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The section in the lower middle Cambrian Thorntonia Limestone one kilometre south of Thorntonia Homestead, described by Whitehouse (1940, 1941), has been re-investigated using acid-etching techniqu...

The ophiuroid Bronthaster retus gen. et sp. nov. is described from a single specimen preserved as external dorsal and ventral moulds, and is assigned to the Protasteridae. It occurs in the Namurian...

JELL, P.A., WOODS, J.T. & COOK, A.G., May 2017. Mecochirus Germar (Decapoda: Glypheoidea) in the Lower Cretaceous of Queensland. Alcheringa. ISSN 0311-5518.Three new species of glypheoid decapod crustaceans, Mecochirus mcclymontorum, M. bartholomaii and M. lanceolatus, are described from the late Aptian of the Eromanga, Carpentaria and Maryborough basins, respectively. The first two occur in the Doncaster Member of the Wallumbilla Formation and the last in the Maryborough Formation. This is the first record of Mecochirus Germar, 1827 or the Mecochiridae Van Straelen, 1925 in Australia and one of only a few Cretaceous occurrences of this largely Jurassic genus.Peter A. Jell [amjell@bigpond.com], Jack T. Woods and Alex G. Cook [alex.cook@y7mail.com], School of Earth Sciences, The University of Queensland, St Lucia Queensland 4072, Australia.

The Jack Formation forms part of the Silurian Graveyard Creek Group within the Graveyard Creek Subprovince in northeast Queensland. The formation comprises alternating intervals of carbonate and siliciclastic rocks deposited in a shallow-marine setting. It is very fossiliferous at a number of levels, and contains numerous species of conodonts, rugose and tabulate corals, stromatoporoids, trilobites, brachiopods, crinoids, low-spired gastropods, molluscs, other invertebrates, microvertebrates, and algae. Conodont data indicate that the succession is Wenlock to Ludlow in age at the type section along the Broken River in the Jack Hills Gorge area. Fourteen rugose coral species and one subspecies, referable to eleven genera, are described from the type section of the Jack Formation. New taxa described are Aphyllum pachystele sp. nov., Pycnostylus polyphyllodus sp. nov., Multicarinophyllum vepreculatum sp. nov., Dokophyllum hillae sp. nov., Vesicospina julli gen. et sp. nov. and Ptychophyllum variatum sp. nov. The rugose coral fauna shows a high degree of endemism with only four species recorded outside the Broken River Province. Within eastern Australia, it is comparable with a Gorstian to early Ludfordian fauna of the Yass district, New South Wales (3 species in common), and 1–2 species are also shared with coral faunas from other Silurian localities in New South Wales, Victoria and Tasmania. At the species level, there is very little in common with overseas faunas.

Cook, A.G., Jell, P.A., Webb, G.E., Johnson, M.E. & Baarli, B.G., 21.4.2015. Septate gastropods from the Upper Devonian of the Canning Basin: implications for palaeoecology. Alcheringa 39, 519–524. ISSN 0311-5518Septate murchisoniid gastropods are documented from the Upper Devonian (Frasnian) Pillara Limestone, Canning Basin, Western Australia. Two localities were investigated corresponding to a peri-island and back reef setting. Extensive septation is reviewed for Palaeozoic gastropods and is interpreted to be an adaptation to shallow water, apical breakage in non-euomphaloidean gastropods, or combined with the possible need to adjust calcium levels in the mantle. Fletcherviewia from the Middle Devonian of north Queensland is reassigned to the Murchisoniidae.Alex G. Cook [alex.cook@y7mail.com], Peter A. Jell [p.jell@uq.edu.au] and Gregory E. Webb [g.webb@uq.edu.au], School of Earth Sciences, The University of Queensland, Queensland, 4072, Australia; Markes E. Johnson [mjohnson@williams.edu] and B. Gudvei...

