| 1. |
- Claybourn, Thomas M., 1989-, et al.
(författare)
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BRACHIOPODS FROM THE BYRD GROUP (CAMBRIAN SERIES 2, STAGE 4) CENTRAL TRANSANTARCTIC MOUNTAINS, EAST ANTARCTICA: BIOSTRATIGRAPHY, PHYLOGENY AND SYSTEMATICS
- 2020
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Ingår i: Papers in Palaeontology. - : Wiley. - 2056-2799 .- 2056-2802. ; 6:3, s. 349-383
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Tidskriftsartikel (refereegranskat)abstract
- Brachiopods from Cambrian Series 2, Stage 4 carbonate strata of the Byrd Group in the Central Transantarctic Mountains, East Antarctica, are described for the first time. These include six lingulate, one paterinate, and one rhynchonelliform taxa, including the new lingulate brachiopod Plicarmus wildi gen. et sp. nov. The biostratigraphy correlates closely to the brachiopods recently reported from the Xinji Formation (Shuiyu section) in North China, as well as brachiopods recovered from the Dailyatia odyssei Zone across the Arrowie Basin of South Australia. These findings also support the previously identified close palaeobiogeography of these regions. The first unambiguous example of the acrotretid brachiopod Eohadrotreta zhenbaensis Li and Holmer outside South China is also identified in the context of its ontogenetic stages. Well preserved specimens of the acrotheloid Schizopholis yorkensis (Holmer and Ushatinskaya in Gravestock et al.) facilitates a new reconstruction of its musculature and visceral region. This data is synthesised into a new cladistic analysis that resolves Acrotheloidea as a well-supported monophyletic clade and supports previous hypotheses of a morphocline in acrotheloid evolution.
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| 2. |
- Claybourn, Thomas M., 1989-
(författare)
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Mollusks from the upper Shackleton Limestone (Cambrian Series 2), Central Transantarctic Mountains, East Antarctica
- 2019
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Ingår i: Journal of Paleontology. - USA : Cambridge University Press. - 0022-3360 .- 1937-2337. ; 93:3, s. 437-459
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Tidskriftsartikel (refereegranskat)abstract
- An assemblage of Cambrian Series 2, Stages 3–4, conchiferan mollusks from the Shackleton Limestone, Transantarctic Mountains, East Antarctica, is formally described and illustrated. The fauna includes one bivalve, one macromollusk, and 10 micromollusks, including the first description of the species Xinjispira simplex Zhou and Xiao, 1984 outside North China. The new fauna shows some similarity to previously described micromollusks from lower Cambrian glacial erratics from the Antarctic Peninsula. The fauna, mainly composed of steinkerns, is relatively low diversity, but the presence of diagnostic taxa, including helcionelloid Davidonia rostrata (Zhou and Xiao, 1984), bivalve Pojetaia runnegari Jell, 1980, cambroclavid Cambroclavus absonus Conway Morris in Bengtson et al., 1990, and bradoriid Spinospitella coronata Skovsted et al., 2006, as well as the botsfordiid brachiopod Schizopholis yorkensis (Ushatinskaya and Holmer in Gravestock et al., 2001), in the overlying Holyoake Formation correlates the succession to the Dailyatia odyssei Zone (Cambrian Stages 3–4) in South Australia
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| 3. |
- Betts, Marissa, J., et al.
(författare)
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A new lower Cambrian shelly fossil biostratigraphy for South Australia
- 2016
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Ingår i: Gondwana Research. - : Elsevier BV. - 1342-937X .- 1878-0571. ; 36, s. 163-195
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Tidskriftsartikel (refereegranskat)abstract
- Definition of early Cambrian chronostratigraphic boundaries is problematic with many subdivisions stillawaiting ratification. Integrated multi-proxy data from well-resolved regional-scale schemes are ultimately the key to resolving broader issues of global correlationwithin the Cambrian. In Australia, early Cambrian biostratigraphy has been based predominantly on trilobites. Phosphatic shelly fauna have great potential as biostratigraphic tools, especially in pre-trilobitic strata because they are widespread and readily preserved, but they have remained underutilised. Here we demonstrate their value in a new biostratigraphic scheme for the early Cambrian of South Australia using a diverse shelly fauna including tommotiids, brachiopods, molluscs and bradoriids. Biostratigraphic data are derived from ten measured stratigraphic sections across the Arrowie Basin, targeting Hawker Group carbonates including the Wilkawillina, Wirrapowie and Ajax limestones and the Mernmerna Formation. The stratigraphic ranges of shelly fossils are predictable and repeatable across the Arrowie Basin, allowing three discrete shelly biozones to be identified, spanning Terreneuvian, Stage 2 to Series 2, Stages 3–4. The Kulparina rostrata Zone (new) and part of the overlyingMicrina etheridgei Zone (new) are pre-trilobitic (predominantly Terreneuvian). The Cambrian Series 2, Stage 3 Dailyatia odyssei Zone (new) features a very diverse shelly fauna and will be described in detail in a separate publication. These zones provide robust means to correlate Terreneuvian–Series 2 successions in neighbouring coeval basins in Australia, particularly the Stansbury Basin. Wider correlation is possible throughout East Gondwana, and especially with South China.
