from these shell patches were subsequently cast at the 50 51 University of Leeds using silicone rubber. Some of the larger gastropod specimens were 52 whitened using ammonium chloride; the smaller specimens were imaged using a scanning 53 54 electronic microscopy (SEM) at ALUAR (Aluminio Argentino, Pto. Madryn, Chubut, 55 56 Argentina) 57 58 59 60 Palaeontology Page 5 of 64 Palaeontology

1 2 3 The newly collected data was augmented with gastropod occurrences from the Toarcian 4 5 and Aalenian rocks of the Yorkshire coast sections listed in Tate & Blake (1876), 6 7 Hudleston (1887─1896) and Gründel et al. (2011). 8 9 Institutional abbreviations. YORYM, Yorkshire Museum, England. 10 11 12 13 14 SYSTEMATIC PALAEONTOLOGY 15 16 17 18 19 Subcclass CAENOGASTROPODA Cox, 1960 20 21 Family COELODISCIDAE Schulbert, Nützel & Gründel in Schulbert & Nützel, 2013 22 23 Genus COELODISCUS Brösamlen, 1909 24 25 26 Type species. Euomphalus minutus Schübler in Zieten, 1832; from the Lower Jurassic of 27 28 Germany. 29 30 Remarks. The genus Coelodiscus is known from the Pliensbachian to the Aalenian of 31 32 Europe, but is most abundant in the Toarcian Posidonienschiefer of Southern Germany 33 (Brösamlen 1909). Coelodiscus is small, multi-whorled and thin-shelled. The teleoconch of 34 35 the type species has fine spiral ornament (Schulbert & Nützel 2013). Jefferies & Minton 36 37 (1965), Bandel & Hemleben (1987) and Schulbert & Nützel (2013) interpreted Coelodiscus 38 as having had a planktonic, rather than benthic lifestyle. Recently, Teichert & Nützel 39 40 (2015) recognized the type species of the genus (C. minutus) as being the oldest known 41 42 holoplanktonic gastropod. This is the first certain occurrence of the genus in the late 43 44 Toarcian of the UK. 45 Occurrence. Early Pliensbachian-early Aalenian; Southern Germany, Northern 46 47 Switzerland, England and Argentina. 48 49 50 51 52 Coelodiscus minutus (Schübler in Zieten, 1833) 53 54 Figures 3 A─E 55 56 57 58 59 60 Palaeontology Palaeontology Page 6 of 64

1 2 3 ?2001 Coelodiscus sp. Gründel, p. 59, pl. 5, figs. 9─10. 4 5 2013 Coelodiscus minutus Schübler in Zieten, 1833; Schulbert & Nützel, p. 738, fig. 6 7 12A─C. 8 2015 Coelodiscus minutus Schübler in Zieten, 1833; Teichert & Nützel, fig. 2. 9 10 11 12 Material. YORYM: 2019.315 and YORYM: 2019.316; two specimens preserved as 13 external moulds. 14 Description. Planispiral, wider than high, small- sized, very low- and slightly concave 15 16 spired shell. The protoconch consists of one convex, globose whorl (Fig. 3 C). The 17 18 teleoconch consists of five convex whorls; last whorl markedly more expanded than the 19 spire. The upper portion of last whorl strongly convex, becoming straight to slightly convex 20 21 to the lower portion. Suture deeply incised in a deep spiral furrow. The shell lacks spiral 22 23 and collabral elements. Aperture is holostomatous and oval, forming an acute adapical 24 channel. Basal and umbilical characters are unknown. 25 26 Dimensions (mm). YORYM: 2019.315: height, 1.83; width, 2.14. YORYM: 2019.316: 27 28 height, 1.73; width, 2.18. 29 30 Remarks. Coelodiscus minutus (Schübler in Zieten, 1833) has been reported by Schulbert & 31 Nützel (2013) and Teichert & Nützel (2015) from the early-late Toarcian and early 32 33 Aalenian of Southern Germany. According to the description in Bandel & Hemleben 34 35 (1987) and Teichert & Nützel (2015), C. minutus is ornamented by fine longitudinal spiral 36 37 cords (striae) with 33 striae on last whorl, and smooth opisthocyrt growth lines with a 38 concave sinus near the suture. However, in the two specimens here described the typical 39 40 spiral cords are not visible. 41 42 Gründel (2001, p. 59, pl. 5, figs. 9─10) reported Coelodiscus sp., from the Lower Jurassic 43 (early Pliensbachian) of Argentina, which is also very similar to C. minutus in size and 44 45 shell morphology; here we include Gründel’s species as a doubtful synonym of C. minutus. 46 47 Another very similar species to C. minutus is C. brevispira Conti & Fischer, 1984, from the 48 49 Middle Jurassic (Bajocian) of Italy. C. brevispira, however, lacks the spiral cords on the 50 teleoconch whorls (Conti & Fischer 1984; p. 134, pl. 1, figs. 12a─c, 13a─b). Another 51 52 species possibly comparable to C. minutus is C. wrightianus Tate in Tate & Blake, 1876, 53 54 reported from the Lower Jurassic (early Pliensbachian) of England; however, the authors 55 56 did not describe nor figure the species. 57 58 59 60 Palaeontology Page 7 of 64 Palaeontology

1 2 3 Occurrence. Lower Jurassic (early Pliensbachian)-Middle Jurassic (early Aalenian); 4 5 Andean region of Argentina, Southern Germany, Northern Switzerland and England. 6 7 8 Superfamily CERITHIOIDEA Fleming, 1822 9 10 Family PROCERITHIIDAE Cossmann, 1906 11 12 Genus PROCERITHIUM Cossmann in Chartron & Cossmann, 1902 13 14 Type species. Procerithium quinquegranosum Cossmann, 1902; from the Lower Jurassic 15 16 (Hettangian) of France. 17 18 Remarks. Here we follow the diagnosis of Gründel (1999a, p. 3) for the genus. 19 Occurrence. Lower Jurassic (Hettangian)–Lower Cretaceous (Barremian); Europe, Africa, 20 21 New Zealand, Asia, Antarctica (?), and South America. 22 23 24 25 26 Procerithium quadrilineatum (Römer, 1836) 27 28 29 Figures 3 F─L 30 31 1876 Cerithium quadrilineatum Römer, 1836; Tate & Blake, p. 351. 32 33 1889 Cerithium quadrilineatum Römer, 1836; Hudleston, p. 145, pl. 8, fig. 1 34 35 36 37 Material. YORYM: 2019.317, YORYM: 2019.318, YORYM: 2019.319 (Fig. 3I-L), 38 39 YORYM: 2019.320 (Fig. 3F-G), YORYM: 2019.321, YORYM: 2019.322, YORYM: 40 41 2019.323, YORYM: 2019.324, YORYM: 2019.325, YORYM: 2019.326, YORYM: 42 43 2019.327, YORYM: 2019.328, YORYM: 2019.329, YORYM,: 2019.330, YORYM: 44 2019.331, YORYM: 2019.332, YORYM: 2019.333, YORYM: 2019.334, YORYM: 45 46 2019.335, YORYM: 2019.336, YORYM: 2019.337, YORYM: 2019.338, YORYM: 47 48 2019.339, YORYM: 2019.341, YORYM: 2019.342, YORYM: 2019.343; twenty six 49 specimens preserved as external moulds. YORYM: 2019.340; one specimen preserved as a 50 51 recrystallized shell. 52 53 Description. Turriculate, slender, small-sized and high-spired shell. Protoconch consists of 54 55 2-4 conical and convex whorls with a width of 0.36 mm and height of 0.41 mm. First two 56 57 58 59 60 Palaeontology Palaeontology Page 8 of 64

1 2 3 protoconch whorls smooth; fourth whorl bears a very weak abapical spiral cord near suture 4 5 (Fig. 3 L). Clear demarcation between protoconch and teleoconch. Teleoconch consists of 6 7 7-10 whorls. Sutural ramp narrowly horizontal on earliest whorls, becoming sloped and 8 inclined 45º from suture toward mature growth stages. Suture deeply incised in a spiral 9 10 furrow; a very thin, almost smooth and adapical spiral cord borders suture on mature 11 12 whorls. Four earliest teleoconch whorls are flattened; at mature growth stages the whorls 13 14 become slightly convex. Earliest 2-3 teleoconch whorls ornamented by straight to slightly 15 opisthocline axial ribs; on mature whorls axial ribs become strongly opisthocline to 16 17 opisthocyrt, and number 14/16 per whorl. From third teleoconch whorl to mature growth 18 19 stages axial ribs intercepted by 5-6 regularly spaced spiral cords forming small and rounded 20 nodes at crossing points. Shell base slightly convex and ornamented by several (4-7) 21 22 smooth and acute spiral cords. Fine and weak collabral lines visible on shell surface. 23 24 Aperture is holostomatous and oval. 25 26 Dimensions (mm). Table 1. 27 Remarks. Our specimens seem to be conspecific with Cerithium quadrilineatum, Römer, 28 29 1836 described from the ‘Yellow Sandstones’ at Ravenscar by Hudleston (1889), although 30 31 it is worth noting that the specimen illustrated by Hudleston (1889, pl. 8, fig. 1) is a 32 33 fragmentary teleoconch without juvenile whorls. Tate & Blake (1876) also recorded this 34 species from the highest beds of the Alum Shale in the Lofthouse Alum Works and in the 35 36 Blea Wyke Beds. Based on the diagnosis of Gründel (1999a) for Procerithium, our 37 38 specimens definitely belong to this genus, because they also have ‘protoconch conical with 39 several whorls, at first smooth, later with one spiral near to the abapical suture…First 40 41 teleoconch whorl only with distinct axial ribs. Spirals become visible on the second 42 43 teleoconch whorl or later’. Our specimens also show some diagnostic features of the genus 44 45 Rhabdocolpus (see diagnosis in Gründel 1999), including ‘a sutural ramp nearly horizontal 46 or sloping. The outline of the teleoconch whorls is straight to convex…axial ribs at first 47 48 straight, later opisthocyrt…their crossing point with the spirals are nodose…base convex 49 50 with 5-7 spirals…aperture oval’. However, representatives of Rhabdocolpus have a conical 51 52 protoconch with two spirals on later whorls, a character that is absent in our specimens, 53 which instead have the protoconch typical of Procerithium. 54 55 56 57 58 59 60 Palaeontology Page 9 of 64 Palaeontology

1 2 3 P. quadrilineatum is very similar to P. muricatum (Sowerby, 1825) (Hudleston, 1887, p. 4 5 146, pl. 8, figs. 2 a, b), from the Dogger Formation (early Aalenian) of England. However, 6 7 P. quadrilineatum is larger, has fewer spiral cords (about 4 or 5 per whorl) and has adapical 8 spiral cords that are slightly stronger than the others. P. compactum Gründel, 1999a (p. 4, 9 10 pl. 1, figs. 7─9; Schulbert & Nützel 2013, p. 742, fig. 14H─J), from the late Toarcian and 11 12 early Aalenian of Germany also resembles P. quadrilineatum. However, P. compactum has 13 14 a protoconch with slightly more convex whorls, a more step-like or gradate shell outline 15 with broader sutural ramp on juvenile whorls, weaker and less rounded nodes at the 16 17 crossing points of the axial and spiral elements, and a pronounced and strongly nodular 18 19 adapical spiral cord on the upper portion of the whorl, bordering the narrow ramp. P. 20 oderinensis Gründel, 1999a (p. 5, pl. 1, figs. 10 14; Gründel 2007, p. 239, pl. 4, fig. J K), 21 ─ ─ 22 from the late Toarcian and early Aalenian of northern Germany differs from P. 23 24 quadrilineatum in having two strong spiral cords on earliest teleoconch whorls at the 25 26 adapical and abapical position, and more acute nodes at the crossing points with the axial 27 ribs. P. pseudocostellatum (d’Orbigny, 1850) (Gatto et al. 2015, p. 891, fig. 9c─s), from 28 29 the Toarcian-Aalenian of Southern France, differs from P. quadrilineatum in having a more 30 31 gradate shell, stronger axial ribs, and more conspicuous nodes at the crossing point of the 32 33 axial and spiral elements. P. nulloi (Ferrari, 2009) (p. 457; 2012, p. 328), from the 34 Pliensbachian-Toarcian of Argentina differs from P. quadrilineatum in being larger, and 35 36 having spiral ornament predominant on adult whorls, where the axial ribs become weaker 37 38 P. quadrilineatum bear some resemblance to those of Rhabdocolpus (Rhabdocolpus) 39 multinodosum Gründel, 1999a (p. 7, pl. 1, figs. 15 20), from the Middle Jurassic (late 40 ─ 41 Bathonian) of Poland, but the latter species has a slightly weaker and narrower sutural 42 43 ramp, and the crossing points of the axial and spiral elements are only weakly nodose. R. 44 45 patagoniensis (Ferrari, 2012) (p. 329, figs. 4G-P, 5A─K, as Procerithium (Rhabdocolpus) 46 patagoniensis Ferrari, 2017, p. 6, fig. 2.14─2.17), from the Sinemurian-Toarcian of 47 48 Argentina, differs from P. quadrilineatum in having a step-like outline shell with a broader 49 50 and horizontal sutural ramp, and weaker and less rounded nodes at the crossing points of 51 52 the axial and spiral elements. Finally, P. quadrilineatum is similar to R. (Infacerithium) 53 excavatus Ferrari & Damborenea, 2015 (p. 635, fig. 2. 20─22), from the Middle Jurassic 54 55 (early Bajocian) of Argentina. Both species share similar outline shell, with a narrow and 56 57 58 59 60 Palaeontology Palaeontology Page 10 of 64

1 2 3 sloped sutural ramp, and opisthocyrt axial ribs on mature whorls. However, the Argentinian 4 5 species has slightly stronger nodes on the adapical spiral of mature whorls. 6 7 Occurrence. Lower Jurassic (late Toarcian); Northern England, Germany and France. 8 9 10 11 12 Suborder PTENOGLOSSA Gray, 1853 13 14 Superfamily ZYGOPLEUROIDEA Wenz, 1940 15 Family ZYGOPLEURIDAE Wenz, 1940 16 17 Subfamily AMPEZZOPLEURINAE Nützel, 1998 18 19 Genus KATOSIRA Koken, 1892 20 21 22 23 24 Type species. Chemnitzia periniana d’Orbigny, 1853; from the Lower Jurassic 25 26 (Pliensbachian) of France. 27 Remarks. The type species designation for the genus Katosira was discussed by Nützel & 28 29 Gründel (2015) and they argued that two species have been considered in the literature as 30 31 the types of Katosira: K. periniana (d’Orbigny, 1853) from the Lower Jurassic 32 (Pliensbachian) of France, and K. fragilis Koken, 1892, from the Upper Triassic (Carnian) 33 34 of the Southern Alps. Nützel & Gründel (2015) examined the holotypes of both species and 35 36 observed that the axial ribs are continuous from suture to suture in all teleoconch whorls, 37 38 and that there is no reduction of the axial ribs during ontogeny. However, they suggest that 39 the morphology of K. fragilis is still not known completely and that the subsequent 40 41 designation of Chemnitzia periniana as type species of Katosira by Cossmann 42 43 (1909) is valid. 44 45 Occurrence. Upper Triassic (Carnian)-Upper Jurassic (Oxfordian); cosmopolitan. 46 47 48 Katosira? bicarinata sp. nov. 49 50 (Fig. 3 M─R) 51 52 53 54 55 2007a Katosira sp. Gründel, p. 83, pl. 4, fig. 15─17. 56 57 58 59 60 Palaeontology Page 11 of 64 Palaeontology

