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Fig. 1 in Regional Fish-Based Biostratigraphy Of The Late Neogene And Pleistocene Of Southeastern Europe

Fig. 1. Localities with fossil remains of freshwater fishes dated back to late Miocene, Pliocene and Pleistocene age (indicated by black circles) at the territory of southeastern Europe.

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Data from: Network-based biostratigraphy for the late Permian to mid-Triassic Beaufort Group (Karoo Supergroup) in South Africa enhances biozone applicability and stratigraphic correlation

The Permo-Triassic vertebrate assemblage zones (AZs) of South Africa's Karoo Basin are a standard for local and global correlations. However, temporal, geographical, and methodological limitations challenge the AZs reliability. We analyze a unique fossil dataset comprising 1408 occurrences of 115 species grouped into 19 stratigraphic bin intervals from the Cistecephalus, Daptocephalus, Lystrosaurus declivis, and Cynognathus AZs. Using network science tools we compare six frameworks: Broom, Rubidge, Viglietti, Member, Formation, including a framework suggesting diachroneity of the Daptocephalus/Lystrosaurus AZ boundary (Gastaldo). Our results demonstrate that historical frameworks (Broom, Rubidge) still identify the Karoo AZs. No scheme supports the Cistecephalus AZ, and it likely comprises two discrete communities. The Lystrosaurus declivis AZ is traced across all frameworks, despite many shared species with the underlying Daptocephalus AZ, suggesting the extinction event across this interval is not a statistical artifact. A community shift at the upper Katberg to lower Burgersdorp formations may indicate a depositional hiatus, which has important implications for regional correlations and Mesozoic ecosystem evolution. The Gastaldo model still identifies a Lystrosaurus and Daptocephalus AZ community shift, does not significantly improve recent AZ models (Viglietti), and highlights important issues with some AZ studies. Localized bed-scale lithostratigraphy (sandstone datums), and singleton fossils cannot be used to reject the patterns shown by hundreds of fossils, and regional chronostratigraphic markers of the Karoo foreland basin. Meter-level occurrence data suggest that 20–50 m sampling intervals capture Karoo AZs, unifying the use of meter-level placements of singleton fossils to delineate biozone boundaries and make regional correlations.

opencc-zeroSep 2022View details →

Fig. 7 in A new Late Ordovician bubble-headed trilobite species from South West Wales and its implications for biostratigraphy

Fig. 7. Chart showing the frequency distribution of numbers of denticles on lateral margins of complete librigenae of Staurocephalus oliveae sp. nov. from the upper Katian (Upper Ordovician) Sholeshook Limestone Formation at Talfan Farm, Llanddowror, Carmarthenshire, Wales, UK. n = 36.

Fig. 3 in A new Late Ordovician bubble-headed trilobite species from South West Wales and its implications for biostratigraphy

Fig. 3. Encrinurid trilobite Staurocephalus oliveae sp. nov. from the upper Katian (Upper Ordovician) Sholeshook Limestone Formation at Talfan Farm, Llanddowror, Carmarthenshire, Wales, UK. A. Holotype, NMW 2013.11G.1, cephalon in dorsal (A1), oblique anterolateral (A2), and frontal (A3) views. B. Paratype, NMW 2013.11G.2, cephalon in dorsal (B1), oblique anterolateral (B2), and dorsolateral (B3) views. C. Paratype, NMW 2013.11G.6, cranidium in dorsal view. D. Paratype, NMW 2013.11G.7, partial cranidium, dorsal view of internal mould (D1), ventral view of external mould (D2), and latex cast of external mould (D3). E. Paratype, NMW 2013.11G.8, cephalon, external mould in ventral view (E1) and latex cast of external mould (E2). F. Paratype, NMW 2013.11G.9, genal angle of cranidium, showing marginal denticles decreasing in size posteriorly. Scale bars 2 mm, except F 1 mm.

