Late Devonian Acritarchs from the Gneudna formation in the Western Carnarvon basin,Western Australia

The Gneudna Formation is a Late Devonian(Frasnian) sequence of marine calcareous sediments that occurs in the Carnarvon Basin, Western Australia. The present palynological study is based upon subsurface silty strata from a borehole (Pelican Hill or Bibbawarra Bore) that was drilled early this century near the western coastal limit of the Carnarvon Basin.The subject strata have previously been attributed to the Gneudna Formation on lithostratigraphic grounds. They contain a rich and varied assemblage of marine microphytoplankton (acritarchs), associated with trilete miospores of which Geminospora lemurataBalme, 1962 is the dominant form. Forty-seven species of acritarchs are recognizable in the palynoflora, which corresponds very closely with that described recently (Playford & Dring, 1981) from the Gneudna Formation in the vicinity of its type section on the opposite (eastern) side of the Carnarvon Basin. The apparently parochial complexion of the Gneudna acritarch suite is probably illusory, insofar as early Late Devonian acritarchs have not been studied extensively or intensively from either the northern or southern hemispheres.The following new species of acritarchs areformally instituted herein: Elektoriskos villosa, Lophosphaeridium pelicanensis, and Pterospermella tenellula.     

Diverse small spinose acritarchs from the Ediacaran Doushantuo Formation, South China

The Ediacaran Doushantuo Formation in South China is underlain by the Cryogenian Nantuo Formation (glacial rocks) and overlain by the late Ediacaran Dengying Formation. It is characterized by well-preserved, large (normally >100 μm in size) spinose acritarchs (LSAs), which have been shown to be probably the only useful biostratigraphic tool for the global correlation of the early- and middle-Ediacaran. Acritarchs are organic microfossils normally known as single-celled eukaryotic organisms (protists). Although recent research suggests that some large spinose acritarchs may represent diapause egg cysts of metazoans, the biological affinities of the Ediacaran spinose acritarchs, especially for those displaying remarkable size ranges, are still debatable.Recently, smaller specimens of the Ediacaran spinose acritarchs have been found in cherts and phosphorites of the Doushantuo Formation in South China. Many described Ediacaran spinose acritarch taxa display large size variation (from tens to hundreds of microns in vesicle diameter), but some taxa only have smaller (<70 μm) specimens. The morphological comparison with Paleozoic counterparts indicates that some Ediacaran spinose acritarchs may have phylogenetic affinity to eukaryotic algae. More evidence, including wall ultra-structure, geochemical analysis and comparison with modern analogs, is needed to understand the biological affinity of the Ediacaran spinose acritarchs. The remarkable radiation of planktonic protists, characterized by abundant, diverse spinose acritarchs, occurred as early as in the late Neoproterozoic, i.e., 40–60 million years earlier than previously thought.     

Ordovician chitinozoans and acritarchs from southern and southeastern Turkey

Revision of the lithostratigraphy of Ordovician deposits in southern and southeastern Turkey led to a re-evaluation of the age assignments of formations identified in the subsurface and at outcrop. Previous datings were based on macrofauna (mainly trilobites and graptolites). The present paper focuses exclusively on organic-walled microfossils (chitinozoans and acritarchs), which provide numerous chronostratigraphical improvements, especially in successions barren or poor in macrofossils. Close to 200 samples were collected in the Taurus chain (i.e. from Kemer, Seydisehir, Ovacik, Kozan, to Sariz regions in southern Turkey) and in the Border Folds (Mardin and Hakkari regions), usually regarded as part of the Arabian Plate in palaeogeographical reconstructions. Many samples are productive and yield chitinozoans and/or acritarchs of extremely variable preservation, depending on their geographical and geological location. In the Taurus chain, the material is “coalified” and frequently fragmented whereas, in the Border Folds, maturation of the organic matter is much lower and preservation of the microfossils is good to excellent. Several Ordovician chitinozoan biozones (northern Gondwana zonation) as well as diagnostic acritarch assemblages are identified in southern and southeastern Turkey. These Ordovician formations are assigned here to the new global stages of the Ordovician chronostratigraphical scale. The Seydisehir (upper part), Sobova, and Kilgen Lake (lower part) formations are referred to the Darriwilian. The Kilgen Lake (upper part), Sort Tepe, and Bedinan formations are attributed to the Sandbian and to the Katian, and the Halevikdere Formation (glacio-marine part) is assigned to the Hirnantian. Reworking of Early Ordovician acritarchs is documented in pre-glacial and in glacial Late Ordovician deposits. They indicate that active erosive processes occurred during the Middle and Late Ordovician sedimentation. The organic-walled microfossils recorded in the Ordovician of south and southeastern Turkey belong to the northern Gondwana realm. Interestingly however, some Baltoscandian influences are noted in the Border Folds during Early Late Ordovician.     