1 2 3 Derivation of name. Referring to the two strong and nodular spiral cords bordering the 4 5 sutures on mature whorls. 6 7 Type material. Holotype, YORYM: 2019.344 (Fig. 3M-N); paratype, YORYM: 2019.345 8 (Fig. 3Q-R); complete teleoconch and juvenile specimen preserved as external moulds. 9 10 Additional material. YORYM: 2019.346 (Fig. 3O), YORYM: 2019.347 (Fig. 3P), 11 12 YORYM: 2019.348, YORYM: 2019.349, YORYM: 2019.350, YORYM: 2019.351, 13 14 YORYM: 2019.352; seven fragmentary specimens preserved as external moulds. 15 Type locality. Ravenscar, North Yorkshire, England. 16 17 Type level. Late Toarcian (Blea Wyke Sandstone Formation, Yellow Sandstone Member), 18 19 Cleveland Basin. 20 Diagnosis. Turriculate, slender shell; teleoconch whorls with opisthocline to opisthocyrt 21 22 axial ribs; spiral elements missing on earliest whorls appearing weakly on third or fourth 23 24 whorl; small and rounded nodes at crossing points of axial and spiral elements; adapical 25 26 and abapical cords nodular and stronger than others; base ornamented by spiral cords; 27 aperture holostomatous and oval. 28 29 Description. Turriculate, slender, small-sized and high-spired shell. Protoconch 30 31 fragmentary, consisting of two (probably three originally) convex and smooth whorls (Fig. 32 33 3 Q─R); height 0.47 mm, width 0.38 mm. Clear demarcation between protoconch and 34 teleoconch. Teleoconch consists of eight whorls; outline of earliest whorls flattened and 35 36 becomes slightly convex abapically toward mature whorls. Suture incised. First teleoconch 37 38 whorl begins with opisthocline to opisthocyrt axial ribs which run from suture to suture; 39 pattern conservative throughout ontogeny. Juvenile whorls have 16-17 axial ribs per whorl; 40 41 mature whorls have 19-20 axial ribs per whorl. Spiral cords missing on earliest whorls and 42 43 appear weakly at the third or fourth whorl. Spiral ornament of 7-8 regularly spaced cords 44 45 that intercept axial ribs on mature whorls to form small and rounded nodes at crossing 46 points. Adapical and abapical spiral cords border suture of each whorl and are stronger than 47 48 other spiral cords. Nodes clearly more conspicuous and rounded on the two stronger spiral 49 50 cords (Fig. 3 Q─R). Shell base conoidal with moderately convex surface and ornamented 51 52 by seven regularly spaced spiral cords. Aperture holostomatous and oval. 53 Dimensions (mm). Table 2. 54 55 56 57 58 59 60 Palaeontology Palaeontology Page 12 of 64

1 2 3 Remarks. The type species Katosira periniana (d’Orbigny, 1853) (p. 36, pl. 243, figs. 1─2; 4 5 Fischer & Weber 1997, p. 14, pl. 1, fig. 5; Szabó 2009, p. 93, fig. 84 E─I; Nützel & 6 7 Gründel 2015, p. 16, pl. 8 F─I) differs from Katosira? bicarinata sp. nov. in being larger, 8 having a large number of spiral cords on all teleoconch whorls, and with axial ribs that are 9 10 slightly less opisthocryt on juvenile whorls and becoming obsolete toward mature growth 11 12 stages. K. fragilis Koken, 1892 (in Nützel & Gründel 2015, p. 16 pl. 8 F─I) is also higher- 13 14 spired than K.? bicarinata sp. nov., has indistinct spiral cords, and strong and slightly 15 orthocline axial ribs. K. suessii (Stoliczka, 1861) (p. 163, pl. 1, fig. 2; Szabó 2009, p. 93, 16 17 fig. 85), from the Lower Jurassic (late Sinemurian) of Hungary, differs from K.? bicarinata 18 19 sp. nov. in having a more convex periphery below the mid-whorl, more dense and feebly 20 parasigmoidal axial ribs, and two abapical spiral threads with tubercles. K. hierlatzensis 21 22 (Stoliczka, 1861) (p. 164, pl. 1, figs. 3 a─b; Szabó 2009, p. 94, fig. 86), from the Lower 23 24 Jurassic (Sinemurian-Pliensbachian) of Austria, has more developed tubercles at the 25 26 crossing points of the axial ribs, and a sub-sutural spiral swelling; it also has more dense 27 collabral growth lines. Another comparable species to K.? bicarinata sp. nov. is K. 28 29 anaroides (Schmidt, 1905) (p. 188, pl. 9, figs. 28─29; Kaim & Gründel, 2006, p. 143, text- 30 31 fig. 19A─C), from the Upper Jurassic (Oxfordian) of Poland. The latter species, however, 32 33 has a less slender shell with more convex whorls, and a strong axial ornament consisting of 34 6-8 orthocline to opisthocline ribs, which occur throughout ontogeny. K. basistriata 35 36 Gründel, 2007b (p. 13, pl. 4, fig. 7), from the Lower Jurassic (Sinemurian) of Germany, is 37 38 very similar to K.? bicarinata sp. nov., but differs in having parasigmoidal axial ribs on last 39 whorl. K. contii Fischer et al., 2002 (p. 450, fig. 4.10 11), from the Lower Jurassic 40 ─ 41 (Sinemurian) of Italy differs greatly from K.? bicarinata sp. nov. in being much larger, 42 43 having stronger spiral and nodular elements, and less developed opisthocyrt axial ribs. 44 45 Finally, K.? bicarinata sp. nov. is also very similar to Camponaxis jurassica Nützel & 46 Gründel (2015), from the Lower Jurassic (late Pliensbachian) of southern Germany. 47 48 However, Camponaxis jurassica has a clearly developed heterostrophic larval shell. This 49 50 character is not clearly visible in our specimens and, thus, bicarinata is retained doubtfully 51 52 within Katosira. 53 Occurrence. Lower Jurassic (late Pliensbachian-late Toarcian); Northeastern Germany and 54 55 England. 56 57 58 59 60 Palaeontology Page 13 of 64 Palaeontology

1 2 3 Genus PSEUDOKATOSIRA Nützel & Gründel, 2007 4 5 6 7 8 Type species. Turritella undulata Benz in von Zieten, 1832, Pliensbachian, Southern 9 10 Germany. 11 12 Remarks. According to Nützel & Gründel (2007) the genus Pseudokatosira is monotypic. 13 14 There are many Mesozoic species that could belong to Pseudokatosira, but the diagnostic 15 generic characters are unknown for most of these. Pseudokatosira resembles the genus 16 17 Katosira but differs from it in several respects, e.g. Pseudokatosira has a marked change in 18 19 teleoconch ontogeny with a reduction of the axial ribs toward mature growth stages, which 20 also become round and nodular after several whorls. 21 22 Occurrence. Lower Jurassic (Pliensbachian-late Toarcian); Southern Germany, Hungary, 23 24 Austria and England. 25 26 27 28 Pseudokatosira undulata (Benzin von Zieten, 1832) 29 30 31 (Fig. 3 S─U) 32 33 1832 Turritella undulata Benz in Von Zieten, p. 43, pl. 32, fig. 2. 34 35 2002 Katosira undulata (Benz, 1832); Nützel & Hornung, p. 58, pl. 1, 36 37 figs 4–5. 38 2007 Pseudokatosira undulata (Benz, 1832); Nützel & Gründel, p. 62, pl. 1, figs. 1 6. 39 ─ 40 2008 Pseudokatosira undulata Nützel, p. 46, pl. 2, fig. 1. 41 42 2009 Pseudokatosira undulata (Benz, 1832); Szabó, p. 91, pl. 84, figs. C─D, 43 44 2015 Pseudokatosira undulata (Benz, 1832); Nützel & Gündel, p. 16, pl. 8, fig. A─E. 45 46 47 Material. YORYM: 2019.353 (Fig. 3T-U), YORYM: 2019.354 (Fig. 3S), YORYM: 48 49 2019.355, YORYM: 2019.356, YORYM: 2019.357; five fragmentary specimens preserved 50 51 as external moulds. 52 Description. Turriculate, slender, high-spired and medium-sized shell. Protoconch not 53 54 preserved. Teleoconch partial, consisting of six convex whorls in most complete specimens. 55 56 Suture incised. Juvenile whorls smooth and less convex than mature whorls. Mature whorls 57 58 59 60 Palaeontology Palaeontology Page 14 of 64

1 2 3 ornamented by strong and opisthocyrt axial ribs. Axial ribs strongest and almost node-like 4 5 below mid-whorl. Mature whorls covered with numerous irregularly spaced spiral cords, 6 7 numbering 13-18 per whorl and intercalated by spiral furrows. Weak opisthocyrt collabral 8 growth linesvisible on last whorl. Shell base strongly convex and ornamented by 13-14 9 10 regularly spaced spiral cords. Aperture strongly oval, higher than wide, elongated with 11 12 acute anterior siphonal canal. 13 14 Dimensions (mm). YORYM: 2019.354: height, 10.54*; width, 5.38. YORYM: 2019.355: 15 height, 8.77*; width, 2.74*. YORYM: 2019.353: height, 8.33*; width, 4.11. YORYM: 16 17 2019.357: height, 5.03*; width, 2.79*. YORYM: 2019.356: height, 11.97; width, 4.46. * = 18 19 partial specimens. 20 Remarks. Based on the updated description of Pseudokatosira undulata in Nützel & 21 22 Gründel (2015) our specimens belong to this species, because they are large and high- 23 24 spired with broad, round axial ribs, which become increasingly nodular and do not extend 25 26 to adapical suture on the mature teleoconch. P. undulata has been reported from Southern 27 Germany (e.g., Quenstedt 1884, Brösamlen 1909, Nützel & Hornung 2002, Nützel & 28 29 Gründel 2007), Hungary (Szabó 1983), Austria (Szabó 2009) and England (Todd & Munt 30 31 2010). The specimens described by Szabó (2009) as Pseudokatosira? aff. undulata from the 32 33 Hierlatz Limestone (Late Sinemurian, Austrian Alps) resemble P. undulata, but lack node- 34 like ribs on mature teleoconch whorls, so their specific identity remains unclear. 35 36 Occurrence. Lower Jurassic (Pliensbachian-Toarcian); Southern Germany, Hungary, 37 38 Austria and England. 39 40 41 42 Superfamily RISSOIDEA Gray, 1847 43 44 Family PALAEORISSOINIDAE Gray, 1847 45 Genus PALAEORISSOINA Gründel, 1999b 46 47 48 49 Type species. Palaeorissoina compacta Gründel, 1999b; from the late Bajocian and 50 51 Callovian of Northeast Germany and Poland. 52 Occurrence. Lower Jurassic (Toarcian)-Lower Cretaceous (Valanginian). 53 54 55 56 Palaeorissoina aff. acuminata (Gründel, 1999b) 57 58 59 60 Palaeontology Page 15 of 64 Palaeontology

1 2 3 (Fig. 3 V─X) 4 5 6 7 1990. Rissoina acuta (Sowerby, 1818); Gründel 1990, p. 1145, pl. 2: 8 [non Sowerby 1818: 8 230, pl. 609: 2 - Bralitzia acuta (Sowerby, 1818)]. 9 10 1999b. Palaeorissoina acuminata Gründel; p. 97, pl. 4: 12–16. 11 12 2004 Bralitzia acuminata (Gründel, 1999b); Kaim, p. 80, fig. 61. 13 14 15 16 17 Material. YORYM: 2019.358 and YORYM: 2019.359; two specimens preserved as 18 19 external moulds. 20 Description. Turriculate, slender, small-sized and high-spired shell. Protoconch 21 22 trochospiral, formed of three smooth and strongly convex whorls; height 0.35 mm, width 23 24 0.36 mm. Clear demarcation between protoconch and teleoconch. Teleoconch formed of 5- 25 26 6 flattened to slightly convex whorls. Suture incised. Ornament predominantly strongly 27 opisthocline to opisthocyrt acute axial ribs, running from suture to suture. Shell base 28 29 slightly convex to flattened; aperture strongly oval. 30 31 Dimensions (mm). YORYM: 2019.358: height, 3.77*; width, 1.42. YORYM: 2019.359: 32 33 height, 4.08; width, 1.44. * = partial specimens. 34 Remarks. Our specimens are very similar in shell shape and ornamentation to 35 36 Palaeorissoina acuminata Gründel, 1999b (p. 97, pl. 4, fig. 12-16; Kaim, 2004, as Bralitzia 37 38 acuminata, p. 80, fig. 61), from the Middle Jurassic (Callovian) of Germany. Accordig to 39 the diagnosis of Gründel (1999b), this species has a highly conical protoconch without 40 41 sculpture. The shell is slender with many whorls with the apical part sharpened. Teleoconch 42 43 whorls with strong and symmetrical axial ribs, and the spiral cords are mostly densely 44 45 packed. In our material, the spiral cords are not visible (most probably due bad 46 preservation); thus, it is left in open nomenclature. Palaeorissoina tenuistriata Gründel 47 48 (1999b) (p. 99, pl. 2 fig. 4.11), differs from P. aff. acuminata in having more developed and 49 50 visible spiral striae in all teleoconch whorls, and weak nodes in the middle of axial ribs on 51 52 mature whorls. 53 Occurrence. Early Lower Jurassic (Late late Toarcian)–Middle Jurassic (Callovian); 54 55 Germany, Poland and England. 56 57 58 59 60 Palaeontology Palaeontology Page 16 of 64