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| 4. |
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| 5. |
- Betts, Marissa, J., et al.
(författare)
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Early Cambrian chronostratigraphy and geochronology of South Australia
- 2018
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Ingår i: Earth-Science Reviews. - : Elsevier BV. - 0012-8252 .- 1872-6828. ; 185, s. 498-543
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Tidskriftsartikel (refereegranskat)abstract
- The most successful chronostratigraphic correlation methods enlist multiple proxies such as biostratigraphy and chemostratigraphy to constrain the timing of globally important bio- and geo-events. Here we present the first regional, high-resolution shelly fossil biostratigraphy integrated with δ13C chemostratigraphy (and corresponding δ18O data) from the traditional lower Cambrian (Terreneuvian and provisional Cambrian Series 2) of South Australia. The global ZHUCE, SHICE, positive excursions II and III and the CARE are captured in lower Cambrian successions from the Arrowie and Stansbury basins. The South Australian shelly fossil biostratigraphy has a consistent relationship with the δ13C results, bolstering interpretation, identification and correlation of the excursions. Positive excursion II straddles the boundary between the Kulparina rostrata and Micrina etheridgei zones, and the CARE straddles the boundary between the M. etheridgei and Dailyatia odyssei zones, peaking in the lower parts of the latter zone. New CA-TIMS zircon dates from the upper Hawker Group and Billy Creek Formation provide geochronologic calibration points for the upper D. odyssei Zone and corresponding chemostratigraphic curve, embedding the lower Cambrian successions from South Australia into a global chronostratigraphic context. This multi-proxy investigation demonstrates the power of integrated methods for developing regional biostratigraphic schemes and facilitating robust global correlation of lower Cambrian successions from South Australia (part of East Gondwana) with coeval terranes on other Cambrian palaeocontinents, including South and North China, Siberia, Laurentia, Avalonia and West Gondwana.
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| 6. |
- Betts, Marissa, J., et al.
(författare)
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Global correlation of the early Cambrian of South Australia: Shelly faunaof the Dailyatia odyssei Zone
- 2017
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Ingår i: Gondwana Research. - Amsterdam : Elsevier BV. - 1342-937X .- 1878-0571. ; 46, s. 240-279
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Tidskriftsartikel (refereegranskat)abstract
- A lack of well resolved biostratigraphic data has prevented robust regional and global correlation of lower Cambriansuccessions from South Australia. A new early Cambrian biostratigraphy, based on data derived from 21measured stratigraphic sections and drill cores (11 described herein) reveals the abundance and diversity ofshelly fauna from the Arrowie Basin, and the value of early Cambrian “small shelly fossils” (SSF) for biostratigraphicstudies. Here we examine shelly fauna associated with the youngest of three recently establishedbiozones, the Dailyatia odyssei Taxon Range Zone (hereafter D. odyssei Zone), and their correlative potential.The D. odyssei Zone features a diverse suite of tommotiids, organophosphatic brachiopods, bradoriid arthropods,molluscs and phosphatic problematica. This fauna permits strong correlation (often at species-level) with othermajor early Cambrian terranes, particularly Antarctica, South China and Laurentia, and suggest a Cambrian Series2, Stages 3–4 age for the D. odyssei Zone. Bradoriids have proven to be useful biostratigraphic tools. Four newspeciesand three new genera are described herein: Acutobalteus sinuosus gen. et sp. nov., Eozhexiella adnyamathanha gen. etsp. nov., Manawarra jonesi gen. et sp. nov. and Mongolitubulus descensus sp. nov. The description of Eohadrotreta sp.cf. zhenbaensis represents the first occurrence of the acrotretoid brachiopod Eohadrotreta from Australia.
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| 7. |
- Jacquet, Sarah, M., et al.
(författare)
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Watsonella crosbyi from the lower Cambrian (Terreneuvian, Stage 2) Normanville Group in South Australia
- 2016
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Ingår i: Geological Magazine. - 0016-7568 .- 1469-5081. ; , s. 1-17
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Tidskriftsartikel (refereegranskat)abstract
- Correlation of lower Cambrian strata is often confounded by provincialism of key fauna. The widespread occurrence of themicromollusc Watsonella crosbyi Grabau, 1900 is therefore an important biostratigraphic signpost with potential for international correlation of lower Cambrian successions. Previous correlations of W. crosbyi from Australia (Normanville Group) suggested an Atdabanian- to Botoman-equivalent age. However, in the upper part of the Mount Terrible Formation, stratigraphic ranges of W. crosbyi and Aldanella sp. cf. golubevi overlap prior to the incoming of vertically burrowed ‘piperock’, which is indicative of an age no earlier than Cambrian Stage 2. The stratigraphic range of W. crosbyi in the Normanville Group, South Australia correlates with the ranges of the taxon in China, France, Mongolia and Siberia (though not Newfoundland). The new Australian data add further support for considering the first occurrence of W. crosbyi a good potential candidate for defining the base of Cambrian Stage 2. The stratigraphic range of W. crosbyi through the lower Cambrian Normanville Group has been determined based on collections from measured sections. Although rare, W. crosbyi is part of an assemblage of micromolluscs including Bemella sp., Parailsanella sp. cf. murenica and a sinistral form of Aldanella (A. sp. cf. A. golubevi). Other fauna present include Australohalkieria sp., Eremactis mawsoni, chancelloriids and Cupitheca sp.
