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A-N, Graptolites from the Elmside Formation, transgrediens Biozone, Black Range Road, NW of Yass, W430. A,B, Pristiograptus shearsbyi n.sp., respectively AMF 102925, AMF 102926. C, Monograptus transgrediens Perner, 1899, AMF 102927a. D-G, Monograptus hornyi Jaeger (in K rí et al., 1986), respectively AMF 102920, AMF 102923, AMF 102924, AMF 102921. H,I, Monograptus perneri elmsidensis n.subsp., respectively holotype AMF 102922, and paratype AMF 103001. J-L, Monograptus formosus formosus Bouek, 1931b, respectively redrawn from Jaeger (1967, pl. 14b,c) and Packham (1968, pl. 11.4: AMF 71942, formerly SUP 23260), Derringullen Creek, Rosebank Shale, level 4 of Fig. 2. M,N, Monograptus formosus jenkinsi n.subsp., holotype ANU 35910, part and counterpart. Scale bars 1 mm.
Source publication
Graptolites from the Yass district of New South Wales include important material from: low in the Black Bog Shale; from the Yarwood Siltstone Member; 2 levels high in the Black Bog Shale; 2 levels low in the Rosebank Shale; low in the Cowridge Siltstone; and in the lower part of the Elmside Formation. The faunas from the lower 4 levels are late Lud...
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Citations
... The casts appear to be composed of grains of fine sand and silt cemented together by pyrite or limonite, possibly with small amounts of reprecipitated silica. Preliminary identifications of genera were made based on previously studied graptolites of similar age (Maletz et al. 2002, Manda et al. 2012, Rickards and Wright 1999. The preservation of the graptolite casts, as well as a surrounding highly pyritized interval of the lower member of the Henryhouse Formation at Section Dougherty West (samples 614-617) is suggestive of euxinic bottom waters favoring the precipitation of pyrite. ...
Fossilized graptolites from the Silurian Henryhouse Formation of South-Central Oklahoma are preserved as internal casts. The fragments are provisionally identified as the monograptolid genera Pristiograptus, Saetograptus, and Bohemograptus.
Abstract:
In the Arbuckle Mountains and Lawrence Uplift of south-central Oklahoma, strata of the Hunton Group are exposed, including the Late Silurian (Ludlow-Pridoli) Henryhouse Formation. The Henryhouse Formation consists mainly of argillaceous wackestone and mudstone with some beds of skeletal wackestone and packstone. The lower member extends from the Gorstian (Kockelella crassa Zone) into the middle Ludfordian (Polygnathoides siluricus Zone). The top of the lower member is a disconformity that coincides with Lau Event and Isotope Excursion. The lower member of the Henryhouse is particularly argillaceous and contains several graptolite-bearing shale beds. Compressed, carbonized fragments of Ludlovian graptolites have previously been recovered from the lower member of the Henryhouse Formation, but internal casts of graptolites have not previously been identified from this region. Indeed, internal graptolite casts are rare worldwide.
At sections Highway 77 and Dougherty West, internal graptolite casts of the monograptolid genera Pristiograptus, Saetograptus, and Bohemograptus are found in samples from the upper part of Unit 2 and Unit 3 in the middle and upper parts of the lower member of the Henryhouse Formation. The casts appear to be composed of grains of silt and fine sand cemented together with an acid-insoluble binder. The surface and interior portions of the casts became coated in pyrite and limonite during diagenesis. A reflective black carbonaceous film remains attached to a small number of specimens.
The internal casts are a mixture of siculae and rhabdosome fragments composed of two to five conjoined thecae. The casts represent the interior shape of the tubarium, and often show banding of fusellar growth rings in thecae and internal constrictions of siculae. However, the external details of the original chitinous structures such as the thecal apertures are not preserved.
... Pridolian and early Devonian graptolite faunas have been observed in many continents: North America, North Africa, Europe, Asia, and Australia (Jaeger, 1978;Koren', 1979;Garratt and Rickards, 1987;Lenz et al., 1996;Teller, 1997;Urbanek, 1997a;Rickards and Wright, 1999;Rickards, 2000;Sherwin and Rickards, 2002;Manda et al., 2012;Kraft and Kvaček, 2017; among others), however, Pridolian or younger graptolite faunas have not been reported in South America. ...