1 2 3 Superfamily STROMBOIDEA Rafinesque, 1915 4 5 Family APORRHAIDAE Gray, 1850 6 7 Genus PIETTEIA Cossmann, 1904 8 9 10 11 12 Type species. Rostellaria hamus Eudes−Deslongchamps, 1842: 173; original designation. 13 14 Bajocian (Middle Jurassic), Bayeux, France. 15 Remarks. Kaim (2004, p. 74) characterized representatives of the genus Pietteia Cossmann, 16 17 1904. This genus is mostly known from the Middle and Upper Jurassic of Europe and 18 19 Africa (Cox 1965; Szabó 1983; Conti & Fischer 1984; Conti & Monari 1986; Kaim 2004; 20 Gründel 2003; Gründel et al. 2012), but few reports have given accurate stratigraphical data 21 22 about its occurrence in the Lower Jurassic. One exception is Pietteia (Trietteia?) mipa (De 23 24 Gregorio, 1886) which Conti & Szabó (1989) described from different stratigraphical levels 25 26 in the latest Toarcian (Aalensis Zone) to the earliest Bajocian (Discites Subzone) of Italy. 27 Occurrence. Lower Jurassic-Upper Jurassic; Europe. 28 29 30 31 32 Pietteia unicarinata (Hudleston, 1884) 33 34 (Fig. 4 A─L) 35 36 37 1884 Alaria unicarinata Hudleston, p. 149, pl. 6, fig.s 1, 2, 2a. 38 1887 Alaria unicarinata Hudleston, p. 118, pl. 4, fig. 13a, b, c. 39 40 41 42 43 44 Material. YORYM: 2019.360 (Fig. 4A-C), YORYM: 2019.361 (Fig. 4E), YORYM: 45 2019.362 (Fig. 4D), YORYM: 2019.363, YORYM: 2019.364 (Fig. 4K-L), YORYM: 46 47 2019.365, YORYM: 2019.366, YORYM: 2019.367, YORYM: 2019.368, YORYM: 48 49 2019.369 (Fig. 4F), YORYM: 2019.370, YORYM: 2019.371, YORYM: 2019.372, 50 YORYM: 2019.373, YORYM: 2019.374, YORYM: 2019.375, YORYM: 2019.376 (Fig. 51 52 4G-H); seventeen specimens preserved as external moulds. YORYM: 2019.377 (Fig. 4I-J); 53 54 one teleoconch preserved as a recrystallized shell. 55 56 57 58 59 60 Palaeontology Page 17 of 64 Palaeontology

1 2 3 Emended diagnosis. Step-like or gradate and small-sized shell; protoconch 1 of one smooth 4 5 and convex whorl; protoconch 2 of two smooth and convex whorls; first teleoconch whorl 6 7 with opistocline axial ribs and without spiral elements; from second teleoconch whorl to 8 mature growth stages spiral cords and axial ribs are predominant, with pointed nodes at 9 10 periphery; axial ribs missing on last whorls; base angular, ornamented by six spiral cords; 11 12 aperture oval with strongly developed and expanded abapically siphonal channel; outer lip 13 14 with long spine-like extension ornamented by four regularly spaced spiral cords. 15 Description. Gradate, angular in shape, small-sized and moderately high-spired shell. 16 17 Protoconch 1 partial, formed of one smooth and convex whorl. Protoconch 2 formed of two 18 19 smooth and strongly convex whorls; height 1.01 mm, width 0.83 mm. Clear demarcation 20 between protoconch 2 and first teleoconch whorl (Fig. 4 D, F). Teleoconch formed of up to 21 22 seven whorls; first teleoconch whorl convex; toward mature growth stages whorls become 23 24 strongly angular in outline. Suture incised. Ornament pattern changes during ontogeny. 25 26 First teleoconch whorl ornamented by 16 slightly opisthocline axial ribs without spiral 27 elements; toward second teleoconch whorls axial ribs intercepted by two very weak spiral 28 29 cords forming small nodes at crossing points. From third to mature whorls ornament 30 31 comprises opisthocline axial ribs, more prominent over the outer face of whorls. Mature 32 33 whorls strongly angular; axial ribs reduced to opisthocline pointed nodes visible on whorl 34 peripheries. On mature whorls ramp flattened, inclined 45º and ornamented by up to six 35 36 regularly spaced spiral cords, intercalated by spiral furrows. Outer face of mature whorls 37 38 inclined abaxially and ornamented by four spiral cords. Nodes at periphery of penultimate 39 whorl strongly pointed and acute, 16 in number. Last teleoconch whorl strongly angular 40 41 with periphery delimited by smooth and acute spiral keel without peripheral nodes. Shell 42 43 base flattened and angular, delimited on the outer face by strong and acute spiral cord; 44 45 ornamented by six spiral cords with spiral furrows between. Aperture oval with strongly 46 developed siphonal channel, expanded abapically. Outer lip bears long spine-like extension 47 48 ornamented by four regularly spaced spiral cords (Fig. 4 G─H). 49 50 Dimensions (mm). Table 3. 51 52 Remarks. This species was originally assigned by Hudleston (1884) to the genus Alaria. 53 We transfer it here to Pietteia Cossmann, 1904 following Kaim (2004) (see above). Alaria 54 55 arenosa Hudleston, 1884 (p. 198, pl. 7, fig 7; Hudleston 1887, p. 110, pl. 4, fig. 1), also 56 57 58 59 60 Palaeontology Palaeontology Page 18 of 64

1 2 3 from Blea Wyke Sandstone Formation at Ravenscar, differs from Pietteia unicarinata in 4 5 having a larger, more slender and turriculate shell, two spiral keels per whorl with the 6 7 adapical keel stronger and with more developed tubercles than the abapical keel, and 8 having a strongly expanded siphonal canal. Moore (1866) described three aporrhaid species 9 10 from Toarcian sections in the Ilminster area of Somerset in Southern England that should 11 12 be compared to P. unicarinata. Alaria angulata Moore, 1866 (p. 197, pl. 4, fig. 4) differs 13 14 from P. unicarinata in lacking pointed nodes at the peripheral cords on mature whorls, and 15 in lacking opisthocline axial ribs on juvenile whorls, being ornamented by spiral elements 16 17 only. Alaria coronata Moore, 1866 (p. 198, pl 4, fig. 3) differs from the P. unicarinata in 18 19 having small and regular granulation in the periphery of each whorls. Alaria unispinosa 20 Moore, 1866 (p. 197, pl. 4, figs. 1, 2), like P. unicarinata, has an expanded siphonal 21 22 channel and a spine-like projection extended from the adapical margin of the outher lip. 23 24 However, in Moore’s species the lateral projection is smooth without spiral cords, and is 25 26 finer. It curves upwards and extends more than the diameter of the shell beyond the margin. 27 A. unispinosa also lacks nodular and axial elements on the shell surface, being ornamented 28 29 only by spiral cords. P. unicarinata can be easily distinguished from P. (Trietteia?) mipa 30 31 (De Grogorio, 1886) (in Conti & Szabó 1989; p. 37, pl. 2, figs. 12─14) (see above) because 32 33 the Italian species has a higher-spired shell, more convex whorls, and a strongly reticulate 34 ornament pattern consisting of spiral cords intercepted by collabral opisthocyrt growth lines 35 36 and small spiny nodes at the whorl angulations; these characters are all missing in P. 37 38 unicarinata. P. unicarinata also has a resemblance to P. hamus (Eudes-Deslongchamps, 39 1843) (in Gründel 2003; p. 83, pl. 11, fig. 6 8, 12 15), from the Middle Jurassic 40 ─ ─ 41 (Bathonian) of Southern Germany and France, but P. hamus is much larger, has better 42 43 developed axial ribs and more pointed nodes at the periphery of mature whorls, and the 44 45 peripheral spiral keel on the final whorls is stronger. P. trispinigera Szabó, 1983 (p. 40, pl. 46 3, figs. 12─13; Conti & Fischer, 1984; p. 156, pl. 5, fig. 23 as P. apenninica Conti & 47 48 Fischer, 1984), from the Middle Jurassic (Bajocian) of Hungary and Italy, differs from P. 49 50 unicarinata in being larger, with a higher spire, a reticulate ornament pattern formed by 51 52 opisthocyrt growth lines and axial ribs restricted only to the juvenile shell, parabolic nodes 53 at the angulation up to the penultimate whorl, and embryonic whorls bearing two 54 55 suprasutural (abapical) spiral cords. P. subbicarinata (Münster, 1844) and P. pellati (Piette, 56 57 58 59 60 Palaeontology Page 19 of 64 Palaeontology

1 2 3 1867) (in Kaim, 2004; ps. 75─76, figs. 56─57), both from the Middle Jurassic (Callovian) 4 5 of Poland, are larger than P. unicarinata, have axial ribs and tubercles on only the earliest 6 7 two teleoconch whorls. They have later teleoconch whorls ornamented only by regularly 8 spaced spiral cords, and a stronger peripheral spiral keel on last whorl. Pietteia sp. (in 9 10 Gründel et al. 2012; p. 34, pl. 8, fig. 9), from the Middle Jurassic (Bajocian) of Southern 11 12 Germany, differs from P. unicarinata in being larger, having more convex teleoconch 13 14 whorls and in being completely smooth. P. callamus Gründel, 2001 (p. 72, pl. 8, fig. 15 12─15) from the Middle Jurassic (Callovian) of Northern Germany, differs from P. 16 17 unicarinata in having more variable axial ribs in shape and number, which run from suture 18 19 to suture, giving the whorl periphery a more convex appearance, and in having a stronger 20 peripheral keel on the last teleoconch whorl. 21 22 Occurrence. Lower Jurassic (late Toarcian)-Middle Jurassic (early Aalenian); Northern 23 24 England. 25 26 27 28 Superfamily CAMPANILOIDEA Douvillé, 1904 29 30 Family AMPULLINIDAE Cossmann in Cossmann & Peyrot, 1919 31 32 Genus GLOBULARIA Swainson, 1840 33 34 35 36 37 Type species. Ampullaria sigaretina Lamarck, 1804, Eocene, France; 38 39 original designation. 40 Remarks. Ferrari (2013) stated that specimens belonging to the genus Globularia, including 41 42 some from the Jurassic, have been commonly referred to Natica, and gave reasons to keep 43 44 both genera separate. Here we follow the criteria of Ferrari (2013) in recognizing 45 Globularia. 46 47 Occurrence. Triassic?, Jurassic–Holocene; Cosmopolitan. 48 49 50 51 52 53 Globularia cf. canina (Hudleston, 1882) 54 (Fig. 4 M─N) 55 56 1850 Natica lorieri d’Orbigny: p. 190, pl. 289, fig. 6─7. 57 58 59 60 Palaeontology Palaeontology Page 20 of 64

1 2 3 ?1882 Natica lorieri var. canina Hudleston: p. 260, pl. 20, fig. 9a─b. 4 5 6 7 Material. YORYM: 2019.378; one complete teleoconch preserved as a recrystallized shell. 8 Description. Globose, step-like, gradate, low-spired and medium- to large-size shell. The 9 10 teleoconch consist of 5 whorls. Sutural ramp narrowly horizontal and canaliculated. Earliest 11 12 whorls flattened to slightly convex. Last whorl strongly convex and markedly more 13 14 expanded than spire. Upper portion of last whorl slightly concave and delimited by weak 15 angulation with the flank; outer face of last whorl strongly convex. Fine collabral lines 16 17 visible on outer face of last whorl. Base strongly convex. Aperture obliquely oval with 18 19 weakly developed adapical canal and slightly expanded abapical lip. Outer lip very fine and 20 convex; columellar lip thickened. Umbilicus visible with narrow opening. 21 22 Remarks. Globularia canina was originally described under the genus Natica by d’Orbigny 23 24 (1850), from the Middle Jurassic (Bajocian) of France, and it was later reported by 25 26 Hudleston 1884, from the Dogger Formation (early Aalenian) (Hudleston 1884, p. 260, pl. 27 20, fig 9a, b). Hudleston (1884) proposed a new name for d’Orbigny species, Natica 28 29 canina, characterized by the absence of an umbilicus, a very large aperture and sometimes 30 31 having fine spiral lines on the shell surface. 32 33 The species here described as Globularia cf. canina is very similar in shell shape and 34 ornamentation to Natica adducta Phillips, 1829 (in Hudleston, 1884, p. 257, pl. 20, fig. 3) 35 36 from the Dogger Formation (early Aalenian). However, N. adducta has more gradate spire 37 38 whorls, and a more developed and horizontal sutural ramp. Natica adducta var. globata 39 Phillips (in Hudleston 1884, p. 259, pl. 20, fig. 5 6), from the Aalenian Concavus-bed, 40 ─ 41 Bradford Abbas, England, has a more globose and convex last teleoconch whorl and a more 42 43 thickened columellar lip that covers the umbilical area. Natica proxima (Hudleston, 1882) 44 45 (p. 260, pl. 20, fig. 7), from the Dogger Formation (early Aalenian), differs from 46 Globularia cf. canina in having a more step- like spire, a thick callus on the inner lip, and 47 48 more developed collabral growth lines on last teleoconch whorl. Finally, Natica punctura 49 50 (Bean) (in Hudleston 1892, p. 264, pl. 20, fig. 14), from the Dogger Formation (early 51 52 Aalenian), differs from Globularia cf. canina in having a more pointed apex with less 53 gradate and more convex spire whorls, a reticulate ornament pattern with spiral and 54 55 collabral ribs, and a less expanded last whorl. 56 57 58 59 60 Palaeontology Page 21 of 64 Palaeontology

1 2 3 Occurrence. Lower Jurassic (late Toarcian)-Middle Jurassic (Bajocian); Northern England 4 5 and France. 6 7 8 Subclass HETEROBRANCHIA Burmeister, 1837 9 10 Superfamily MATHILDOIDEA Dall, 1889 11 12 Family MATHILDIDAE Dall, 1889 13 14 Genus TRICARILDA Gründel, 1973 15 16 17 18 19 Type species. Mathilda (Tricarilda) plana Gründel, 1973, original designation; Callovian; 20 Northwestern Poland. 21 22 Remarks. Representatives of the genus Tricarilda Gründel, 1973 are very similar to Jurilda 23 24 but differ in that ‘the first teleoconch whorl immediately with three primary spiral ribs; 25 26 middle one is strongest, and can be keel-like; additional secondary spiral ribs may lack or 27 are abundant; microornament of spiral striae either absent or weak’ (Gründel & Nützel, 28 29 2013). Kaim (2004) considered Tricarilda as a junior synonym of Mathilda Semper, 1865, 30 31 based on the similar pattern of ornamentation of ‘three-to-four spiral ribs on the early 32 teleoconch’. However, here we follow Gründel & Nützel (2013) who place shells with 33 34 three primary spiral ribs in Tricarilda. 35 36 Occurrence. Lower Jurassic (Sinemurian)–Lower Cretaceous (Valanginian); Germany, 37 38 England, France, Italy, Poland, Russia, Ukraine, New Zealand. 39 40 41 Tricarilda? sp. 42 43 (Fig. 4 O─P) 44 45 46 Material. YORYM: 2019.379; one specimen preserved as an external mould. 47 48 Description. Anomphalous, turriculate, slender, small-sized. Protoconch not preserved. 49 50 Teleoconch formed of six angular whorls. Suture distinct and impressed. Whorl face 51 angulated near mid-whorl. Spiral ornament consists of three spiral cords and a fourth 52 53 emerges at abapical suture. A weak spiral cord (S1), and two other spiral cords, (S2) and 54 55 (S3) are much stronger than S1; S2 is located at mid-whorl. The basal spiral (BS) emerges 56 57 58 59 60 Palaeontology Palaeontology Page 22 of 64

