Microfossils from the late Mesoproterozoic – early Neoproterozoic Atar/El Mreïti Group, Taoudeni Basin, Mauritania, northwestern Africa

“This range of d(13)Ccarb values differs from the positive values (d(13)Ccarb > +5‰) recorded in post-850 Ma Neoproterozoic (Kaufman and Knoll, 1995; Knoll, 2000; Halverson et al., 2005, 2010; Macdonald et al., 2010) and in early Neoproterozoic strata (Knoll et al.”

“These species are considered as unambiguous eukaryotes because they combine two or more of the following characters unknown in extant prokaryotes (Javaux et al., 2003, 2004; Knoll et al, 2006a, 2006b).”

“Strontium isotope compositions from geographically distant locations within the Taoudeni Basin range from 0.70773 to 0.70814 and support the early Ediacaran age of the Jbéliat barite-bearing cap dolostones overlying the Jbéliat Group tillite (Shields et al., 2007; Halverson et al., 2007, 2010).”

“…(Pang et al., 2015) and in the 1.65 Ga Mallapunyah Formation, Australia (Javaux et al., 2004), and more complex opening structure at the end of a neck-like process (e.g. Tappania plana) were found in the Roper Group at around 1.5– 1.4 Ga (Javaux et al., 2001, 2003, 2004; Javaux and Knoll, 2016).”

“The morphological features observed in the Taoudeni microfossils interpreted as unambiguous eukaryotes have been reported previously in other contemporaneous assemblages and their significance as evidence for biological innovations discussed in details (e.g. Butterfield, 2004; Butterfield, 2015; Javaux et al., 2003; J…”

“These species are considered as unambiguous eukaryotes because they combine two or more of the following characters unknown in extant prokaryotes (Javaux et al., 2003, 2004; Knoll et al, 2006a, 2006b).”

“However, other palaeogeographic reconstructions of Rodinia are possible (e.g. Evans, 2013; Johansson, 2014).”

“Additional criteria, untested here, may also include a complex wall ultrastructure and a wall chemistry unique to extant eukaryotes: protists (Javaux et al., 2003, 2004; Marshall et al., 2005).”

“…Western Africa (abundant in the En Nesoar Fm., El Mreïti Group, Mauritania, this study); in tidal flats or lagoonal settings (Draken conglomerate, Knoll et al., 1991a, 1991b); in shallow-water to intertidal settings in Canada (the Franklin Mountains, level G-52, Samuelsson and Butterfield,…”

“The morphological features observed in the Taoudeni microfossils interpreted as unambiguous eukaryotes have been reported previously in other contemporaneous assemblages and their significance as evidence for biological innovations discussed in details (e.g. Butterfield, 2004; Butterfield, 2015; Javaux et al., 2003; J…”

“, 2001), in the Bylot Supergroup and Dismal Lake Group, Arctic Canada (Kah et al., 1999; Frank et al., 2003), the Anabar Massif, northwestern Siberia (Knoll et al.”

“This range of d13Ccarb values differs from the positive values (d13Ccarb > +5‰) recorded in post-850 Ma Neoproterozoic (Kaufman and Knoll, 1995; Knoll, 2000; Halverson et al., 2005, 2010; Macdonald et al., 2010) and in early Neoproterozoic strata (Knoll et al., 1995; Bartley et al., 2001), but are…”

“…174 unambiguous specimens of T. aimika have been identified with confidence in the En Nesoar Formation and are thus constrained by Re/Os datings (Rooney et al., 2010) on black shales in the S2 core between the 1107 ± 12 Ma overlying Touirist Formation (139.45–143.82 m depth) and the 1109 ± 22…”

“The sedimentary basin (Liulaobei Formation) in the Huainan region, China, may be related to rifting and drifting phases during Rodinia breakup in the early Neoproterozoic (Tang et al., 2013).”

“Additional criteria, untested here, may also include a complex wall ultrastructure and a wall chemistry unique to extant eukaryotes: protists (Javaux et al., 2003, 2004; Marshall et al., 2005).”

“25 Ga (Bartley et al., 2001), in the Bylot Supergroup and Dismal Lake Group, Arctic Canada (Kah et al.”

“However, other palaeogeographic reconstructions of Rodinia are possible (e.g. Evans, 2013; Johansson, 2014).”

“In total, four Megasequences or Supergroups bound by cratonscale unconformities are recognized (Trompette, 1973; Trompette and Carozzi, 1994; Deynoux et al., 2006).”

