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Discoveries from the Late Devonian Gogo Formation, in the Canning Basin, Western Australia have provided insights into the origin and evolution of many unique gnathostome features such as the origins of teeth, internal fertilisation, air-breathing, transitional tissues between bone and cartilage, and insights into the fin to limb transition. Although vertebrate studies have dominated evolutionary work, invertebrate studies have added important insights into the palaeoecology of the site and demonstrated close faunal affinities along the margins of northern Gondwana and China. Geochemical analyses have broadened the understanding of the pathways involved in the exceptional preservation of this Devonian Konservat-Lagerstatte. Fossils from the Gogo Formation show extensive soft tissue preservation through phosphatization recording anatomical details not normally obtained from fossil sites.

The tetrapodomorph fish, Gogonasus andrewsae is a three dimensionally well-preserved sarcopterygian from the Gogo Formation (Frasnian, early Upper Devonian, ∼380 million years ago) in Western Australia. High-resolution X-ray Micro-Computed Tomography and 3D printouts were used to obtain a digital reconstruction of its shoulder girdle and opercular series. Our new findings show the opercular series in a close fit against the upper bones of the shoulder girdle only if the anocleithrum, supracleithrum and post-temporal are aligned more horizontally than in previous reconstructions. The lowermost subopercular bone also differs, in partly covering the clavicle of the shoulder girdle. The ascending process of the clavicle, and the ventral process of the anocleithrum, do not fit closely inside the cleithrum, and perhaps functioned for ligamentous attachment. A rugose area on the anocleithral process is in a similar relative position to the attachment of a muscle ligament on the shoulder girdle of various living actinopterygians. Our manipulation of 3D printouts permits testing of the morphological fit of extremely fragile acid-etched bones, and indicates a new way to investigate the constructional morphology of one or more mechanical units of the vertebrate skeleton. It is suggested that Micro-CT imaging, reconstruction, visualisation and 3D printing techniques will provide a rigorous new test leading to modification of previous reconstructions of extinct vertebrates that were based on graphical methods and 2D imaging.

The mudstones of the Western Australian Gogo Formation harbour numerous carbonate concretions which often contain preserved fossils of Lagerstätte-like quality. These are especially notable in places where the mudstone has eroded, giving way to nodule fields, which afford valuable paleobiological records. It is, however, a challenge to determine their paleoenvironmental context. Here, we analysed concretions from a core drilled in the Canning Basin Gogo Formation. At two different depths, concretions were compared to the surrounding mudstone found at the same depth. Electron microscopy and X-ray spectroscopy showed that the concretions were carbonate-rich and contained detrital fragments. Biomarker data showed that mudstone and concretions had very similar distributions and presented marine biosignatures including indicators of anoxic depositional conditions, a stratified water column, and photic zone euxinia. The concretions contained higher amounts of C27 steranes, indicating that more labile organic matter such as animal remains could have triggered concretion formation. Statistical analyses of the results showed that concretions and shales differed (p < 0.1) in indices diagnostic for lithologies (and often related to maturity), particularly in the sample recovered from the younger section of the core: the diasterane/sterane indices at each of the depths were 0.34 in the shale vs 0.12 in the concretion in the younger set of samples, and 0.21 vs 0.19 in the older set. The homohopane isomerisation indices of the mudstone and concretion were 0.66 vs 0.58 and 0.62 vs 0.60 (47 and 54 m depth, respectively). Furthermore, shales contained higher relative amounts of moretanes. Concretions also differed from the mudstone in their methylhopane distributions, with shales showing higher amounts of 3-methylhopanes. Conversely, when biomarker composition was compared at the two depths, they only differed significantly (p < 0.1) in the 2-methylhopane index,%C31 homohopanes, and hopane/sterane ratios (p < 0.1). Our results show that the biomarker composition of the mudstone at the time of deposition is largely preserved in the concretions with only a minor overprint from diagenesis, bacterial communities involved in concretion formation, or the organic matter nucleus. It is therefore possible to use biomarker analysis on carbonate concretions to determine their provenance if found outside their immediate geological context., NASA Astrobiology Institute (Award NNA13AA90A)

