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Fig. 8 in Jurassic and Cretaceous gastropods from hydrocarbon seeps in forearc basin and accretionary prism settings, California

Fig. 8. Gastropods of uncertain taxonomic position, Atresius liratus Gabb, 1869 and Bathypurpurinopsis stantoni sp. nov., from Early Cretaceous seep carbonates in California, USA. A–F. Atresius liratus. A. Specimen (CAS 70395) with broad shoulder, from Rocky Creek (Valanginian; site 7). B. Specimen (CAS 70396) from Rocky Creek, note fine spiral sculpture on shoulder. C. Specimen (CAS 70397) with strong axial ribs, from Rocky Creek. D. Large specimen (CAS 70398) with rounded basal margin, from Rocky Creek. E. Specimen (USNM 23075a) illustrated by Stanton (1895: pl. 11: 6). F. Another specimen (USNM 23075b) from Stanton's lot with fewer but stronger spirals, and a more angular basal margin. G–L. Bathypurpurinopsis stantoni, from Cold Fork of Cottonwood Creek (Albian; site 1). G. Specimen (CAS 70399) with thin apertural fold and preserved siphonal column. H. Specimen (CAS 70400) with excavated aperture. I. Specimen (UCMP 555102) showing fine spiral sculpture and sinuous growth lines. J. Specimen (CAS 70401) with well−developed apertural fold, note the indented shell on the left. K. Holotype (CAS 70402). L. Smooth specimen (UCMP 555103) with excavated aperture.

Fig. 7 in Jurassic and Cretaceous gastropods from hydrocarbon seeps in forearc basin and accretionary prism settings, California

Fig. 7. Abyssochrysoid gastropod Paskentana spp. from Late Jurassic and Early Cretaceous seep carbonates in California, USA. A–C. Paskentana berryessaensis sp. nov. A. Holotype (UCMP 555098), small specimen with nodular sculpture from NW Berryessa (Tithonian; site 10). B. Paratype (UCMP 555099), specimen with beaded spiral cords from NW Berryessa (Tithonian; site 10). C. Paratype (UCMP 555100) from Bear Creek (Valanginian; site 4), specimen with spiral sculpture and fine axial growth increments. D–F. Paskentana globosa sp. nov. D. Paratype (UCMP 555101) from Little Indian Valley (Valanginian?; site 6). E. Holotype (CAS 70394), large specimen from Knoxville (Early Cretaceous?, site 9). F. Rubber cast of a last whorl, from Knoxville.

Fig. 6 in Jurassic and Cretaceous gastropods from hydrocarbon seeps in forearc basin and accretionary prism settings, California

Fig. 6. Abyssochrysoid gastropod Paskentana paskentaensis (Stanton, 1895) from Late Jurassic and Early Cretaceous seep carbonates in California, USA. A. Small specimen (CAS 70392) with strong scaly sculpture from Bear Creek (Valanginian; site 4); apertural (A1) and lateral (A2) views. B. Specimen (CAS 70393) with broad shoulder from Bear Creek (Valanginian; site 4). C. Specimen (UCMP 555097) with broad shoulder and almost smooth spiral sculpture, from Little Indian Valley (Valanginian?; site 6). D. Juvenile specimen (UCMP 555104) from Bear Creek (Valanginian; site 4), close−up on first whorls (D1) and entire specimen (D2). E. Isolated partial larval shell (UCMP 555105) from Bear Creek (Valaginian; site 4) that most likely belongs to Paskentana paskentaensis. F. Specimen (UCMP 154113) without shoulder and fine scaly sculpture, from Rice Valley (Hauterivian?; site 3). G. Specimen (UCMP 13701) without shoulder, from Wilbur Springs (Hauterivian; site 5). H. "Turbo" wilburensis Stanton, 1895 (pl. 12: 15), lectotype (USNM 23068) from Wilbur Springs (Hauterivian; site 5). I. "Turbo" paskentaensis Stanton, 1895 (pl. 12: 6), lectotype (USNM 23067) from Paskenta (Tithonian; site 2). J, K. "Turbo?" humerosus Stanton, 1895 from Wilbur Springs (Hauterivian; site 5). J. Lectotype (USNM 23072). K. Paralectotype (specimen illustrated by Stanton 1895: pl. 12: 10).