... The tubaria have rela-tively simple thecae with dorsal retroversion. The studied material is more robust than E. yassensis (Rickards and Wright, 1999) (0.20- (Jaeger, 1975), INGEO-PI-1935-1938, 1942. Proximal ends with first thecae; E-F, cf. ...
... It is worth mentioning that the measured specimens by Urbanek (1997a) possess a shorter sicula (1.41 to 1.76 mm) than those from Rinconada Formation. On the other hand, the colonies studied by Rickards and Wright (1999), Lenz and Kozlowska-Dawidziuk (2004), and Rickards et al. (2005) have more similar dimensions to the presented herein (sicula of 1.6 to 2 mm long). ...
Graptolites were planktonic organisms that constitute one of the essential biostratigraphic tools used in Paleozoic successions worldwide. Notably, Pridolian (upper Silurian) graptolites have been globally recognized in several geological units, but completely absent from South American sections until now. This study introduces the first Pridolian graptolite assemblage in this subcontinent. The Rinconada Formation, from the Eastern Precordillera of San Juan Province, Argentina, has an abundant fossil content that includes: graptolites, brachiopods, bivalves, trilobites, corals, plant remains, and microfossils. Two graptolite taxa have been identified and described, including Skalograptus parultimus (Jaeger) and cf. Enigmagraptus. Both genera are mentioned for the first time in South America. As a result, the S. parultimus Biozone is recorded from the upper outcropping levels of the Rinconada Formation at its eponymous section, indicating an early Pridolian age. This discovery represents the first mention of Pridolian graptolites for South America, and increases the knowledge about the graptolite content of the studied formation as well. In addition, the assemblage might represent the faunal recovery interval after the Kozlowskii-Lau Event, a globally recorded episode of biotic crisis. The co-occurrence of graptolites and plant remains within the same stratigraphic levels in the Rinconada Formation represents the first and oldest record in western Argentina. Finally, the age of the Rinconada Formation is reviewed, and a local, regional, and global correlation is proposed with several Pridolian sections around the globe.
... Graptolites from the site sampled in the Wallace Shale near Mirrabrook 'homestead' give a definitive P r ıdol ı age (Sherwin & Rickards 2002). The shale contains a fauna, mainly dominated by monograptid species, that are very similar to those described from the Rosebank Shale and Cowridge Siltstone at Yass, NSW (Jenkins 1982, Rickards & Wright 1999 and the Humevale Formation, Ghin Ghin, Victoria (Rickards & Garratt 1990, Rickards 2000, Packham et al. 2001. The conodont species Belodella anomalis Cooper, 1974 described from an allochthonous (likely contemporaneous) block within the unit at Boree Creek, NSW (Cockle 1999) supports a P r ıdol ı age (Farrell 2004) for the Wallace Shale. ...
Evidence of successful predation or scavenging in the fossil record represents important palaeobiological data to more thoroughly understanding extinct ecosystems. Shelly coprolites are particularly useful indications of durophagous predation in deposits, as they can have a higher preservational potential than their producers. Here we present a new shelly coprolite from the Silurian (Přídolí) Wallace Shale of New South Wales, Australia. This specimen contains abundant fragments of the trilobite Denckmannites rutherfordi Sherwin, 1968 that show limited disarticulation across exoskeletal sections. We propose that a pterygotid eurypterid was the most likely producer of this coprolite, although trilobites and fishes are not completely excluded as possible trace-makers. In documenting this specimen, we highlight that the Wallace Shale likely preserves a more complex palaeoecosystem than previously thought and renewed efforts to understand this deposit are needed in light of this new insight.
R.D.C. Bicknell [rdcbicknell@gmail.com], Palaeoscience Research Centre, School of Environmental and Rural Science, University of New England, Armidale, New South Wales, 2351, Australia;
P.M. Smith [Patrick.Smith@austmus.gov.au], Palaeontology Department, Australian Museum Research Institute, Sydney, New South Wales, 2010, Australia; Department of Biological Sciences, Macquarie University, Sydney, New South Wales, 2109, Australia;
J. Kimmig [julien.kimmig@smnk.de], Abteilung Geowissenschaften, Staatliches Museum für Naturkunde Karlsruhe, Karlsruhe, 76133, Germany.