1 2 3 at the suture. Spiral cords intercepted by strongly opisthocline axial ribs producing 4 5 reticulate pattern. Small and rounded nodes at the crossing points of spiral and axial 6 7 elements. Shell base convex with one spiral cord. Apertural characters not preserved. 8 Dimensions (mm). YORYM: 2019.379: height, 3.80*; width, 1.13. 9 10 Remarks. The single specimen here described could be considered to belong to the genus 11 12 Tricarilda, but for the fact that Tricarilda species have three spiral cords with the centre 13 14 one being keel-like and stronger than those on either side. In our specimen the two 15 strongest spiral cords are at mid whorl (S2), and abapically (S3), so we only tentatively 16 17 assign it to this genus, until more and better preserved material is discovered. The 18 19 Yorkshire Toarcian Tricarilda? sp. is very similar in shell shape and ornamentation to 20 Tricarilda sp. in Schulbert & Nützel (2013, p. 752, fig. Gründel, 2014, p. 80, pl. 2, 21 22E─H; 22 figs. 10), from the Lower and Middle Jurassic (late Toarcian-early Aalenian) of Southern 23 24 Germany; but that Tricarilda sp. has a clearly visible and strong spiral cord at mid whorl 25 26 and a more angulated shell outline. Tricarilda sp. 1 in Gründel et al. (2011; p. 498, text- 27 figure 11A─B) from the Lower Jurassic (Hettangian-Sinemurian) of the Cleveland Basin, 28 29 England, differs from the Yorkshire Tricarilda? sp. in having two abapical and stonger 30 31 spiral cords which angulated the whorls separated to each other by a a concave area. 32 33 Tricarilda toddi Gründel et al., 2011 (p. 498, text-figure 12A─I), from the Lower Jurassic 34 (late Pliensbachian) of Dorset, Southern England, differs from Tricarilda? sp. in being 35 36 slightly larger, having more convex whorls and secondary spiral threads that are 37 38 intercalated between the primary spiral threads. The axial ribs are stronger on the early 39 teleoconch whorls, becoming weaker as growth lines toward mature whorls, and the 40 41 intersections of axial and spiral elements are nodular. 42 43 44 45 46 Genus JURILDA Gründel, 1973 47 48 49 Type species. Mathilda (Jurilda) crasova Gründel, 1973, (=subjective junior synonym of 50 51 Promathilda (Teretrina) concava Walther, 1951); Bajocian to Bathonian; Poland. 52 Occurrence. Upper Triassic?/Lower Jurassic (Hettangian) ─Lower Cretaceous; Germany, 53 54 England, Italy, Poland, Ukraine. 55 56 57 58 59 60 Palaeontology Page 23 of 64 Palaeontology

1 2 3 4 5 Jurilda sp. 6 7 (Fig. 4 Q) 8 9 10 Material. YORYM: 2019.380; one specimen preserved as an external mould. 11 12 Description. Turriculate, small-sized. Protoconch not preserved. The fragmentary 13 14 teleoconch is formed of three angular whorls. Suture distinct and impressed. Whorl face 15 angulated near mid-whorl. Spiral ornament consists of three spiral cords. One spiral cord 16 17 (S1) weak and distant from the upper suture; (S2) and (S3) on the abapical portion of the 18 19 whorls and with the same strenght than (S1). Spiral cords intercepted by strongly 20 opisthocline axial ribs producing reticulate pattern; opisthocline axial ribs become slightly 21 22 orthocline between median strongest spiral cord and abapical cord. Small and rounded 23 24 nodes at crossing points of spiral and axial elements. Basal and apertural characters not 25 26 preserved. 27 Dimensions (mm). YORYM: 2019.380: height, 2.24*; width, 1.01. * = partial specimen. 28 29 Remarks. Jurilda sp. is very similar in shell shape and ornamentation to Jurilda zapfi 30 31 Schulbert & Nützel (2013, p. 754, fug. 23 A-G), from the late Toarcian-early Aalenian of 32 33 Germany. However, Jurilda zapfi has more angular whorls and more straight flanks than 34 Jurilda sp. Jurilda concava (Walther, 1951) (in Gründel 1997 as Promathildia concava, p. 35 36 134, pl. 1, figs. 1-4) from the Middle Jurassic (Bathonian) of Poland, has a stronger and 37 38 more acute peripheral spiral cord than Jurilda sp. and a more step-like teleoconch. Jurilda 39 sp. (in Nützel & Gründel, 2015, p. 28, pl. 14J), from the Lower Jurassic (Pliensbachian) of 40 41 Germany, has a more distinct carination low on the whorls than Jurilda sp. Tricarilda sp. 1 42 43 in Gründel et al., 2011 (p. 498, text-fig. 11 A-B), from the Lower Jurassic (Hettangian- 44 45 Sinemurian) of England is very similar to Jurilda sp., but Tricarilda sp. 1 has two stronger 46 and more acute spiral ribs which angulated the whorls. Turritella (Mathilda) quadrivittata, 47 48 Phillips, 1829 (in Hudleston 1887, p. 233, pl. 17, fig. 6), from the Dogger Formation, 49 50 differs from Jurilda sp. in having sub-globose whorls and four granular spirals on each 51 52 whorl. Finally, Tricarilda tareka Gründel, 1997 (p. 142, pl. 4, figs. 51, 53─54) from the 53 Middle Jurassic (late Bathonian) of Poland, is very similar to Jurilda sp. nov. Both species 54 55 have opisthocyrt axial ribs on the shell surface intercepted by three spiral cords. However, 56 57 58 59 60 Palaeontology Palaeontology Page 24 of 64

1 2 3 the last teleoconch whorl of T. tareka is slightly more expanded than the spire and the shell 4 5 outline is more gradate. 6 7 Occurrence. Lower Jurassic (late Toarcian); Northern England. 8 9 10 Family GORDENELLIDAE Gründel, 2000 11 12 13 14 Remarks. Schulbert & Nützel (2013) stated that gordenellids differ from mathildids in the 15 ‘rather large size, slender to very slender shape, high number of whorls, early teleoconch 16 17 whorls with mathildid ornament (three primary spiral ribs, middle and abapical spiral 18 19 strongest and angulating whorl profile, numerous opisthocyrt axial ribs), and change of the 20 ornament on mature teleoconch whorls (sometimes complete reduction)’. Here we follow 21 22 Schulbert & Nützel (2013) for separation of these two families. 23 24 25 26 Genus TURRITELLOIDEA Walther, 1951 27 28 29 30 Type species. Turritella opalina Quenstedt, 1852, original designation, Toarcian to 31 Aalenian, South Germany. 32 33 Occurrence. Lower Jurassic (Hettangian)-Upper Cretaceous; Germany, England, France, 34 35 ?Luxemburg (Gründel & Nützel 2013). 36 37 38 39 40 Turritelloidea stepheni sp. nov. 41 42 (Fig. 4 R─S) 43 44 45 Derivation of name. Named for the second author’s father, Stephen Stanley-Little. 46 47 Type material. Holotype, YORYM: 2019.381; paratype, YORYM: 2019.382; two 48 49 specimens preserved as external moulds. 50 Type locality. Ravenscar, North Yorkshire, England. 51 52 Type level. Late Toarcian (Blea Wyke Sandstone Formation, Yellow Sandstone Member), 53 54 Cleveland Basin. 55 56 57 58 59 60 Palaeontology Page 25 of 64 Palaeontology

1 2 3 Diagnosis. Dextral, turriculate, slender shell; teleoconch up to nine whorls; earliest whorls 4 5 with weakly nodular axial ribs; two adapical and abapical cords on earliest whorls, adapical 6 7 cord stronger; spiral ornament dominant on mature whorls, 5-6 in number; opisthocyrt 8 growth lines; shell base convex with spiral cords; aperture oval. 9 10 Description. Dextral, anomphalous, slender, turriculate and small-sized shell. The 11 12 protoconch not preserved. Teleoconch has nine slightly convex whorls. Suture incised. 13 14 Earliest teleoconch whorls have very weak, and slightly wide and opisthocyrt axial ribs 15 with faint nodes abapically (Figure 4R). Two adapical and abapical spiral cords are situated 16 17 near suture on earliest whorls; adapical cord stronger than abapical cord. Towards mature 18 19 growth stages nodular axial ribs tend to disappear, and strongly opisthocyrt growth lines are 20 visible. Spiral ornament dominant on mature whorls, comprising 4-5 thick and wide spiral 21 22 cords intercalated by equally spaced, narrow spiral furrows. On last whorl 5-6 spiral cords 23 24 present. Shell base strongly convex with six strong and regularly spaced broad spiral cords 25 26 of equal strength, intercalated by narrower spiral furrows. Very fine prosocline growth lines 27 intercept spiral cords on base. Aperture strongly oval with abapical channel. 28 29 Dimensions (mm). Holotype, YORYM: 2019.381: height, 7.82*; width, 2.34. Paratype, 30 31 YORYM: 2019.382: height, 10.45*; width, 2.32*. (* = partial specimens). 32 33 Remarks. Following Gründel (2005) and Gründel & Nützel (2013), our specimens belong 34 to the genus Turritelloidea. T. opalina Walther, 1951 (in Schulbert & Nützel 2013; p. 758, 35 36 fig. 26A─D), from the Lower and Middle Jurassic (late Toarcian-early Aalenian) of 37 38 Southern Germany, differs from T. stepheni sp. nov. in having a more developed spiral 39 ornament on all teleoconch whorls, which forms a reticulate pattern with faint opisthocyrt 40 41 axial threads, having small and pointed nodes at the crossing points, and in lacking the 42 43 weakly nodular axial ribs on the earliest whorls. Turritella (Mathilda) abbas Hudleston, 44 45 1892 (p. 230, pl. 17, fig. 2), from the Middle Jurassic (Aalenian-Bathonian) of Bradford 46 Abbas, Dorset, Southern England, differs from Turritelloidea stepheni sp. nov. in being 47 48 slightly narrower and elongated, and in lacking axial elements on earliest whorls. Turritella 49 50 (Mathilda) strangulata Hudleston, 1892 (p. 233, pl. 17, fig. 5), from the Middle Jurassic 51 52 (Aalenian) of England, differs from Turritelloidea stepheni sp. nov. in having a deeply 53 sulcated shell with a very oblique sutural angle. 54 55 Occurrence. Lower Jurassic (late Toarcian); Northern England. 56 57 58 59 60 Palaeontology Palaeontology Page 26 of 64

1 2 3 4 5 Order ARCHITECTIBRANCHIA Haszprunar, 1985 6 7 Family TUBIFERIDAE Cossmann, 1895 8 Genus COSSMANNINA Gründel & Nützel, 2012 9 10 11 12 Type species. Actaeonina (Ovactaeonina) abdominiformis Schröder, 1995, Pliensbachian, 13 14 North Germany. 15 Occurrence. Lower Jurassic (Pliensbachian)-Middle Jurassic (Callovian); Europe. 16 17 18 19 Cossmannina sp. 20 (Fig. 4 T V) 21 ─ 22 23 24 Material. YORYM: 2019.383; one specimen preserved as an external mould. 25 26 Description. Fusiform, elongated, moderately high-spired and medium-sized shell; height 27 10.90 mm, width 5.32 mm. Partial protoconch heterostrophic. Teleoconch formed of five 28 29 whorls; last whorl higher than spire. Sutural ramp lacking; suture incised. Upper portion of 30 31 spire whorls broad, flattened and smooth, inclined 45º from sutures; outer face becomes 32 33 straight. Flank of last whorl strongly convex. Shell surface with irregularly spaced, slightly 34 prosocyrt to orthocline growth lines. Shell base slightly convex; aperture oval. 35 36 Remarks. Based on Gründel & Nützel (2012) our single specimen belongs to the genus 37 38 Cossmannina. A very similar species to Cossmannina sp. is Cossmannina? franconica 39 (Kuhn, 1935), from the Lower Jurassic (Pliensbachian) of Southern Germany. Both have 40 41 the same general shell morphology and size, but C.? franconica has weak, narrow and 42 43 irregularly spaced spiral furrows on the shell surface and base. C. kalchreuthensis (Gründel 44 45 & Nützel, 1998) (p. 81 pl. 7, figs. 5─8 and Gründel 2007, p. 96, pl. 8, fig. 7 as 46 Ovactaeonina kalchreuthensis; Nützel & Gründel 2015, p. 36, pl. 21, fig. I), from the 47 48 Lower Jurassic (Pliensbachian) of Southern Germany, differs from Cossmannina sp. in 49 50 being much smaller and having a more slender shell. Cossmannina sp. also resembles the 51 52 type species C. abdominiformis (Schröder, 1995) (p. 68, pl. 12, figs 1–5, pl. 15, fig. 6 and 53 Gründel 2007, p. 97, pl. 8, fig. 8 as Ovactaeonina abdominiformis; Nützel & Gründel 2015, 54 55 p. 35, pl. 21 G), from the Lower Jurassic (Pliensbachian) of Northern Germany, but C. 56 57 58 59 60 Palaeontology Page 27 of 64 Palaeontology

1 2 3 abdominiformis is much smaller and has an egg-shaped and more bulbous shell, with the 4 5 last whorl markedly more expanded than the spire. C. sendelbachensis (Kuhn, 1936) (p. 6 7 294, pl. 12, fig. 31, pl. 13, fig. 9 as Pseudomelania sendelbachensis; Gründel & Nützel, 8 1998, p. 80, pl. 6, figs 8–11 as Ovactaeonina sendelbachensis; Nützel & Gründel 2015, p. 9 10 36, pl. 21 J─L), from the Lower Jurassic (Pliensbachian) of Southern Germany, differs 11 12 from Cossmannina sp. in being smaller, having a more slender and elongated shell, a 13 14 higher spire with the rate of whorl expansion decreasing during ontogeny, and an aperture 15 that is more elongated and rounded on its anterior part. C. malzi (Schroder, 1995) (p. 67, pl. 16 17 11, figs 16–20; Gründel & Nützel, 1998, p. 81, pl. 7, figs 2–4 as Ovactaeonona malzi; 18 19 Nützel & Gründel 2015, p. 36, pl. 21 H), from the Lower Jurassic (Pliensbachian) of 20 Southern Germany, differs from Cossmannina sp. in being much smaller, in having a more 21 22 slender shell and a teleoconch consisting of three whorls. 23 24 Occurrence. Lower Jurassic (late Toarcian); Northern England. 25 26 27 28 29 Genus STRIACTAEONINA Cossmann, 1895 30 31 32 33 Type species. Orthostoma avena Terquem, 1855; Hettangian; Luxemburg. 34 Occurrence. Lower Jurassic-Upper Jurassic; Europe, South America. 35 36 37 38 39 Striactaeonina cf. richterorum Schulbert, Nützel & Gründel (in Schulbert & Nützel, 2013) 40 41 (Fig. 4 W─Y) 42 43 44 45 2007c Cylindrobullina sp. 1 Gründel, p. 248, fig. 3E. 46 2013 Striactaeonina richterorum Schulbert, Nützel & Gründel in Schulbert & Nützel, p. 47 48 768, fig. 32E─G. 49 50 51 52 Material. YORYM: 2019.384 and YORYM: 2019.385; two specimens preserved as 53 external moulds. 54 55 56 57 58 59 60 Palaeontology Palaeontology Page 28 of 64