Fig. 4 in Jurassic and Cretaceous gastropods from hydrocarbon seeps in forearc basin and accretionary prism settings, California

Fig. 4. Late Jurassic and Early Cretaceous eucyclid Amberleya spp. from seep carbonates in California, USA. A–C. Amberleya dilleri Stanton, 1895, type specimens from Paskenta (site 2). A. Spire of juvenile specimen (USNM23074a). B. Spire of large specimen (USNM 23074b). C. Lectotype (USNM 23074c) showing the aperture. D. Amberleya cf. dilleri (UCMP 555090) from NW Berryessa (site 10). E–I. Amberleya morganensis (Stanton, 1895) from Rocky Creek (site 7). E. Lectotype (USNM 23071). F. Spire (CAS 70386) with two tuberculate spiral cords. G. View on flank and basal margin (CAS 70387). H. Spire (CAS 70388) with lower tuberculate spiral largely concealed by succeeding whorl. I. Specimen (CAS 70389) with narrow apical angle. F–I, rubber casts.

Fig. 3 in Jurassic and Cretaceous gastropods from hydrocarbon seeps in forearc basin and accretionary prism settings, California

Fig. 3. Hand sample and petrographic thin section (plane polarized light) occurrences of selected Mesozoic seep gastropod fossils, California, USA. A. Fossil coquina of Paskentana paskentensis from Bear Creek (site 4) carbonate pod. B. Thin section photomicrograph of Bathypurpurinopsis stantoni in clotted micrite with pore−filling fibrous cement, from Cold Fork of Cottonwood Creek (site 1). C. Longitudinal section through Paskentana paskentensis encased in early diagenetic (seafloor) anhedral yellow calcite cement (dark; cf. Campbell et al. 2002), with pores filled by lighter−colored fibrous cement, from Paskenta (site 2). D. Small individual of Paskentana paskentensis preserved in clotted micrite within serpulid worm tube; Bear Creek site (site 4).

Fig. 1 in Jurassic and Cretaceous gastropods from hydrocarbon seeps in forearc basin and accretionary prism settings, California

Fig. 1. Mesozoic (solid circles) and Cenozoic (open circles) seep carbonate occurrences, California, showing their broad geologic setting and overall geographic extent over ~130 m.y. and>600 km along the continental margin. Numbered sites indicate the 16 fossil gastropod−bearing deposits of this study. Relevant geologic features of the north−south trending, Mesozoic– Paleogene convergent margin include: belts of mélange, broken formation and ophiolites (Franciscan Accretionary Complex and Coast Range Ophiolite, CRO); siliciclastic forearc turbidites (Great Valley Group); and present−day root of the volcanic arc (Sierra Nevada Batholith). Geology simplified from the 1:2,500,000 Geologic Map of California (1966, U.S. Geological Survey and California Division of Mines and Geology). Appendix 1 lists locality data, ages and fossil lists for each of the 16 sites. 1, Cold Fork of Cottonwood Creek; 2, Paskenta; 3, Rice Valley; 4, Bear Creek; 5, Wilbur Springs; 6, Little Indian Valley; 7, Rocky Creek; 8, Foley Canyon; 9, Knoxville; 10, NW Berryessa; 11, W Berryessa; 12, E Berryessa; 13, Romero Creek; 14, Moreno Gulch; 15, Gravelly Flat; 16, Charlie Valley.

Fig. 2 in Jurassic and Cretaceous gastropods from hydrocarbon seeps in forearc basin and accretionary prism settings, California