RAVEN, R.J., JELL, P.A. & KNEZOUR, R.A., 9.02.2015. Edwa maryae gen. et sp. nov. in the Norian Blackstone Formation of the Ipswich Basin—the first Triassic spider (Mygalomorphae) from Australia. Alcheringa 39, 000–000. ISSN 0311-5518Edwa maryae gen. et sp. nov. is described as the first fossil diplurid mygalomorph from Australia and the fourth Triassic mygalomorph worldwide. Other fossil diplurids are reviewed: Edwa gen. nov. is included in the Masteriinae; Cretadiplura Selden, Dinodiplura Selden are transferred to the Euagrinae along with Seldischnoplura seldeni gen. et sp. nov., which had been originally assigned to Dinodiplura ambulacra Selden.Robert J. Raven [robert.raven@qm.qld.gov.au] Queensland Museum, GPO Box 3300, South Brisbane, Queensland, 4101, Australia; Peter A. Jell [p.jell@uq.edu.au] School of Earth Sciences, University of Queensland, St Lucia, Queensland, 4072, Australia; Robert A. Knezour [annandrob@optusnet.com.au] 14 Glebe Road, Newtown, Queensland, 4305, Australia.

Jell, P.A., 2014. A Tremadocian asterozoan from Tasmania and a late Llandovery edrioasteroid from Victoria. Alcheringa 38, 528–540. ISSN 0311-5518.An asterozoan, Maydena roadsidensis gen. et sp. nov., is described from the mid-Tremadocian (La1b Zone) Florentine Valley Formation in southwestern Tasmania and is the oldest known asterozoan in the world. Although only a single, largely dissociated, specimen is available, enough is preserved to recognize distinctive ambulacral plates similar to those of Archegonaster Jaekel from the Llanvirn of the Czech Republic. Reciprocodiscus transambus n. gen., n. sp. is an isorophid edrioasteroid from the uppermost late Llandovery Springfield Formation exposed in the bed of Deep Creek, near Springfield, 65 km north northwest of Melbourne. It occurs with a low-diversity trilobite fauna indicating a deepwater, subphotic environment. This edrioasteroid has in each ambulacrum a single series of floor plates that are not visible on the oral surface, indicating its isorophid a...

The distribution of all known Cambrian echinoderm taxa, encompassing both articulated specimens and taxonomically diagnostic isolated ossicles, is documented for the first time. The database described by 2011 comprises 188 species recorded from 65 formations from around the world. Formations that have yielded articulated echinoderms are unequally distributed in space and time. Only Laurentia and West Gondwana provide reasonably complete records at the resolution of Stage. The review of the biogeographical distributions of the eight major echinoderm clades shows that faunas from Laurentia and Northeast Gondwana (China and Korea) are distinct from those of West Gondwana and Southeast Gondwana (Australia); other regions are too poorly sampled to make firm palaeobiogeographical statements. Analysis of alpha diversity (species per formation) shows that diversity rose initially to Cambrian Stage 5, declined into Guzhangian and Paibian before returning to Stage 5 levels by the end of the Cambrian. This pattern is replicated in Laurentia and West Gondwana. We show that taxonomically diagnostic ossicles found in isolation typically occur significantly earlier than the first articulated specimens of the same taxa and provide important information on the first occurrence and palaeobiogeographical distribution of key taxa, and of the phylum as a whole. Supplementary material: Articulated Cambrian echinoderms and Isolated plates of Cambrian echinoderms are provided at: http://www.geolsoc.org.uk/SUP18668

Australian Cretaceous sponge and coral faunas are reviewed and increased with new discoveries. The largest new fauna described, from the very thin Maastrichtian Miria Formation, an uncemented chalky marl, in the Carnarvon Basin, Western Australia, includes a poriferan, Ventriculites sp., the hydrozoans, Stylaster cretaceous sp. nov. and Astya nielseni Wells, 1977 originally described from the Eocene of Tonga and the scleractinian corals Smilotrochus carnarvonensis sp. nov., Conotrochus giraliensis sp. nov., Parasmilia cyensis sp. nov., Palaeopsammia cardabiaensis sp. nov., Flabellum miriaensis sp. nov., Ballanophyllia acostae sp. nov., representatives of five genera left in open nomenclature and Caryophyllia arcotensis (Forbes, 1846), originally described from south India. The Santonian Gingin Chalk, in the northern Perth Basin, Western Australia has yielded the scleractinian corals Ceratotrochus ginginensis (Etheridge 1913), originally assigned to Coelosmilia and Caryophyllia arcotensis (Forbes, 1846), h...