Fig. 6 in A new Late Ordovician bubble-headed trilobite species from South West Wales and its implications for biostratigraphy

Fig. 6. Historic specimens of the encrinurid trilobite Staurocephalus from museum collections. A. SM A31592, cranidium in dorsal view labelled Staurocephalus cf. murchisoni Barrande" from the Sholeshook Limestone Formation (upper Katian, Upper Ordovician) in the Sholeshook railway cutting, Haverfordwest area, herein assigned to S. oliveae sp. nov.? B. BIRUG 48862, cranidium in dorsal view labelled "Staurocephalus cf. murchisoni" from the lower Tre-wylan Beds (Cautleyan) (upper Katian, Upper Ordovician) in the Llansantffraid-ym-Mechain district of the south-eastern Berwyn Hills, Mid Wales (Whittington 1938: 451, locality 42), herein assigned to S. oliveae sp. nov.? C, D. Specimens from the King collection, Sedgwick Museum, from the (locally) basal Ashgill mudstones (lower Rawtheyan, Ashgill Zone 5) (upper Katian, Upper Ordovician) of Aber Marchnant, Berwyn Hills, Mid Wales, originally identified as Staurocephalus cf. murchisoni by King (1923) and assigned to S. clavifrons by Whittington (1968), herein assigned to S. aff. oliveae. C. SM A39813, incomplete cranidium in dorsal view. D. SM A39814.A, incomplete cranidium in dorsal view (D1) and close up of left genal area (D2) to show large lateral denticles (arrowed). E. SM A31589, dorsal view of incomplete cranidium labelled "Staurocephalus globiceps" from the Marr collection, Sedgwick Museum, from the Slade and Redhill Mudstone Formation at Pelcomb Cross, Haverfordwest, herein assigned to S. cf. clavifrons. Note the prominent genal spine on the right side. Scale bars 1 mm, except D2 0.5 mm.

Fig. 2 in A new Late Ordovician bubble-headed trilobite species from South West Wales and its implications for biostratigraphy

Fig. 2. Stratigraphical column showing the age of the Sholeshook Limestone Formation (in blue) and the underlying and overlying formations together with the shelly and chitinozoan biozonations of the Anglo-Welsh succession. Asterisk shows approximate age of the Talfan Farm locality, in the lower part of the formation (equivalent to Cautleyan Zone 1).

Fig. 5 in A new Late Ordovician bubble-headed trilobite species from South West Wales and its implications for biostratigraphy

Fig. 5. Reconstruction drawings of the encrinurid trilobite Staurocephalus oliveae sp. nov. A. Cephalon, in anterior (A1), left lateral (A2), ventral (A3), and dorsal (A4) views. B. Pygidium, in ventral (B1) and dorsal (B2) views. Cephalon has a mean maximum width (tr.) of 10.15 mm; pygidium has a mean maximum width (tr.) of 3.96 mm.

Fig. 4 in A new Late Ordovician bubble-headed trilobite species from South West Wales and its implications for biostratigraphy

Fig. 4. Encrinurid trilobite Staurocephalus oliveae sp. nov. from the upper Katian (Upper Ordovician) Sholeshook Limestone Formation at Talfan Farm, Llanddowror, Carmarthenshire, Wales, UK. A. Paratype, NMW 2013.11G.5, rostral plate in ventral view. B. Paratype, NMW 2013.11G.3, right librigena in lateral view. C. Paratype, NMW 2013.11G.10, left librigena in lateral view. D. Paratype, NMW 2013.11G.12, right librigena in lateral view. E. Paratype, NMW 2013.11G.13, thoracic segment in dorsal view. F. Paratype, NMW 2013.11G.4, pygidium in dorsal view. G. Paratype, NMW 2013.11G.11, pygidium in dorsal view. H. Paratype, NMW 2013.11G.15, pygidium in ventral view of external mould (H1) and latex cast of external mould (H2). Scale bars 2 mm.

Fig. 8 in A new Late Ordovician bubble-headed trilobite species from South West Wales and its implications for biostratigraphy

Fig. 8. Graph showing the number of lateral denticles on librigenae of various Staurocephalus species through time. Circle represents the mean, vertical lines the range where one was observed in that species. Chatterton and Campbell (1980) described S. struszi as having "twelve (possibly eleven on some specimens)" denticles. Species names in black font represent occurrences in England and Wales, those in red font occur outside Avalonia. Note that Cautleyan and Rawtheyan are regional stages from the AngloWelsh chronostratigraphy and belong in the upper part of the international Katian Stage. The remaining stages are international. The Telychian is approximately twice the length of the other stages (e.g., Ogg et al. 2008: fig. 1.1), hence the wider spacing allocated to it.