Fig. 2. Stratigraphic distribution of the 16 fossil−bearing, seep carbonate deposits of this study (Fig. 1), correlated with petrofacies (Ingersoll, 1983, for Sacramento Valley), and a Buchia bivalve biostratigraphy (Tithonian through Valanginian stages; Jones et al., 1969, as modified by Bralower, 1990). Geologic time divisions (Gradstein et al. 2004) for each stage are shown to the nearest 1 m.y. Ages of these seep carbonate deposits are relatively poorly known, with most sites resolved to stage level only. A few others are even more poorly known, e.g., probable Early Cretaceous age, and one is more finely resolved to sub−stage level (i.e., Late Campanian). Tithonian and Valanginian sites comprise the majority of the gastropod−rich deposits, with relative ages constrained by a six species Buchia zonation. Hauterivian sites contain the seep−restricted brachiopod, Peregrinella whitneyi (see Campbell and Bottjer, 1995, for discussion of caveats with respect to using this genus to establish relative ages). Albian and younger Cretaceous sites are dated based on ammonite occurrences. See Appendix for complete fossil lists. Most deposits occur within forearc mudstone of the Great Valley Group, except for two sites (3, 5) associated with serpentinite (diapir) deposits. A further two (6, 16) are enclosed in accretionary prism rocks of the Franciscan Complex, and one (3) is in a Great Valley outlier within Franciscan rocks. Similar seep fossil assemblages and associated buchiids allow relative age correlations for these Franciscan−related deposits.

Fig. 5 in Jurassic and Cretaceous gastropods from hydrocarbon seeps in forearc basin and accretionary prism settings, California

Fig. 5. Late Jurassic and Early Cretaceous abyssochrysoids Hokkaidoconcha spp. and Abyssochrysos? giganteum sp. nov. from seep carbonates in California, USA. A–C. Hokkaidoconcha occidentalis (Stanton, 1895). A. Lectotype (USNM 23077) from Paskenta (Tithonian; site 2). B. Specimen (CAS 70391) with well−developed spiral sculpture from Wilbur Springs (Hauterivian; site 5). C. Specimen (UCMP 555091) with poorly developed spiral sculpture from NW Berryessa (Tithonian; site 10). D, E. Hokkaidoconcha tehamaensis sp. nov. from Paskenta (Tithonian; site 10). D. Holotype (UCMP 555092); apertural (D1) and lateral (D2) views. E. Paratype (CAS 70390), note fading axial ribs on flank. F, G. Hokkaidoconcha morenoensis sp. nov. from Moreno Gulch (Santonian; site 14) F. Holotype (LACMIP 13483) with well−developed axial ribs and spiral sculpture on base. G. Paratype (LACMIP 13484) with fading axial ribs on later whorls. H. Hokkaidoconcha bilirata sp. nov., holotype (UCMP 555093) from Wilbur Springs (Hauterivian; site 5). I. Hokkaidoconcha sp. (UCMP 555094) from NW Berryessa (Tithonian; site 10). J, K. Abyssochrysos? giganteum sp. nov. from E Berryessa (Lower Cretaceous; site 12). J. Holotype (UCMP 555095). K. Paratype (UCMP 555096).

Fig. 7 in Early ontogeny and palaeoecology of the Mid-Miocene rissoid gastropods of the Central Paratethys

Fig. 7. Four species of Alvania (Alvania) Risso, 1826. A. Alvania (Alvania) oceani (d'Orbigny, 1852). Specimen (NHMW 2002z0030/0012) from the Badenian of Steinebrunn, Lower Austria (A1). Protoconch of the same specimen as in A1 in lateral view (A2). The protoconch is terminated by a slightly thickened, fractionated sinusigera notch. B. Alvania (Alvania) perregularis (Sacco, 1895). Specimen (NHMW 2002z0030/0013) from the Early Badenian of Sedlec/Nový Rybník, Czech Republic (B2). Lateral and apical view of the protoconch of the same specimen as in B2 (B1, B3). The protoconch is terminated by a sinusigera notch. Detailed apical view of the initial whorl of the same protoconch as in B3 (B4). The embryonic shell consists of one inflated whorl, which is terminated by a thickened rim, reflecting the thickened apertural margin of the hatchling. C. Alvania (Alvania) transiens (Sacco, 1895). Specimen (NHMW 2002z0030/0014) from the Badenian of Steinebrunn, Lower Austria (C1). Protoconch of the same specimen as in C1 in lateral and apical view (C2, C3). The larval shell is sculptured by spiral rows of tubercles. It is terminated by a well developed sinusigera notch. D. Alvania (Alvania) schwartzi (Hörnes, 1865). Specimen (NHMW 2002z0030/0015) from the Badenian of Steinebrunn, Lower Austria (D2). Lateral and apical views of the protoconch of the same specimen as in D2 (D1, D3, D4). The protoconch is terminated by a well developed sinusigera notch. Detailed view of the initial whorl of the same protoconch as in D4 (D5). The embryonic shell is demarcated from the subsequent larval shell by a thickened rim.