New graptolite,chitinozoan and acritarch records from the Pascha-Incamayo area,Cordillera Oriental,Argentina

A new fossil assemblage bearing graptolites, chitinozoans and acritarchs is analyzed based on material collected in the Pascha-Incamayo area, Salta Province, NW Argentina. The occurrence of Hunnegraptus copiosus (Lindholm, 1991), associated with specimens of the genus Tetragraptus (Salter, 1863), is highly relevant to improve the age assignment and correlate the fossil-bearing levels previously assigned to the Devendeus Formation. Different stages in the development of the index species of the Upper Tremadocian H. copiosus Biozone are described and illustrated. The precise stratigraphic ranges of the associated chitinozoans and acritarchs are discussed, according to the biostratigraphic analysis, and the stratigraphic relationships for the studied section are considered.     

Palynostratigraphy and palaeogeography of the Padeha, Khoshyeilagh, and Mobarak formations in the eastern Alborz Range (Kopet-Dagh region), northeastern Iran

A total of 113 surface samples collected from the Padeha, Khoshyeilagh, and Mobarak formations of Kuh-e-Ozum, northeast of Jajarm town were processed for palynomorphs, in order to determine age relationships. Well-preserved and abundant palynomorphs dominated by organic-walled-marine microphytoplankton (acritarchs and prasinophyte phycomata), miospores and subordinate chitinozoans, and scolecodonts were recovered. Seven species of prasinophyte phycomata (four genera), 19 acritarch species (14 genera), one species of chitinozoa, and 26 miospore species (19 genera) were recorded and assigned to eight local Assemblage Zones. Assemblage Zones I-IV occur in the Padeha Formation and suggest an Early Late Devonian (Frasnian) age whilst assemblages zones V-VII are present in the Khoshyeilagh Formation and indicate Late Devonian (Famennian) ages. Assemblage zone VIII, which occurs in the basal part of Mobarak Formation, suggests a Lower Mississippian (Tournaisian) age for this formation. Many of the palynomorph groups encountered are closely comparable with coeval assemblages recorded from Western Australia, southwest Ireland, England, Turkey, Saudi Arabia, North Africa, and South America, indicating the close relationship of the Iranian Platform to other parts of the northern Gondwana Domain during the time interval represented by these strata. The presence of marine palynomorphs (acritarchs/prasinophyte phycomata, chitinozoans, and scolecodonts), and shelly macrofauna (brachiopods, gastropods, and corals) in Member c of the Padeha Formation (as well as the Khoshyeilagh and Mobarak formations), together with associated miospores, indicate an open marine (moderately nearshore) depositional environment for the Upper Devonian and Lower Carboniferous deposits in northeastern Alborz Range (Kopet-Dagh region) of Iran.     

Environmental changes reflected by palynomorphs in the early Middle Ordovician Hanadir Member of the Qasim Formation, Saudi Arabia

Core samples from the QASIM-801 (QSIM-801) water well in the Qasim Region of central Saudi Arabia were investigated palynologically. The interval studied contains the transgressive succession from the Sajir Member of the Saq Formation to the Hanadir Member of the Qasim Formation, and yields well-preserved and abundant cryptospores, microphytoplankton (acritarchs and chlorophycean algae), and chitinozoans, indicative of a Darriwilian (Llanvirn) age. The lowermost portion of the cored interval from the upper Sajir Member consists of fine-grained sandstones deposited in tidal flat, and shallow-marine settings. It is characterized by abundant and diverse cryptospores (permanent tetrads, dyads, monads), cuticle-like phytoclasts, and a low diversity assemblage of marine palynomorphs. The upper part of the cored interval from the Hanadir Member is composed of hemipelagic to pelagic, organic-rich, graptolitic shales, and micaceous shales, of middle- to outer-shelf depositional settings, which yield abundant marine palynomorphs (acritarchs and chitinozoans). Cryptospore-bearing horizons are interspersed in the succession. Changes in the composition of palynomorph assemblages reflect higher frequency environmental changes within an overall transgressive succession. Four new acritarch species are described in open nomenclature, Tyrannus sp. A, Clypeolus sp. A,?Pulvinosphaeridium sp. A, and?Tinacula sp. A.     