Fig. 8 in Camenellan tommotiids from the Cambrian Series 2 of East Antarctica: Biostratigraphy, palaeobiogeography, and systematics

Fig. 8. The camenellan tommotiid Dailyatia sp. 1 A sclerites and fragments from the Cambrian Series 2, Stages 3, 4, Shackleton Limestone, Holyoake Range, Transantarctic Mountains, East Antarctica. A. A sclerite, NRM X10006, apical (A1), anterior (A2), oblique posterior (A3), and posterior (A4) views, magnification of radial plicae on the lateral field (A5), magnification of single plica showing the densely stacked growth series of the radial plicae (A6). B. Fragment of A sclerite anterior field, NRM X10007, general view (B1), oblique view showing cross section of plicae (B2). C. Fragment of A sclerite anterior field, NRM X10008, top of specimen (C1), general view (C2), detail showing plicae (C3). D. Fragment of A sclerite with partial lateral and anterior field, NRM X10009. E. Fragment of sclerite lateral field, NRM X10010. F. Fragment of A sclerite lateral field, NRM X10011. G. Fragment of unknown sclerite type, with chaotically distributed plicae, NRM X10012, general view (G1), detail (G2). Scale bars 200 µm.

Fig. 11. The tommotiid Shetlandia multiplicata Wrona, 2004, unknown type sclerite fragments from the Cambrian Series 2, Stages 3, 4 in Camenellan tommotiids from the Cambrian Series 2 of East Antarctica: Biostratigraphy, palaeobiogeography, and systematics

Fig. 11. The tommotiid Shetlandia multiplicata Wrona, 2004, unknown type sclerite fragments from the Cambrian Series 2, Stages 3, 4, Shackleton Limestone, Holyoake Range, Transantarctic Mountains, East Antarctica. A. NRM X10020, general view (A1), detail showing arched growth series (A2). B. NRM X10021, general view (B1), detail of broken margin (B2). C. NRM X10022, general view (C1), detail of comarginal ribs and broken edge (C2). D. NRM X10023. E. NRM X10024. Scale bars 200 µm, except B2, 100 µm. A–C taken with backscattered electron detector.

Fig. 5 in Camenellan tommotiids from the Cambrian Series 2 of East Antarctica: Biostratigraphy, palaeobiogeography, and systematics

Fig. 5. The camenellan tommotiid Dailyatia icari sp. nov. C1 sclerites and sclerite fragments from the lower Cambrian Schneider Hills limestone, Schneider Hills, Argentina Range, East Antarctica. A. Dextral sclerite, KUMIP 585059, apical view (A1), view of dorsal (A2) and ventral (A3) surfaces, view of distal (A4) and proximal (A5) edges. B. Sinistral sclerite, KUMIP 585060, apical view (B1), oblique view of proximal edge and dorsal surface (B2), oblique view of distal edge and ventral surface (B3), view of distal edge (B4). C. Dextral sclerite, KUMIP 585061, dorsal (C1), apical (C2), and oblique dextral (C3) views. D. Dextral sclerite, KUMIP 585062, apical (D1), apical-dorsal (D2), ventral (D3), and lateral (D4) views. E. Large fragment from unknown sclerite type, KUMIP 585063. F. Sclerite of unknown chirality, KUMIP 585064, apical (F1) and lateral (F2) views. G. Sclerite fragment from unknown sclerite type, KUMIP 585065, detail showing distinctive pseudoplicae (G1), general view (G2). H. Sclerite of unknown chirality, KUMIP 585066, detail of apertural margin (H1), oblique views of the aperture (H2, H3). I. Fragment of unknown sclerite type showing pseudoplicae, KUMIP 585067. Scale bars 200 µm.

Fig. 2 in Camenellan tommotiids from the Cambrian Series 2 of East Antarctica: Biostratigraphy, palaeobiogeography, and systematics

Fig. 2. Stratigraphic columns of the sampled sections in the Holyoake Range (HRA) and Churchill Mountains (CM2). Grain size: B, boundstone; G, grainstone; M, mudstone; P, packstone; W, wackestone.