The early Middle Cambrian Monastery Creek Phosphorite (Beetle Creek Formation, Queensland, Australia) contains an assemblage of disarticulated echinoderm ossicles that are exquisitely preserved. Amongst this material we recognize pelmatozoan brachials, radials, basals and holomeric columnals. Although we cannot reconstruct the complete animal with precision, these elements represent the oldest known pelmatozoan with crinoid-like appendages. Key elements include isotomously to heterotomously branched uniserial appendage plates with a tripartite adoral food groove, a longitudinal central canal interpreted as housing entoneural nerve, and differentiated articulation facets. There are also epispire-bearing radials bearing one to four arm insertion-facets, each one pierced by a central neural canal. These canals run internal towards the oral area beneath the external food groove. Co-occuring material includes single truncated cone-shaped basals and holomeric columnals, both with a similar articulation pattern, and irregular, epispire-bearing thecal plates. This mosaic of crinozoan (uniserial isotomous to heterotomous arms with neural canal), blastozoan (epispire-bearing thecal plates, appendage leading to oral thecal food groove without direct connection with body cavity) and apomorphic characters (circumoral instead of basal entoneural plexus) is unexpected and demonstrates that crinoid-like pelmatozoans with uniserial, branched arms appeared significantly earlier than the Tremadocian, when the first articulated crinoid skeletons are found. It also raises questions about the polyphyletic appearance of feeding appendages among pelmatozoan echinoderms.

Jell, P.A., 2013. Placocystella in the Early Devonian (Lochkovian) of central Victoria. Alcheringa, 567–569. ISSN 0311–5518.The South African allanicytidiid mitrate carpoid Placocystella africana (Reed) is recorded for the first time from Australasia having been collected from a Lochkovian bed of the Humevale Formation at Mooroolbark in eastern Melbourne. The Southern Hemisphere Allanicytidiidae incorporating five monospecific genera in Brazil, South Africa, Tasmania, Victoria and New Zealand is now known to have a species in common between South Africa and Victoria. The previously suggested synonymy of these five is revised to accept Placocystella, Tasmanicytidium, Allanicytidium and Australocystis (but not Notocarpos) as synonymous so that the family contains Placocystella with four species and monospecific Notocarpos.Peter A. Jell [p.jell@uq.edu.au], School of Earth Sciences, The University of Queensland, St Lucia Queensland 4072, Australia. Received 10.4.2013; revised 6.6.2013; accepted 17.6.2013.

Molds of numerous Early Carboniferous echinoderms collected by Christian van de Loo for James Hall in 1867 from four miles south of Crawfordsville, Montgomery County, Indiana and now in the collection of the New York State Museum have been examined using latex casting techniques. Described here are the ophiuroidsVandelooaster plicatilisnew genus and species,Schoenaster fimbriatusMeek and Worthen,Aganaster gregariusMeek and Worthen andLumectaster howellinew genus and species. The types ofCalyptactis confragosusMiller are redescribed for comparison. Nine crinoids, a blastoid, and an echinoid are recognized in van de Loo's collection; all have been recorded from Crawfordsville.