Upper Ordovician microphytoplankton of the Bill's Creek Shale and Stonington Formation,Upper Peninsula of Michigan,U.S.A.: Biostratigraphy and paleogeographic significance

An abundant, diverse, and well-preserved organic-walled microphytoplankton assemblage is described from the Upper Ordovician Bill's Creek Shale and the lower Stonington Formation (Bay de Noc Member) in the Upper Peninsula of Michigan, U.S.A. Based on graptolite and conodont evidence, the Bill's Creek Shale and Stonington Formation are Richmondian (=Ashgill) in age. The assemblage is dominated by acritarchs, which comprise 29 species (including the enigmatic palynomorph Gloeocapsomorpha prisca) assigned to 20 genera. The prasinophyte phycomata are represented by undifferentiated species of Leiosphaeridia and Tasmanites. In addition, chitinozoans are abundant, and scolecodonts and graptolite fragments are common. Paleontologic-palynologic and sedimentologic evidence indicates that the Bill's Creek Shale was deposited in a low-energy, shallow, nearshore marine environment. The overlying Bay de Noc Member of the Stonington Formation also accumulated in a low-energy, normal marine environment, but in a more offshore, somewhat deeper water setting. Both formations experienced minor transgressive and regressive episodes as indicated by fluctuations in the composition of the palynoflora. The combined Bill's Creek/Stonington acritarch assemblage closely resembles those described from the Richmondian-aged Maquoketa Shale (Missouri and Kansas), Sylvan Shale (Oklahoma), and Vauréal Formation (Anticosti Island, Québec, Canada). The overall composition of the acritarch assemblage from these four formations reflects a distinctive, recognizably Laurentian character. Nonetheless, many of the Bill's Creek/Stonington acritarchs have been reported from Upper Ordovician localities elsewhere, providing additional evidence for Late Ordovician cosmopolitanism of the marine microphytoplankton community. Additionally, the restricted stratigraphic range of many of the taxa further enhances their biostratigraphic application, both regionally and globally, and reaffirms the Richmondian (=Ashgill) age of the Bill's Creek Shale and Stonington Formation.     

Microplankton associations, biofacies and palaeoenvironment of the type lower Ludlow Series, Silurian

The acritarchs and prasinophyte algae from the type lower Ludlow Series of the Goggin Road section, Ludlow, England, are resolved into seven recurrent associations comprising taxa with similar environmental preferences. Endemic and environmentally sensitive associations of acritarchs and prasinophytes are identified and high-resolution fluctuations in the early Ludlow palaeoenvironment are established. An early Ludlow crisis in the acritarchs is recognized in the lower part of the Middle Elton Formation, when an abrupt palaeoenvironmental change in the Ludlow area resulted in a large decline in the abundance of the acritarchs, but allowed Tasmanites and retiolitid graptolites to flourish briefly. Cymbosphaeridium sp. A, Pulvinosphaeridium ludlowense and Multiplicisphaeridium arbusculum forma A are taxa possibly specialized, or produced as a response, to a stressed palaeoenvironment, as they are most abundant when other acritarchs and prasinophytes are uncommon. The low abundance of acritarchs and prasinophytes in the Upper Elton Formation may be related to high sedimentation rates and to the slumping of sediments caused by instability on the shelf of the Welsh Basin, or to lower plankton productivity.     

First record of organic-walled microfossils from the Tonian Shiwangzhuang Formation of the Tumen Group in western Shandong,North China

