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(A) Tetragraptus askerensis (Monsen). Reverse view with maeandrograptid proximal symmetry. (B) Isograptus victoriae (Harris). Reverse view with isograptid symmetry; sicula shown in grey with a darker prosicula, presence of proximal webs indicated for Isograptus victoriae, proximal thecae on stipe 1 labeled. c1, crossing canal 1; c2, crossing canal 2. Based on various specimens.
Source publication
The Lower to Middle Ordovician of Scandinavia is largely dominated by endemic Atlantic Province graptolite faunas, which are useful only for local biostratigraphy and paleoecology, but are difficult for correlation on an inter-continental scale. Isograptids, regarded as essential for inter-continental biostratigraphic correlations in the Lower to M...
Contexts in source publication
Context 1
... are highly symmetrical dichograptoid graptolites with two reclined stipes and simple, slowly widening thecal tubes with a distinct ventral lip, the rutellum (Fig. 2B). The proximal development is of the simple isograptid type or may be formed from more complexly curved thecae in Parisograp- tus, but these details can only be recognized in relief material (Maletz & Zhang 2003). The isograptid symmetry (Cooper 1973;Cooper & Fortey 1982) of the isograptids is character- ized by a symmetry plane passing ...
Context 2
... type or may be formed from more complexly curved thecae in Parisograp- tus, but these details can only be recognized in relief material (Maletz & Zhang 2003). The isograptid symmetry (Cooper 1973;Cooper & Fortey 1982) of the isograptids is character- ized by a symmetry plane passing between the sicula and th1 1 . These form a symmetrical pair (Fig. 2B). Most other dicho- graptid graptolites show a maeandrograptid symmetry in which the plane of symmetry passes through the sicula and the stipes are placed symmetrically at both sides ( Fig. ...
Context 3
... 1973;Cooper & Fortey 1982) of the isograptids is character- ized by a symmetry plane passing between the sicula and th1 1 . These form a symmetrical pair (Fig. 2B). Most other dicho- graptid graptolites show a maeandrograptid symmetry in which the plane of symmetry passes through the sicula and the stipes are placed symmetrically at both sides ( Fig. ...
Context 4
... in his publications. Cooper & Sadler (2010) have already indicated that the distribution of most isograptids is worldwide, which differs from the inclusion of the isograptids in the Pacific Faunal Realm by Cooper et al. (1991: fig. ...
Context 5
... as Isograptus specimens as done by Monsen (1937) and probably by Erdtmann (1965; specimens were not figured), but they are often associated in the Tøyen Shale with three-stiped morphs here included in the same taxon (Fig. 5a, c-d). Robust specimens are similar in dimensions to Isograptus victoriae, but lack the typical webbing of this species (Fig. 2b), while slender specimens are more similar to Isograptus lunatus. Maletz (1992a) illustrated specimens clearly possessing three reclined stipes and the typical nearly isograptid proximal symmetry of the material as Tetragraptus isograptoides Geh, 1964. The distal ends of the proximal thecae are downward directed instead of out- ward ...
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Citations
... 3.5 mm long sicula. The material may be referred to Tetragraptus(?) norvegicus (Monsen 1937) or even to Isograptus spjeldnaesi Maletz 2011 (see Maletz 2011), but as the material is not available for verification, this remains unclear and the taxon is listed as Isograptus sp.? here. The specimens of Jishougraptus novus Beckly & Maletz 1991(Jishougraptus sp. in Lindholm 1992 are typical of the middle part of the Pseudophyllograptus angustifolius elongatus Biozone in Scandinavia (Beckly & Maletz 1991) or the upper part of the Baltograptus minutus Biozone (Maletz & Ahlberg 2011). ...
... Nielsen (1995, p. 31) recognized Megistaspis polyphemus in the basal part of the Huk Formation. The youngest graptolites below the Huk Formation at Slemmestad belong to the Isograptus mobergi and Maeandrograptus schmalenseei Biozone, indicating that the Megistaspis polyphemus trilobite zone overlaps with the aforementioned graptolite zone (Maletz 2005(Maletz , 2011. It is possible that the Tøyen Shale at Kinnekulle reaches into the basal Dapingian, but there is no graptolite record at the moment to check this. ...
The graptolites of the Tøyen Shale Formation of Kinnekulle in Västergötland, south-central Sweden, are described for the first time and their biostratigraphic distribution is documented from drill core and outcrop material. The faunas indicate an age of mid to late Floian (Billingenian), thus showing a reduced biostratigraphic range of the Tøyen Shale as compared to other areas where this rock unit occurs. A considerable stratigraphic gap is apparent at its base, from the late Tremadocian to mid-Floian, as the limestones of the Ceratopyge acicularis trilobite Zone (late Tremadocian Bjørkåsholmen Formation) are followed by shales with a fauna of the Baltograptus jacksoni graptolite Biozone. Unverified records suggest that mid–late Ottenbyan (Hunnebergian) strata (Megistaspis planilimbata trilobite Zone s.l.) locally may be present in the uppermost Bjørkåsholmen Formation as identified herein. There is no indication that the Tøyen Shale reaches into the Dapingian, as Dapingian graptolites have not been recognized. The overlying limestones of the “Lanna Limestone” belong to the Megistaspis polyphemus trilobite Zone and the Baltoniodus triangularis conodont Zone, suggesting a gradual contact of the lithological units.