“Vidal (1976) reported spheroidal vesicles from the 840–800 Ma Visingsö Group, and Vidal and Ford (1985), from the 780–740 Ma Chuar Group (Trachysphaeridium laufeldi and Leiosphaeridia sp. A., respectively), showing an operculated excystment opening, with conical processes, or tightly arranged…”

“Additional criteria, untested here, may also include a complex wall ultrastructure and a wall chemistry unique to extant eukaryotes: protists (Javaux et al., 2003, 2004; Marshall et al., 2005).”

“…a sp p. d d d Tr ac hy hy st ri ch os ph ae ra ai m ik a d d d d d Tr ac hy hy st ri ch os ph ae ra bo tu la V al er ia lo ph os tr ia ta d d d V id al op pa la sp . the 1000–811 Ma, but poorly constrained, Liulaobei Formation, Huainan region, North China (Tang et al., 2013; Xiao et al., 2014).”

“…in mid to late Mesoproterozoic strata after 1.25 Ga (Bartley et al., 2001), in the Bylot Supergroup and Dismal Lake Group, Arctic Canada (Kah et al., 1999; Frank et al., 2003), the Anabar Massif, northwestern Siberia (Knoll et al., 1995), and the southern Urals, Russia (Bartley et al., 2007).”

“Also similarly to recent suggestions for Tappania (Javaux and Knoll, 2016), Trachyhystrichosphaera also could also be osmotrophic, using its processes to increase the surface area for absorption.”

“The earliest record of excystment structures show vesicle opening by medial split in Palaeoproterozoic leiospheres (Zhang 1986; Lamb et al., 2009) but their eukaryotic or prokaryotic affinities is ambiguous because of similar openings in a few large pleurocapsalean cyanobacteria envelopes…”

“Relatively new Re-Os geochronologic dating (Rooney et al., 2010) and chemostratigraphy (Fairchild et al., 1990; Teal and Kah, 2005; Kah et al., 2009, 2012) suggest a late Mesoproterozoic ( 1.2–1.1 Ga) age for the stratigraphically lower deposits of the Atar/El Mreïti Group in the Taoudeni Basin…”

“A small assemblage of smooth-walled acritarchs, colonies of small vesicles, and simple filamentous microfossils was previously reported in early studies conducted on outcrop and subsurface samples in the Adrar region on the northwestern part of the basin (Ivanovskaya et al., 1980; Amard, 1986; Lottaroli et al., 2009;…”

“The glacial deposits of the Jbéliat Group unconformably overlying the Assabet el Hassiane/Cheikhia Group are interpreted as late Cryogenian or Marinoan correlative based on lithology and chemostratigraphy on d13Ccarb and d18Ocarb from cap carbonates or dolostones (Álvaro et al., 2007; Shields et al., 2007) and 87Sr/86…”

“Liu et al. (2014) reported the presence of Osculosphaera hyalina, a species of psilate spheroidal vesicle showing an oral collar projecting outward around a well-defined circular opening (osculum), in the 636.4 ± 4.9 to 551.1 ± 0.7 Ma Doushantuo Formation, China.”

“The age of the Atar/El Mreïti Group was first poorly constrained by Rb-Sr geochronology (Clauer, 1976, 1981; Clauer et al., 1982) performed on glauconite and illite in shaley intervals (Fig.”

“The sedimentary basin (Liulaobei Formation) in the Huainan region, China, may be related to rifting and drifting phases during Rodinia breakup in the early Neoproterozoic (Tang et al., 2013).”

“aggregated in pairs, tetrads or octads, nor in close contact but clearly isolated (Vorob’eva et al., 2009; Vorob’eva et al., 2015).”

“the 1000–811 Ma, but poorly constrained, Liulaobei Formation, Huainan region, North China (Tang et al., 2013; Xiao et al., 2014).”

“The sedimentary basin (Liulaobei Formation) in the Huainan region, China, may be related to rifting and drifting phases during Rodinia breakup in the early Neoproterozoic (Tang et al., 2013).”

“…C. contexta (Pl. 2e) has indistinct rows of cells and cell diameter 5 lm wide, C. kanshiensis (Pl. 2f) has 2– 3 distinct rows of cells, 10–15 lm in diameter, and C. zairensis (Pl. 2g) has 2-4 distinct rows of cells 8-10 mm in diameter (revision in Hofmann and Jackson, 1994; Baludikay et al., 2016).”