Fig. 10 in Early ontogeny and palaeoecology of the Mid-Miocene rissoid gastropods of the Central Paratethys

Fig. 10. Two species of Mohrensternia Stoliczka, 1868. A, B. Mohrensternia inflata (Hörnes, 1856). A. Specimen (NHMW 2002z0029/0005) from the Early Sarmatian of Hollabrunn. B. Specimen (NHMW 2002z0029/0006) from the Early Sarmatian of Vienna−Nussdorf. Protoconch in lateral (B2) and apical (B3) views. The embryonic shell is separated from the subsequent larval shell by a slightly thickened rim. The onset of the teleoconch is indicated by the formation of weak axial folds, grading into regular axial ribs. C. Mohrensterniamoesinensis Jekelius, 1944. Specimen (collection A. Papp, NHMW 2002z0029/ 0008) from the Early Sarmatian of Eichkogel (C1). Lateral views of the protoconch of the same specimen as in C1 (C2, C3). The protoconch is terminated by a slightly projecting rim, which is slightly thickened in its adapical portion. Detailed apical view of the initial whorl of the same protoconch as in C3 (C4). The embryonic shell has fine spiral sculpture and it is terminated by a slightly thickened rim.

Fig. 6 in Early ontogeny and palaeoecology of the Mid-Miocene rissoid gastropods of the Central Paratethys

Fig. 6. Four species of Alvania (Alvania) Risso, 1826. A. Alvania (Alvania) mamillata (Risso, 1826). Specimen (NHMW 2002z0030/0008), Recent, from the Adriatic Sea (A1). Apical and lateral views of the protoconch of the same specimen (A2, A3). Thickened, closely spaced growth lines are terminating the protoconch. The onset of the teleoconch is indicated by the formation of a regular reticulate sculpture. B. Alvania (Alvania) montagui (Payraudeau, 1826). Specimen (NHMW 2002z0030/0009), Recent, from the Adriatic Sea (B1). Lateral views of the protoconch of the same specimen (B2, B3). The protoconch is terminated by a slightly thickened sinuous rim and a subsequent slight incision. C. Alvania (Alvania) curta (Dujardin, 1837). Specimen (NHMW 2002z/0030/0010) from the Early Badenian of Sedlec/Nový Rybník, Czech Republic (C1). Protoconch of the same specimen in lateral view (C2). The protoconch is terminated by a well−developed sinusigera notch. D. Alvania (Alvania) ampulla (Eichwald, 1853). Specimen (NHMW 2002z0030/0011) from the Badenian of Steinebrunn, Lower Austria (D1). Lateral view of the protoconch of the same specimen as in D1 (D2). The protoconch is terminated by a sinusigera notch which is thickened in its adapical portion. Detailed apical view of the embryonic shell of the same protoconch as in D2 (D3). The embryonic shell is sculptured by fine spiral threads and it is terminated by an indistinct rim on the shell.

Fig. 2 in Early ontogeny and palaeoecology of the Mid-Miocene rissoid gastropods of the Central Paratethys

Fig. 2. General map of Austria (A) with position of the studied area i.e., Vienna Basin, the Styrian Basin and the Molasse Basin (B). Stars that indicate outcrops with Badenian and Sarmatian rissoid faunas are plotted on a tentative reconstruction of the Early Sarmatian shoreline (grey areas indicate land).

Fig. 5 in Early ontogeny and palaeoecology of the Mid-Miocene rissoid gastropods of the Central Paratethys

Fig. 5. Two species of Rissoa Desmarest, 1814. A. Rissoa similis Scacchi, 1836. Specimen (NHMW 2002z0030/0005), Recent, from the Adriatic Sea (A1). Protoconch of the same specimen in lateral view (A2). B. Rissoa costeiensis sp. nov. Holotype (NHMW 2002z0030/0006) from the Badenian of Coştei, Romania (B1). Protoconch of the same specimen in lateral and apical views (B2, B3). The protoconch is terminated by closely spaced, sinuous, thickened growth lines. The onset of the teleoconch is indicated by a prominent incision of the whorl.