Understanding of the palaeoecology of Early Palaeozoic shallow-marine communities in sandy habitats is incomplete. Reasons for this include the poor preservation of body fossils and the dominance of Skolithos piperock in sandstones of that age. Cambrian and Ordovician deposits preserving diverse nearshore trace-fossil assemblages are therefore of critical importance for assessing the early evolution of marine ecosystems. The basal part of the Cambro-Ordovician Bynguano Formation of the Mootwingee area (New South Wales, Australia) is a series of interbedded sandstones and mudstones, which were deposited under nearshore conditions. These strata provide an early example of the Arenicolites ichnofacies. Two ichnocoenoses are distinguished in the sandstones of this unit. A ‘predepositional’ ichnocoenosis, which reflects the benthic community prior to episodes of sand deposition, includes dense aggregations of Rusophycus with rare Planolites. The ‘postdepositional’ ichnocoenosis is more diverse and includes Thalassinoides, Arenicolites (various types), Monocraterion, Skolithos, Trichichnus, and epichnial grooves. The tiered structure developed in this ichnocoenosis is preserved as a ‘frozen tiered profile’ and is characterised by a Thalassinoides tier, 10–30 cm in depth, which is cross-cut by Skolithos and Arenicolitesin the middle tier, and by Arenicolites and Trichichnusin the shallowest tier. The pattern of tiering indicates that a complex ecosystem of opportunistic organisms, capable of exploiting shifting substrates, had evolved by the earliest Ordovician. □Predepositional, postdepositional frozen tier profile, ichnocoenosis, nearshore clastics, RUSOPHYCUS, Cambro-Ordovician, Bynguano Formation, Mootwingee, New South Wales.

Hughes, N. C. & Jell, P. A. 1992 07 15: A stdlislical/compuler-graphic technique for assessing variation in tectonically deformed fossils and its application to Cambrian trilobites from Kashmir. A combined approach using statistics and computer graphics can help resolve patterns of morphological variation in tectonically deformed fossils. Bivariate analyses and Principal Components Analysis can be used to identify a generalized strain vector in populations of deformed fossils, the identification of which permits discrimination of biological and tectonically induced variation. Results can be used to determine the number of taxa and growth relationships within the population. Statistically resolved taxa can be compared with species described from other areas using computer-aided shape restorations. Application of these techniques to a sample of trilobite cranidia from the Cambrian of Kashmir demonstrates that the variation of characters used to diagnose several genera and species are ontogeny- or deformation-controlled. Seven previously described species of Saukia, Prosaukia, Hundwarella and Anomocare are best considered as a single species, Hundwarella personara. These results suggest a Middle Cambrian age for the fauna, which has affinities with other faunas described from India and northern China. Hundwarella personara shows a pattern of developmental flexibility similar to that seen in other Cambrian trilobites. Morphometrics, computer-aided restoration, deformed fossils, allometry, trilobites, Cambrian, Kashmir, developmental flexibility.