Organic-walled microfossils offer important information on the biospheric evolution in pre-Cryogenian and provide biostratigraphic implications for many Proterozoic fossiliferous sequences that are poorly age constrained for the lack of reliable radiometric date. Recently, macroscopic carbonaceous compression fossils have been reported for the first time from the Tonian Shiwangzhuang Formation of the Tumen Group in western Shandong, North China. However, organic-walled microfossils have never been discovered from this formation up till now. To improve our knowledge about Proterozoic biodiversity in North China, we conducted a micropaleontological survey on the argillaceous limestone samples of the Shiwangzhuang Formation, which also contain macroscopic carbonaceous compression fossils, from the Baishicun section in Anqiu, western Shandong, North China. Our investigation shows that the Shiwangzhuang microfossil assemblage is dominated by smooth-walled sphaeromorphic acritarchs and cyanobacterium-like filaments and relatively low abundance of other acritarchs, including 16 taxa, such as Polysphaeroides filliformis, Ostiana microcystis, Simia annulare, ?Jacutianema sp., Arctacellularia tetragonala, Pellicularia tenera, Polythrichoides lineatus, and Navifusa actinomorpha. The Shiwangzhuang organic-walled microfossil assemblage, although consisting of long-ranging and not age diagnostic taxa, is consistent with a Tonian age suggested by macroscopic carbonaceous compression fossils, including the Chuaria-Tawuia and Sinosabellidites-Protoarenicola-Pararenicola assemblages, revealed from the same fossiliferous horizon of the Shiwangzhuang Formation and by organic-walled microfossil assemblage, including the late Mesoproterozoic to Tonian index fossil Trachyhystrichosphaera aimika, from the underlying Tongjiazhuang Formation. However, it is also worth noting that a Cryogenian or Ediacaran age cannot be completely excluded based just on the Shiwangzhuang microfossils because of their limited biostratigraphic utility.     

Microfossils from the Krol ‘A’ of the Lesser Himalaya,India: Additional supporting data for its early Ediacaran age

An assemblage of microfossils of moderate diversity, with the remarkable occurrence of ECAP acritarchs, is reported from the Ediacaran Krol ‘A’ (= the Mahi Formation) succession of Lesser Himalaya, India. Microfossils occur in the chert nodules exposed in Solan district, Himachal Pradesh. Two microfossils, Barogophycus symmetricus n. gen. n. sp. and Botominella lineata are new to the well-established Krol assemblage. The paper concentrates predominantly on fossil eukaryotic filamentous and coccoidal micro-organism of simple morphology. The assemblage is dominated by remains of prokaryotic cyanobacteria and demonstrates the diversity achieved by microorganisms at the beginning of the Ediacaran Period in the aftermath of the Marinoan glaciation. Filamentous and coccoidal microorganisms differ in taxonomic composition from the Mesoproterozoic microbiotas. The Krol microfossils assemblage has biostratigraphic potential and usefulness in broadly demarcating the different levels of the Ediacaran strata. Because of the presence of ECAP acritarchs, along with the appearance of other eukaryotic microorganisms of filamentous and coccoidal morphology, the general level of the Krol ‘A’ assemblage is considered as Ediacaran.     

Turonian–Santonian radiolarians and planktonic foraminifers of the Upper Cretaceous sequences between Trabzon and Giresun areas in the Eastern Pontides,NE Turkey

In the “Eastern Pontides” (NE Turkey), the intense volcanic activity accompanying carbonate-siliceous sedimentation during the Late Cretaceous period ensured the occurrence of thick volcano-sedimentary sequences. Seventy-one radiolarian species belonging to 26 genera were identified from five stratigraphic sections of the Upper Cretaceous sequences between Trabzon and Giresun areas in NE Turkey. These species were obtained from the lower Turonian–lower Coniacian strata of the Çe?meler Formation, the Coniacian–lower Santonian strata of the Elmal? Dere Formation and the upper Santonian strata of the Ça?layan Formation. Coniacian–Campanian fauna, consisting of planktonic foraminifera Hedbergella, Marginotruncana, Globotruncana, Whiteinella and biserial heterohelicids as well as radiolarians, was recovered from the red pelagic limestones of the Elmal? Dere Formation known as marker horizon.     

Aeronian (Llandovery, Lower Silurian) palynomorphs and graptolites from the Lipeón Formation, Eastern Cordillera, north-west Argentina

The lower levels of the Lipeón Formation, in the Eastern Cordillera, north-west Argentina, yield a marine-dominated palynomorph assemblage, together with graptolites of mid to late mid Llandovery age (Demirastrites convolutus and probably Stimulograptus sedgwickii zones). The palynomorph assemblage is dominated by acritarchs, but also contains algae and terrestrial cryptospores. Crassiangulina variacornuta, considered a potentially good global biostratigraphical marker for the Upper Llandovery is recovered for the first time from the Silurian of Argentina. The occurrence of this species in strata not younger than late Aeronian, and independently dated by graptolites, indicates an early first appearance for Crassiangulina variacornuta, in the Lipeón Formation, below the Aeronian/Telychian boundary. The lower part of the unit corresponds to a quiet marine environment; thus supporting that Crassiangulina variacornuta is a facies-sensitive acritarch.     

