Carboniferous platyceratid gastropods from Western Australia and a possible alternative lifestyle adaptation

Cook, A.G. &; Jell, P.A., September 2015. Carboniferous platyceratid gastropods from Western Australia and a possible alternative lifestyle adaptation. Alcheringa 40, XX–XX. ISSN 0311-5518

Platyceratid gastropods, common and in many cases abundant as elements of middle Palaeozoic gastropod faunas worldwide, are rare or absent in Australian Devonian faunas. In Australia, the earliest abundant platyceratids occur in the Lower Carboniferous (Tournaisian) echinoderm-rich Septimus Limestone and Enga Sandstone in the Bonaparte Gulf Basin, Western Australia. Four taxa, each with significant morphological plasticity, are recognized. In Platyceras (Platyceras) tubulosus (de Koninck, 1883 Koninck, L.G. De, 1883. Faune du calcaire Carbonifère de La Belgique, Quatrième Partie, Gastropodes (suite et fin). Annales du Musée Royal D’Histoire Naturelle de Belgique Tome VIII, Text, 1–240, pls 1–54. [Google Scholar]), three rows of long radially arranged spines and common pentameral symmetry of re-entrants on the aperture suggest an alternative possibility that a relationship between echinoderms and platyceratids developed, and that this may be with archaeocidaroids that are commonly preserved with the gastropods. Similarly in the singly spinose Platyceras (Platyceras) emmemmjae sp. nov., re-entrants suggest an echinoderm relationship. It is proposed that an echinoderm–Platyceras relationship possibly developed in Australia only after a suitable echinoid host had evolved allowing an alternative way for a gameto- or coprophagous habit to be exploited fully.

Alex G Cook [alex.Cook@y7mail.com] and Peter A. Jell [p.jell@uq.edu.au], School of Earth Sciences, The University of Queensland, Queensland 4072, Australia.     

Devonian trilobites from the Shogrām Formation,Kurāgh,Chitral (NW Pakistan)

Late Devonian trilobites from horizons close to the Frasnian-Famennian boundary in the Shogrām Formation at Kurāgh, Chitral (NW Pakistan) are described. A new species of Asteropyginae, Neocalmonia chitralensis sp. nov., and a new subpecies, Neocalmonia batillifera orientalis subsp. nov., are described; these extend the range of Asteropyginae eastwards from Iran and southern Afghanistan. The Upper Kellwasser Event is located within KUR 19 of Talent et al. (1999).     

Healed injuries in Early Cambrian trilobites from South Australia

Examples of an undescribed species of the trilobite Redlichia from the Emu Bay Shale (Early Cambrian), Kangaroo Island, South Australia, show damage to the exoskeleton attributed to the action of predators. Injury was probably not lethal. The identity of the predators is unresolved, notwithstanding soft-part preservation within the fossil assemblage. Possible culprits include either a rare and presumably large animal such as an arthropod or conceivably cannibalism by Redlichia itself. This report provides new data on the occurrence of Cambrian predators, and casts further doubt on earlier suggestions that macrophagous predation was insignificant at this time. Aspects of trilobite predation during the Palaeozoic are reviewed, with emphasis placed on their ability to withstand substantial injuries and the possible repair mechanisms that promoted wound healing and survival.     

A second incisoscutid arthrodire (Pisces,Placodermi) from the Late Devonian Gogo Formation,Western Australia

Long, J. A., 1994:03:28. A second incisoscutid arthrodire (Pisces, Placodermi) from the Late Devonian Gogo Formation. Western Australia. Alcheringa 18. 59–69. ISSN 0311-5518.

A new incisoscutid arthrodire is described from the Upper Devonian Gogo Formation of Western Australia as Gogosteus sarahae gen. et sp. nov. It is characterised by its narrow headshield with cheek unit firmly attached to skull roof, crushing gnathal plates, deep postnasal plates, elongate anterior lateral plate with deeply embayed postbranchial notch and squarely cut posterior margin, and fine dermal ornamentation. The family Incisoscutidae Denison 1984 is redefined to include Incisoscutum ritchiei Dennis & Miles 1981 and Gogosteus gen. nov., and the superfamily Incisoscutoidea nov. defined to include Incisoscutidae and Camuropiscidae.     

Relationships of tristichopterids (osteolepiform lobe-finned fishes) from the Middle–Late Devonian of East Gondwana

Wang, Z-B., Gao, J-H., Wang, G-H. &; Kang, Z-H., June 2018.2018. Foraminiferal biostratigraphy and facies analysis of the Permian Longge Formation in the Rongma Area, Tibet, China: implications for the palaeogeography of the South Qiangtang Block. Alcheringa XX, x–x.

