Review of the Cambrian acrotretid brachiopod Neotreta

The Cambrian acrotretid brachiopod Neotreta Sobolev 1976 is reviewed and re-illustrated, based on new material of the type species, N. tumida Sobolev 1976, from the lower Upper Cambrian of Siberia; Neotreta orbiculata Koneva 1990, originally described from the Middle Cambrian of Kazakhstan, has been obtained from roughly coeval beds in Shropshire, England; Neotreta pusilla Koneva 1986 was unavailable for study. Two new species, N. davidi and N. karagailensis, are described from Queensland, Australia, and Kirgizia, Central Asia respectively.     

Late Middle Cambrian trilobites from St Valentines Peak and Native Track Tier,northwestern Tasmania

Late Middle Cambrian trilobites are described from two localities in northwestern Tasmania. Twenty-four trilobite taxa are documented. The 15 agnostoid species include Paraclavagnostus longus sp. nov. which is placed in the Utagnostinae, a new subfamily of the Clavagnostidae. The nine polymeroid species include a new member of the Rhyssometopidae, Tasmana truncata gen. et sp. nov. Three other new species of polymeroids are erected: Fuchouia tasmaniensis, Nepea delicata and Nepea hellyeri. Both faunas correlate with the Lejopyge laevigata Zone on the northern Australia biostratigraphic scale, possibly with the L. laevigata II Zone. When compared with Hunan, China, correlation is with the upper part of the Lejopyge laevigata Zone, and particularly with the lower part of the Proagnostus bulbus Zone.     

Biostratigraphic potential of Middle Cambrian hyoliths from the eastern Georgina Basin

Fourteen hyolith taxa are documented from the Middle Cambrian (Templetonian to Floran) of the eastern (Queensland) portion of the Georgina Basin, Australia, as a contribution toward a prospective Australian Cambrian hyolith biozonation. The described fauna is from the Beetle Creek Formation (including Monastery Creek Phosphorite Member) and Gowers Formation. Additionally, the enigmatic Cupittheca and some indeterminate hyoliths are figured to illustrate aspects of hyolith morphology. Guduguwan hardmani, widespread in Ordian-early Templetonian strata of northern Australia, is here recorded from the early Templetonian of the eastern Georgina Basin. A new family Gakidae is established for sulcavitide hyolithomorphs with a conch of pentagonally tabernacular transverse section, to include Gaka, Kalkatungu gen. nov. and possibly Dorsolinevitus. New genera are the hyolithid Yalarrnga mara gen. et sp. nov., sulcavitid Kulangarra kutjurru gen. et sp. nov., gakid Kalkatungu murlu gen. et sp. nov. and angusticornid Yuku tjurtu gen. et sp. nov.; new species are Loculitheca kunka sp. nov., Carinolithes tjikilirri sp. nov., ?Sololites kankari sp. nov., ?Shandongolithes thakal sp. nov., ?Gerkella thuka sp. nov. and ?Yacutolituus rakatju sp. nov. Taxa in open nomenclature are Foersteotheca cf. dubecensis, ?Holmitheca sp. and ?Dorsojugatus sp. On present knowledge, the potential for an Australian Cambrian hyolith biozonation is limited in the Early Cambrian, but for the Middle Cambrian, G. hardmani is a widespread Ordian-early Templetonian indicator, while hyolith distribution in the Monastery Creek Phosphorite Member suggests a faunal turnover at or about the incoming of Acidusus atavus which may provide a basis for biozonation in the Floran stage.     

The coral Cothonion from the lower Cambrian of North Greenland

Originally described from the Coonigan Formation of New South Wales, Australia, a second occurrence of the operculate coral Cothonion sympomatum is here described from the Paralledal Formation of North Greenland. Both finds are of late early Cambrian age, Series 2, Stage 4 in the emerging fourfold classification of the Cambrian. The new find supports widespread distribution patterns seen in early Cambrian Small Shelly Fossils, although associated trilobites belong to traditional redlichiid (Australia) and olenellid (Greenland) realms, respectively.     

Middle Cambrian to Lower Ordovician faunas from the Chingiz Mountain Range,central Kazakhstan

Tolmacheva, T.JU., Degtyarev, K.E., Samuelsson, J. & Holmer, L.E., December, 2008. Middle Cambrian to Lower Ordovician faunas from the Chingiz Mountain Range, central Kazakhstan. Alcheringa 32, 443–463. ISSN 0311-5518.