... The same is true also for two other species including Parisograptus caduceus and Paraglossograptus tentaculatus. Both have narrow stratigraphical ranges confined to the lower part of the Darriwilian (Maletz and Mitchell 1995;Maletz 2011). Therefore, it is likely that the interval of the Didymograptus murchisoni Zone is not represented in the Kyrgyz graptolite succession, or else corresponds to the upper part of the Ptilograptus delicatulus Zone. ...
The region of Kyrgyzstan, Tajikistan and Uzbekistan includes five first-order tectonic units with an Early Palaeozsoic sedimentary record, comprising North Tien Shan, Karatau Naryn, Turkestan - Alai, Zeravshan - Hissar and the Central Pamirs. Available palaeobiogeographical and palaeomagnetic data suggest that these were widely dispersed in the Ordovician. North Tien Shan, Karatau Naryn, Turkestan - Alai were separate microcontinents located in the low southern latitudes throughout the Ordovician in relative proximity to the western Gondwana margin. Zeravshan - Hissar and the Central Pamirs were also parts of the Gondwana supercontinent but were located in temperate latitudes. The geological literature on the Ordovician of the region is assessed to provide an updated palaeontological record, outline of lithostratigraphy, and biostratigraphic correlation based on the International Chronostratigraphical Chart. The Ordovician biostratigraphy of Central Asia is mainly graptolite-based; however, that record is discontinuous and the absence of detailed faunal logs and lack of monographic studies causes difficulty in precisely locating system and stage boundaries. Although an extensive faunal record has been documented, often it is based on preliminary taxonomical identifications which are not reliable for high-resolution biostratigraphy and tracing biodiversity patterns.
... As discussed below, the record of Nereites ichnofacies trace fossils in the Fjellvollen Formation indicates that the difference in faunal compositions between the Fjellvollen Formation and Hølonda Group can be related to the depositional settings, with the Fjellvollen Formation representing distal, deep-water deposits, compared to more shallow marine deposits, with richer biodiversity in the Hølonda Group. Some of the warm-water faunal assemblages of the Hølonda Group (Hølonda Platform) are of distinct North American affinity (Bergströ m, 1979;Neuman and Bruton, 1989;Maletz, 2011), providing evidence for the tectonic model with the Hølonda Shelf located to the west of the Ilfjellet Basin (Fig. 8) as outlined by Gasser et al. (in press). ...
The late Early to early Middle Ordovician Fjellvollen Formation, Central Norwegian Caledonides, is a part of the Ilfjellet Group volcano-sedimentary succession formed in a rift basin that opened along the Laurentian margin. Depositional facies and trace fossils indicate the Nereites ichnofacies, typically found in distal turbidites and deep marine deposits. The recovered trace fossils include ?Alcyonidiopsis, Chondrites, Dictyodora, Gordia, Helminthoidichnites, Macaronichnus, Monomorphichnus, Nereites, Oikobesalon, Palaeophycus, Protovirgularia and Treptichnus. No body-fossils have been reported from the Fjellvollen Formation, but the trace fossils indicate the presence of varied epi- and infaunas of arthropods, bivalves, gastropods and polychaets. The abundance of meandering and looping trace fossils is comparable to what is found in the inferrably time-equivalent Vuddudalen Group farther north, although lack of graphoglyptids like Megagrapton in the Fjellvollen Formation may indicate more proximal, unstable depositional conditions in fan-fringe and adjacent basin-plain settings.
... According to modern concepts (Maletz, 2011;Maletz and Zhang, 2016), the family Isograptidae Harris is divided into two subfamilies: Isograptinae Harris and Arienigraptinae Yu et Fang (=Pseudisograptinae Cooper et Ni) (Maletz and Zhang, 2016). The type genus of the first subfamily is Isograptus Moberg. ...
... At present, zones successively replace each other and contain index species (or index subspecies) of the genus Isograptus in this interval. In Scandinavia, these are spjeldnaesi, rigidus, and mobergi; in Britain, these are victoriae victoriae and gibberulus; in North America, victoriae linanus and victoriae victoriae are present (Maletz, 2011). In Australia are primulus, linanus, and victoriae (Loydell, 2012); in southern Siberia, deflexus, maximo-divergens, and caduceus imitatus were identified (Bukolova, 2010;Sennikov et al., 2019). ...