“…(Lahondère et al., 2003; Kah et al., 2012), geochronology (Clauer, 1976, 1981; Clauer et al., 1982; Clauer and Deynoux, 1987; Rooney et al., 2010), chemostratigraphy (Kah et al., 2012; Gilleaudeau and Kah, 2013a), and palaeoredox conditions (Gilleaudeau and Kah, 2013b; Gilleaudeau and Kah, 2015).”

“T. aimika is also reported in the 1025 ± 40 Ma Lakhanda Group, Uchur-Maja region, southeastern Siberia, Russia (Timofeev et al., 1976; Hermann, 1990; Jankauskas et al., 1989; Semikhatov et al., 2015 for datings); the 1000–800 Ma Mirojedikha Formation, Siberia and Urals, Russia (Hermann, 1990; Veis et al., 1998); the N…”

“The Proterozoic and Phanerozoic strata unconformably overlie an Archean-Palaeoproterozoic basement (Lahondère et al., 2003; Rooney et al., 2010; Kah et al., 2012; Gilleaudeau and Kah, 2013a, 2013b, 2015).”

“, 2014 for datings) in China (Yin et al., 2005) in addition to Spiromorpha sp.”

“…in the 1025 ± 40 Ma Lakhanda Group, Uchur-Maja region, southeastern Siberia, Russia (Timofeev et al., 1976; Hermann, 1990; Jankauskas et al., 1989; Semikhatov et al., 2015 for datings); the 1000–800 Ma Mirojedikha Formation, Siberia and Urals, Russia (Hermann, 1990; Veis et al., 1998); the…”

“Peat et al. (1978) reported possible circular excystment structures in specimens from the McMinn Formation, 1.5–1.4 Ga Roper Group in northern Australia but this was not observed by Javaux and Knoll (2016) and a taphonomic origin has been suggested instead (Schopf and Klein, 1992).”

“A specimen of Synsphaeridium (Pl. 3r) could be alternatively identified as Squamosphaera colonialica (Tang et al., 2015; Porter and Riedman, 2016), but the diagnostic feature of domical protrusions freely communicating with the single vesicle interior is not clearly obvious under the light…”

“Arctacellularia tetragonala (recently other species of this genus have been synonymized to the type species; Baludikay et al., 2016) and Spiromorpha segmentata might also have a biostratigraphic potential.”

“…common in Proterozoic successions, besides the ubiquist Leiosphaeridia spp. and Siphonophycus spp. Based on summaries in Jankauskas et al. (1989), Sergeev and Schopf (2010) and a review of the contemporaneous assemblages, Baludikay et al. (2016) proposed an assemblage characteristic of the…”

“…assemblage from the 1.1 Ga Atar/El Mreïti Group, in the Palaeopro terozoic/Mesoproterozoic Ruyang Group (1750–1400 Ma, see Lan et al., 2014 and Hu et al., 2014 for datings) in China (Yin et al., 2005) in addition to Spiromorpha sp. (Pang et al., 2015), possibly in the Yurubchen (1499 ± 43 to…”

“It is reported as such in the 1092 ± 59 Ma Bylot Supergroup, Baffin Island, Canada (Hofmann and Jackson, 1994); in the Sarda ( 1.35–1.25 Ga) and Avadh (ca 1.2–1.15 Ga) formations, Bahraich Group, Ganga Supergroup, of the Ganga Basin, in India (Prasad and Asher, 2001); in the 1.1 Ga Atar/El Mreïti Group, Mauritania (th…”

“…the 1.75–1.4 Ga Ruyang Group, China, although some of these could be ripping structures rather than true pylome structures, but were confirmed by Agić et al. (2015) who reported medial split or occasionally pylome for Dictyosphaera macroreticulata, and excystment by medial split or partial…”

“A in Nagy et al., 2009) but this species has an ornamented operculum.”

“, 2001), in the Bylot Supergroup and Dismal Lake Group, Arctic Canada (Kah et al., 1999; Frank et al., 2003), the Anabar Massif, northwestern Siberia (Knoll et al.”

“This species was first described in the 820 Ma ( 811.5–788 Ma) Svanbergfjellet Formation (Butterfield et al., 1994), and also reported in the 850–750 Ma Wynniatt Formation with other unnamed species with circular openings (Butterfield and Rainbird, 1998), the 1025 ± 40 Ma Lakhanda Group and coeval strata (see Nagovits…”

“The earliest record of excystment structures show vesicle opening by medial split in Palaeoproterozoic leiospheres (Zhang 1986; Lamb et al., 2009) but their eukaryotic or prokaryotic affinities is ambiguous because of similar openings in a few large pleurocapsalean cyanobacteria envelopes…”

“Peat et al. (1978) reported possible circular excystment structures in specimens from the McMinn Formation, 1.5–1.4 Ga Roper Group in northern Australia but this was not observed by Javaux and Knoll (2016) and a taphonomic origin has been suggested instead (Schopf and Klein, 1992).”