山西永济白草坪组具刺疑源类的发现及其地质意义

该文着重报道了山西永济白草坪组(一般认为系中元古界上部相当于蓟县系的层位),以具刺疑源类为主的微化石群,计有4类6属15种,其中包括1新属,4新种,1新组合,1亲近种,2未定种,新属是具细网状纹饰的复杂具刺疑源类Shuiyousphaeridium Yan gen.nov.,4新种是Shuiyousphaeridium membraniferum Yan sp.nov.,Dictyosphaera incrassate Yan sp.nov.,Foliomorpha stipuliferaYan sp.nov.,Manicosiphoninema shuiyouense Yan sp.nov.。本微化石群以球形疑源类为主体,以具刺疑源类的大量发育为特征,并伴生有推测是绿藻和褐藻的化石,其组合面貌与蓟县上前寒武系各组皆有明显区别,具有更高的进化程度,从生物地层标志推测白草坪组所在的汝阳群应归入震旦系。白草坪组具刺疑源类可能是横裂甲藻的原始分子,它在地层对比和藻类进化方面皆具有重要意义。     

Pollen stratigraphy of coal-bearing deposits in the Neogene Jidong Basin,Heilongjiang Province,NE China: New insights on palaeoenvironment and age

The palaeoenvironment and age of coal-bearing lacustrine deposits in the Jidong Basin, Heilongjiang Province, is poorly understood. New pollen data from the Yongqing Formation and the overlying lower part of the Daqingshan Formation recovered in borehole 91-205 revealed a rich and diverse palynoflora representing approximately 70 taxa at the genus/family level. Of these taxa, Ulmus, Quercus, Carya, Liquidambar, Pinus, Tilia, Fagus, and Alnus are the main woody elements; these occur together with numerous pteridophytes, subordinate herbs, and rare algae and acritarchs. Abundant woody taxa suggest a mixed deciduous/conifer forest in the region in association with local shrubs, herbs and algal communities. Some of the pollen types, especially those of climate sensitive genera such as Ulmus, Carya, Liquidambar and Fagus, vary considerably in relative abundances, suggesting climate variability. The reflected climate shows an overall trend towards cooling or deterioration which is largely in agreement with global climate change during the Neogene.Comparisons of the pollen record with representative datasets from neighbouring areas, together with the appearance of the highly-evolved genus Artemisia, suggest that the Yongqing Formation and the lower part of the Daqingshan Formation are of Miocene age.     

The nature and origin of nucleus‐like intracellular inclusions in Paleoproterozoic eukaryote microfossils

The well‐known debate on the nature and origin of intracellular inclusions (ICIs) in silicified microfossils from the early Neoproterozoic Bitter Springs Formation has recently been revived by reports of possible fossilized nuclei in phosphatized animal embryo‐like fossils from the Ediacaran Doushantuo Formation of South China. The revisitation of this discussion prompted a critical and comprehensive investigation of ICIs in some of the oldest indisputable eukaryote microfossils—the ornamented acritarchs Dictyosphaera delicata and Shuiyousphaeridium macroreticulatum from the Paleoproterozoic Ruyang Group of North China—using a suite of characterization approaches: scanning electron microscopy (SEM), transmission electron microscopy (TEM), and focused ion beam scanning electron microscopy (FIB‐SEM). Although the Ruyang acritarchs must have had nuclei when alive, our data suggest that their ICIs represent neither fossilized nuclei nor taphonomically condensed cytoplasm. We instead propose that these ICIs likely represent biologically contracted and consolidated eukaryotic protoplasts (the combination of the nucleus, surrounding cytoplasm, and plasma membrane). As opposed to degradational contraction of prokaryotic cells within a mucoidal sheath—a model proposed to explain the Bitter Springs ICIs—our model implies that protoplast condensation in the Ruyang acritarchs was an in vivo biologically programmed response to adverse conditions in preparation for encystment. While the discovery of bona fide nuclei in Paleoproterozoic acritarchs would be a substantial landmark in our understanding of eukaryote evolution, the various processes (such as degradational and biological condensation of protoplasts) capable of producing nuclei‐mimicking structures require that interpretation of ICIs as fossilized nuclei be based on comprehensive investigations.     