The structure of the proximal part of colonies of the Middle Ordovician Isograptinae and the species composition of the genera Oncograptus Hall and Cardiograptus Harris et Keble were discussed. Two new species Oncograptus hastatus sp. nov. and Cardiograptus altaicus sp. nov. were monographically described when studying a collection of graptolites from the Middle Ordovician (Dapingian Stage) of Gorny Altai. These taxa are important for the zonal biostratigraphy of the Ordovician of southern Siberia and for interregional correlations.
... The first appearance of the genus Unicornigraptus Chen & Goldman in Chen et al., 2016(see Maletz 2020b) is in the Levisograptus sinicus Subzone and a number of species range into the Nemagraptus gracilis Biozone of early Sandbian age (Maletz 1997a(Maletz , 2011b(Maletz , 2021. Unicornigraptus differs from Levisograptus and Archiclimacograptus in having a strongly upturned th1 2 lacking an apertural spine. ...
The Krapperup drill core from Scania (Skåne), southern Sweden, includes one of the most important graptolitic Darriwilian (upper Middle Ordovician) successions of Baltica. Only some intervals have been documented previously and especially the uppermost part of the succession has been completely unknown. A fairly complete succession of mid- to late Darriwilian age provides insight into the early evolution of the axonophoran (biserial) graptolites and demonstrates a distinct biogeographical faunal differentiation during this time. Graptolites from the mid-Darriwilian Holmograptus lentus and Nicholsonograptus fasciculatus biozones are discussed and important specimens and species from the Krapperup drill core are illustrated. Ekstroemograptus inexpectatus n. gen., n. sp. from the Holmograptus lentus Biozone is described as new.
... wang and others (2013) described the graptolite fauna of the GSSP section and provided a detailed international correlation of the graptolite faunas. The base of the Dapingian is approximately correlatable with the base of the Isograptus victoriae Biozone in other regions (Maletz, 2011). The Dapingian is characterized by a succession of isograptid species (Isograptus, Oncograptus, Cardiograptus) as important index taxa (Cooper, 1973;vandenBerg & Cooper, 1992;Maletz, 2011). ...
... The base of the Dapingian is approximately correlatable with the base of the Isograptus victoriae Biozone in other regions (Maletz, 2011). The Dapingian is characterized by a succession of isograptid species (Isograptus, Oncograptus, Cardiograptus) as important index taxa (Cooper, 1973;vandenBerg & Cooper, 1992;Maletz, 2011). Recently, Herrera-sánCHez, toro, & lovalvo (2019) and toro and others (2020) discussed the correlation of the Floian and Dapingian succession of Argentina and correlated the regional Azygograptus lapworthi Biozone with the early Dapingian (Fig. 3), followed by the Isograptus victoriae Biozone of the Central Andean Basin of Argentina and Bolivia. ...
... Graphic correlation and quantitative biostratigraphy is very useful-and in some cases, absolutely key-to determining biostratigraphic successions and gaining insight into the correlation of various fossil groups as well as to integrating sedimentological data and event horizons with paleontological data (sadler, 2004sadler, Cooper, & MelCHin, 2009, 2011sadler, Cooper & CraMpton, 2014;goldMan, nõlvaK, & Maletz 2015). Efforts to produce a more precise chronostratigraphic time scale for the Palaeozoic have been undertaken by integration of various means. ...
... On the basis of these records, a biostratigraphy was established (Fig. 2). The base of the studied interval is taken at the lowest occurrence of Isograptus mobergi Maletz, 2011a and Maeandrograptus schmalenseei Moberg, 1892 indicating a Dapingian age. Lindholm (1981) identified the interval from 72.30 to 75.35 m as the Phyllograptus angustifolius elongatus Biozone, but defined the base of the interval on the occurrence of Diymograptus gracilis crassus Monsen, 1937 (=Acrograptus crassus) and Didymograptus deflexus scanicus Tjernvik, 1960 (=Baltograptus scanicus). ...
... The oldest available sample for this investigation comes from the 67.74-67.78 m level and clearly belongs to the Isograptus mobergi and Maeandrograptus schmalenseei Biozone of Dapingian age in southern Scandinavia (see Maletz 2011a). Maletz (2011a) and Maletz & Ahlberg (2011a) discussed the graptolite biostratigraphy of the Dapingian-lower Darriwilian interval in southern Scandinavia in some detail. ...
... m level and clearly belongs to the Isograptus mobergi and Maeandrograptus schmalenseei Biozone of Dapingian age in southern Scandinavia (see Maletz 2011a). Maletz (2011a) and Maletz & Ahlberg (2011a) discussed the graptolite biostratigraphy of the Dapingian-lower Darriwilian interval in southern Scandinavia in some detail. Maletz (2005) described the basal Dapingian Isograptus victoriae Biozone of Scandinavia on the basis of the succession in the Lovisefred drill core. ...