The middle Cambrian to Lower Ordovician back-arc sedimentary succession studied in the Kol'denen River and in the Zerbkyzyl Mountains of the central Chingiz Mountain Range is composed predominantly of siltstones, sandstones and volcaniclastic rocks with rare beds of micritic carbonates, black shales and cherts. Fossil assemblages including conodonts, lingulate brachiopods, arthropods, sponges and probable Tasmanites cysts were recorded both from the carbonate and chert beds showing that richly diverse marine environments existed directly adjacent to the volcanic arcs. The Kol'denen River localities contain a diverse upper Cambrian paraconodont assemblage of the open-sea affinity. The representatives of Rossodus, Cordylodus, Drepanodus and Variabiloconus, having an almost pandemic distribution and characteristic of basinal facies, dominate the Lower Ordovician conodont fauna. The Cambrian–Ordovician boundary transition is characterized by chert production that was more likely caused by a local productivity increase than by general changes in palaeooceanographic and palaeogeographical conditions.     

First records from Laurentia of some middle Cambrian (Series 3) sponge spicules

Peel, J.S., February 2017. First records from Laurentia of some middle Cambrian (Series 3) sponge spicules. Alcheringa 41, 000–000. ISSN 0311-5518.

Spicules of the sponges Silicunculus Bengtson, Australispongia Dong & Knoll and Thoracospongia Mehl are described from the middle Cambrian (Cambrian Series 3) of North Greenland. The occurrences document the first records from the Cambrian of Laurentia of spicules initially reported from Australia. Obese spicules of Thoracospongia are now known to occur in strata of Cambrian Series 2 (Stage 4, Botoman) to Cambrian Series 3 (Stage 5 and Drumian) age in Australia, northern and southeastern Siberia and in the uppermost Henson Gletscher Formation (Cambrian Series 3, Stage 5) of western Peary Land. Morphologically similar obese spicules from the USA, Jordan, Iran and Sweden suggest an evolutionary trend towards armouring of the outer sponge surface during the middle and late Cambrian. New species described are Silicunculus saaqqutit sp. nov., Thoracospongia lacrimiformis sp. nov.

John S. Peel [john.peel@pal.uu.se], Department of Earth Sciences (Palaeobiology), Uppsala University, Villavägen 16, SE-752 36 Uppsala, Sweden. Received 3.7.2016; revised 13.9.2016; accepted 15.9.2016.     

Early Cambrian endolithic algae

Phosphate fillings of the tunnels made by endolithic micro-organisms in the shells of Early Cambrian molluscs have been observed on phosphatic internal moulds at several sites. The best preserved examples are from the shells of the gastropod Yuwenia bentleyi from the Parara Limestone of South Australia. Three distinct types of borings are found in these shells: long unbranched tunnels that are either about 10 µm or 3 µm in diameter, and short vertical holes. The nature and distribution of the borings suggest that they were made by photosynthetic algae rather than fungi.     

First record of Procariama simplex Rovereto, 1914 (Phorusrhacidae,Psilopterinae) in the Cerro Azul Formation (upper Miocene) of La Pampa Province; remarks on its anatomy,palaeogeography and chronological range

Vezzosi, R.I., June 2012. First record of Procariama simplex Rovereto, 1914 (Phorusrhacidae, Psilopterinae) in the Cerro Azul Formation (upper Miocene) of La Pampa Province; remarks on its anatomy, palaeogeography and chronological range. Alcheringa, 157–169. ISSN 0311-5518.

New records of Procariama simplex in central and northwestern Argentina are reported. The fossil material includes mandibular bones, cervical vertebrae and several elements of the fore and hindlimbs. After an exhaustive comparison of anatomical characters and morphometric analysis, the fossil specimens are assigned to the psilopterine Procariama simplex. The specimen from La Pampa Province represents the first record of a psilopterine in this central region of Argentina and derives from upper Miocene sediments of the Cerro Azul Formation. Lithological features and biostratigraphical data allow the host bed to be assigned to the Huayquerian faunal stage (late Miocene). The La Pampa record broadens the geographical distribution of Procariama simplex, which was previously restricted to northwestern Argentina.

Raúl Ignacio Vezzosi [vezzosiraul@gmail.com], Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción CICYTTP-CONICET, Materi y España s/n (3105), Diamante, Entre Ríos, Argentina. Received 1.4.2011, revised 28.5.2011, accepted 14.6.2011.     

Gracilitheca and Nephrotheca (Hyolitha,Orthothecida) in the Cambrian of the Barrandian area,Czech Republic

VALENT, M., FATKA, O. & MAREK, L., iFirst article. Gracilitheca and Nephrotheca (Hyolitha, Orthothecida) in the Cambrian of the Barrandian area, Czech Republic. Alcheringa, 1–10. ISSN 0311-5518.