... Several graptolite zones were recognized across the Přídolí strata worldwide. Shale dominated sections showing a continuous graptolite record were described from Arctic Canada (Lenz and Kozlowska-Dawidziuk 2004), Bohemia (Jaeger in Kříž et al. 1986), Central Asia (Koren' and Suyarkova 1997), New South Wales (Rickards and Wright 1999) and Poland (Urbanek and Teller 1997). Adequately recognized boundary of a graptolite zone in a carbonate-dominated section is hard to find (e. ...
... 11). The species is well defined, relatively abundant, morphologically distinct among rather uniform Přídolí monograptids, and geographically widespread being recorded in the Czech Republic (Přibyl 1940, Přibyl 1981, Přibyl 1983Kříž et al. 1986), Poland (Teller 1964, Urbanek andTeller 1997), France (Jaeger et al. 1965, Picarra et al. 1998), Portugal (Picarra et al. 1998, Morocco (Willefert 1962), Central Asia (Obut et al. 1968, Koren' andSujarkova 1997), Kazakhstan (Koren' 1983, Přibyl 1986), NW China (Ni et al. 1998), Yukon Territory of NW Canada (Jackson and Lenz 1972), Canadian Arctic Islands (Lenz and Kozlowska-Dawidziuk 2004) and SW Australia (Jaeger 1967, Rickards andWright 1999). Thus, the species, which occurs in both shaly and distal carbonate facies is known also from several palaeocontinents. ...
Abstract. Přídolí, the fourth series of the Silurian System, represents an interval of faunal changes, which heralded the middle Palaeozoic transformation of marine ecosystem. Understanding of the faunal changes has been limited by lack of widely applicable correlation markers. Consequently, the Přídolí Series remained undivided formally into stages. Herein, the subdivision of the Series is proposed into a lower Jarovian Stage and an upper Radotinian Stage. The base of the Jarovian Stage would correspond to the base of the Přídolí in its defined GSSP. Correlation markers applicable for subdivision of the Series are discussed based on data from sections of the type area of Central Bohemia. The graptolite Wolynograptus bouceki is suggested as the most promising marker to define the base of the Radotinian stage. The conodont Oulodus detortus enters close to the base of the bouceki Biozone as did also the cephalopod Kopaninoceras fluminese, which is abundant in the Přídolí strata across peri-Gondwana. The bouceki Biozone witnessed successive appearance of faunas previously reported from the upper Přídolí transgrediens graptolite Biozone. Benthic faunas complement graptolite-conodont biozonation on the regional scale, bivalves and the brachiopod Dayia bohemica allow for tentative interregional correlation. The appearance and proliferation of scyphocrinid crinoids represent a time specific biofacies in the upper stage. A shift from slightly negative to slightly positive δ13Ccarb values coincides with the base of the bouceki Biozone in Bohemian sections. Most of the relevant biohorizons occur in the lower Přídolí. The base of regionally limited graptolite perneri Biozone and conodont eosteinhornensis s.s. and klonkensis biozones in the Radotinian Stage are the youngest markers, preceding the Transgrediens Event and carbon isotope excursions of the uppermost Přídolí. The Hvížďalka section with uninterrupted sedimentation and integrated graptolite and conodont biostratigraphy and geochemical records may be considered a potential stratotype of the proposed Radotinian Stage.
... The unit contains an extremely diverse fossil fauna, most of which were sporadically described over the past 135 years. This includes 22 trilobite species (Mitchell 1887(Mitchell , 1920Etheridge and Mitchell 1890, 1892, 1893, 1897, 1916, 1917Chatterton 1971;Chatterton and Perry 1979;Chatterton and Campbell 1980;Strusz 1980;Thomas 1981;Adrain and Chatterton 1996;Holloway 2013), 24 brachiopod species (Mitchell 1921;Strusz 2002Strusz , 2003Strusz , 2005Strusz , 2007Strusz , 2009Strusz , 2011, seven coral species (Foerste Strusz and Garratt 1999;Munson et al. 2001), three bryozoa species (Crockford 1942), one species of dendroid graptolite (Rickards and Wright 1999), three scolecodonts species, and one species of machaeridian (Etheridge and Mitchell 1890). This fauna is typical of the Aegiria-Alveolitid Community found in relatively deeper water, likely subtidal to mid-shelf environments assigned to benthic assemblage 4 (BA4) of Boucot (1975). ...