The lowermost Famennian deposits of the Kowala quarry (Holy Cross Mountains, Poland) are becoming famous for their rich fossil content such as their abundant phosphatized arthropod remains (mostly thylacocephalans). Here, for the first time, palaeontological and geochemical data were integrated to document abundance and diversity patterns in the context of palaeoenvironmental changes. During deposition, the generally oxic to suboxic conditions were interrupted at least twice by the onset of photic zone euxinia (PZE). Previously, PZE was considered as essential in preserving phosphatised fossils from, e.g., the famous Gogo Formation, Australia. Here, we show, however, that during PZE, the abundance of arthropods drastically dropped. The phosphorous content during PZE was also very low in comparison to that from oxic-suboxic intervals where arthropods are the most abundant. As phosphorous is essential for phosphatisation but also tends to flux off the sediment during bottom water anoxia, we propose that the PZE in such a case does not promote the fossilisation of the arthropods but instead leads to their impoverishment and non-preservation. Thus, the PZE conditions with anoxic bottom waters cannot be presumed as universal for exceptional fossil preservation by phosphatisation, and caution must be paid when interpreting the fossil abundance on the background of redox conditions.

One of the first endocasts of a dipnoan (lungfish) to be realised was that of the Upper Devonian taxon Chirodipterus australis. This early interpretation was based on observations of the shape of the cranial cavity alone and was not based on a natural cast or ‘steinkern’ nor from serial sectioning. The validity of this reconstruction is therefore questionable and continued reference to and use of this interpretation in analyses of sarcopterygian cranial evolution runs the risk of propagation of error. Here we present a new detailed anatomical description of the endocast of ‘Chirodipterus’ australis from the Upper Devonian Gogo Formation of Western Australia, known for exceptional 3D preservation which enables fine-scale scrutiny of endocranial anatomy. We show that it exhibits a suite of characters more typical of Lower and Middle Devonian dipnoan taxa. Notably, the small utricular recess is unexpected for a taxon of this age, whereas the ventral expansion of the telencephalon is more typical of more derived taxa. The presence of such ’primitive’ characters in ‘C.’ australis supports its relatively basal position as demonstrated in the most recent phylogenies of Devonian Dipnoi.

Micro computed tomography has revealed as yet undescribed internal braincase anatomy of the tetrapodomorph fishGogonasus andrewsaefrom the Frasnian Gogo Formation, Paddy's Valley, Kimberley Region, Western Australia. The complete material, including the cranial cavities and channels for blood vessels and nerves, reveals several notable features inside the endocranium. The ethmosphenoid unit includes a median capsule, which lies underneath the median postrostral and rostral series. Based on innervation and association with cutaneous vessels, potential electroreceptive function is inferred for this capsule. Several regions of poor ossification, including foramina for the glossopharyngeal and abducens nerves, as well as the apparent suture separating the ethmoid from the sphenoid portions of the braincase, are possibly indicative of early ontogenetic features. Former interpretations of the course for the superficial ophthalmic nerve inside the nasal capsule ofOsteolepisandGyroptychiusmay be incorrect, with new research supporting a path through the nasal septum, as inGogonasus.

Photic zone euxinia (PZE) has proven important for elucidating biogeochemical changes that occur during oceanic anoxic events, including mass extinction and conditions associated with unique fossil preservation. Organic geochemical analyses of a 380 Ma invertebrate fossil, which included well-preserved soft tissues, from the Gogo Formation (Canning Basin, Western Australia) showed biomarkers and stable isotopic values characteristic of PZE and a consortium of sulfate-reducing bacteria, which lead to exceptional fossil and biomarker preservation. The carbonate concretion contained phytoplankton, green sulfur bacteria (Chlorobi), and sulfate-reducing bacteria biomarkers with an increasing concentration toward the nucleus where the fossil is preserved. The spatial distribution of cholestane unequivocally associated with the fossilized tissue and its high relative abundance to the total steranes suggest that the fossil is a crustacean. The presence of an active sulfur cycle in this Devonian system, including sulfate reduction and the resulting PZE, played a pivotal role in the preservation of soft tissue from the fossil and its associated low-maturity biomarker ratios.