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| 8. |
- Larsson, Cecilia M., et al.
(författare)
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Paterimitra pyramidalis from South Australia : Scleritome, shell structure and evolution of a lower Cambrian stem group brachiopod
- 2014
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Ingår i: Palaeontology. - : Wiley. - 0031-0239 .- 1475-4983. ; 57:2, s. 417-446
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Tidskriftsartikel (refereegranskat)abstract
- The tommotiid Paterimitra pyramidalis Laurie, 1986, is redescribed based on well-preserved material from the lower Cambrian Wilkawillina, Wirrapowie and Ajax limestones of the Flinders Ranges, South Australia. The material shows that the scleritome of Paterimitra pyramidalis includes three sclerite morphotypes (S1, S2 and L). Detailed shell microstructure studies show striking similarities with both the paterinid brachiopod Askepasma toddense and the tommotiid Eccentrotheca helenia, which strengthens the suggested evolutionary link between tommotiids and brachiopods. Based on the partly articulated specimens and similarities in shell microstructure and sclerite morphology with Eccentrotheca, Paterimitra pyramidalis is reconstructed as a tube-dwelling, epifaunal, sessile, filter-feeder with an organic pedicle-like attachment structure. The proposed reconstruction of the scleritome comprises a basal unit composed of one S1 and one S2 sclerite, as well as an unresolved number of L sclerites lining a coniform tubular structure.
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| 9. |
- Skovsted, Christian, 1974-, et al.
(författare)
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The early Cambrian tommotiid Kulparina rostrata from South Australia
- 2016
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Ingår i: Journal of Paleontology. - : Cambridge University Press (CUP). - 0022-3360 .- 1937-2337. ; 89:6, s. 920-932
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Tidskriftsartikel (refereegranskat)abstract
- The early Cambrian (Terreneuvian, Stage 2) tommotiid Kulparina rostrata Conway Morris and Bengtson in Bengtson et al., 1990 is revised. The pyramidal sclerites of K. rostrata are shown to be bilaterally symmetrical and homologues of the symmetrical S1 sclerites of Paterimitra pyramidalis Laurie, 1986. The scleritome of K. rostrata is also shown to include flattened asymmetrical sclerites that were originally described under the name Eccentrotheca guano Bengtson in Bengtson et al., 1990 and which correspond to the L-sclerites of Paterimitra. A modified tubular scleritome and a sessile filter-feeding mode of life is envisaged for Kulparina rostrata.
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| 10. |
- Topper, Timothy P, et al.
(författare)
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The oldest brachiopods from the lower Cambrian of South Australia
- 2013
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Ingår i: Acta Palaeontologica Polonica. - : Polska Akademia Nauk Instytut Paleobiologii (Institute of Paleobiology, Polish Academy of Sciences). - 0567-7920 .- 1732-2421. ; 58:1, s. 93-109
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Tidskriftsartikel (refereegranskat)abstract
- The morphology and organophosphatic shell structure of the paterinate brachiopod Askepasma is documented using new and previously collected specimens from the lower Cambrian of South Australia. Lack of adequately preserved material has seen the majority of paterinate specimens previously reported from South Australia referred to the genus Askepasma and treated under open nomenclature. Large collections of paterinates from the lower Cambrian Wilkawillina, Ajax, and Wirrapowie limestones in the Arrowie Basin, South Australia have prompted redescription of the type species Askepasma toddense and the erection of a new species, Askepasma saproconcha sp. nov. Askepasma saproconcha sp. nov. currently represents the oldest known brachiopod from the lower Cambrian successions in South Australia with a FAD in pre−trilobitic (Terreneuvian, Cambrian Stage 2, lower Atdabanian) strata in the basal part of the Wilkawillina and Wirrapowie limestones. Askepasma toddense predominantly occurs in Abadiella huoi Zone equivalent strata (Unnamed Cambrian Series 2, Stage 3, middle–upper Atdabanian) in the upper part of the lower Wilkawillina, Wirrapowie, and Ajax limestones. The shell microstructure of Askepasma suggests a proximal stem group position within the Brachiopoda and similarities with tommotiid taxa provides further evidence that the ancestry of crown group brachiopods is firmly entrenched within the Tommotiida.
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