1 2 3 Description. Oval to cylindrical, slightly step-like or gradate, small-sized and moderately 4 5 high-spired shell. Protoconch not preserved. Teleoconch consists of five whorls. Spire 6 7 whorls strongly gradate in outline. Ramp broad, slightly convex and oblique; distinct spiral 8 furrow delimits ramp from outer whorl faces. Ramp edge marked by distinct, wide, 9 10 peripheral bulge. Outer face of spire whorls straight; outer face of last whorls slightly 11 12 convex. Last whorl markedly more expanded than spire. The shell is smooth; very weak 13 14 prosocline to prosocyrt growth lines visible on last whorl. Rounded transition between last 15 whorl and base. Shell base ornamented by 5-6 regularly spaced spiral cords intercalated 16 17 with equally developed spiral furrows. Apertural characters not preserved. 18 19 Dimensions (mm). YORYM : 2019.384: height, 2.38; width, 1.86. YORYM : 2019.385: 20 height, 4.00, width, 1.84. 21 22 Remarks. Schulbert & Nützel (2013) described Striactaeonina richterorum from the early 23 24 Aalenian of Southern Germany and considered Cylindrobullina sp. (in Gründel 2007, p. 25 26 248, fig. 3E), from the late Toarcian of Northern Germany as conspecific. Our two 27 specimens are also very similar to Striactaeonina richterorum in Gründel (2007) and 28 29 Schulbert & Nützel (2013), so we also consider them as being conspecific with 30 31 Striactaeonina richterorum. However, the specimens described by Schulbert & Nützel 32 33 (2013) have stronger spiral ornament on base and ramp is more vertical and more distinctly 34 demarcated than the Yorkshire specimens, so we use the cf. designation for comparison. 35 36 Actaeonina (Striactaeonina) humeralis Hudleston (1887, p. 472, pl. 42, figs. 20a, b), from 37 38 the Dogger Formation (early Aalenian) of England is very similar to Striactaeonina 39 richterorum, although the former species is smaller and has a broader and more convex 40 41 ramp. S. waltschewi Schulbert & Nützel, 2013 (p. 766, fig. 32 H─J), from the Lower 42 43 Jurassic (late Toarcian) of Southern Germany is similar to S. richterorum, however, S. 44 45 waltschewi has a distinctly more elevated spire, a narrower ramp with rounded edge and 46 two spiral furrows, and a very faint spiral striation on whorls flanks. S. pseudmoorei 47 48 (Gründel & Buchholz, 1999) (p. 626, pl. 1, figs. 1─6 as Actaeonina pseudmoorei; Gründel, 49 50 2007, p. 93, pl. 7, fig. 14 as Cylindrobullina pseudmoorei; Gründel et al., 2011, p. 500, 51 52 text-figure 13 A─H as Cylindrobullina pseudmoorei; Gründel & Nützel, 2012, p. 40, fig. 5 53 d─e), from the Lower Jurassic (late Pliensbachian) of Northern Germany and England, 54 55 resembles S. richterorum, but S. pseudmoorei has a distinct peripheral spiral cord 56 57 58 59 60 Palaeontology Page 29 of 64 Palaeontology

1 2 3 delimiting the ramp and the outer face of whorls,and this spiral cord is bounded on both 4 5 sides by a spiral furrow. 6 7 Occurrence. Lower Jurassic (late Toarcian)-Middle Jurassic (early Aalenian); Northern and 8 Southern Germany, England. 9 10 11 12 13 14 Striactaenonina elegans sp. nov. 15 (Fig. 5 A─E) 16 17 18 19 Derivation of name. Latin, adjective elegans = elegant; referring to the graceful appearance 20 in shell shape and ornamentation. 21 22 Type material. Holotype, YORYM: 2019.386; paratype, YORYM: 2019.387; two 23 24 specimens preserved as external moulds. 25 26 Type locality. Ravenscar, North Yorkshire, England. 27 Type level. Late Toarcian (Blea Wyke Sandstone Formation, Yellow Sandstone Member), 28 29 Cleveland Basin. 30 31 Additional material. YORYM: 2019.388; one specimen preserved as an external mould. 32 33 Diagnosis. Oval, cylindrical shell; gradate spire; smooth, broad, oblique ramp delimited by 34 a peripheral spiral bulge with a spiral furrow; shell surface ornamented by spiral furrows of 35 36 unequal width;; shell base with 4-5 spiral furrows; aperture oval; concave columellar lip. 37 38 Description. Oval to cylindrical shape, gradate, small-sized shell. The protoconch and 39 juvenile whorls not preserved. Teleoconch consists of four whorls; spire whorls with 40 41 strongly gradate outline. Sutures incised. Ramp broad, smooth, slightly convex and oblique. 42 43 Ramp edge marked by distinct, wide, peripheral spiral bulge. Outer face of spire whorls 44 45 straight; outer face of last whorl faintly convex. Last whorl markedly more expanded than 46 spire. Shell surface ornamented by irregularly spaced spiral furrows much narrower than 47 48 interspaces between; opisthocline growth lines on the ramp of last whorl. Base convex and 49 50 ornamented by 4-5 spiral cords. Aperture is partially preserved, oval, with thick and 51 52 concave columellar lip. 53 Dimensions (mm). YORYM: 2019.386: height, 5.20; width, 2.69. YORYM: 2019.388: 54 55 height, 4.65; width, 3.16. YORYM: 2019.387: height, 5.52; width, 3.29. 56 57 58 59 60 Palaeontology Palaeontology Page 30 of 64

1 2 3 Remarks. Our specimens fit the diagnosis of the genus Striactaeonina, following Gründel 4 5 and Nützel (2012) (see above). S. richterorum Schulbert & Nützel, 2013 (p. 768, fig. 6 7 32E─G; see above) differs from S. elegans sp. nov. in lacking the spiral cords on the shell 8 surface, the weak spiral furrow and the opisthocline growth lines on the ramp. S. 9 10 waltschewi Schulbert & Nützel, 2013 (p. 766, fig. 32 H─J), from the Lower Jurassic (late 11 12 Toarcian) of Southern Germany, differs from S. elegans sp. nov. in having a distinctly more 13 14 elevated spire, a narrower ramp and very faint spiral striation on the whorls flanks, rather 15 than irregularly spaced spiral cords. S. pseudmoorei (Gründel & Buchholz, 1999) (p. 626, 16 17 pl. 1, figs. 1─6 as Actaeonina pseudmoorei; Gründel, 2007, p. 93, pl. 7, fig. 14 as 18 19 Cylindrobullina pseudmoorei; Gründel et al. 2011, p. 500, text-figure 13 A─H as 20 Cylindrobullina pseudmoorei; Gründel & Nützel 2012, p. 40, fig. 5 from the Lower 21 d─e), 22 Jurassic (late Pliensbachian) of Northern Germany and England, lacks the spiral cords on 23 24 the shell surface, has more distinct prosocyrt growth lines on last teleoconch whorl, and has 25 26 a more prominent spiral bulge at the outer edge of the ramp. C. dorsetensis Gründel et al., 27 2011 (p. 500, text-figure 14A─E), from the Lower Jurassic (late Pliensbachian) of England, 28 29 differs from S. elegans sp. nov. in having a more slender shell with an acute spire and more 30 31 convex whorls, a narrower and oblique sutural ramp without edge, weaker spiral cords and 32 33 furrows on the shell surface, and a high number of spiral cords on the base. Gründel et al. 34 (2011) introduced a new combination for the type species S. avena (Terquem, 1855) and 35 36 placed this into the genus Cylindrobullina. C. avena (Terquem, 1855) (p. 260, pl. 15, fig. 8, 37 38 8a as Orthostoma avena; Gründel et al., 2011, p. 500, text─figure 11E, F; Gründel & 39 Nützel 2012, p. 40, fig. 5 c), from the Lower Jurassic (Hettangian-Sinemurian) of 40 41 Luxemburg and England, differs from S. elegans sp. nov. in having a more slender shell, a 42 43 more horizontal ramp demarked by a sharp edge, and smooth whorls. Actaeonina 44 45 (Striactaeonina) supraliasica Cox (1965) (p. 173, pl. 29, figs. 4a, b, c), from the Lower 46 Jurassic (Toarcian) of Kenya, differs S. elegans sp. nov. in being larger, having a more 47 48 gradate spire with a steep and flattened ramp, a more cylindrycal last whorl, and regularly 49 50 spaced spiral cords on the outer face of last whorl. S. transatlantica (Behrendsen, 1891) (p. 51 52 383, pl. 22, fig. 9 as Actaeonina transatlantica; Gründel 2011, p. 65, pl. 6, figs. 10─11; 53 Ferrari 2017, p. 260, fig. 4.15─4.20), from the Lower Jurassic (Pliensbachian) of Argentina 54 55 resembles S. elegans sp. nov. However, S. transatlantica is much larger, has a more 56 57 58 59 60 Palaeontology Page 31 of 64 Palaeontology

1 2 3 horizontal sutural ramp, lacks the spiral peripheral bulge below the ramp, and has stronger 4 5 and regularly spaced spiral cords on the shell surface. Finally, S. atuelensis Gründel, 2001 6 7 (p. 66, pl. 6, figs. 7─8), from the Lower Jurassic (early Pliensbachian) of Argentina is 8 larger than S. elegans sp. nov. and has more convex whorls and lacks the peripheral spiral 9 10 bulge. 11 12 Occurrence. Lower Jurassic (late Toarcian); Northern England. 13 14 15 16 17 Striactaenonina aff. tenuistriata (Hudleston, 1887) 18 19 (Fig. 5 F─I) 20 21 22 1887 Actaeonina (Striactaeonina) tenuistriata Hudleston, p. 471, pl. 42, figs. 18, 19. 23 24 25 26 Material. YORYM: 2019.389; one specimen preserved as an external mould. 27 Description. Oval to cylindrical shape, gradate and small-sized shell. Protoconch not 28 29 preserved. Teleoconch consists of five whorls; spire whorls strongly gradate in outline and 30 31 last whorl higher than the spire. Suture incised. Ramp broad, concave, smooth, oblique, and 32 33 delimited by a bulge and a spiral furrow on mature whorls. A slightly adpressed bulge is 34 visible; the second is stronger and peripheral, delimiting the ramp edge. Ramp edge marked 35 36 by distinct, wide, peripheral spiral bulge. Outer face of spire whorls straight and 37 38 ornamented with a faint spiral striation; outer face of last whorl faintly convex and 39 ornamented by very thin and regularly spaced spiral cords intercalated by spiral furrows of 40 41 same strength as spiral cords. Slightly prosocline growth lines on outer face of last whorl. 42 43 Basal and apertural characters not preserved. 44 45 Dimensions (mm). YORYM: 2019.389: height, 6.68; width, 3.96. 46 Remarks. Striactaeonina aff. tenuistriata (Hudleston, 1887) is very similar in shell shape 47 48 and ornamentation to Actaeonina (Striactaeonina) tenuistriata described by Hudleston 49 50 (1887) from the Dogger Formation (early Aalenian) of England, but the latter species has 51 52 spiral cords on last whorl and an ovate and elongated aperture. Because these characters are 53 not preserved in our specimen, we cannot be entirely certain they are synonymous. 54 55 56 57 58 59 60 Palaeontology Palaeontology Page 32 of 64

1 2 3 Striactaeonina aff. tenuistriata differs from S. elegans sp. nov. in being larger, having a 4 5 concave ramp delimited by two spiral cords on mature whorls, and very thin and regularly 6 7 spaced spiral cords on the outer face of last whorl. S. richterorum Schulbert & Nützel, 2013 8 (p. 768, fig. 32E─G; see above) and S. waltschewi Schulbert & Nützel, 2013 (p. 766, fig. 9 10 32 H─J) differ from Striactaeonina aff. tenuistriata in lacking both fine and regularly 11 12 spaced spiral cords on the outer face of last whorl, and a concave ramp with the two 13 14 adapical and peripheral spiral cords. S. transatlantica (Behrendsen, 1891) (p. 383, pl. 22, 15 fig. 9 as Actaeonina transatlantica; Gründel 2011, p. 65, pl. 6, figs. 10─11; Ferrari 2017, p. 16 17 260, fig. 4.15─4.20) and S. atuelensis Gründel, 2001 (p. 66, pl. 6, figs. 7─8), both from the 18 19 Lower Jurassic (early Pliensbachian) of Argentina, differ from S. aff. tenuistriata in having 20 a straight and smooth ramp and stronger spiral cords and furrows on the shell surface. 21 22 Occurrence. Lower Jurassic (late Toarcian)-Middle Jurassic (Aalenian); Northern England. 23 24 25 26 27 Family CYLINDROBULLINIDAE Wenz, 1938 28 29 Genus CYLINDROBULLINA von Ammon, 1878 30 31 32 33 Type species. Cylindrobullina fragilis (Dunker, 1846); Lower Jurassic 34 (Hettangian) of Northern Germany. 35 36 Remarks. Based on Gründel (2010) and Gründel & Nützel (2012) representatives of the 37 38 genus Cylindrobullina have the following characters: cylindrical shell shape, the whorls 39 embrace just below the subsutural ramp, the aperture is high and narrow, the spire is low 40 41 and distinct, whorls are smooth or weakly ornamented with strengthened growth lines, 42 43 spiral striae or spiral threads on base, growth lines on the flanks weakly prosocyrt and on 44 45 the ramp directed backward and opisthocyrt, aperture very high, and the protoconch 46 (although unknown from the type species) is heterostrophic. 47 48 Occurrence. Upper Triassic−Upper Jurassic; Europe, South America. 49 50 51 52 53 Cylindrobullina sp. 54 55 (Fig. 5 J─L) 56 57 58 59 60 Palaeontology Page 33 of 64 Palaeontology