Fig. 1. A in Camenellan tommotiids from the Cambrian Series 2 of East Antarctica: Biostratigraphy, palaeobiogeography, and systematics

Fig. 1. A. Topographic map of the Central Transantarctic Mountains (adapted from the USGS 2008) with the main geographic features and the sites visited by the Kansas University expeditions (study areas marked by section names GM, 87-L2, M, H, S). The locality GM is the type locality for Dailyatia braddocki, which is close to the location of the CM2 section. The locality M is the type locality of Dailyatia odyssei). B. The area of the Churchill Mountains visited by the Swedish-Australian expedition, showing the location of the CM2 section. C. The area of the Holyoake Range visited by the Swedish-Australian expedition, showing the location of the HRA section. D. Overview of Antarctica showing the extent of the Transantarctic Mountains, including the the location of the Argentina Range, and IC (location on sections unknown) in the Schneider Hills (sampled by the Kansas Expeditions).

Fig. 10. The tommotiid Kennardiidae indet. from the Cambrian Series 2, Stages 3, 4 in Camenellan tommotiids from the Cambrian Series 2 of East Antarctica: Biostratigraphy, palaeobiogeography, and systematics

Fig. 10. The tommotiid Kennardiidae indet. from the Cambrian Series 2, Stages 3, 4, Shackleton Limestone, Holyoake Range, Transantarctic Mountains, East Antarctica. A. Symmetrical first sclerite type, KUMIP 585077, apical view (A1), oblique view of posterior field (A2), lateral field (A3). B. Third sclerite type, KUMIP 585078, apical (B1) and lateral (B2) views. C. Third sclerite type, KUMIP 585079, apical view (C1), ventral side (C2), dorsal side (C3). D. Third sclerite type, KUMIP 585080, ventral side (D1), apical view (D2). E. Third sclerite type, KUMIP 233002, apical view (E1), detail of dorsal side (E2), detail of ventral side (E3), ventral side (E4). F. Third type of sclerite, KUMIP 585081, ventral side (F1), detail showing plicae on ventral surface (F2), distal edge (F3). G. Second type of sclerite, KUMIP 585082, apical view (G1), oblique view of posterior field (G2), lateral field (G3). H. Third type of sclerite, KUMIP 585083, posterior side (H1), distal edge (H2), apical view (H3). I. Third type of sclerite, KUMIP 585084, ventral side (I1), detail showing plicae on the ventral surface (I2). Scale bars 200 µm, except E2, E3, I2, 100 µm.

Fig. 7. The camenellan tommotiids from from the Cambrian Series 2, Stages 3, 4 in Camenellan tommotiids from the Cambrian Series 2 of East Antarctica: Biostratigraphy, palaeobiogeography, and systematics

Fig. 7. The camenellan tommotiids from from the Cambrian Series 2, Stages 3, 4, Shackleton Limestone, Transantarctic Mountains, East Antarctica. Dailyatia braddocki Evans and Rowell, 1990, Churchill Mountains (A, B), Dailyatia decobruta Betts in Betts et al., 2019, Holyoake Range (C–F), and Dailyatia cf. odyssei, Holyoake Range (G–I). A. C sclerite, NRM X10001, ventral view (A1), detail showing fold in the margin of the ventral field (A2). B. Sclerite of unknown chirality, NRM X10002, dorsal view (B1), detail showing apex (B2). C. Dextral C sclerite, KUMIP 585071, details showing micro-ornament on the anterior-lateral (C1) and the posterior (C3) fields, apical view (C2). D. Dextral C sclerite, KUMIP 585072, apical view (D1), view of proximal edge and dorsal field (D2). E. Sclerite of unknown chirality, KUMIP 585073, oblique view of ventral field (E1), view of apical area showing perforated apex (E2). F. Sclerite of unknown chirality, KUMIP 585074, dorsal (F1) and oblique apical (F2) views. G. Dextral C sclerite, NRM X10003, view of broken dorsal field (G1), detail showing fine growth series (G2), apex (G3), oblique basal view showing plicae at distal edge (G4). H. Sinistral C sclerite, NRM X10004, apical view (H1), oblique view of distal edge and part of ventral field (H2). I. Unknown sclerite type, NRM X10005, ventral view (I1), detail showing fine growth series (I2). Scale bars 200 µm, except E2, 50 µm.