A new acanthodiform acanthodian Halimacanthodes ahlbergi n. gen. n. sp., based on a single uncrushed, partial articulated specimen, represents the first acanthodian collected from the Gogo Formation, Canning Basin, Western Australia. The delicate perichondral ossifications of the lower jaws, branchial skeleton and endoskeletal shoulder girdle are preserved in 3D. H. ahlbergi n. gen. n. sp. is characterised by having a tall slender scapular shaft, paired pelvic fin spines, mineralised branchial arches and scales with an anterior median depression and a microornament of tiny smooth tubercles randomly distributed on the crown. In having paired pelvic spines and lacking prepelvic spines, it is most closely related to Howittacanthus kentoni from Frasnian lacustrine deposits of eastern Victoria. Isolated scales, here attributed to the new taxon, are found in the coeval Gneudna Formation, Carnarvon Basin, Western Australia.

A new basal actinopterygian fish, Donnrosenia schaefferi gen. et sp. nov., is described from the Middle Devonian (Givetian) Aztec Siltstone of southern Victoria Land, Antarctica. Donnrosenia gen. nov. is characterized by the large parietals which are of almost equivalent size to the frontals, very small intertemporals, a small accessory operculum situated dorsally to the prominent anterodorsal process of the suboperculum, a deep dentary with anterior flexure, porous ornamentation on the clavicle, an elongate body form with macromeric squamation, an absence of paired fringing fulcra on the fins, and pectoral lepidotrichia which are unsegmented for much of their length. A phylogenetic analysis based on dermal skeletal features of Devonian actinopterygians indicates that Donnrosenia gen. nov. is the sister taxon to Howqualepis from the Middle Devonian of Victoria, Australia, and is embedded within a possible clade containing the actinopterygians from the Gogo Formation, Western Australia. This supports the concept of an endemic radiation of East Gondwanan actinopterygians, and reinforces the already strong biogeographical similarities between the Middle Devonian palaeofaunas of Australia and Antarctica.

A new eurypterid, Rhenopterus waterstoni sp. nov., is described from the Gogo Formation (Frasnian, Upper Devonian) of Western Australia. This species is distinguished from related forms by the tuberculation of the anteriormost tergite and crenulated posterior margins of the carapace and opisthosomal segments. It is the only eurypterid specimen known from the Gogo Formation, the most complete eurypterid from Australia, and also the youngest representative of Rhenopterus in the fossil record. Structures retrieved from between the prosomal-opisthosomal juncture comprise polygonal tubes 30–40 μm in diameter, which are interpreted as sarcomeral sheaths of muscular tissue. Rhenopterus is reviewed: R. latus Stormer, 1936 is synonymized with R. diensti Stormer, 1936 as it is here recognized as a female sexual dimorph; R. maccarthyi (Kjellesvig-Waering, 1934) is an orthocone nautiloid.

