John R. Laurie

Phosphatic fauna of the Early Cambrian Todd River Dolomite, Amadeus Basin, central Australia

Ten species of phosphatic or phosphatised fossils are described from the Early Cambrian Todd River Dolomite of the Amadeus Basin in central Australia. The tannuolinid genus Micrina nov. is erected to include Platyceras etheridgei Tate 1892. The family Kennardiidae nov. is erected to include phosphatic organisms having three distinct forms of mitral sclerite. Assigned to this family are Kennardia reticulata gen. et sp. nov. and tentatively Dailyatia ajaxBischoff. Other phosphatic problematica are Paterimitra pyramidalis gen. et sp. nov., Eccentrotheca cf. kanesia Landing, Nowlan & Fletcher. Also described are phosphatised Chancelloria sp., Lenastella sp. and Pelagiella sp. and the phosphatic inarticulate brachiopods Askepasma toddensegen. et sp. nov., Edreja aff. distincta Koneva and ?Lingulella sp. Two species of tubular problematica are illustrated but not discussed in detail.

Global Cambrian trilobite palaeobiogeography assessed using parsimony analysis of endemicity

Abstract Palaeobiogeographical data on Cambrian trilobites obtained during the twentieth century are combined in this paper to evaluate palaeoceanographic links through c. 30 myr, once these arthropods biomineralized. Worldwide major tectonostratigraphic units are characterized at series intervals of Cambrian time and datasets of trilobite genera (629 for Cambrian Series 2, 965 for Cambrian Series 3, and 866 for the Furongian Series) are analysed using parsimony analysis of endemicity. Special attention is given to the biogeographical observations made in microcontinents and exotic terranes. The same is done for platform-basinal transects of well-known continental margins. The parsimony analysis of endemicity analysis resulted in distinct palaeogeographical area groupings among the tectonostratigraphic units. With these groupings, several palaeobiogeographical units are distinguished, which do not necessarily fit the previously proposed biogeographical realms and provinces. Their development and spatial distributions are broadly controlled by Cambrian palaeoclimates, palaeogeographical conditions (e.g. carbonate productivity and anoxic conditions) and ocean current circulation. Supplementary material: Global dataset of Cambrian Epoch 2 (A), Cambrian Epoch 3 (B) and the Furongian Epoch (C) trilobite genera are provided at: http://www.geolsoc.org.uk/SUP18669

Revision of some Australian Ptychagnostinae (Agnostida, Cambrian)

The taxonomic relationships of some Australian species of the agnostid subfamily Ptychagnostinae are discussed and some revisions made. The genus Ptychagnostus consists of two species, P. punctuosus and P. affinis. Zeteagnostus is emended to include Z. incautus and Z. scarifatus. Acidusus is emended to include A. atavus, A. acidusus, A. germanus, A. occultatus, A. michaeli, A. aculeatus and tentatively A. cassis. Onymagnostus includes O.hybridus, O. mundus and O. semiermis. Pentagnostus is monospecific, consisting of P. praecurrens. Triplagnostus is subdivided into two subgenera: T.(Triplagnostus) containing T.(T.) gibbus, T.fT.J scopus and T.(T.) ultimus; and T.(Aotagnostus) containing T.(A.) culminosus, T.(A.) aotus and T.(A.) magniceps.

BIOGEOGRAPHIC SIGNIFICANCE OF ORDOVICIAN BRACHIOPODS FROM THAILAND AND MALAYSIA

Early Ordovician brachiopods Spanodonta floweri (Cooper) and Aporthophyla tianjingshanensis ? Fu from peninsular Thailand and the Langkawi Islands, Malaysia, and described and offer important confirmatory evidence for the Ordovician juxtaposition of the Shan-Thai terrane, the North China terrane, and Western Australia.