Five orthothecid hyoliths, Gracilitheca mirabilis sp. nov., Gracilitheca triangularis sp. nov., Gracilitheca sp., Nephrotheca betula sp. nov. and Nephrotheca sp. are described from the ‘middle’ Cambrian Buchava Formation of the Skryje–Tý?ovice Basin in the Czech Republic. The new forms are based on about forty well-preserved external and internal moulds of conchs; opercula of all species remain unknown. Stratigraphic ranges and geographic distributions within the Skryje Tý?ovice Basin are established for all taxa.     

A phosphatic stromatolite (Ilicta cf. composita Sidorov) from the Middle Cambrian,northern Australia

Phosphatic stromatolites from the early Middle Cambrian (Ordian) of the Georgina Basin are described and identified as Ilicta cf. composita Sidorov. Based on Öpik's interpretation of the early Middle Cambrian, the age of the Georgina Basin specimens is similar to that of the type specimens described from the late Early Cambrian of Eastern Siberia. Phosphatic stromatolites occur at the base of dolomitized and partially silicified bioherms up to 4 m thick. The phosphatic forms overlie impermeable, cemented pavement surfaces which were covered by stratiform stromatolites from which rose columnar forms up to 5 cm in height. The stromatolites were phosphatized by penecontemporaneous diagenetic reactions that took place just below the sediment water interface and above the impermeable substrates.     

Techniques of exuviation in Australian species of the Cambrian trilobite Redlichia

Three forms of exuviation, involving inversion of exoskeletal elements, are described in three Australian species of the Cambrian trilobite Redlichia: R. forresti (Foord), R. idonea Whitehouse and R. micrograpta Öpik. They are: inversion of the pygidium, in four specimens of R. forresti; inversion of some thoracic segments of R. idonea; and lateral inversion of a free cheek, in single specimens of R. forresti and R. micrograpta. This is the first record of thoracic segment inversion during exuviation in trilobites. Exuviae with inverted exoskeletal elements provide information on the techniques of exuviation, in particular the direction of egression of the postecdysial trilobite from the proecdysial exuvia and also in this genus, the extent of enrolment of the thorax.     

Organic-walled microfossils from the Early Cambrian of South Australia

Microfossils which are hollow, possess a two-layered vesicle wall, and occur as single elements or, more rarely, as compound forms, have been recovered from the Early Cambrian Heatherdale Shale, on the Fleurieu Peninsula, South Australia. The microfossils, which range in size from 4 to 14.5 μm, are informally and tentatively assigned to the genus Sphaerocongregus Moorman 1974. Superficially they resemble forms assigned to Pyritosphaera Love 1958 and its probable junior synonym, Bavlinella Shepeleva 1962. Topotypes of these genera, however, have yet to be studied using SEM techniques, and their morphologic details remain uncertain. The organic composition of the present microfossils is supported by energy-dispersive X-ray analyses. Samples of the Heatherdale Shale were also analysed using pyrolysis techniques; the organic matter is, however, over-mature with respect to petroleum generation, and no geochemical assessment of original kerogen type is possible.     

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.     

The Late Cambrian trilobite Hamashania from Korea

The Late Cambrian trilobite genus Hamashania Kobayashi, 1942a has hitherto been poorly understood and is herein revised based on well-preserved specimens from Korea. Platysaukia Kobayashi, 1960 and Goumenzia Guo & Duan, 1978 are treated as junior synonyms of Hamashania. Hamashania comprises only two species, H. pulchera Kobayashi, 1942a and Pterocephalus busiris Walcott, 1905, and is restricted to North Chinaand Korea. The new genus Pacootasaukia is proposed to accommodate the Australian species Platysaukia jokliki Shergold, 1991 as type species, and Platysaukia tomichi Shergold, 1991, which are so distinct that they cannot be included within Hamashania. The generic concept of Mareda Kobayashi, 1942b, which was often confused with Hamashania, is confined to the type material.     

Eoshumardia (Trilobita,Cambrian), a junior synonym of Koldinioidia

Well-preserved internal and external moulds of a shumardiid species are described from the late Furongian (Late Cambrian) “Fengshan Formation” at Poben, Napo, southwestern Guangxi, which is close to the type locality of Shumardia orientalis, the type species of Eoshumardia. All features observed on the internal moulds indicate that the new material is definitely S. orientalis, whereas the morphology of the external moulds indicates that S. orientalis should be referred to Koldinioidia. The change of generic assignment of the type species means that Eoshumardia is a junior synonym of Koldinioidia.     

Early Middle Cambrian corals from western New South Wales

Three forms, Cothonion sympomatum gen. et sp. nov. with a bi-radially septate operculum, and the new species lissa and daseia of the genus Lipopora gen. nov., are described from the early Middle Cambrian Coonigan Formation in the Mootwingee district of western New South Wales, Australia. They may be representatives of hitherto unknown groups of organisms, but they are tentatively interpreted as coelenterates that reached a level of development comparable with the Anthozoa. Cothonion is placed in the new family Cothoniidae and questionably referred to the Rugosa. Lipopora is considered to be similar to Coelenteratella Korde; both are grouped in the new family Lipoporidae and tentatively referred to the Tabulata.     