1 2 3 4 5 Material. YORYM: 2019.390, YORYM: 2019.391, YORYM: 2019.392, YORYM: 6 7 2019.393, YORYM: 2019.394; five specimens preserved as external moulds. 8 Description. Oval to cylindrical shape, small-sized and moderately low-spired shell. 9 10 Protoconch not preserved. Teleoconch consists of 5-6 strongly convex whorls. Spire 11 12 slightly gradate in outline and last whorl higher than spire. Whorls are embrace just below 13 14 the sutural ramp giving the ramp a very narrow appearance. Specimen YORYM: 2019.393 15 shows instead a very narrow sutural ramp. Suture impressed in deep concave furrow. Last 16 17 whorl delimited by adapical spiral keel. Shell smooth, with fine and very weak prosocline 18 19 to prosocyrt growth lines on last whorl. Shell base convex; aperture strongly oval with 20 acute adapical channel and rounded basal lip. 21 22 Dimensions (mm). YORYM: 2019.392: height, 5.69*; width, 3.09. YORYM: 2019.390: 23 24 height, 4.51*; width, 2.96. YORYM: 2019.393: height, 5.44*; width, 3.08. YORYM: 25 26 2019.394: height, 4.33; width, 2.98. * = partially preserved specimens. 27 Remarks. Based on the updated diagnosis of Gründel & Nützel, 2012, we assign our 28 29 specimens to Cylindrobullina. Typical representatives of the genus have the whorls 30 31 embrace just below the sutural ramp giving the ramp a very narrow appearance. However, 32 33 specimen YORYM: 2019.393 has a very narrow sutural ramp; we consider this difference 34 to be intraspecific variability. Cylindrobullina sp. differs from C. arduenensis (Piette, 1856) 35 36 (in Gründel & Nützel 2012, p. 36, fig. 2), from the Lower Jurassic (Hettangian) of France, 37 38 in being larger, having a more elevated spire and a narrower sutural ramp. Another similar 39 species to Cylindrobullina sp. is Actaeonina novozealandica Bandel et al., 2000 (p. 101, pl. 40 41 10, figs. 8─10─12), from the Lower/Middle Jurassic of New Zealand. However, 42 43 Cylindrobullina sp. is smaller, has a more slender shell with rounded sutural ramp grading 44 45 into a narrow spiral groove. C. avenoides Haas, 1953 (p. 261, pl. 17, figs. 35, 36, 39─42, 46 46, 49─51, 58, 59), from the Upper Triassic of Peru, differs from Cylindrobullina sp. in 47 48 having a more gradate shell outline with a broader sutural ramp, a steeper and higher spire, 49 50 spiral cords on the shell surface, and an aperture with a better developed adapical channel. 51 52 C. vespertina Haas, 1953 and C. obesa Haas, 1953 (p. 258, pl. 17, figs. 1─34; p. 264, pl. 53 17, figs. 54─57, 60─63), also from the Upper Triassic of Peru, differ from C. convexa sp. 54 55 nov. in having a more gradate spire with a broader sutural ramp and a markedly more 56 57 58 59 60 Palaeontology Palaeontology Page 34 of 64

1 2 3 expanded last teleoconch whorl. The type species, C. fragilis Dunker, 1846 (p. 111, pl. 13, 4 5 figs. 19a─b; Jaworski 1926, p. 205; Weaver 1931, p. 389), from the Lower Jurassic 6 7 (Hettangian) of Germany and Argentina, is much larger than Cylindrobullina sp. and has a 8 more gradate spire. 9 10 Occurrence. Lower Jurassic (late Toarcian); Northern England. 11 12 13 14 Family BULLINIDAE Gray, 1850 15 Genus SULCOACTAEON Cossmann, 1895 16 17 18 19 Type species. Actaeonina striatosulcatus Zittel & Goubert, 1861; Upper Jurassic 20 (Oxfordian), France. 21 22 Remarks. Gründel (1997) established the new family Sulcoactaeonidae based on the genus 23 24 Sulcoactaeon and placed the family within the superfamily Cylindrobullinoidea Wenz, 25 26 1947. The diagnosis of the genus Sulcoactaeon was recently updated by Kaim (2004), 27 Kaim & Beisel (2005) and Gründel & Nützel (2012). Representatives of this genus have the 28 29 following characters: slender to broadly oval shell. The protoconch is smooth and mostly 30 31 coaxial with one to two visible whorls. The teleoconch whorls have a narrow and 32 33 sometimes indistinct ramp with rounded abaxial edge as transition to the whorls flanks. The 34 whorls are ornamented with spiral grooves, which may be frequent on the base. A spiral 35 36 furrow demarcates the ramp. The growth lines are prosocyrt from the suture to the centre of 37 38 the base. The aperture is narrowly oval. 39 Occurrence. Lower Jurassic (Pliensbachian)-Lower Cretaceous (Valanginian); Europe. 40 41 42 43 44 45 Sulcoactaeon sedgvici (Phillips, 1829) 46 (Fig. 5 M─R) 47 48 49 50 1829-35. Auricula sedgvici, Phillips. Geol. Yorks, part 1, pl. 11, fig. 33. 51 52 1850. Acteon sedgvici d’Orbigny. Prod., 1, p. 263. 53 1851. Acteon sedgvici Phillips. Morris and Lycett, Grt. Ool. Moll., part 1, p. 118, pl. 15, fig. 54 55 9. 56 57 58 59 60 Palaeontology Page 35 of 64 Palaeontology

1 2 3 1885. Acteon sedgvici Phillips. Hudleston, Geol. Mag., 1885, p. 252, pl. 5, fig. 4. 4 5 1887. Actaeonina sedgvici Phillips. Hudleston, p. 469, pl. 42, fig. 15. 6 7 8 Material. YORYM: 2019.395 (Fig. 5Q-R), YORYM: 2019.396 (Fig. 5M-O), YORYM: 9 10 2019.397 (Fig. 5P), YORYM: 2019.398, YORYM: 2019.399, YORYM: 2019.400, 11 12 YORYM: 2019.401, YORYM: 2019.402, YORYM: 2019.403, YORYM: 2019.404, 13 14 YORYM: 2019.405; eleven specimens preserved as external moulds. 15 Description. Globose, broadly oval, small-sized and low-spired shell. Protoconch not 16 17 preserved. Teleoconch formed of 4-5 whorls; last whorl higher than spire. Spire more or 18 19 less gradate; outer face of spire whorls slightly concave (see Figure 5M). Sutural ramp 20 narrow and horizontal and suture impressed in deep spiral furrow. Last teleoconch whorl 21 22 strongly convex and ornamented by more or less regularly spaced spiral grooves; spiral 23 24 grooves located below the middle of last whorl slightly broader than the rest. Spiral grooves 25 26 absent from juvenile whorls. Shell base strongly convex and also ornamented by spiral 27 grooves; the former are thinner and more crowded than on outer face of whorls. Aperture 28 29 strongly oval with acute adapical channel and strongly rounded basal lip. Very weak 30 31 growth lines intercept spiral grooves on base. 32 33 Dimensions (mm). Table 4. 34 Remarks. Our specimens are conspecific with Actaeon sedgvici Phillips, 1829, also from 35 36 the late Toarcian and Aalenian-Bajocian of England. Gründel, Nützel & Schulbert in 37 38 Gründel (2007) reported the species Sulcoactaeon laevis from the late Toarcian?-early 39 Aalenian of Northern Germany. However, this species differs considerably from true 40 41 representatives of Sulcoactaeon. Sulcoactaeon sendelbachensis Nützel & Gründel, 2015 (p. 42 43 37, fig. 4; Gründel & Nützel 1998, p. 82, pl. 7, figs. 11─12 as Sulcoactaeon? sp.), from the 44 45 Lower Jurassic (late Pliensbachian) of Southern Germany, has more convex whorls, a 46 slightly more elevated spire and a less expanded last whorl than S. sedgvici. Ragactaeon 47 48 spiralosulcata Gründel, 1997 (p. 94, pl. 7, figs. 18─20), from the Lower Jurassic (late 49 50 Pliensbachian) of Germany, differs considerably from S. sedgvici in having a strongly more 51 52 developed sutural ramp with a stronger adapical spiral furrow, and weaker and indistinct 53 spiral furrows on the flank of whorls. S. bojarkensis Kaim & Biesel, 2005 (p. 55, fig. 13), 54 55 from the Upper Jurassic (early Kimmeridgian) of Russia, differs from S. sedgvici in having 56 57 58 59 60 Palaeontology Palaeontology Page 36 of 64

1 2 3 more convex whorls, an indistinct sutural ramp, whorl ornamentation consisting of pitted 4 5 and weaker spiral cords, and a slightly more oval aperture with an acute adapical channel. 6 7 S. timanicus Kaim & Biesel, 2005 (p. 54, fig. 12), also from the Upper Jurassic of Russia, 8 has a more spindle-like and slender shell than S. sedgvici a weakly angulated sutural ramp, 9 10 and prosocline growth lines that thicken into narrow riblets when crossing the ramp. S. 11 12 polonicus Kaim, 2004 (p. 153, fig. 131) from the Middle Jurassic (Bathonian) of Poland, 13 14 has a broader sutural ramp, a more slender shell, and a teleoconch starting with two distinct 15 adapical spiral cords. 16 17 Occurrence. Lower Jurassic (late Toarcian)-Middle Jurassic (Bajocian); Northern England. 18 19 20 21 22 EARLY TOARCIAN EXTINCTION AND RECOVERY OF GASTROPOD FAUNAS 23 24 IN THE CLEVELAND BASIN 25 26 27 Gastropods formed only a small component of the molluscan diversity in the pre-extinction 28 29 faunas of the late Pliensbachian and early Toarcian in the Cleveland Basin (e.g. Harries & 30 31 Little 1999), with seven species in six families (Eucyclidae, Gosseletinidae, Coelodiscidae, 32 33 Tubiferidae, Zygopleuridae and Ptychomphalidae) recorded in the late Pliensbachian 34 (Margaritatus to Spinatum Zones) and early Toarcian Tenuicostatum Zone [Ferrari et al. 35 36 (2020, table 2)]. The onset of laminated black shale facies at the top of the early Toarcian 37 38 Tenuicostatum Zone resulted in the disappearance of all gastropods (and many other taxa, 39 Harries and Little 1999) in the Cleveland Basin, and gastropods were absent in the basin 40 41 until the upper part of the early Toarcian Falciferum Zone, where there is single occurrence 42 43 of the caenogastropod species Cryptaulax cf. slatteri (Tate, 1870). In the middle Toarcian 44 45 Bifrons and Variabilis Zones, with the amelioration of benthic oxygen conditions, the 46 gastropod fauna increased to four species in three families (Procerithiidae, Aporrhaidae and 47 48 Cylindrobullinidae) (Figure 6A). The gastropod diversity then increased substantially to 18 49 50 species in 11 families in the Blea Wyke Sandstone Formation of the late Toarcian 51 52 (Thoarsense and Levesquei Zones) [Ferrari et al. (2020, table 2), Figure 6A], where they 53 became a much more dominant component of the contemporary molluscan faunas, both 54 55 numerically and in diversity, compared to those of the late Pliensbachian and early 56 57 58 59 60 Palaeontology Page 37 of 64 Palaeontology

1 2 3 Toarcian Tenuicostatum Zone (JWA, unpublished data). In the Dogger Formation of the 4 5 early Aalenian (Opalinum? Zone) gastropod diversity increased again to 44 species in 17 6 7 families [Ferrari et al. (2020, table 2), Figure 6A]. 8 In the Cleveland Basin the impact of the early Toarcian extinction event on the gastropod 9 10 faunas resulted in the almost complete replacement of species. It also had important 11 12 implications for higher taxa, because the late Pliensbachian species Sisenna cf. pinguis 13 14 (Deslongchamps, 1849) and Angulomphalus expansus (J. Sowerby, 1821) were amongst 15 the last representatives of their families (Gosseletinidae and Ptychomphalidae respectively) 16 17 globally. The post-extinction gastropod faunas of the middle and late Toarcian contained 18 19 some of the first representatives of higher taxa that would later become common elements 20 in Middle Jurassic gastropod assemblages: Pietteia arenosa (Hudleston 1884) and Pietteia 21 22 unicarinata (Hudleston 1884) (family Aporrhaidae), Procerithium armatum (Goldfuss 23 24 1843), Procerithium quadrilineatum (Römer, 1836) (Family Procerithiidae), and 25 26 Turritelloidea stepheni sp. nov. and Turritelloidea quadrivittata (Phillips, 1829) (Family 27 Gordenellidae) being good examples. However, only four species (Pietteia unicarinata, 28 29 Globularia cf. canina, Sulcoactaeon sedgvici, and Striactaenonina aff. tenuistriata) are 30 31 shared between the late Toarcian and Aalenian Dogger Formation faunas in the Cleveland 32 33 Basin [Ferrari et al. (2020, table 2)]. The Dogger Formation contains typical representatives 34 of European Middle Jurassic gastropod assemblages (e.g. the families Pseudomelaniidae, 35 36 Ataphridae, Nerineidae, Neritidae, Neritopsidae, Trochotomidae), and also typical of 37 38 Middle Jurassic gastropod assemblages, has a greater diversity of gastropods at all 39 taxonomic levels, compared to Lower Jurassic faunas (Figure 6B). There may be a facies 40 41 control on the pattern of gastropod recovery from the early Toarcian extinction event in the 42 43 Cleveland Basin. The late Pliensbachian sedimentary rocks are very heterogeneous, with 44 45 oolitic ironstones, fine sandstones and siltstones (Cleveland Ironstone Formation), and were 46 deposited in shallow water settings (Hesselbo 2008), whereas the early and middle 47 48 Toarcian rocks are fine grained (Whitby Mudstone Formation; Figure 2), representing 49 50 transgressive, deeper water facies (Hesselbo 2008). These fine grained facies were 51 52 generally not optimum for gastropod diversity in the Lower Jurassic. Post-extinction 53 diversity only increased in the Blea Wyke Sandstone Formation, three ammonite zones 54 55 after the extinction event, when shallower-water, coarser-grained sediments started to be 56 57 58 59 60 Palaeontology Palaeontology Page 38 of 64