Nonmarine Cretaceous sediments representing fluvial/lacustrine deposits occur in 22 of Australia's 23 Mesozoic depositional basins. They are associated with open to marginal marine sediments whose enclosed planktic faunas and floras provide tie points to the Tethyan and European stages. Integration of marine and nonmarine sequences has been effected through spore-pollen biostratigraphies which in turn are linked to macroplant zones, vertebrate ranges and radiometric dates. This evidence is reviewed and it is concluded that the C. hughesii-P. pannosus spore-pollen Zones define Aptian to Albian ages and that their zonal boundaries are isochronous across Australia; the P. mawsonii-F. longus spore-pollen Zones in south-eastern Australia are datable as Turonian-Maastrichtian. However, evidence for a Cenomanian age for the intervening A. distocarinatus Zone is not indubitable. Also, the position of the Jurassic-Cretaceous boundary and the temporal significance of several index taxa of the ?latest Jurassic-Barremian C. australiensis-F. wonthaggiensis Zones in eastern Australia and the B. eneabbaensis-lower B. limbatus Zones in Western Australia is not certain. Isochronous incomings of individual spore-pollen taxa on a regional scale relate to the mode of dispersal of the source plant, and to the distribution of environments suitable for dispersal. For the Aptian-Albian, when Australia was inundated by shallow seas and lake/river systems that fed into them, several index taxa sourced from aquatic and strandline plants appear to have temporal significance. By contrast, anemophilous pollen are stratigraphically useful and temporally significant in the Turonian-Maastrichtian of south-eastern Australia. Throughout the Cretaceous, Australia supported a succession of coniferous forests. Early Cretaceous podocarp/araucarian/ Ginkgo canopy associations were modified in the Late Cretaceous by the loss of Ginkgo and the introduction of rainforest Proteaceae and Nothofagus . Regional variations in the vegetation reflect topographic, edaphic and climatic variations between the disparate sedimentary basins. Floral migration within Australia and between associated land masses occurred in a step-wise fashion, and was mostly west to east. Two dinosaur faunas are recognized: one, in the Aptian-early Albian of Victoria, consists of small ornithopods and theropods; and the other, in the middle Albian-Cenomanian of Queensland, comprises ankylosaurs, sauropods and theropods. The Victorian herbivorous dinosaurs were low feeders and probably shared a single mode of feeding, whereas those from Queensland may have had several feeding modes and fed up to 6 m from the ground. The small ornithopods, mostly from Victoria, were hypsilophodontians with grinding dentitions; their food source may have been lycopods or diaspores of podocarps and Ginkgo . Ankylosaurs seem to have preferred soft vegetation, some possibly aquatic. The Queensland sauropods may have fed on living and dead vegetation, perhaps including fleshy seeds of podocarps/taxads and gleicheniaceous ferns that apparently proliferated in the region. The lungfish had grinding toothplates and were probably omnivorous like extant Neoceratodus forsteri . Victorian faunas contain several relicts including the youngest known temnospondyl, the theropod Allosaurus , the lungfish Ceratodus avus , and the freshwater mussel Mesohydridella ipsviciensis . Australian earliest Cretaceous climates were temperate with cool temperatures (0–12°C) and high precipitation levels (750–1150 mm/year) in southern regions where winter freezing may have occurred during the Aptian. A warming trend during the Albian is indicated by land vegetation and verified by isotope palaeotemperatures (12–16°C) from the marine realm. Cool to warm temperate climates prevailed in the south-east during Turonian-Maastrichtian times; sea water temperatures were 16–28°C, and the vegetation is indicative of high humidities.

A rich assemblage of early Middle Cambrian brachiopods from the ‘first discovery limestone’ of the Coonigan Formation, western N.S.W. contains 20 taxa (eight Articulata, 11 Inarticulata and one which cannot be assigned with certainty to either class). New articulate species are Nisusia grandis grandis, N. grandis glabra, Wimanella tricavata, Arctohedra alata, Acareorthis jelli, Cymbricia spinicostata, Austrohedra mimica and Glaphyrorthis fastigata, with the last four mentioned new genera. Inarticulate taxa include species of Trematosia and ?Kutorgina, Hadrotreta primaeva (Walcott), Micromitra nerranubawu Kruse and new species of Kleithriatreta lamellosa, Eothele granulata, Dictyonina australis, Palaeoschmidites horizontalis, Lingulella bynguanoensis, Westonia cymbricensis, and an indeterminate lingulacean; Kleithriatreta is a new genus. The enigmatic new genus and species Bynguanoia perplexa cannot be placed within either the Articulata or Inarticulata. Seven taxa are endemic, six are comparable with taxa...

Guest Editors: KEITH M. SCOTT and PETER A. JELL Research School of Earth Sciences, The Australian National University and CSIRO Earth Sciences and Resource Engineering, PO Box 136, North Ryde, NSW 1670, Australia. E-mail: keith.scott@csiro.au Geological Survey of Queensland, Department of Natural Resources and Mines, GPO Box 15216, City East, QLD 4002, Australia. E-mail: peter.jell@deedi.qld.gov.au

Geologist with a passion for ancient corals, and the first woman to reach the pinnacles of Australian science