Fig. 4 in Early ontogeny and palaeoecology of the Mid-Miocene rissoid gastropods of the Central Paratethys

Fig. 4. Four species of Rissoa Desmarest, 1814. A. Rissoa turricula Eichwald, 1853. Specimen (collection A. Papp, NHMW 2002z0030/0001) from the Early Sarmatian of Waldhof/Styria (A1). Protoconch of the same specimen in lateral view (A2). The protoconch is terminated by a thickened rim, reflecting the thickened apertural margin of the veliger ready for metamorphosis. B. Rissoa parva (Da Costa, 1778). Specimen (NHMW 2002z0030/0002), Recent, from the Northern Adriatic Sea (B1). Protoconch of the same specimen in lateral view (B2). The protoconch is terminated by a prominent slightly sinuous, thickened rim. C. Rissoa acuticosta (Sacco, 1895). Specimen (NHMW 2002z0030/0003) from the Badenian of Steinebrunn, Lower Austria (C1). Apical and lateral view of the protoconch of the same specimen (C2, C3). The protoconch is terminated by sinuous, closely spaced, thickened growth lines. D. Rissoa clotho Hörnes, 1856. Specimen (NHMW 2002z0030/0004) from the Badenian of Steinebrunn, Lower Austria (D1). Protoconch of the same specimen in lateral view (D2). The protoconch is terminated by an indistinct, very fine thickened rim on the shell. Regular closely spaced growth lines indicate the onset of the teleoconch.

Fig. 9 in Early ontogeny and palaeoecology of the Mid-Miocene rissoid gastropods of the Central Paratethys

Fig. 9. Four species of Mohrensternia Stoliczka, 1868. A, B. Mohrensternia angulata Eichwald, 1853. Specimen (NHMW 2002z0029/0001) from the Early Sarmatian of Lednicé, Czech Republic (A1). Protoconch of the same specimen as in A1 in apical view (A2). The onset of the teleoconch is indicated by the formation of wavy axial folds which grade into axial ribs. B. Apex fragment of the specimen (NHMW 2002z0029/0001) from the Early Sarmatian of Lednicé, Czech Republic. C. Mohrensternia banatica (Jekelius, 1944). Specimen (NHMW 2002z0029/0002) from the Early Sarmatian of Eichkogel/ Mödling, Vienna Basin (Austria) (C1). Apical and lateral view of the protoconch of the same specimen as in C1 (C2, C3). The protoconch is terminated by a slightly thickened rim. Detailed view of the embryonic shell of the same protoconch as in C3 (C4). The embryonic shell is well separated from the larval shell by a marked incision and a subsequent thickened rim. D. Mohrensternia hollabrunnensis sp. nov. Holotype (NHMW 2002z0029/0003) from the Early Sarmatian of Hollabrunn (Molasse Basin, Lower Austria) (D1). Lateral and apical view of the protoconch of the same specimen (D2, D3). E, F. Mohrensternia hydrobioides Hilber, 1897. Specimen (NHMW 2002z0029/0004) from the Early Sarmatian of Waldhof, Styria/Austria (E1). Apical view of the initial whorl of the same specimen (E2). F. Specimen (collection A. Papp, NHMW 2002z0029/0004) from the Early Sarmatian of Siebenhirten (F1). Protoconch of the same specimen in lateral view (F2).