1 2 3 deposited in the Cleveland Basin, and this facies tends to have greater gastropod diversity 4 5 in the Jurassic. The facies changed again with the Aalenian Dogger Formation, with the 6 7 deposition of oolitic sandy ironstones; oolitic facies of the Middle Jurassic tend to have 8 high diversity gastropod faunas. Interestingly, vetigastopods were only present the 9 10 Cleveland Basin during the late Pliensbachian to Aalenian interval when oolitic ironstones 11 12 were being deposited, perhaps further indicating a facies control on the gastropod faunas 13 14 (Figure 6B). 15 16 17 18 19 LATE TOARCIAN WESTERN EUROPEAN GASTROPOD FAUNAS 20 21 Comparing the late Toarcian gastropod fauna of the Cleveland Basin with those in the 22 23 marine deposits of Southern Germany (Franconia Basin; Schulbert & Nützel, 2013), 24 25 Northern Germany (Jurensismergel Formation, North German Basin; Gründel, 2007) and 26 Southern France (Causses Basin; Gatto et al., 2015) allows us to analyse the 27 28 palaeobiographic distribution of gastropods in Western Europe during this time period, 29 30 showing that there are some major differences [Figure 7, Ferrari et al. (2020, table 3)]. The 31 32 Cleveland Basin late Toarcian gastropod fauna is well represented by several 33 caenogastropod and heterobranchid families, including the Procerithiidae, Coelodiscidae, 34 35 Aporrhaidae, Ampullinidae, Zygopleuridae, Palaeorissoinidae, Mathildidae, Gordenellidae, 36 37 Tubiferidae, Cylindrobullinidae and Bullinidae; two families, the Zygopleuridae and 38 39 Ampullinidae, only occur in the Cleveland Basin during this time interval (Fig. 7 C). In 40 contrast, members of the orders Vetigastropoda and Cycloneritimorpha, and the families 41 42 Discohelicidae, Iravadiidae, Lamelliphoridae, Cryptaulicidae, Strombidae, Maturifusidae, 43 44 Tofanellidae, Ebalidae and Cornirostridae, typical of the Jurensismergel Formation, and 45 Franconia and Causses Basins, are missing from the Cleveland Basin late Toarcian faunas 46 47 [Fig. 7 C, Ferrari et al. (2020, table 3)]. The sediments of Jurensismergel Formation and in 48 49 the Franconia Basin represent typical marine epicontinental deposits of mudstones and 50 51 marls deposited in calm conditions below storm wave base (e.g., Etter 1995; in Schulbert & 52 Nützel, 2013). These resulted in soft bottom conditions with soupy substrates and variable 53 54 oxygen availability (fully aerobic to dysaerobic), contrasting strongly with the sandy 55 56 sediments of the Blea Wyke Sandstone Formation being deposited above storm wave-base 57 58 59 60 Palaeontology Page 39 of 64 Palaeontology

1 2 3 at the same time in the Cleveland Basin. This suggests a facies control on the composition 4 5 of contemporary gastropod faunas between these regions. The low diversity in the late 6 7 Toarcian gastropod faunas from the Causses area (Figure 7 A, B) may have been due to the 8 restricted nature of the Causses Basin, which was confined largely by land masses and open 9 10 only towards the central part of western Tethys Ocean. The geographic isolation and 11 12 marginal location of the Causses Basin probably restricted faunal exchange with the 13 14 Western European epicontinental seas, preventing a rapid recovery after the early Toarcian 15 extinction event. According to Fürsich et al. (2001), the changes in the macrobenthic 16 17 associations recorded in the Causses succession after the early Toarcian anoxic event were 18 19 related to changes in oxygenation and substrate consistency. In the lower part of the 20 sequence the low diversity reflected oxygen fluctuations, whereas the extremely soupy 21 22 substrate resulting from the activity of burrowing organisms was the main controlling factor 23 24 during the late Toarcian time period. Gastropods from the central region of the Western 25 26 Tethys were probably unable to settle and colonize the Causses area at this time because of 27 differences in environment (Gatto et al. 2015). 28 29 30 31 32 33 ACKNOWLEDGEMENTS 34 35 The new late Toarcian gastropod material was collected by JWA with support from a 36 37 Geological Society of London Undergraduate Research Bursary. The visit by MF to the 38 39 University of Leeds, England, to revise this materialwas made possible in part by a Senior 40 Research Grant project entitled “Systematics of new Jurassic marine gastropods from the 41 42 Cleveland Basin (UK)” financed by the Malacological Society of London, UK, to whom 43 44 we thank. We also thank Mr Mauricio Luquet (ALUAR, Argentina) for allowing access to 45 the SEM and Mr Rob Taylor for donating his gastropod finds from the Yorkshire coast. 46 47 Alexander Nützel, Stefano Monari and Michael Hautmann gave valuable comments to an 48 49 earlier draft of this paper. 50 51 52 53 54 55 56 57 58 59 60 Palaeontology Palaeontology Page 40 of 64

1 2 3 DATA ARCHIVING STATEMENT 4 5 6 7 This published work and the nomenclatural acts it contains, have been registered in 8 ZooBank: http://zoobank.org/References/XXXXXXXXX 9 10 11 12 Data for this study are available in the Dryad Digital Repository: 13 14 https://datadryad.org/stash/share/nhYDj6xiGWcDrEia0J9vssLmIghbupAPoEdH9g98jYQ 15 16 17 REFERENCES 18 19 20 ABERHAN, M. and FÜRSICH, F. 2000. Mass origination versus mass extinction: the 21 biological contribution to the Pliensbachian–Toarcian extinction event. Journal of the 22 23 Geological Society, 157, 55–60. 24 25 AMMON, L. VON. 1878. Die Gastropoden des Hauptdolomites und des Plattenkalkes der 26 Alpen. Abhandlungen des zoologisch-mineralogischen Vereines in Regensburg, 11, 1– 27 28 72. 29 30 BANDEL, K. and HEMLEBEN, C. 1987. Jurassic heteropods and their modern 31 32 counterparts (planktonic Gastropoda, Mollusca). Neues Jahrbuch für Geologie und 33 Paläontologie, Abhandlungen, 174, 1–22. 34 35 BANDEL, K., GRÜNDEL, J. and MAXWELL, P. 2000. Gastropods from the upper Early 36 37 Jurassic/early Middle Jurassic of Kaiwara Valley, North Canterbury, New Zealand. 38 39 Freiberger Forschungshefte, C490, 67–132. 40 BEHRENDSEN, O. 1891. Zur Geologie des Ostabhanges der argentinischen Cordillere. 41 42 Teil I. Zeitschrift der Deutschen Geologischen Gesellschaft, 43, 369–420. 43 44 BOULILA, S., GALBRUN, B., HURET, E., HINNOV, L.A., ROUGET, I., GARDIN, S. 45 and BARTOLINI, A. 2014. Astronomical calibration of the Toarcian Stage: Implications 46 47 for sequence stratigraphy and duration of the early Toarcian OAE. Earth and Planetary 48 49 Science Letters, 386, 98-111. 50 51 BRÖSAMLEN, R. 1909. Beitrag zur Kenntnis der Gastropoden des schwäbischen 52 Jura. Palaeontographica, 56, 177–321. 53 54 BURMEISTER, H. 1837. Zoologie. Handbuch der Naturgeschichte, 2, 369–858. 55 56 57 58 59 60 Palaeontology Page 41 of 64 Palaeontology

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1 2 3 SCHRÖDER, M. 1995. Frühontogenetische Schalen jurassischer und unterkretazischer 4 5 Gastropoden aus Norddeutschland und Polen. Palaeontographica, 238, 1–95. 6 7 SEMPER, O. 1865. Dugenre Mathilda. Journal de Conchyliologie, 13, 323–341. 8 SEPKOSKI, J.J. 1996. Patterns of Phanerozoic extinction: A perspective from global data 9 10 bases. In WALLISER, O.H. (ed.). Global Events and Event Stratigraphy in the 11 12 Phanerozoic. Springer, Berlin, 35–51 pp. 13 14 SOWERBY, J. 1818. Mineral Conchology of Great Britain. No. XXXVIII, 29–39. 15 Sherwood and Co., London. 16 17 SOWERBY, J. 1825. Mineral Conchology of Great Britain. Sherwood and Co., London, 18 19 86, 153–168. 20 STOLICZKA, F. 1861. Über die Gastropoden und Acephalen der Hierlatz-Schichten: 21 22 Sitzungberichte der Mathematisch-naturwissenschaflichen Classe der k. Akademie der 23 24 Wissenschaften Wien, 43, 157–204. 25 26 SZABÓ, J. 1983. Lower and Middle Jurassic Gastropods from the Bakony Mountains 27 (Hungary), Part V. Supplement to Archaeogastropoda; Caenogastropoda. Annales 28 29 Historico−Natulares Musei Nationalis Hungarici, Budapest, 75, 27–46. 30 31 SZABÓ, J. 2009. Gastropods of the Early Jurassic Hierlatz Limestone Formation; Part 1: a 32 33 revision of type collections from Austria and Hungarian localities. Fragmenta 34 Palaeontologica Hungarica, 26, 1–108. 35 36 TATE, R. and BLAKE, J.F. 1876. The Yorkshire Lias. Van Voorst, London. 37 38 475 pp. 39 40 TEICHERT, S. and NÜTZEL, A. 2015. Early Jurassic anoxia triggered the evolution of 41 the oldest holoplanktonic gastropod Coelodiscus minutus by means of heterochrony. 42 43 Acta Palaeontologica Polonica 60: 269–276. 44 45 TERQUEM, O. 1855. Paléontologie de l’étage inferieur de la formation liassique de la 46 47 province de Luxembourg, Grand-Duché (Hollande) et de Hettange, du department de la 48 Moselle: Mémoires de la Société Géologique de France, v. 5, p. 219–343. 49 50 TERQUEM, O. and JOURDY, E. 1871. Monographie de l’étage Bathonien dans le 51 52 département de la Moselle. Mémoires de la Société géologique de France, 9, 1–175. 53 THIBAULT, N., RUHL, M., ULLMANN, C.V., KORTE, C., DAVID, KEMP, B., 54 55 GRÖCKE, D.R. and HESSELBO, S.P. 2018. The wider context of the Lower Jurassic 56 57 58 59 60 Palaeontology Palaeontology Page 50 of 64

1 2 3 Toarcian oceanic anoxic event in Yorkshire coastal outcrops, UK. Proceedings of the 4 5 Geologists’Association, 129, 372–391. 6 7 TODD, J.A. and MUNT, M.C. 2010. Mollusca – Gastropods. In Lord, A.R. and Davis, 8 P.G. (eds). Fossils from the Lower Lias of the Dorset Coast. Palaeontological 9 10 Association, London. 147–168 pp. 11 12 WALTHER, H. 1951. Jurassische Mikrofossilien, insbesondere Gastropoden, am Südrand 13 14 des Hils. Paläontologische Zeitschrift, 25, 35–106. 15 WEAVER, C. 1931. Paleontology of the Jurassic and Cretaceous of West Central 16 17 Argentina. Memoir, University of Washingto, 1, 1–469. 18 19 WENZ, W., 1938–1944, Teil 1: Allgemeiner Teil und Prosobranchia, In SCHINDEWOLF, 20 O.H. (ed). Handbuch der Paläozoologie, Band 6, Gastropoda. Berlin, Borntraeger, 1639 21 22 p. 23 24 WENZ, W. 1947. Zur Taxonomie der Euthyneura. Archiv für Molluskenkunde, 76, 36. 25 26 WIGNALL, P.B., HALLAM, A., NEWTON, R.J., SHA, J.G., REEVES, E., MATTIOLI, 27 E. and CROWLEY, S. 2006. An eastern Tethyan (Tibetan) record of the Early Jurassic 28 29 (Toarcian) mass extinction event. Geobiology, 4, 179–190. 30 31 XU, W., RUHL, M., JENKYNS, H.C., LENG, M.J., HUGGETT, J.M., MINISINI, D., 32 33 ULLMANN, C. V., RIDING, J.B., WEIJERS, J.W.H., STORM, M.S., PERCIVAL, 34 L.M.E., TOSCA, N.J., IDIZ, E.F., TEGELAAR, E.W. and HESSELBO, S.P. 2018. 35 36 Evolution of the Toarcian (Early Jurassic) carbon cycle and global climatic controls on 37 38 local sedimentary processes (Cardigan Bay Basin, UK). Earth and Planetary Science 39 Letters, 484, 396–411. 40 41 ZAKHAROV, V.A., SHURYGIN, B.N., IL’INA, V.I. and NIKITENKO, B.L. 2006. 42 43 Pliensbachian–Toarcian biotic turnover in north Siberia and the Arctic region. 44 45 Stratigraphy and Geological Correlation, 14, 399–417. 46 ZIETEN, C.H. VON. 1830–33. Die Versteinerungen Württembergs, erstes Heft. Verlag und 47 48 Lithographie der Expedition des Werkes unserer Zeit, Stuttgart, 102 pp. 49 50 ZITTEL, K.A. von and GOUBERT, E. 1861. Description des fossiles du coral rag de Glos. 51 52 Journal de Conchyliologie, 9, 192–208. 53 54 55 56 57 58 59 60 Palaeontology Page 51 of 64 Palaeontology

1 2 3 4 5 6 7 CAPTIONS 8 9 FIG. 1. A. Map of England showing Lower Jurassic outcrops, sedimentary basins and 10 11 location of the Ravenscar section. B. Detailed geological map of the Ravenscar area, North 12 13 Yorkshire. 14 15 FIG. 2. Log of the Ravenscar section from the top of the Alum Shale Member to the 16 17 Dogger Formation, showing sampling horizons. 18 19 20 FIG. 3. A–E, Coelodiscus minutus (Schübler in Zieten, 1833). A–E, YORYM: 2019.315., 21 A–B, apical views; C, apical view detail; D–E protoconch and earliest whorls details; 22 23 specimen from sample horizon ys-d.400. F–L, Procerithium quadrilineatum (Römer, 24 25 1836). F-H, YORYM: 2019.320., F-G, lateral and apertural views, H, apertural detail; 26 specimen from sample horizon ys-d.400. I–L, YORYM: 2019.319, I–J, lateral views, K–L, 27 28 juvenile teleoconch details; specimen from sample horizon ys-d.100. M–R, Katosira? 29 30 bicarinata sp. nov. M–N, YORYM: 2019.344, holotype, lateral and apertural views; 31 32 specimen from sample horizon ys-d.400. O, YORYM: 2019.346, lateral view; specimen 33 from sample horizon ys-d.400. P, YORYM: 2019.347, lateral view; specimen from sample 34 35 horizon ys-d.400. Q–R, YORYM: 2019.345, paratype, lateral views; specimen from sample 36 37 horizon ys-d.500. S–U, Pseudokatosira undulata (Benz, 1830 in von Zieten). S, YORYM: 38 2019.354, fragmentary specimen in lateral view, last whorl and basal details are shown; 39 40 specimen from sample horizon ys-d.500. T–U, YORYM: 2019.353, lateral views; specimen 41 42 from sample horizon ys-d.400. V–X, Palaeorissoina aff. acuminata (Gründel, 1999b). V– 43 44 W, YORYM: 2019.358, lateral and apertural views; specimen from sample horizon ys- 45 d.200. X, YORYM: 2019.359, lateral view; specimen from sample horizon ys-d.200. Scale 46 47 bars represent 500 mm (A, B, D, E, O, P, V, W, X); 1 mm (F, G, H, I, J, K, M, N, Q, R, S, 48 49 T, U); 100 mm (C); 200 mm (L). 50 51 52 FIG. 4. A–L, Pietteia unicarinata (Hudleston, 1884). A–C, YORYM: 2019.360. A, C, 53 54 lateral views; B, protoconch and early teleoconch details; specimen from sample horizon 55 56 ys-d.200. D, YORYM: 2019.362, lateral and apertural views; specimen from sample 57 58 59 60 Palaeontology Palaeontology Page 52 of 64