The Permian Longge Formation in the South Qiangtang Block, Tibet, is overwhelmingly composed of carbonate rocks with various skeletal (brachiopods, foraminifers, gastropods, echinoderms, ostracods, corals, bivalves, algae, and bryozoans) and non-skeletal (intraclasts and ooids) components. Three stratigraphic sections of the Longge Formation in the Rongma area of north-central Tibet—known as South Yibug Caka, Niushan and East Yibug Caka—were selected for this study, which examined both sedimentary facies and foraminiferal assemblages. The foraminifers in these sections consist of at least 38 species belonging to 18 genera. Based on the distribution of the foraminifers throughout the composite section, two foraminiferal assemblages were established, and the age of the Longge Formation was determined to be late Kungurian to Capitanian. During lithological studies, ten microfacies were identified using depositional textures, petrographic analysis and faunal content: mudstone, bioclast wackestone, bioclast perforated-foraminifera packstone, bioclast crinoid grainstone, intraclast wackestone, breccia, intraclast grainstone, ooid grainstone, fine crystalline dolostone and residual-grain dolostone. These microfacies are interpreted to represent four depositional environments—restricted lagoon, open marine, shoal and slope—which together suggest a shoal-rimmed carbonate platform. The non-fusuline foraminifers show transitional palaeobiogeographic affinities (Tethyan Cimmerian subregion), and the assemblage is considered to be influenced by the northward drift of the South Qiangtang Block, the climatic warming after the Late Paleozoic Ice Age and warm-water oceanic currents caused by the newly formed Neotethys Ocean. This indicates that the South Qiangtang Block was located in a relatively warm-water, low-latitude area during the middle Permian. The Permian depositional sequences in the Rongma area were also influenced by the palaeogeographic evolution of the South Qiangtang Block.

Zhong-Bao Wang [zbwang@cugb.edu.cn] and Zhi-Hong Kang [kangzh98@cugb.edu.cn] School of Energy Resource, China University of Geosciences (Beijing), 29 Xueyuan Road, Beijing 100083, PR China; Jin-Han Gao* [wang_zhongbao@126.com] and Gen-Hou Wang [wgh@cugb.edu.cn] School of Earth Sciences and Resources, China University of Geosciences (Beijing), 29 Xueyuan Road, Beijing 100083, PR China.     

Emwadea microcarpa gen. et sp. nov.—anatomically preserved araucarian seed cones from the Winton Formation (late Albian), western Queensland,Australia

Dettmann, M.E., Clifford, H.T., Peters, M., June 2012. Emwadea microcarpa gen. et sp. nov.—anatomically preserved araucarian seed cones from the Winton Formation (late Albian), western Queensland, Australia. Alcheringa, 217–237. ISSN 0311-5518.

A new genus and species, Emwadea microcarpa Dettmann, Clifford & Peters, is established for ovulate/seed cones with helically arranged cone scales bearing a centrally positioned, inverted ovule from the basal Winton Formation (late Albian), Eromanga Basin, Queensland. The cones are small, prolate ellipsoidal (9.5–14 mm vertical axis, 6.3–8.7 mm transverse axis) with wedge-shaped cone scales bearing winged seeds attached adaxially to the scale only by tissues surrounding the vasculature entering the ovule. Ovuliferous tissue that is free from the cone scale extends distally from the chalaza; the seeds' lateral wings are derived from the integument. Foliage attached to the cones is spirally arranged, imbricate and with spreading and incurved bifacial blades with acute tips; stomata are arranged in longitudinal files and are confined to the adaxial surface. The cone organization testifies to placement within the Araucariaceae, and is morphologically more similar to Wollemia and Agathis than to Araucaria.

Mary Dettmann [mary.dettmann@qm.qld.gov.au] and Trevor Clifford, Queensland Museum, PO Box 3300, South Brisbane, Q 4101, Australia; Mark Peters, PO Box 366 Gumeracha, SA 5233, Australia. Received 31.3.2011; revised 23.8.2011; accepted 5.9.2011.

     

Non-marine ?Late Silurian-Early Devonian trace fossils,Darling Basin,western New South Wales

An ichnofauna consisting of four types of trackways and five types of traces, largely made by arthropods, was discovered in the ?Late Silurian-Early Devonian Mt Daubeny Formation in western New South Wales. The trackways include forms of Diplichnites gouldi, Merostomichnites strandi (most common) and Palmichnium antarticum (form A), and the traces include Cruziana sp. Didymaulichnus lyelli, Didplodichnus biformis, Planolites sp. and Rusophysus sp. The formation, >6 km thick, was deposited during semi-arid and humid climates in a terminal fan environment. The discovery of Palmichnium antarticum (form B) from the Givetian Gum Creek beds at Moona Vale Station is also reported.