Archaeocyaths from Yorke Peninsula,South Australia and archaeocyathan Early Cambrian zonation

Zhuravlev, A. Yu., & Gravestock, D. I., 1994:03:28. Archaeayaths from Yorke Peninsula, South Australia and archaeocyathan Early Cambrian zonation. Alcheringa 18, 1–54. ISSN 0311-5518.

Two assemblages of archaeocyaths are documented from Lower Cambrian outcrops and drillholes on Yorke Peninsula. South Australia. The older assemblage (11 species) occurs in the uppermost Kulpara Formation and conformably overlying basal Parara Limestone, and is equivalent to Lower Faunal Assemblage II in the Flinders Ranges. The younger assemblage (28 species plus Acanthhcyathus and Rodiocyathus) occurs in the Koolywurtie Member near the top of the Parara Limestone. Equivalent taxa are widespread in the Flinders Ranges, western New South Wales and Antarctica. Archaeocyathan distribution is now sufficiently well known to propose three assemblage zones and two informal assemblages for regional correlation. No new taxa have been added, but Erugatocyathus scutatus (Hill) and Pycnoidocyathus latiloculatus (Hill), hitherto known only from Antarctica, are found in the upper assemblage on Yorke Peninsula. Irregular archaeocyathan systematics are discussed, the ontogeny of Archaeopharetra irregularis (Tylor) clarified, and Kruseicnema Debrenne. Gravestock & Zhuravlev, represented by K. gracilis (Gordon), is fully described.     

Microdictyon plates from the lower Cambrian Ajax Limestone of South Australia: Implications for species taxonomy and diversity

A small assemblage of isolated Microdictyon plates is described from the lower Cambrian Ajax Limestone, Mt Scott Range (Flinders Ranges), South Australia. Microdictyon plates are primarily known from single, isolated, perforated phosphatic sclerites; only one species (M. sinicum) from the Chengjiang Lagerstätte is known from soft-bodied preservation of the complete organism. The isolated plates from South Australia display a wide range of morphologies potentially reflecting: 1, considerable diversification within the group at this time; 2, extensive intraspecific morphological variation; 3, different plate morphotypes along the trunk of the animal; or 4, significant ontogenetic variation in successive growth stages. The South Australian specimens are similar to several individual sclerites described from other Cambrian palaeocontinents, but appear closest to faunas described from South China. Problems associated with the taxonomy of isolated Microdictyon plates are discussed, including the lack of knowledge associated with intraspecific and/or ontogenetic variability and how individual plate morphology may relate to size or relative position along the length of the complete organism.     

New occurrence of Cambroclavus absonus from the lowermost Cambrian of North China and its stratigraphical importance

Li, L.-Y., Zhang, X.-L., Yun, H. & Li, G.-X., October 2015. New occurrence of Cambroclavus absonus from the lowermost Cambrian of North China and its stratigraphical importance. Alcheringa 40, xxx–xxx. ISSN 0311-5518.

The problematic Small Shelly Fossil Cambroclavus absonus is described from the Xinji Formation in the Longxian area, which is located near the southwestern margin of the North China Platform. The Xinji Formation, the basal rock unit of the Cambrian in the studied area, yields an assemblage of skeletal fossils that share many common elements with contemporary faunas from South Australia. Sclerites of C. absonus reported herein represent the first occurrence of the species outside Australia, thus extending the palaeogeographic range of the taxon to northern China. To date, palaeogeographic occurrences of Cambroclavus sclerites are restricted to the Peri-Gondwana realm, including South China, Australia, Tarim, Kazakhstan, North China and Western Europe. These occurrences are divided into a Southern Group realm and Northern Group realm. Stratigraphically, Cambroclavus occurs mostly in Cambrian Stage 3 and has three occurrences in Stage 5, separated by Stage 4 in which Cambroclavus has not yet been found. The first appearance datum of Cambroclavus in Cambrian Stage 3 is of importance for regional and inter-regional correlations. In particular, the presence of Cambroclavus absonus in North China allows species-level correlation between North China and South Australia.

Luoyang Li [lly@stumail.nwu.edu.cn], Xingliang Zhang [xzhang69@nwu.edu.cn], Hao Yun [yunhao@stumail.nwu.edu.cn], Early Life Institute and State Key Laboratory Of Continental Dynamics, Department of Geology, Northwest University, Xian 710069, PR China; Guoxiang Li [gxli@nigpas.ac.cn], Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, PR China.