This work is a contribution to IGCP 596., Here we present new data from the first well-preserved chondrichthyan fossil from the early Late Devonian (ca. 380–384 Mya) Gogo Formation Lägerstatte of Western Australia. The specimen is the first Devonian shark body fossil to be acid-prepared, revealing the endoskeletal elements as three-dimensional undistorted units: Meckel’s cartilages, nasal, ceratohyal, basibranchial and possible epibranchial cartilages, plus left and right scapulocoracoids, as well as teeth and scales. This unique specimen is assigned to Gogoselachus lynnbeazleyae n. gen. n. sp., This work was supported by grants from the Australian Research Council DP 0772138 awarded to GCY and JAL for travel and scanning of specimens at the ANU; and DP1092870 awarded to KMT for travel to collaborate. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Lenticular stromatolite-barite-sulfide mounds, interpreted as sedimentary exhalative deposits, are exposed at several localities in Devonian reef complexes of the Canning basin, Western Australia. These mounds, hundreds of meters long and tens of meters thick, occur along contacts between basinal shales (Gogo Formation) and marginal-slope limestones (Sadler Limestone) and adjacent to synsedimentary faults cutting the Gogo Formation. The mounds are limestone buildups, composed of stromatolites intergrown with barite and cut by iron sulfide veins. The iron sulfides (marcasite and pyrite) are weathered to gossans at the surface. They fill fissures that probably formed as a result of contemporary seismic activity and the early compaction of underlying and adjoining shales. The stromatolite-barite-sulfide deposits also occur as allochthonous clasts in penecontemporaneous debris-flow deposits. Postdepositional compaction of basinal shales in the Gogo Formation commonly amounted to about 75 percent. This resulted in the expulsion of large volumes of fluids along permeable interbeds, shale-limestone contacts, and synsedimentary faults, reaching the sea floor as cool-fluid seepages. The expelled fluids carried dissolved carbonate, barium, iron, and reduced sulfur. They probably nourished chemosynthetic bacteria that mediated the deposition of stromatolites, barite, and iron sulfides, resulting in growth of the stromatolite-barite-sulfide buildups. There is no known economic mineralization in the exhalative buildups, but some drill holes encountered minor uneconomic veins of epigenetic Zn-Pb mineralization, filling narrow fissures that postdate the exhalative deposits. Economic epigenetic Zn-Pb deposits that have been mined elsewhere in the same general area of the Canning basin were formed during the early Carboniferous or latest Devonian, many millions of years after the exhalative deposits. Both exhalative and epigenetic phases of mineralization are thought to have been sourced through the compaction-driven dewatering of shales. The exhalative deposits are interpreted to have formed over seepages of cool fluids having salinities close to that of seawater, whereas the epigenetic deposits formed from much hotter fluids, probably brines, expelled during subsequent shale compaction.

The squamation of a complete palaeoniscoid, M. durgaringa Gardiner & Bartram, 1977, from the Frasnian Gogo Formation is described. A variety of isolated scales from the Gneudna Formation, Carnarvon Basin, are referred to M. durgaringa on the basis of comparison with the described articulated specimen. Scales of various forms are attributed to specific regions of the body.

Lungfish, or dipnoans, have a history spanning over 400 million years and are the closest living sister taxon to the tetrapods. Most Devonian lungfish had heavily ossified endoskeletons, whereas most Mesozoic and Cenozoic lungfish had largely cartilaginous endoskeletons and are usually known only from isolated tooth plates or disarticulated bone fragments. There is thus a substantial temporal and evolutionary gap in our understanding of lungfish endoskeletal morphology, between the diverse and highly variable Devonian forms on the one hand and the three extant genera on the other. Here we present a virtual cranial endocast of Rhinodipterus kimberleyensis, from the Late Devonian Gogo Formation of Australia, one of the most derived fossil dipnoans with a well-ossified braincase. This endocast, generated from a Computed Microtomography (µCT) scan of the skull, is the first virtual endocast of any lungfish published, and only the third fossil dipnoan endocast to be illustrated in its entirety. Key features include long olfactory canals, a telencephalic cavity with a moderate degree of ventral expansion, large suparaotic cavities, and moderately enlarged utricular recesses. It has numerous similarities to the endocasts of Chirodipterus wildungensis and Griphognathus whitei, and to a lesser degree to 'Chirodipterus' australis and Dipnorhynchus sussmilchi. Among extant lungfish, it consistently resembles Neoceratodus more closely than Lepidosiren and Protopterus. Several trends in the evolution of the brains and labyrinth regions in dipnoans, such as the expansions of the utricular recess and telencephalic regions over time, are identified and discussed.

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.