Documentation of malformed trilobites has presented invaluable insight into the palaeobiology of a wholly extinct euarthro-pod group. Although the northern hemisphere record is relatively well documented, examples of abnormal trilobites from Australia are limited. Furthermore, most recorded specimens are from Cambrian-aged rocks. To extend this limited record, we document five new examples of malformed Australian trilobites from the Middle and Late Silurian (Wenlock and Ludlow) deposits of the Yarralumla Formation of the Australian Capital Territory and Yarwood Siltstone Member, Black Bog Shale in New South Wales. We record the first examples of abnormal pygidial and thoracic nodes and present new evidence for bifurcating pygidial ribs. These abnormal features are considered teratological morphologies. The aberrant nodes likely arose through developmental malfunctions, while the bifurcating ribs represent either similar defects, or an injury that developed into a teratological feature. Explanations for the limited record of malformed Australian trilobites and for the decrease in injured trilobites after the end-Ordovician are presented. Further documentation of malformed Australian trilobites from the middle-to-late Paleozoic will undoubtedly paint a more complete picture of how Gondwanan taxa recovered from injuries or unfortunate developmental complications.
... The age of most of the Yass Syncline sedimentary succession (Fig. 4) is based on graptolites (Rickards & Wright 1999, 2004 and conodonts (Link & Druce 1972;Simpson 1995); see also the synthesis by Percival & Zhen (2017 Below the Bowspring Limestone Member, ages based on conodonts are much less certain, and there are no graptolites in the lower Yass succession, which at these levels is dominated by volcanic rocks. Percival & Zhen (2017) have reinterpreted the age, based on a reassessment of the conodont evidence plus information from recent radiometric dating of some of the volcanic rocks, and the following is a summary of their conclusions. ...
The last major undescribed brachiopod fauna of Silurian age in New South Wales occurs at Quidong, on the Delegate River, east of the Snowy Mountains and west of Bombala in the far southeast of the state. Here the Silurian succession commences with the unfossiliferous Tombong Formation, which is succeeded conformably by the Merriangaah Siltstone containing graptolites of the late Llandovery Oktavites spiralis Zone. This formation is unconformably overlain by the Quidong Limestone which yields conodonts of Wenlock age and only a few brachiopods, including Kirkidium?, Leptaena and rare Atrypoidea. The transition to the overlying Delegate River Mudstone is gradational, passing from massive and bedded limestone into sporadically pyritic, bioturbated mudstone with abundant small plectambonitoid brachiopods (Epelidoaegiria) and less frequent Leptaena. The diverse and abundant brachiopod fauna from the Delegate River Mudstone described herein is dominated by strophomenates, particularly Mesoleptostrophia, Mesopholidostrophia, Leptaena and Epelidoaegiria as well as Eopholidostrophia (Megapholidostrophia). Also commonly present are Isorthis (Arcualla), Salopina, Morinorhynchus, Nucleospira, Retziella and Howellella, together with less frequent Ascanigypa, Atrypoidea and Atrypa, and rare Endospirifer, Janius and Dolerorthis.
New taxa described include Leptaena (Leptaena) australis sp. nov., Eopholidostrophia (Megapholidostrophia) gigas sp. nov., Isorthis (Arcualla) delegatensis sp. nov., Morinorhynchus tucksoni sp. nov. and Nucleospira quidongensis sp. nov. Many of the
brachiopods identified at Quidong have previously been recognised from Homerian (late Wenlock) to earliest Ludfordian (mid Ludlow) strata of the Canberra and Yass districts in southern New South Wales. Of the species common to both regions, those of restricted range in the Canberra and Yass faunas indicate an age for the Delegate River Mudstone of mid to late Wenlock. The depositional environment of the Delegate River Mudstone is interpreted as predominately slow, quiet sedimentation below storm base. Above the mudstone at the base containing abundant Epelidoaegiria is an upward-deepening succession, in which the brachiopod-dominated communities are progressively characterised by leptostrophiids and eopholidostrophiids. As water depth subsequently shallows, these strophomenates are replaced in abundance by the small spiriferide Howellella and the gypidulid Ascanigypa. The upper layers include crossbedded fine sandstone, and towards the preserved top of the Silurian succession there is a recurrence of bedded limestone with stromatoporoids, indicative of a subtidal environment at or above storm base.