Preliminary palynological investigation of Saudi Arabian Upper Ordovician glacial sediments

An Ordovician stratigraphically admixed palynomorph assemblage that contains palynomorphs eroded from Middle through Upper Ordovician strata characterizes the Hawban Member (restricted) of the Sarah Formation in central Saudi Arabia. This distinctive assemblage, combined with detailed sedimentology, helps identify the presence of Hirnantian Gondwanan glacial sediments on the Arabian Plate. Similar Ordovician admixed assemblages have been recognized from Upper Ordovician glacial sediments elsewhere along the Gondwanan margin. Within Saudi Arabia the composition of reworked assemblages depends upon the stratigraphic succession exposed to glacial erosion. Sylvanidium? hawbanense, which is one of the acritarchs found in glacial sediments, is newly described from Arabian Upper Ordovician strata.     

论山西中元古代晚期汝阳群微体化石组合

我国北方18-19亿年前的串岭沟组中获得的大球形疑源类,迄今,被认为是可信的最古老真核化石记录。自上世纪80年代以来,东秦岭北坡的中元古代晚期汝阳群陆续发现了丰富的球形光面疑源类,具刺疑源类,丝状微体化石和一些有疑问的动物遗迹。很显然,在中元古代晚期真核生物曾有重大辐射。     

Habitats and probable nature of acritarchs from the Upper Riphean Chencha Formation

Morphology and taphonomy of acritarchs from the Upper Riphean deposits of the Baikal Folded Region (eastern Siberia) are analyzed. The morphotypes of acritarchs are compared to various stages in the life cycle of modern green algae of the order Chlorococcales. The acritarchs Dictyotidium minor Stan. and the modern coenobial taxon Pediastrum boryanum (Turp). Menegh. showed the greatest similarity of structure.     

Ediacaran acanthomorphic acritarchs from the Outer Krol Belt,Lesser Himalaya,India: Their significance for global correlation

Large acanthomorphic acritarchs have been previously reported from the Ediacaran successions of the Pachmunda and Krol Hill synclines in the Outer Krol Belt of Lesser Himalaya, India. Thin sections of chert from Krol ‘A’ Formation in Khanog and Rajgarh synclines, Outer Krol Belt, record an equally well developed and diversified assemblage of Ediacaran large acanthomorphic acritarchs. This assemblage contains specimens belonging to seven genera and ten species, identified as: Appendisphaera fragilis, A. grandis, Asterocapsoides sp. A, Asterocapsoides sp. B, Cavaspina acuminata, C. basiconica, Eotylotopalla dactylos, Knollisphaeridium sp., Papillomembrana sp., and Weissiella cf. grandistella. It also contains five unnamed forms, viz. A, B, C, D, and E. The Krol acritarch assemblage shows a close resemblance with the Upper Doushantuo or Tanarium anozos–Tanarium conoideum assemblage of China. However, the absence of biostratigraphically important markers such as Tanarium anozos and T. conoideum from the Krol assemblage, so far, makes it difficult to establish a definite biostratigraphic correlation between the two assemblages. The current observations from this new locality provide additional data for regional and global biostratigraphic correlation, and significantly increase the purview of Ediacaran sequences for global biostratigraphic zonation.     

Miospore assemblages from the Silurian–Devonian boundary,in borehole A1-61, Ghadamis Basin,Libya

Well preserved and diversified miospore assemblages have been recorded from a relatively continuous sequence in borehole A1-61 which spans the Silurian–Devonian boundary in the northwestern part of the Ghadamis Basin, Libya. The sequence is represented by early Devonian Lochkovian beds of the Tadrart Formation that transgress onto the Silurian Ludlow-Pridoli beds of the upper part of the ‘Alternances Argilo-gréseuses’ Formation. The present work demonstrates a succession of miospore assemblages from closely sampled layers that have been stratigraphically dated as Ludlow–middle Pridoli and early Lochkovian by chitinozoans and acritarchs. Over 80 species of cryptospores and trilete spores have been identified. Modified detailed morphological interpretations are given. The miospore assemblages are correlated with miospore zonation schemes established for the type sequences of the Welsh Borderland, and those previously described from Libya. Early occurrences of some species as Streelispora newportensis on the western Gondwana plate, are put forward by comparison with the Old Red Sandstone continent. Phytogeographic and palaeobotanic implications based on these observations are discussed.