Co-occuring conodonts, radiolarians, and sponge spicules from the type locality of the Slaven Chert, northern Shoshone Range, Nevada, indicate that the radiolarian and sponge spicule assemblage described herein correlates with the Late rhenana conodont Zone (late Frasnian). The moderately well preserved radiolarians are the first Frasnian-age fauna described from the Western Hemisphere. They include spumellarians, Ceratoikiscum, and Paleoscenidium, and a radiolarian which we have assigned to a new genus, Durahelenifore Boundy-Sanders and Murchey, with its type species, Durahelenifore robustum Boundy-Sanders and Murchey. Sponge spicules include umbellate microscleres of the Subclass Amphidiscophora, Order Hemidiscosa, previously documented only in Pennsylvanian and younger rocks. INTRODUCTION Most of the documentation of Devonian radiolarian faunas, and all of the documentation of Western Hemisphere faunas, has been of Famennian taxa (Foreman 1963; Coles and Snyder 1985; Cheng 1986; Aitchison 1990; Coles 1991; Noble 1992; Aitchison, in press). Previously, the only well-dated Frasnian faunas have been from the southern Urals (Nazarov 1975), the Gogo Formation of Western Australia (Nazarov et al. 1982; Nazarov and Ormiston 1983; Aitchison, 1993), from the Yarrimie Formation near Tamworth, New South Wales, eastern Australia (Aitchison 1990), and from the Liukiang Formation, eastern and southern Guangxi Province, China (Li and Wang 1991). The fauna described in this paper is the first Frasnian fauna described from the Western Hemisphere. We focus on samples from the type locality of the Slaven Chert in Nevada, but the most distinctive and previously undescribed species in the assemblage also occurs in the Barita de Sonora district near Hermosillo, Mexico, and in the Yugambal terrane of the eastern New England orogen, Western Australia (J.C. Aitchison, written commun. 1992). A similar radiolarian occurs in the Gamilaroi terrane of the New England orogen, Eastern Australia, in rocks thought to be Middle Devonian in age (J.C. Aitchison, written commun. 1993). The Nevada locality has yielded not only sponge spicules and the new radiolarian species, but also an abundance of conodonts which indicate that this assemblage correlates with the late Frasnian Late rhenana Zone (Ziegler and Sandberg 1990). This *Present address: 17859 149th Ave. NE, Woodinville WA 98072-6202 co-occurrence provides an important tie between radiolarian and conodont biochronologies. The new radiolarian, Durahelenifore robustum n. gen. and n. sp., shares many characteristics with the genus Helenifore. We suggest that the heleniforids may be diagnostic of the upper part of the Frasnian Stage, although they do not occur in every deep-water Frasnian assemblage (Li and Wang 1991). The occurrence of hemidiscid sponge spicules in the Slaven Chert samples extends the range of this spicule morphology downward from its previous lowest known occurrence in Pennsylvanian rocks (Finks 1983). Previously published radiolarian biostratigraphies cover Famennian and higher strata (Holdsworth and Jones 1980a, b; Miller et al. 1984; Cheng 1986 and Holdsworth therein; Schwartzapfel 1990). A radiolarian biostratigraphy for Frasnian and lower strata awaits the discovery and study of coherent, continuous sections. GEOLOGIC SETTING The Devonian Slaven Chert traditionally has been regarded as the youngest formation in the Roberts Mountains allochthon (Madrid 1987; Gilluly and Gates 1965). The Roberts Mountains sequence was deposited in a basin that may be described as episodically sediment-starved: cherts of Ordovician, Silurian, and Devonian age alternate with numerous and in places voluminous sequences of clastic rocks. Although the connection between the Roberts Mountains allochthon and other North American sequences is well accepted, several lithostratigraphic, sedimentological, and faunal differences warn against drawing an overly facile correlation between the Roberts Mountains allochthon and the distal miogeoclinal section of east-central Alaska (Turner, Madrid, and Miller micropaleontology, vol. 45, no. 1, pp. 62-68, text-figures 1-2, plates 1-2, table 1, 1999 62 This content downloaded from 207.46.13.120 on Wed, 14 Sep 2016 04:13:00 UTC All use subject to http://about.jstor.org/terms Micropaleontology, vol. 45, no. 1, 1999