“3r) could be alternatively identified as Squamosphaera colonialica (Tang et al., 2015; Porter and Riedman, 2016), but the diagnostic feature of domical protrusions freely communicating with the single vesicle interior is not clearly obvious under the light microscope for this single translucent light-yellow specimen.”

“aggregated in pairs, tetrads or octads, nor in close contact but clearly isolated (Vorob’eva et al., 2009; Vorob’eva et al., 2015).”

“…(Lahondère et al., 2003; Kah et al., 2012), geochronology (Clauer, 1976, 1981; Clauer et al., 1982; Clauer and Deynoux, 1987; Rooney et al., 2010), chemostratigraphy (Kah et al., 2012; Gilleaudeau and Kah, 2013a), and palaeoredox conditions (Gilleaudeau and Kah, 2013b; Gilleaudeau and Kah, 2015).”

“…occurring in the present assemblage from the 1.1 Ga Atar/El Mreïti Group, in the Palaeopro terozoic/Mesoproterozoic Ruyang Group (1750–1400 Ma, see Lan et al., 2014 and Hu et al., 2014 for datings) in China (Yin et al., 2005) in addition to Spiromorpha sp. (Pang et al., 2015), possibly in the…”

“1 and 2) deposited in a shallow marine environment (craton-wide flooding of epeiric/pericratonic sea; Trompette, 1973; Trompette and Carozzi 1994; Bertrand-Sarfati and Moussine-Pouchkine, 1985, 1999; Kah et al., 2012; Gilleaudeau and Kah, 2013a, 2013b).”

“The age of the Atar/El Mreïti Group was first poorly constrained by Rb-Sr geochronology (Clauer, 1976, 1981; Clauer et al., 1982) performed on glauconite and illite in shaley intervals (Fig.”

“…et al., 1994): S. thulenema: 0.5 lm; S. septatum:1–2 lm; S. robustum: 2–4 lm; S. typicum: 4–8 lm; S. kestron: 8–16 lm; and S. solidum: 16–32 lm; and two additional larger species including S. punctatum (Maithy, 1975): 32–64 lm and S. gigas (Tang et al., 2013): 64–128 lm (Table 1, Pl. 3f–n).”

“1 and 2; Trompette and Carozzi, 1994; Moussine-Pouchkine and Bertrand-Sarfati, 1997; Kah et al., 2012).”

“The Taoudeni Basin is known to preserve remarkable stromatolites (Conophyton-Jacutophyton and Baicalia associations) in Mauritania, which were extensively studied by Bertrand-Sarfati (1972) and Bertrand-Sarfati and Moussine-Pouchkine (1985, 1988).”

“Excystment structures are biologically programmed cyst openings (see discussion in Javaux et al., 2003; Moczydłowska, 2010).”

“However, T. aimika is not reported in the contemporaneous (1092 ± 59 Ma) Bylot Supergroup of Canada (Hofmann and Jackson, 1994; age in Turner and Kamber, 2012) but occurs elsewhere in younger (Tonian) Wynniatt Fm., Victoria Island, NWT Canada (Butterfield and Rainbird, 1998), nor in the Tonian of…”

“Peat et al. (1978) reported possible circular excystment structures in specimens from the McMinn Formation, 1.5–1.4 Ga Roper Group in northern Australia but this was not observed by Javaux and Knoll (2016) and a taphonomic origin has been suggested instead (Schopf and Klein, 1992).”

“Relatively new Re-Os geochronologic dating (Rooney et al., 2010) and chemostratigraphy (Fairchild et al., 1990; Teal and Kah, 2005; Kah et al., 2009, 2012) suggest a late Mesoproterozoic ( 1.2–1.1 Ga) age for the stratigraphically lower deposits of the Atar/El Mreïti Group in the Taoudeni Basin…”

“The glacial deposits of the Jbéliat Group unconformably overlying the Assabet el Hassiane/Cheikhia Group are interpreted as late Cryogenian or Marinoan correlative based on lithology and chemostratigraphy on d13Ccarb and d18Ocarb from cap carbonates or dolostones (Álvaro et al., 2007; Shields et al., 2007) and 87Sr/86…”

“Medial splits are reported through the rock record, and in the Taoudeni Basin also (this study, Pl. 2d and h; Lottaroli et al., 2009).”