Fig. 11 in Early ontogeny and palaeoecology of the Mid-Miocene rissoid gastropods of the Central Paratethys

Fig. 11. Four species of Mohrensternia Stoliczka, 1868. A. Mohrensternia pseudoangulata politioanei Jekelius, 1944. Specimen (NHMW 2002z0029/ 0009) from the Early Sarmatian of Waldhof, Styria/Austria (A1). Protoconch of the same specimen in lateral view (A2). The onset of the teleoconch is indicated by the formation of weak axial folds, grading into axial ribs. B. Mohrensternia soceni Jekelius, 1944. Specimen (NHMW 2002z0029/0012) from the Early Sarmatian of Hollabrunn (B1). Protoconch of the same specimen as in B1 in lateral view (B2). The onset of the teleoconch is indicated by the formation of axial folds. Detailed apical view of the initial whorl of the same protoconch as in B2 (B3). The embryonic shell is demarcated from the subsequent larval shell by a slightly thickened rim followed by an incision of the shell. C. Mohrensternia pfaffstaettensis sp. nov. Holotype (NHMW 2002z0029/0014) from the Early Sarmatian of Pfaffstätten, Vienna Basin/Lower Austria (C1). Lateral and apical view of the protoconch of the same specimen as in C1 (C2, C3). The protoconch is terminated by a slightly sinuous rim. The onset of the teleoconch is indicated by the formation of strong axial ribs and subordinated spiral threads. Detailed view of the initial whorl of the same protoconch as in C3 (C4). The embryonic shell has a finely granulated spiral sculpture. It is terminated by a slightly sinuous rim. D. Mohrensternia waldhofensis sp. nov. Holotype (NHMW 2002z0029/0004) from the Early Sarmatian of Waldhof, Styria/Austria (D1). Lateral and apical view of the protoconch of the same specimen (D2, D3). The transition to the teleoconch is indicated by a thickened rim which is not projecting.

Fig. 8 in Early ontogeny and palaeoecology of the Mid-Miocene rissoid gastropods of the Central Paratethys

Fig. 8. Two species of Manzonia (Alvinia) Monterosato, 1884 and two of Manzonia (Manzonia) Brusina, 1870. A. Manzonia (Alvinia) miocrassicosta (Sacco, 1895). Specimen (NHMW 2002z0030/0016) from the Badenian of Steinebrunn (A1). Lateral and apical view of the protoconch of the same specimen (A2, A3). The protoconch is terminated by a short sinusigera notch. Detailed view of the initial whorl of the same protoconch as in A3 (A4). The embryonic shell is demarcated from the subsequent larval shell by a well developed thickened rim. B. Manzonia (Alvinia) partschi (Hörnes, 1856). Specimen (NHMW 2002z0030/0017) from the Badenian of Baden/Sooss, Lower Austria (B1). Lateral and apical view of the protoconch of the same specimen as in B1 (B2, B3). The protoconch is terminated by a short, slightly thickened sinusigera notch. Detailed view of the initial whorl of the same protoconch as in B3 (B4). The embryonic shell is strongly sculptured and terminated by a slightly sinuous rim. C. Manzonia (Manzonia) crassa (Kanmacher in J. Adams, 1798), specimen (NHMW 2002z0030/0018) from the Badenian of Niederleis, Lower Austria. D. Manzonia (Manzonia) scalaris (Dubois, 1831). Specimen (NHMW 2002z0030/0019) from the Badenian of Steinebrunn, Lower Austria (D1). Lateral and apical view of the protoconch of the same specimen as in D1 (D2, D3). The protoconch is terminated by a well developed sinusigera notch. Detailed view of the initial whorl of the same protoconch as in D3 (D4). The transition to the larval shell is indicated by a thickened rim.

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Fig. 4 in A new Early Triassic gastropod genus and the recovery of gastropods from the Permian/Triassic extinction

Fig. 4. Werfenella rectecostata redrawn from Neri and Posenato (1985: pl. 3: 7, 8). This relatively large and undeformed steinkern (composite mould from Val Sorda, western Dolomites, Italy) shows the purpurinid shape of Werfenella and its obliquely elongated, subrectangular aperture. The axial ornament is visible while the nodular ornament at the carinations is obscured.

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Fig. 2 in A new Early Triassic gastropod genus and the recovery of gastropods from the Permian/Triassic extinction

Fig. 2. Limestone slab with several specimens of Werfenella rectecostata; Werfen Formation, Cencenighe Member, Bad Radein/Redgano, Italian Dolomites, Weisshorn (MHI 1819). The specimens show unusually wellpreserved shells with a pronounced nodular ornament at the carinations which cannot be seen in the steinkern−preservation which is usual for gastropods from the Werfen Formation.