1 2 3 horizon ys-d.200. E, YORYM: 2019.361, lateral view; specimen from sample horizon ys- 4 5 d.100. F, YORYM: 2019.369; specimen from sample horizon ys-d.400. G–H, YORYM: 6 7 2019.376, extension of the outer lip detail; specimen from sample horizon ys-d.700. I–J, 8 YORYM 2019.377, lateral views and apex in oblique view; specimen not in-situ. K–L, 9 10 YORYM: 2019.364, lateral and basal views; specimen from sample horizon ys-d.700. M– 11 12 N, Globularia cf. canina (Hudleston, 1882), YORYM: 2019.378, lateral and apical views; 13 14 specimen not in-situ. O–P, Tricarilda? sp., YORYM: 2019.379, lateral views; specimen 15 from sample horizon ys-d.200. Q, Jurilda sp., YORYM: 2019.380, lateral view; specimen 16 17 from sample horizon ys-d.400. R–S, Turritelloidea stepheni sp. nov., YORYM: 2019.381, 18 19 holotype, lateral and apertural views; specimen from sample horizon ys-d.400. T–V, 20 Cossmannina sp., YORYM: 2019.383. T–U, lateral views; V, apertural view; specimen 21 22 from sample horizon ys-d.600. W–Y, Striactaeonina cf. richterorum Schulbert & Nützel, 23 24 2013. W, YORYM: 2019.384, lateral view; specimen from sample horizon ys-d.400. X–Y, 25 26 YORYM: 2019.385, lateral views; specimen from sample horizon ys-d.300. Scale bars 27 represent 1 mm (A, C, D, E, G, H, K, L, M, N, Q, R, S); 5 mm (I, J); 500 m (F, O, P, W, 28 29 X, Y); 200 m (B, T, U, V). 30 31 32 33 FIG. 5. A–E, Striactaeonina elegans sp. nov. A–C, YORYM: 2019.386, holotype, lateral 34 views; specimen from sample horizon ys-d.500. D–E, YORYM: 2019.388, lateral views; 35 36 specimen from sample horizon ys-d.200. F–I, Striactaenonina aff. tenuistriata (Hudleston, 37 38 1887), YORYM: 2019.389; F–G, lateral views; H, spire whorls detail; I, last whorl 39 40 ornament detail; specimen from sample horizon ys-d.700. J–L, Cylindrobullina sp., J, 41 YORYM: 2019.390, apical view; specimen from sample horizon ys-d.400. K–L, YORYM: 42 43 2019.391, apical and lateral views; specimen from sample horizon ys-d.200. M–R, 44 45 Sulcoactaeon sedgvici (Phillips, 1829), M–O, YORYM: 2019.396, lateral views; specimen 46 47 from sample horizon ys-d.100. P, YORYM: 2019.397, lateral view; specimen from sample 48 horizon ys-d.200. Q–R, YORYM: 2019.395, lateral and apertural views; specimen from 49 50 sample horizon ys-d.400. Scale bars represent 500 m (A, B, C, D, E, H, I, J, K, L, O, P, Q, 51 52 R); 1 mm (F, G, M, N). 53 54 55 56 57 58 59 60 Palaeontology Page 53 of 64 Palaeontology

1 2 3 FIG. 6. Effect of the early Toarcian extinction event on gastropod faunas of the Cleveland 4 5 Basin. A. Numbers of gastropod species (Species), genera (Genera) and families (Family) 6 7 for the late Pliensbachian to the Aalenian interval in four time bins. B. Relative percentage 8 of gastropod orders for the same time bins. 9 10 11 12 FIG. 7. A–C, Taxomonic comparison of Late Toarcian gastropods from the Cleveland 13 14 Basin, Franconia Basin (Southern Germany), Jurensismergel Formation, North German 15 Basin (Northern Germany) and Causses Basin (Southern France). A. Pie chart of relative 16 17 proportion of species in the four areas. B. Numbers of species, genera and families in the 18 19 four areas. C. Family composition of gastropod species in the four areas. 20 21 22 TABLE 1. Dimensions (mm) of Procerithium quadrilineatum (Römer, 1836). * = partial 23 24 specimens. 25 26 27 TABLE 2. Dimensions (mm) of Katosira? bicarinata sp. nov. * = partial specimens. 28 29 30 31 TABLE 3. Dimensions (mm) of Pietteia unicarinata (Hudleston, 1884). * = partial 32 33 specimens. 34 35 36 TABLE 4. Dimensions (mm) of Sulcoactaeon sedgvici (Phillips, 1829). * = partial 37 38 specimens. 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Palaeontology Palaeontology Page 54 of 64

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 FIG. 1. A. Map of England showing Lower Jurassic outcrops, sedimentary basins and location of the 20 Ravenscar section. B. Detailed geological map of the Ravenscar area, North Yorkshire. 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Palaeontology Page 55 of 64 Palaeontology

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 FIG. 2. Log of the Ravenscar section from the top of the Alum Shale Member to the Dogger Formation, 46 showing sampling horizons. 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Palaeontology Palaeontology Page 56 of 64

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 FIG. 3. A–E, Coelodiscus minutus (Schübler in Zieten, 1833). A–E, YORYM: 2019.315., A–B, apical views; 46 C, apical view detail; D–E protoconch and earliest whorls details; specimen from sample horizon ys-d.400. 47 F–L, Procerithium quadrilineatum (Römer, 1836). F-H, YORYM: 2019.320., F-G, lateral and apertural views, H, apertural detail; specimen from sample horizon ys-d.400. I–L, YORYM: 2019.319, I–J, lateral views, K–L, 48 juvenile teleoconch details; specimen from sample horizon ys-d.100. M–R, Katosira? bicarinata sp. nov. M– 49 N, YORYM: 2019.344, holotype, lateral and apertural views; specimen from sample horizon ys-d.400. O, 50 YORYM: 2019.346, lateral view; specimen from sample horizon ys-d.400. P, YORYM: 2019.347, lateral view; 51 specimen from sample horizon ys-d.400. Q–R, YORYM: 2019.345, paratype, lateral views; specimen from 52 sample horizon ys-d.500. S–U, Pseudokatosira undulata (Benz, 1830 in von Zieten). S, YORYM: 2019.354, 53 fragmentary specimen in lateral view, last whorl and basal details are shown; specimen from sample horizon 54 ys-d.500. T–U, YORYM: 2019.353, lateral views; specimen from sample horizon ys-d.400. V–X, Palaeorissoina aff. acuminata (Gründel, 1999b). V–W, YORYM: 2019.358, lateral and apertural views; 55 specimen from sample horizon ys-d.200. X, YORYM: 2019.359, lateral view; specimen from sample horizon 56 ys-d.200. Scale bars represent 500 mm (A, B, D, E, O, P, V, W, X); 1 mm (F, G, H, I, J, K, M, N, Q, R, S, T, 57 58 59 60 Palaeontology Page 57 of 64 Palaeontology

1 2 3 U); 100 mm (C); 200 mm (L). 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Palaeontology Palaeontology Page 58 of 64

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 FIG. 4. A–L, Pietteia unicarinata (Hudleston, 1884). A–C, YORYM: 2019.360. A, C, lateral views; B, 46 protoconch and early teleoconch details; specimen from sample horizon ys-d.200. D, YORYM: 2019.362, 47 lateral and apertural views; specimen from sample horizon ys-d.200. E, YORYM: 2019.361, lateral view; specimen from sample horizon ys-d.100. F, YORYM: 2019.369; specimen from sample horizon ys-d.400. G– 48 H, YORYM: 2019.376, extension of the outer lip detail; specimen from sample horizon ys-d.700. I–J, YORYM 49 2019.377, lateral views and apex in oblique view; specimen not in-situ. K–L, YORYM: 2019.364, lateral and 50 basal views; specimen from sample horizon ys-d.700. M–N, Globularia cf. canina (Hudleston, 1882), YORYM: 51 2019.378, lateral and apical views; specimen not in-situ. O–P, Tricarilda? sp., YORYM: 2019.379, lateral 52 views; specimen from sample horizon ys-d.200. Q, Jurilda sp., YORYM: 2019.380, lateral view; specimen 53 from sample horizon ys-d.400. R–S, Turritelloidea stepheni sp. nov., YORYM: 2019.381, holotype, lateral and apertural views; specimen from sample horizon ys-d.400. T–V, Cossmannina sp., YORYM: 2019.383. T– 54 U, lateral views; V, apertural view; specimen from sample horizon ys-d.600. W–Y, Striactaeonina cf. 55 richterorum Schulbert & Nützel, 2013. W, YORYM: 2019.384, lateral view; specimen from sample horizon 56 ys-d.400. X–Y, YORYM: 2019.385, lateral views; specimen from sample horizon ys-d.300. Scale bars 57 58 59 60 Palaeontology Page 59 of 64 Palaeontology

1 2 3 represent 1 mm (A, C, D, E, G, H, K, L, M, N, Q, R, S); 5 mm (I, J); 500 ฀m (F, O, P, W, X, Y); 200 ฀m (B, 4 T, U, V). 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Palaeontology Palaeontology Page 60 of 64

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 FIG. 5. A–E, Striactaeonina elegans sp. nov. A–C, YORYM: 2019.386, holotype, lateral views; specimen from sample horizon ys-d.500. D–E, YORYM: 2019.388, lateral views; specimen from sample horizon ys-d.200. 37 F–I, Striactaenonina aff. tenuistriata (Hudleston, 1887), YORYM: 2019.389; F–G, lateral views; H, spire 38 whorls detail; I, last whorl ornament detail; specimen from sample horizon ys-d.700. J–L, Cylindrobullina 39 sp., J, YORYM: 2019.390, apical view; specimen from sample horizon ys-d.400. K–L, YORYM: 2019.391, 40 apical and lateral views; specimen from sample horizon ys-d.200. M–R, Sulcoactaeon sedgvici (Phillips, 41 1829), M–O, YORYM: 2019.396, lateral views; specimen from sample horizon ys-d.100. P, YORYM: 42 2019.397, lateral view; specimen from sample horizon ys-d.200. Q–R, YORYM: 2019.395, lateral and apertural views; specimen from sample horizon ys-d.400. Scale bars represent 500 ฀m (A, B, C, D, E, H, I, 43 J, K, L, O, P, Q, R); 1 mm (F, G, M, N). 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Palaeontology Page 61 of 64 Palaeontology

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 FIG. 6. Effect of the early Toarcian extinction event on gastropod faunas of the Cleveland Basin. A. 32 Numbers of gastropod species (Species), genera (Genera) and families (Family) for the late Pliensbachian to 33 the Aalenian interval in four time bins. B. Relative percentage of gastropod orders for the same time bins. 34 35 165x127mm (300 x 300 DPI) 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Palaeontology Palaeontology Page 62 of 64

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 FIG. 7. A–C, Taxomonic comparison of Late Toarcian gastropods from the Cleveland Basin, Franconia Basin 41 (Southern Germany), Jurensismergel Formation, North German Basin (Northern Germany) and Causses Basin (Southern France). A. Pie chart of relative proportion of species in the four areas. B. Numbers of 42 species, genera and families in the four areas. C. Family composition of gastropod species in the four areas. 43 44 165x171mm (300 x 300 DPI) 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Palaeontology Page 63 of 64 Palaeontology

1 2 3 4 Procerithium quadrilineatum (Römer, 1836) 5 6 Specimen height (mm) width (mm) 7 YORYM : 2019.317 7.00 1.90 8 YORYM : 2019.318 1.81 0.74 9 10 YORYM : 2019.319 6.51 2.17 11 YORYM : 2019.337 4.00* 1.89 12 YORYM : 2019.338 4.64* 1.67* 13 YORYM : 2019.339 0.92* 1.13 14 15 YORYM : 2019.320 8.14 2.13 16 YORYM : 2019.321 4.88 2.11 17 YORYM : 2019.341 7.53 2.69 18 YORYM : 2019.342 8.32 2.41 19 20 YORYM : 2019.343 5.98* 3.16 21 YORYM : 2019.322 6.94* 3.97 22 YORYM : 2019.323 7.44* 2.09 23 YORYM : 2019.340 15.29* 5.25 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

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1 2 3 4 5 6 7 8 9 Katosira? bicarinata sp. nov. 10 11 Specimen Type height (mm) width (mm) 12 YORYM : 2019.350 ─ 3.72* 1.72 13 YORYM : 2019.344 Holotype 7.11 2.51 14 YORYM : 2019.346 ─ 4.54* 1.76 15 16 YORYM : 2019.345 Paratype 4.61* 2.06 17 YORYM : 2019.349 ─ 4.71 2.02 18 YORYM : 2019.351 ─ 6.62 2.10 19 YORYM : 2019.348 ─ 4.45* 2.03 20 21 YORYM : 2019.347 ─ 4.26* 1.73 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

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1 2 3 4 Pietteia unicarinata (Hudleston, 1884) 5 6 Specimen height (mm) width (mm) 7 YORYM : 2019.364 7.62* 3.49 8 YORYM : 2019.365 5.70 2.43 9 YORYM : 2019.366 4.48* 2.41 10 11 YORYM : 2019.362 6.79 2.59 12 YORYM : 2019.360 5.68* 3.05 13 YORYM : 2019.367 4.52* 2.8* 14 15 YORYM : 2019.368 7.03* 4.18* 16 YORYM : 2019.369 3.71* 1.61* 17 YORYM : 2019.370 2.73* 2* 18 YORYM : 2019.371 5.98* 3.79* 19 20 YORYM : 2019.377 24.81 7.94 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Palaeontology Palaeontology Page 66 of 64

1 2 3 4 5 6 7 8 Sulcoactaeon sedgvici (Phillips, 1829) 9 Specimen height (mm) width (mm) 10 11 YORYM : 2019.400 3.04* 2.13 12 YORYM : 2019.401 2.98 2.23 13 YORYM : 2019.397 3.35* 1.93* 14 YORYM : 2019.398 3.63* 2.87 15 16 YORYM : 2019.402 4.04* 2.65 17 YORYM : 2019.395 4.76 3.36 18 YORYM : 2019.396 4.79 3.57 19 YORYM : 2019.403 3.72 2.40* 20 21 YORYM : 2019.404 3.31 2.17* 22 YORYM : 2019.405 3.95* 3.12 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Palaeontology