This is the first of two publications dealing with a study of the family Entactiniidae and the taxonomy of a diverse assemblage of Late Devonian spumellarians. A well-preserved radiolarian fauna from the Gogo Formation, Western Australia, has made it possible to clarify the relation of the shell wall and internal structure in this family. The entactiniid shell is of two types: spongy and latticed. The former has apophyses on rays of the internal spicule, whereas those with latticed shells have an internal spicule without apophyses. On the basis of the internal spicule structure the Entactiniidae can also be divided into four types: (1) six-rayed spicule without a median bar, (2) four-rayed spicule without median bar, (3) sixto eight-rayed spicule with a median bar, and (4) twelveto twenty-rayed spicule with a median bar. The Gogo fauna includes more than 100 species. Entactiniids or taxa having characteristics similar to Entactiniidae are treated here. They comprise 17 genera and 72 species and subspecies, of which 13 genera and 66 species and subspecies are new. Bisphaera, Radiobisphaera, Plenoentactinia, Apophysisphaera, Retentactinia, Retisphaera, Spongosphaera, Duodecimentactiniaand Multientactinia belong to the Family Entactiniidae. Apophysiactinia, Magnisphaera, Magnentactinia, and Intracorpus, are of uncertain taxonomic position. Entactiniid genera of this fauna are tentatively classified into two subfamilies: (1) Entactiniinae, which has a latticed shell(s) and lacks apophyses, and (2) Retentactiniinae n. subfam., characterized by a spongy shell and possessing apophyses. Taxa belonging to subfamily Entactiniinae plus taxa having characteristics similar to Entactiniidae, and subfamily Retentactiniinae are described respectively in this paper and in a second paper in this volume (Won 1997).

Fifteen taxa of polycystine radiolarians are described and illustrated from calcareous nodules in the Frasnian Gogo Formation. Because of poor preservation most taxa are placed in open nomenclature. The fauna includes Palaeoscenidium and entactiniids common in the Late Devonian of North America and the USSR. Spongentactinella windjanensis is described as new.

Ninety species of conodont are recorded from rocks of Frasnian age in the Bugle Gap area in the Canning Basin of Western Australia: 56 of these species are reported for the first time from the Canning Basin. One new subspecies is described. Two parallel but disparate conodont sequences are present, which are presumed to represent different environments: one, the Palmatolepis sequence of the standard zonation is present in the uppermost beds of the Sadler Limestone at Sadler Ridge, the Gogo Formation, and much but not all of the Virgin Hills Formation, and presumably represents an inter‐reef faunal succession; the other consists of a sequence of Icriodus assemblages which is present in the Sadler Limestone and a part of the Virgin Hills Formation at Lawford Range. An Icriodus zonation is proposed for this sequence. No conodonts were recovered from many samples of the Pillara Limestone (back‐reef facies) in the Bugle Gap area. Conodont data presented here suggest that the Gogo Formation in this are...

SynopsisCoccosteus cuspidatusis shown to be the correct name for the arthrodire commonly referred to asCoccosteus decipiens.An almost complete account of the osteology of this species is given and aspects of the restored head, thoracic armour, fins and posterior unarmoured region, the dermal ornamentation, neuromast system and musculature are discussed; the snout, dermal bones of the palate and neural endocranium receive special treatment in view of the part these structures have played in the interpretation of the relationships of the Arthrodira. Changes in the proportions of certain bones during growth are noted and the mode of life is considered. The family Coccosteidae is redefined; the genusCoccosteusand the type speciesC. cuspidatusare defined and consideration is given to other species included in this genus.