... Kathleen Sherrard, initially with assistance from R.A. Keble, described a considerable number of Silurian graptolites, forming the basis for her subsequent recognition of several biostratigraphically signifi cant assemblages Keble 1937, Brown andSherrard 1952). Many of the earlier identifi cations of Sherrard and co-workers have been systematically revised, initially by Jaeger (1967) and subsequently by Rickards and Wright (1999), establishing ties to the global standard graptolite zonation. ...
... The dendroid graptoloid Dictyonema delicatulum barnbyensis, described from the Silverdale Formation by Rickards and Wright (1999), is otherwise known only from the Barnby Hills Shale near Neurea (SSW of Wellington in central west NSW), where it is associated with a late Ludlovian (inexpectatus/ kozlowskii zones) graptolite assemblage (Rickards and Wright 1997). ...
... Only one graptolite is presently known from the Yarwood Siltstone Member (Rickards and Wright 1999), the dendroid Dictyonema sp. cf. ...
This compilation of all known palaeontological data from Lower Ordovician to Upper Devonian rocks
exposed in the Boorowa–Crookwell–Taralga–Yass–Goulburn–Braidwood region of southeastern New
South Wales, draws on a voluminous scientifi c literature of more than 270 papers and reports. Within this
region are some of the most famous and intensively studied fossiliferous localities in the state, particularly
in the Yass–Taemas area. Revised faunal lists provide the basis for new or refi ned age determinations,
resulting in improved biostratigraphic correlation amongst the 64 formations and their members that yield
fossils in the region. Early Silurian (early Wenlock) conodonts found in allochthonous limestones of the
Hawkins Volcanics, the lowermost unit of the Yass Basin succession, are documented, as are representative
conodonts from allochthonous limestone of late Silurian (Ludlow) age previously erroneously assigned
to the early Silurian (late Llandovery) Jerrawa Formation. A new species of the coniform conodont
Panderodus is described under open nomenclature. It is recommended that the name Hanaminno Limestone
be suppressed.
... Jaeger (1959Jaeger ( , 1991 also studied the Pristiograptus in Germany using isolated material. Rickards (1965) investi− gated pristiograptids from Northern England and from Aus− tralia (Rickards and Wright 1999), and an attempt at under− standing the evolution of the P. dubius group was presented by Rickards and Wright (2003). Holland et al. (1969) described a new species P. jaegeri Holland, Rickards, and Warren, 1969 from the upper Wen− lock and lowermost Ludlow of Great Britain. ...
... widths of P. dubius morphotypes rhabdosomes vary, and the proximal end up to level of the fifth theca varies from straight to slightly ventrally curved. The rhabdosome widens gradually from 0.5 mm (e.g., P. dubius shearsbyi Rickards and Wright, 1999) to 0.8 mm (e.g., P. sardous [Gortani, 1922]), to 1.2 mm (e.g., P. tumescens [Wood, 1900]) at th 5 . ...
The paper focuses on patterns of the evolution of the simplest and longest-ranging (approximately 18 Ma) Silurian graptolite Pristiograptus dubius. The Pristiograptus dubius species group consists of the P. dubius stem lineage represented by a sequence of a number of subspecies displaying only small morphological changes as well as derivative species produced from the stem lineage by means of iterative speciation. This long raging graptolite lineage is the only one, apart of one retiolitid, which survived the most severe environmental event for graptolites, the Cyrtograptus lundgreni Event. Based on three-dimensional, isolated material two P. dubius groups taxa are distinguished. One group has an obtuse angle between the thecal lip and the succeeding thecal wall, the second group has a right or acute angle. Other characters differentiating P. dubius forms are: the shape of the apertural lips, differences in rhabdosome shape and size, and a different number of sicular rings. Sixteen species and subspecies of Pristiograptus from the East European Platform, Poland and Lithuania are discussed. Five new subspecies P. dubius magnus. P. dubius paezerensis, P. dubius praelodenicensis. P. dubius postfrequens, and P. dubius postmagnus are proposed.