“…organic-walled microfossil assemblages seem to be broadly similar worldwide, despite some differences possibly related to redox conditions (e.g. Sergeev et al., 2016), facies preservation, sample preparation, lack of recent detailed taxonomic revision, or sampling bias; but similarities may…”

“Peat et al. (1978) reported possible circular excystment structures in specimens from the McMinn Formation, 1.5–1.4 Ga Roper Group in northern Australia but this was not observed by Javaux and Knoll (2016) and a taphonomic origin has been suggested instead (Schopf and Klein, 1992).”

“…(MbujiMayi Supergroup, DRC, Baludikay et al., 2016); in Spitsbergen (Svanbergfjellet Fm., rich levels in the ‘‘algal dolomite member”, Butterfield et al., 1994); in Canada (Wynniatt Fm., Victoria Island, NWT, Butterfield and Rainbird, 1998; Thomson et al., 2014); and, in China (Tang et al., 2013).”

“Couëffé and Vecoli (2011) reported a putative Trachyhystrichosphaera sp. in the 1.1–1.0 Ga Volta Basin but the available illustration of one specimen is ambiguous and no processes are visible.”

“The 0–300 m thick Char Group – divided into Unit I-1 and Unit I-2 – comprises fluvial sandstones, coastal aeolian deposits and shallow-marine siltstones and shales (Figs. 1 and 2; Benan and Deynoux, 1998; Kah et al., 2012).”

“The glacial deposits of the Jbéliat Group unconformably overlying the Assabet el Hassiane/Cheikhia Group are interpreted as late Cryogenian or Marinoan correlative based on lithology and chemostratigraphy on d13Ccarb and d18Ocarb from cap carbonates or dolostones (Álvaro et al., 2007; Shields et al., 2007) and 87Sr/86…”

“Peat et al. (1978) reported possible circular excystment structures in specimens from the McMinn Formation, 1.5–1.4 Ga Roper Group in northern Australia but this was not observed by Javaux and Knoll (2016) and a taphonomic origin has been suggested instead (Schopf and Klein, 1992).”

“The Taoudeni Basin is known to preserve remarkable stromatolites (Conophyton-Jacutophyton and Baicalia associations) in Mauritania, which were extensively studied by Bertrand-Sarfati (1972) and Bertrand-Sarfati and Moussine-Pouchkine (1985, 1988).”

“A small assemblage of smooth-walled acritarchs, colonies of small vesicles, and simple filamentous microfossils was previously reported in early studies conducted on outcrop and subsurface samples in the Adrar region on the northwestern part of the basin (Ivanovskaya et al., 1980; Amard, 1986; Lottaroli et al., 2009;…”

“925 Ma Podinzer Formation (Jankauskas, 1980; Jankauskas et al., 1989; Stanevich et al., 2012) and are reported here for the first time in the 1.”

“Recent work, using less aggressive separation techniques, hints at higher diversity within individual mid-Proterozoic formations (e.g., Sergeev et al., 2016; Beghin et al., 2017); however, these new findings do not greatly expand the known diversity of pre-Tonian eukaryotes.”

“…studies of microfossil assemblages from the ~1.5 Ga Roper Group (Javaux and Knoll, 2017; Javaux et al., 2001) and from the 1.1 Ga El Mreiti Group (Beghin et al., 2017), where the more diversified assemblages occur in marginal to shallow shelf facies, although one species of possible eukaryote…”

“…1700–800 Ma suggest higher eukaryotic diversity during this earlier interval than previously known (Agić, Moczydłowska, & Yin, 2017; Baludikay, Storme, François, Baudet, & Javaux, 2016; Beghin et al., 2017; Loron, Rainbird, Turner, Greenman, & Javaux, 2019; Miao, Moczydłowska, Zhu, & Zhu, 2019).”

“Although ornamented and process-bearing organic-walled microfossils interpreted as unambiguously eukaryotic are present in El Mreïti Group sediments (58), they do not display evidence of algal affinity.”

“These taxa are indeed globally distributed and morphologically distinctive, but as is typical of Precambrian taxa, they are also rather long-lived: T. aimika ranges from the late Mesoproterozoic through much of the Tonian (Tang et al., 2013; Beghin et al., 2017).”

“These ages are supported by the microfossil assemblage composition suggesting a late Mesoproterozoic–early Neoproterozoic age and evidencing the diversiଏcation of early eukaryotes in Western Africa (Beghin et al., 2017).”