Thylacocephalans are enigmatic arthropods with an erratic Palaeozoic and Mesozoic fossil record. In many of the few localities where they occur, they are quite abundant. This also holds true for the Famennian Thylacocephalan Layer in the Maider (eastern Anti-Atlas of Morocco), a small epicontinental basin hosting some strata with taphonomic properties of a conservation deposit yielding exceptionally preserved gnathostomes and non-vertebrates. In a thin argillaceous interval in the earliest middle Famennian, thylacocephalans occur in such great numbers that they became eponyms of this unit. Therein, we discovered a new taxon of thylacocephalans, Concavicaris submarinus sp. nov., which represent the oldest records of thylacocephalans from Africa. In the CT-imagery, the holotype of Concavicaris submarinus sp. nov. revealed anatomical details including its eyes, appendages and other soft parts. Sedimentary facies and faunal composition of the Thylacocephalan Layer suggest that these animals populated the water column above the low-oxygen sea floor. Thus, thylacocephalans likely represented an important component of the diet of chondrichthyans and placoderms, which are quite common as well. The abundance of thylacocephalans in other conservation deposits like the Cleveland Shale (USA) and the Gogo Formation (Australia) underline their pivotal role in Late Devonian pelagic food webs.

Sixteen polycystine radiolarian species recovered from a single sample of the Gogo Formation, Western Australia, are described and illustrated. The material derives from one of the samples used by Glenister and Klapper (1966) for their conodont zonation of the Canning Basin and is of Polygnathus asymmetrica Zone age. The well-preserved radiolarians include Ceratoikiscum, Palaeoscenidium, and representatives of seven genera similar to entactinid forms known especially in Ohio (Foreman 1963), in the Urals (Nazarov 1975), and Byelorussia (Nazarov and Kruycheck 1977). Somewhat surprisingly, and apparently because of differences in stratigraphic level or biofacies, there is less similarity to the radiolarian assemblage of the Gogo Formation recently described by Nazarov, Cockbain and Playford (1982). Newly described taxa include one new genus, Helenifore, and four new species, Helenifore laticlavium, Helioentactinia perjucunda, Spongentactinella corynacantha, and Ceratoikiscum vimenum. INTRODUCTION As a result of the pioneering work of Helen Foreman on structurally preserved, free specimens of Upper Devonian radiolaria and the continued work on such forms in other widely separated Devonian sections such as the Urals (Nazarov 1975), Alaska (Holdsworth et al. 1978) and Australia (Nazarov et al. 1982), it has become apparent that there is a high level of similarity among contemporaneous Devonian faunas around the world. This is not surprising, in view of the presumed planktic life habit of even ancient Radiolaria and the known wide distribution of other Devonian putative plankton such as conodonts. It suggests that with sufficient documentation of their distribution, Devonian radiolarians could be used to supplement existing Devonian biostratigraphic schemes. What is lacking at this point is sufficient documentation of well-preserved Devonian Radiolaria at various locations as a control for their vertical and lateral distribution. We hope that the present paper will contribute in a small way to the need. The assemblage at hand is also sufficiently different from one recently described by Nazarov et al. (1982) from a similar geographic and stratigraphic position, to provide an instructive contrast. Comparison of material studied with that of Nazarov et al. (1982) The differences between our collection and that of Nazarov et al. 1982 are summarized in table 1. The most conspicuous are the presence of ceratoikiscids (4 species) in the material studied by us and their absence from sample 19656 (Nazarov et al.). Further major differences are the presence in our material only of the entactinid genera Helioentactinia and Haplentactinia and the presence in sample 19656 only of Polyentactinia and Somphoentactinia. Such presence-absence contrasts, of course, may reflect inadequate sampling or differences in preservation. It is important to note in this connection that our material is better preserved than that in sample 19656, and that could contribute to its greater diversity. Preservational differences do not, however, seem to be the whole story. There are differences at the species and subspecies level between the two collections that suggest the influence of other factors, such as slight differences in stratigraphic level or biofacies. The former is probable if not presently provable, as our sample is derived from the upper part of the Gogo Formation, whereas sample 19656, coming from 4 km south of Long's Well, must be nearer the base of the Gogo Formation. Differences at the species level between the representation in these two collections of such genera as Astroentactinia, Spongentactinella, and Entactinia may well have a biostratigraphic basis. micropaleontology, vol. 29, no. 4, pp. 454-466, pls. 1-2, 1983 454 This content downloaded from 207.46.13.105 on Wed, 25 May 2016 04:52:06 UTC All use subject to http://about.jstor.org/terms Micropaleontology, vol. 29, no. 4, 1983