Calibrating the middle and late Permian palynostratigraphy of Australia to the geologic time-scale via U–Pb zircon CA-IDTIMS dating

ABSTRACT The advent of chemical abrasion-isotope dilution thermal ionisation mass spectrometry (CA-IDTIMS) has revolutionised U–Pb dating of zircon, and the enhanced precision of eruption ages determined on volcanic layers within basin successions permits an improved calibration of biostratigraphic schemes to the numerical time-scale. The Guadalupian and Lopingian (Permian) successions in the Sydney, Gunnedah, Bowen and Canning basins are mostly non-marine and include numerous airfall tuff units, many of which contain zircon. The eastern Australian palynostratigraphic scheme provides the basis for much of the local correlation, but the present calibration of this scheme against the numerical time-scale depends on a correlation to Western Australia, using rare ammonoids and conodonts in that succession to link to the standard global marine biostratigraphic scheme. High-precision U–Pb zircon dating of tuff layers via CA-IDTIMS allows this tenuous correlation to be circumvented—the resulting direct calibration of the palynostratigraphy to the numerical time-scale highlights significant inaccuracies in the previous indirect correlation. The new data show: the top of the Praecolpatites sinuosus Zone (APP3.2) lies in the early Roadian, not the middle Kungurian; the top of the Microbaculispora villosa Zone (APP3.3) lies in the middle Roadian, not the early Roadian; the top of the Dulhuntyispora granulata Zone (APP4.1) lies in the Wordian, not in the latest Roadian; the top of the Didecitriletes ericianus Zone (APP4.2) lies in the first half of the Wuchiapingian, not the latest Wordian; the Dulhuntyispora dulhuntyi Zone (APP4.3) is exceptionally short and lies within the Wuchiapingian, not the early Capitanian; and the top of the Dulhuntyispora parvithola Zone (APP5) lies at or near the Permo-Triassic boundary, not in the latest Wuchiapingian.

Early Ordovician orthide brachiopods from southern Tasmania

Five new and one previously named species of orthide brachiopods are described from the Early Ordovician Florentine Valley Formation and Karmberg Limestone in the Florentine Valley, 70 km west of Hobart, Tasmania. The forms described are Apheoorthis humboldtensis sp. nov., Nanorthis carinata sp. nov., Archaeorthis subcarinata sp. nov., Tritoechia lewisi Brown, T. florentinensis sp. nov., and T. karmbergensis sp. nov. Evidence from isolated graptolite and conodont faunas and from the morphological affinities of the brachiopods themselves indicates that the Florentine Valley Formation extends from the Tremadoc to the early Arenig.

Revision of species of Goniagnostus Howell and Lejopyge Corda from Australia (Agnostida, Cambrian)

Relationships of Australian species of the agnostoid genera Goniagnostus and Lejopyge are discussed and some revisions made. Goniagnostus consists of G. (Goniagnostus), containing G. (G.) nathorsti and G. (G.) scarabaeus; G. (Criotypus) containing G. (C.) oxytorus and G. (C.) lemniscatus; and G. (Allobodochus) containing G. (A.) fumicola and G. (A.) spiniger. Representatives of Lejopyge are L. armata, L. laevigata, L. calva, L. dubium, L. multifora and L. cosfordae. Goniagnostus is considered to have evolved from Triplagnostus (Triplagnostus) and Lejopyge possibly from Onymagnostus.

On the Middle Cambrian agnostoid species Agnostus fallax Linnarsson 1869

The types and other specimens of Agnostus fallax Linnarsson 1869 are examined and reinterpreted. It is shown that the application of this specific name to many specimens from around the world is largely in error. The species is considered sufficiently different from the type species of Peronopsis, P. integra (Beyrich, 1845) to warrant erection of a new genus Axagnostus with A. fallax as the type species.

A new species of the Permian trilobite Doublatia from the Manning District, New South Wales

A new species of trilobite, Doublatia matheri is described from the Early Permian Colraine Mudstone (Manning Group) of the Kimbriki district, near Wingham in central eastern New South Wales. Further Early Permian faunas are recorded from the diamictites of the ‘Kullatine Series’ underlying the Manning Group.

A re-assessment of the brachiopod genus spanodonta prendergast from the lower Ordovician of Western Australia

The poorly known plectambonitacean genus Spanodonta Prendergast is re-assessed and its type species, S. hoskingiae Prendergast 1935 from the Lower Ordovician of Western Australia, redescribed. The only other species assigned to the genus, S. tingriensis Liu, is rejected from it. The genus is considered to be most closely related to Aporthophyla Ulrich & Cooper and is therefore assigned to the Taffidae.