Cambrian trilobite faunas from northern India provide data critical for assessing earliest Phanerozoic paleogeography and for constraining tectonic models of Himalayan evolution. Previous investigations suggest that Indian Middle Cambrian trilobite faunas, collected from basins 500 km apart, are strikingly different. The Kashmir fauna, in the west, shows supposed faunal affinities with northern China, while the Spiti fauna, in the east, was considered of European affinity. This counterintuitive faunal distribution in adjacent basins might suggest that the area was made up of several micro-contininents during Cambrian time. Although frequently neglected, this interpretation has major implications for models of Himalayan mountain building, as most models assume a passive northern margin of India throughout the Phanerozoic.Original type material from Kashmir and Spiti and fresh collections from intermediate localities in the Zanskar valley have been evaluated using a new statistical/computer-graphic method which removes the effects of tectonic deformation. Results show that the supposed taxonomic distinctness of the Kashmiri and Spiti faunas is largely superficial. Previous lack of appreciation of deformation has lead to: 1. over-estimation of the number of taxa present; 2. misidentification of many taxa; 3. spurious correlations with other faunas; 4. inaccurate age estimates. The revised assessment indicates that: 1. approximately 12 species of polymerid trilobites are present in the Middle Cambrian of north India; 2. 3 polymerid trilobite species are common to both Kashmir and Spiti faunas; 3. much of the Spiti fauna is significantly older than the Kashmiri fauna; 4. faunal differences between coeval deposits from the two basins are best explained as biofacies differences related to an offshore proximality trend; 5. species show patterns of developmental flexibility similar to that recently reported in other Cambrian trilobites. The faunas do not suggest that Kashmir and Spiti were part of separate continents during the Cambrian.The morphology of Middle Cambrian faunas from Kashmir, Zanskar and Spiti suggests that all polymerid species were benthic and share morphotypes characteristic of trilobites from slope environments. Lithologic evidence suggesting that Kashmiri faunas were deeper water than those from Spiti is complimented by the presence in Kashmir of the atheloptic trilobite Bailiella, which is characteristic of deeper waters. Faunas from Kashmir, Zanskar and Spiti, which lie within the Tethyan belt of the Indian Himalaya, share closest affinity with those described from north China, north Vietnam and south China. They also show affinity with faunas from Iran. This pattern is consistent with recent paleogeographic reconstructions which place these regions in close proximity and at similar latitudes. Most of the Cambrian within the Tethyan Himalaya is of middle Middle Cambrian age.The recognition of developmental flexibility as a general characteristic of Cambrian trilobites suggests many groups may be taxonomically over-split. Over-splitting may have lead to widespread over-estimation of faunal provinciality during Cambrian times.

Plumulites richorum sp. nov. is represented by two complete sclerite assemblages from Early Devonian strata of the Humevale Formation in a small quarry northeast of Kinglake West, Victoria. The completeness of these sclerite assemblages necessitates a revision of terminology applied to machaeridians. Moreover, the sclerite assemblages make it necessary to erect a new Family Plumulitidae and allow several deductions about the animal itself, namely: 1, there was a discrete head possibly with soft anterior projections; 2, there was considerable modification of sclerites and their arrangement near the head, indicating possible sexual dimorphism; 3, sclerites were almost certainly not rigidly attached to the soft parts of the animal. The material shows that Plumulites was neither an arthropod nor an echinoderm, but rather a vagile benthic animal probably belonging to the Annelida.

The acid insoluble sclerites of Thambetolepis delicata gen. et sp. nov. of late Tommotian or immediately post-Tommotian age from near Ardrossan, South Australia, are described. These sclerites, as well as those of Sachites Meshkova 1969 and Halkieria Poulsen 1967, are from multi-sclerite animals similar to Wiwaxia Walcott 1911 together with which they constitute the new class Thambetolepidea. Biological affinities of these fossils are discussed in the light of the complex internal structure of the sclerites. Possible assignments to the opisthobranch gastropods, the polyplacophorans, or the annelids are discussed but the taxonomic position of Thambetolepis and the Thambetolepidea is unresolved.

A small millipede with distinctive tergal ornament is described from the Westgrove Ironstone Member in the upper part of the Early Jurassic Evergreen Formation in the Surat Basin, Queensland. Its taxonomic placement within the class is uncertain at present as the species displays characters of two orders and is incompletely known. It is the first description of fossils of the class Diplopoda from Australia. The material, consisting of two poorly preserved incomplete individuals is described as Decorotergum warrenae gen. et sp. nov.