Fig. 4 in Camenellan tommotiids from the Cambrian Series 2 of East Antarctica: Biostratigraphy, palaeobiogeography, and systematics

Fig. 4. The camenellan tommotiid Dailyatia icari sp. nov. A sclerites from the lower Cambrian Schneider Hills limestone, Schneider Hills, Argentina Range, Antarctica. A. KUMIP 585054, view of anterior field (A1), enlarged view of the anterior apical area (A2), oblique view of the lateral field (A3), apical view with anterior to the top (A4). B. KUMIP 585055, anterior field of broken sclerite. C. KUMIP 585056 anterior field of broken sclerite. D. KUMIP 585057, view of anterior field (D1), apical view with anterior to the top (D2), lateral view (D3). E. KUMIP 585058, view of anterior field (E1), apical view with anterior to the top (E2). Scale bars 200 µm.

Fig. 3 in Camenellan tommotiids from the Cambrian Series 2 of East Antarctica: Biostratigraphy, palaeobiogeography, and systematics

Fig. 3. Palaeobiogeographic maps of the distribution of Dailyatia and other camenellan tommotiids from East Gondwana (dark grey). New occurrences described in this paper in bold. Maps show the Cambrian (A) Terreneuvian Series to basal Series 2, Stage 3 (i.e., upper range of the Micrina etheridgei Zone for South Australia, Betts et al. 2016, 2017) and (B) Series 2 (from the base of the Dailyatia odyssei Zone for South Australia, Betts et al. 2016, 2017). Data for previous occurrences: 1 Laurie 1986; 2 Skovsted et al. 2015; 3 Betts et al. 2016; 4 Betts et al. 2017; 5 Betts et al. 2019; 6 Evans and Rowell 1990; 7 Wrona 2004. Abbreviations: CTM, Central Transantarctic Mountains; KGI, King George Island; AR, Argentina Range. Map adapted from Torsvik and Cocks (2013) and Yang et al. (2015).

Fig. 9. The camenellan tommotiid from the Cambrian Series 2, Stages 3, 4 in Camenellan tommotiids from the Cambrian Series 2 of East Antarctica: Biostratigraphy, palaeobiogeography, and systematics

Fig. 9. The camenellan tommotiid from the Cambrian Series 2, Stages 3, 4, Shackleton Limestone, Transantarctic Mountains, East Antarctica. Dailyatia sp. 1, C sclerites and indeterminate fragments, Holyoake Range and Churchill Mountains (A–G) and Dailyatia braddocki Evans and Rowell, 1990, Churchill Mountains (H, I). A. Dextral C sclerite, NRM X10013, apical view (A1), dorsal field (A2), proximal edge (A4), distal edge (A3), ventral field ( A5), detail showing broken apex (A6). B. Dextral C sclerite, NRM X10014, oblique view of distal edge and dorsal field (B1), oblique view of proximal edge and ventral field (B2), and apical view (B3). C. Sinistral C sclerite, NRM X10015, apical view (C1), oblique view of proximal edge and dorsal →

Fig. 6 in Camenellan tommotiids from the Cambrian Series 2 of East Antarctica: Biostratigraphy, palaeobiogeography, and systematics

Fig. 6. The camenellan tommotiid Dailyatia icari sp. nov. C2 sclerites from the lower Cambrian Schneider Hills limestone, Schneider Hills, Argentina Range, East Antarctica. A. KUMIP 585068, apical (A1), oblique lateral (A2), ventral (A3), lateral (A4), and dorsal (A5) views, detail of pustulose ornament on the central surface of A1 (A6). B. KUMIP 585069, apical (B1), lateral (B2), and ventral (B3) views. C. KUMIP 585070, apical (C1), lateral-dorsal (C2), ventral (C3), lateral (C4), and dorsal (C5) views. Scale bars 200 µm, except A6, 100 µm.