The Dapingian and lower Darriwilian graptolite succession of the Krapperup drill core from Scania, southern Sweden, provides a detailed insight into the axonophoran (biserial) graptolites and their early Palaeozoic evolutionary changes on the Scandinavian platform. Even though earliest Darriwilian axonophorans are not represented, the succession includes faunal elements of the basal Darriwilian Arienigraptus zhejiangensis Subzone of the Levisograptus austrodentatus Biozone, followed by Levisograptus mui and Levisograptus sinicus specimens higher up in the successsion. The highest interval is referred to the Eoglyptograptus cumbrensis Biozone and bears a number of axonophoran elements, including Oelandograptus oelandicus and Undulograptus camptochilus, previously known exclusively from chemically isolated material from the island of Öland. The top of the interval investigated is below the base of a carbonate-rich interval correlated with the Komstad Limestone of Scania, indicating that the investigated interval entirely belongs to the upper part of the Tøyen Shale Formation. Pseudisograptus manubriatus and Pseudisograptus koi are not restricted to the upper Dapingian, but range into the basal Darriwilian. Arienigraptus robustus n. sp. from the uppermost Dapingian, and Arienigraptus delicatus n. sp. and Arienigraptus balticus n. sp. from the basal Darriwilian, are described as new species.
... The situation is slightly different in the Oslo Region of Norway, where the equivalent of the Komstad Limestone, the Huk Formation, is underlain by a succession with a late Castlemainian fauna with Isograptus mobergi and Maeandrograptus schmalenseei (Maletz 2011a) and overlain by the Elnes Formation shales with a fauna of the Nicholsonograptus fasciculatus Biozone, including the index species and Aulograptus climacograptoides (Maletz 1997a). Thus, the Holmograptus lentus Biozone is not confirmed. ...
The graptolite biostratigraphy of the 116.11-m-long Röstånga-2 drill core from Scania, southern Sweden, includes the Darriwilian (Middle Ordovician) Holmograptus lentus, Nicholsonograptus fasciculatus, Pterograptus elegans, Pseudamplexograptus distichus and Jiangxigraptus vagus biozones, and the lower Sandbian (Upper Ordovician) Nemagraptus gracilis Biozone. The early Darriwilian Komstad Limestone was not reached. The succession includes numerous levels of brecciated rocks and slickensides, suggesting considerable tectonic deformation and possible gaps. The boundary between the Almelund Shale Formation (below) and the Sularp Shale Formation (above) has been identified at 19.55–19.70 m, where the Fågelsång Phosphorite Bed has been identified tentatively in the Jiangxigraptus vagus Biozone. The first specimens of Nemagraptus gracilis appear higher in the succession. The international correlation of the Darriwilian graptolite succession is discussed.
... Due to the co-occurrence with other, pandemic faunal elements in mixed assemblages, these endemics can often been correlated indirectly with coeval shallow water endemic faunas from other continental regions. During the Dapingian, the isograptids form the main stock of pandemic faunal elements and were used extensively for long distance biostratigraphic correlations (harrIs, 1933;cooper, 1973;wIllIaMs & stevens, 1988;Maletz, 2011). They were very useful to correlate many largely endemic faunas of this time interval. ...
... He discussed the graptolite biostratigraphy of this interval and illustrated the most relevant taxa. Maletz (2011a) revised the Scandinavian isograptid faunas and identified the base of this interval as the Isograptus mobergi/Maeandrograptus schmalenseei Biozone of early Dapingian age, based on the presence of the index species M. schmalenseei and I. mobergi. A possibly complete succession from this biozone to the lower Darriwilian found in the region and have also not been recognized in the Gislövshammer-2 drill core (Lindholm 1992). ...
The Ordovician Tøyen Shale Formation of the recently retrieved Fågelsång-3 drill core provides some important information on the graptolite biostratigraphy of the unit and its completeness in the region. The drill core reached downwards into the Kiaerograptus supremus Biozone of late Tremadocian age. Above a major fault zone, faunas with a number of specimens referred to Pseudophyllograptus densus are indicative of a late Dapingian age. Rare specimens of Azygograptus sp. also help constrain the age. The presence of Arienigraptus zhejiangensis indicates that the base of the Darriwilian Komstad Limestone Formation is of Levisograptus austrodentatus Biozone age. Specimens of Tetragraptus cor and Levisograptus sinicus in a shale bed within the lower part of the Komstad Limestone Formation can be referred to the upper subzone of the L. austrodentatus Biozone, the Levisograptus sinicus Subzone. This fauna represents the youngest graptolite fauna beneath the massive Komstad Limestone Formation. The Tøyen Shale Formation can be shown to be highly incomplete in Scania, possibly due to post-depositional tectonic deformation and faulting.