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 die new family Lipoporidae and tentatively referred to the Tabulata.

An early Late Cambrian trilobite faunule of fewer than 20 specimens and including Monkaspis sp. cf. M. serrata Mong, ?Blackwelderia sp. and Cyclolorenzella sp. is recorded from the Trahagam Formation near the village of Trahagam in Hundwara Tehsil, Kashmir, India. The faunule occurs in green shales and provides the first unequivocal Late Cambrian date for sediments in Kashmir; Kashmiri fossil faunas previously ascribed Late Cambrian ages by Reed are now considered Middle Cambrian.

Four different types of structures on fossil arthropods are shown to have been grouped under the term ‘genal caeca’. These are distinguished and the most conspicuous (i.e. the fine radiating cephalic ridges of trilobites that anastomose repeatedly before joining a major ridge in the border) are interpreted as the external representation of auxiliary respiratory systems at least in some Cambrian genera. A number of possible functions are considered for these ridges and none but respiration is found to be feasible. Supportive evidence for the hypothesis outlined is drawn from consideration of the paradigm for a dorsal respiratory system and from a comparison with living crustacea.

A new genus and species of fordilloid pelecypod, Pojetaia runnegari gen. et sp. nov., is described from the lower part of the Parara Limestone, Yorke Peninsula, South Australia. Establishing the age of the sample on an international scale is difficult, as with almost all Early Cambrian formations, but evidence tends to suggest that this is the oldest pelecypod so far recorded. Clearly defined hinge teeth and sockets on both valves and on internal moulds help to confirm the pelecypod placement of fordilloids.

Twenty-eight species of fifteen genera of Middle Cambrian molluscs are described from tiny phosphatic moulds or silica replicas of the shells. The molluscs were etched from limestones at two sites: one in the earliest Middle Cambrian Coonigan Formation of the Mootwingee area, 130 km northeast of Broken Hill, New South Wales; and another in the middle Middle Cambrian Currant Bush Limestone of the Thorntonia area, 150 km northwest of Mt Isa, Queensland. These unusually diverse collections show that many different kinds of molluscs lived in the tropical Australian seas of the Middle Cambrian and provide new information on the way the molluscan classes Cephalopoda, Gastropoda, Rostro- conchia, and Pelecypoda evolved. In other sections, we discuss the problems of classifying and naming Cambrian molluscs; define a number of terms that can be used to describe shell form (including a new adjective, gyrogastric); reclassify the Class Monoplacophora after incorporating the helcionellacean and bellerophontacean “gas...

Two species of arthropods are described from the earliest Ordovician (Lancefieldian, La 1) Zone east of Lancefield in central Victoria some 60 km north of Melbourne. Corcorania trispinosa gen. et sp. nov., with three prominent anterior head spines, seven trunk segments, a short distinctive posterior shield and large spinose appendages, is apparently unrelated to any previously known arthropod, fossil or living, and represents a new family (Corcoraniidae). Similarities between a small specimen of Corcorania and Mollisonia from the Burgess Shale are noted but no phylogenetic position for Corcorania is proposed. Caryocaris stewarti sp. nov. is described as a new phyllocarid distinguished by the various spines of its carapace and by the shape of its furcal rami.

The Cambrian Monoplacophora Anabarella, Mellopegma and Stenotheca were incorrectly referred to the Family Procarinariidae Wenz 1938 by Runnegar & Jell (1976) because Horný (1964a) has shown that Procarinaria is a bivalve. A new family, Stenothecidae, is therefore proposed. Also, two genera of Cambrian pelagiellids described by Horný (1964b) were omitted from a discussion of the family in Runnegar & Jell (1976). Information which has been obtained since 1976 shows that the snorkel of Yochelcionella cyrano was much longer than previously thought, that Yochelcionella occurs in Pennsylvania as well as Australia, that the Ordovician and Silurian microfossils Janospira and Jinoncella may be related to Yochelcionella, and that Runnegar & Jell were probably correct in referring all bellerophont univalves to the Monoplacophora, rather than to the Gastropoda where they have been traditionally placed.