“Previous microfossil studies indicate only a modest Mesoproterozoic eukaryote diversity as gauged from acritarchs (Beghin et al., 2017; Javaux et al., 2004), even from settings interpreted as oxic in the Mesoproterozoic ocean (Sergeev, Knoll, Vorob’eva, & Sergeeva, 2016; Sperling et al., 2014).”

“…e.g. Palaeo-/Mesoproterozoic Tappania, the Germinosphaera phase of the Wynniat Formation ‘Tappania’ (Butterfield 2005; Adam et al. 2017; Javaux & Knoll 2017) and late Meso-/Neoproterozoic Trachyhystrichosphaera and Blastanosphaira (Butterfield et al. 1994; Butterfield 2005; Beghin et al. 2017).”

“Mreïti Group from the Taoudeni Basin, is known to bear exquisitely preserved microbial mats and organic-walled microfossils including unambiguous eukaryotes (Beghin et al., 2017).”

“Interestingly, these taxa also often display these ICIs in other fossil assemblages of the same period such as for example the Atar/Al Mreiti Group (Beghin et al. , 2017); the Shaler Supergroup (Loron et al., 2019), the Liulaobei Formation (Pang et al., 2013);the Lakhanda Fm (German, 1990), also…”

“The grooves present on the vesicle surface of S. segmentata are not septae but a surface sculpture (Beghin et al., 2017).”

“If correct, these specimens are morphologically similar to T. magna (Butterfield et al. 1994; Baludikay et al. 2016; Beghin et al. 2017) although they are relatively larger in diameter.”

“Processes would also help a micro-organism’s resting stage in burial prevention during a sedimentary disturbance, so that it can assess when environmental conditions are favourable again and emerge from the cyst (Belmonte et al. 1997).”

“…date of 1085.57 ± 0.25 Ma (Fairchild et al. 2017) on the underlying Lake Shore Traps in the upper part of the Copper Harbor Formation place the timing of deposition of the Nonesuch Formation to c. 1080 – 1060 Ma, immediately after the expansion of eukaryotic diversity (e.g. Beghin et al. 2017).”

“…biosphere because it saw the appearance and initial radiation of eukaryotic life as indicated by numerous occurrences of eukaryotic microfossils (e.g. Adam et al., 2017; Beghin et al., 2017; Buick & Knoll, 1999; Javaux et al., 2001; Knoll & Nowak, 2017; Pang et al., 2020; Strother et al., 2011).”

“…1.03 Ga Mbuyi-Mayi Supergoup, Democratic Republic of Congo, deposited in an intracontinental basin [191] and 1.1 Ga El Mreiti Group, Mauritania [97,183], the late Mesoproterozoic–early Neoproterozoic 1.1−0.9 Ga Shaler Group, Canada [155] and the late Palaeoproterozoic >1642 ± 3.9 Ma Limbunya…”

“, 1999), transitional (Beghin et al., 2017) and terrestrial environments (Wellman and Strother, 2015).”

“The most recent evidence pushes this back slightly, with unambiguous eukaryotes appearing in a taxonomically diverse assemblage from about 1.1 Ga (Beghin et al., 2017).”

“, были обнаружены в отложениях древнее 1074 ± 11 млн лет (Станевич и др., 2009), а также в породах с возрастом от 1107 ± 12 до 1109 ± 22 млн лет (Beghin et al., 2017; Loron et al., 2019).”

“3D–3E; Beghin et al., 2017, p. 72, pls. 4j–4k; Javaux and Lep-ot, 2018, p. 72, text-figs.”

“Tang, 2013 Similarly, the Saradih microfossils population also shows co-occurrence of T. botula with T. aimika , similar to other occurrences from Africa, China, Congo and India (Baludikay et al., 2016; Beghin et al., 2017; Li et al., 2019; Tang et al., 2013; Tang et al., 2017b).”

“Thus, diverse eukaryotic microfossils were reported from Tonian and younger rocks (Battison and Brasier, 2012; Beghin et al., 2017; Butterfield, 2004, 2005a, 2005b; Cohen and Knoll, 2012; Knoll et al., 2006; Lamb et al., 2009; Pang et al., 2013; Porter et al., 2003; Vorob’eva et al., 2015).”

“As critical indicators of paleoclimates and paleoenvironments, they offer invaluable insights into past environmental conditions and are extensively utilized in stratigraphic correlation and dating (Golubkova et al., 2021; Chakraborty et al., 2019; Beghin et al., 2017; Strauss et al., 2014).”