... At least 25 Silurian species of Dictyonema have been identified (Rickards et al. 1995(Rickards et al. , 2003(Rickards et al. , 2005(Rickards et al. , 2009Rickards & Jell 2002;Rickards & Wright 1997, 1999, and their evolution is discussed below. All these records, apart from the Queensland graptolites documented by Rickards & Jell (2002), are from New South Wales; no Victorian dendroids were mentioned by Rickards & Sandford (1998) but some were described by Harris & Thomas (1948). ...
... D. s. sherrardae from the Přídolí, but it and D. s. mumbilensis have a more delicate appearance than either D. s. sherrardae or D. jenkinsi. Both may occur in generally quiet or lagoonal conditions, the former from the Booroo Ponds Group at Yass (Rickards & Wright 1999) and the latter from the Barnby Hills Shale near Wellington (Rickards & Wright 1997). ...
Five evolutionary lineages are proposed for Silurian species of the benthic dendroid graptolite genus Dictyonema, based largely on the exceptional eastern Australian records of the genus, comprising at least 25 species. These are: A, the delicatulum lineage with bifurcating ventral autothecal apertural spines; B, the paululum lineage with single ventral apertural spines or processes; C, the elegans lineage with isolated thecal apertures ± processes; D, the sherrardae lineage with dorsal apertural processes; and E, the venustum lineage with simple autothecal apertures. Brief comments are also made on other dendroid genera occurring in Australian strata, namely: Acanthograptus, Koremagraptus, Callograptus, Dendrograptus, Stelechocladia, Thallograptus and Palaeodictyota. Other non-graptoloid benthic hemichordates also listed are the tuboids Galaeograptus, Reticulograptus and Cyclograptus and the rhabdopleuran ?Rhabdopleura. Age ranges of all the species attributable to all of the above genera are tabulated.
... Hattons Corner Group (Figure 3b) (Rickards & Wright 1999). The persistent intercalation of shallow-marine sedimentary rocks and silicic ignimbrite indicates that the succession was always near sea-level consistent with continual subsidence throughout deposition. ...
The Lachlan Fold Belt of southeastern Australia developed along the Panthalassan margin of East Gondwana. Major silicic igneous activity and active tectonics with extensional, strike-slip and contractional deformation have been related to a continental backarc setting with a convergent margin to the east. In the Early Silurian (Benambran Orogeny), tectonic development was controlled by one or more subduction zones involved in collision and accretion of the Ordovician Macquarie Arc. Thermal instability in the Late Silurian to Middle Devonian interval was promoted by the presence of one or more shallow subducted slabs in the upper mantle and resulted in widespread silicic igneous activity. Extension dominated the Late Silurian in New South Wales and parts of eastern Victoria and led to formation of several sedimentary basins. Alternating episodes of contraction and extension, along with dispersed strike-slip faulting particularly in eastern Victoria, occurred in the Early Devonian culminating in the Middle Devonian contractional Tabberabberan Orogeny. Contractional deformation in modern systems, such as the central Andes, is driven by advance of the overriding plate, with highest strain developed at locations distant from plate edges. In the Ordovician to Early Devonian, it is inferred that East Gondwana was advancing towards Panthalassa. Extensional activity in the Lachlan backarc, although minor in comparison with backarc basins in the western Pacific Ocean, was driven by limited but continuous rollback of the subduction hinge. Alternation of contraction and extension reflects the delicate balance between plate motions with rollback being overtaken by advance of the upper plate intermittently in the Early to Middle Devonian resulting in contractional deformation in an otherwise dominantly extensional regime. A modern system that shows comparable behaviour is East Asia where rollback is considered responsible for widespread sedimentary basin development and basin inversion reflects advance of blocks driven by compression related to the Indian collision.
