Astogenetic aspects of the dendroid graptolite Airograptus (Late Cambrian-Early Ordovician) and their phylogenetic implications

Based on a Backscatter Electron (BSE) examination of partially 3-dimensional graptolite specimens of Airograptus from the Tremadocian (Early Ordovician) Yehli Formation at Dayangcha, Baishan of Jilin Province, NE China, the thecal structure and astogenetic aspects of this genus (except for the missing proximal part) are described and illustrated in detail. In the present collection, no furcating but only peltate thecal apertural processes are confirmed. A comparison between the presumably benthic dendroid Airograptus and Rhabdinopora, the earliest planktonic graptolite, indicates that there are remarkable similarities in astogenetic aspects between them, although there are also differences in the development of dissepiments and thecal apertural processes. A possible ancestor-descendent relationship between the two genera is herein proposed.     

The Hunneberg Stage (Ordovician) in the area east of St. Petersburg, north-western Russia

The bio- and lithostratigraphy of the poorly known early Ordovician (Arenig) Hunneberg Stage is described from the area east of St. Petersburg (Putilovo Quarry and Lava river), where the Lakity Beds (Leetse Fm.) consist of glauconitic sands and silty clays. The described fauna includes graptolites, conodonts, brachiopods, acritarchs, foraminifers, and several problematic groups. The Lakity Beds are unique within the lower Ordovician sequence of the East Baltic in the abundance of graptolites, co-occurring with conodonts. The conodonts from the lower part of the Lakity Beds belong to the uppermost subzone (Oelandodus elongatus — Acodus deltatus deltatus) of theParoistodus proteus Zone, coinciding with the lower part of theTetragraptus phyllograptoides Zone. This suggests that there is a hiatus between the Lakity Beds and the underlying Nazya Formation. The lower Lakity Beds also contain the brachiopodsLeptembolon lingulaeformis andEosiphonotreta cf.acrotretomorpha, which suggest that they may be correlated with the Joa Member of the Leetse Formation in North Estonia. In the upper part of the Lakity Beds, conodonts of thePrioniodus elegans Zone co-occur with graptolites indicating the upper subzone of theTetragraptus phyllograptoides Zone in the Scandinavian sections. There are still problems of defining and correlating the base of the Billingen Regional Stage, which are outside the scope of this paper.     

江西崇义早奥陶世茅坪组的笔石

记述早奥陶世茅坪组笔石9属25种,其中2新种.根据一些新材料的发现和笔石群的详细研究,将茅坪组笔石划分为3个带,即上部的Adelograptus-Clonograptus 带,中部的Aletograptus-Trograptus带,下部的Staurograptus-Anisograptus带.     

Volkhov graptolites from the lower-middle Ordovician boundary beds of the St. Petersburg region,Russia

The lower and lowermost Middle Ordovician strata of the Volkhov Stage exposed in the vicinity of St. Petersburg, Russia, yield a graptolite fauna at several stratigraphic levels, being more often confined to the mud-mound clays than to the normally stratified, Condensed carbonates. Overall taxonomic diversity of the Volkhov graptolites is relatively low and associations include no more than seven species in ail localities. TheTetragraptus, Didymograptus andXiphograptus species found are pandemic and have quite extensive stratigraphie ranges within the mid-Arenig Series. Based on the graptolite zonation, the Volkhov Stage can be correlated to thePseudophyllograptus angustifolius elongatus andDidymograptus (Expansograptus) hirundo graptolite biozones of Baltoscandia and to the upperDidymograptus simulans toDidymograptus (Expansograptus) hirundo biozones of the British graptolite succession. TheIsograptus victoriae lunatus lower zonal boundary probably falls within the graptolite-bearing interval of the lower Volkhov Stage. As the result of indirect biostratigraphic and interpretative lithological correlations, the first appearance ofUndulograptus austrodentatus at the base of the Darriwilian Stage is deemed to be close to the boundary of theMegistaspis simon andM. limbata trilobite biozones and the lowerBaltionodus norrlandicus conodont Biozone of the upper Volkhov Stage. Seven dichograptid species belonging to four genera are described, one of them,Azygograptus volkhovensis n. sp., new.      

LUNGMACHI FORMATION GRAPTOLITES FROM SANLANGPU OF XIXIANG, SOUTHERN SHAANXI

The specimens referred to the Lungmachi Formation graptolites in the present paper were collected from Sanlangpu of Xixiang, Southern Shaanxi, consisting of 8 genera and 51 species or subspecies including 12 new species (see Table l in the Chinese text). This paper describes only the new species, with the rest being shown in tablesand plates. According to the present data on hand, the Lungmachi Formation graptolites studied here may be divided into 4 zones as follows:4. Orthograptus vesiculosus Zone (L_3)3. Parakidograptus acuminatus Zone (L_2)2. Glyptograptus persculptus Zone (L_1)1. Diplograptus bohemicus Zone (W_6)The first graptolite zone belongs to the Upper Ordovician, while the others to the Lower Silurian, indicating that the Lungmachi Formation in our studied area is a lithostratigraphic unit stridling across the Ordovician-Silurian boundary.This paper is in commemoration of the respectable late Prof. Mu En-zhi, to whom the writers are very much obliged for his kindness inguiding their scientific researches.     

Revision of the Zone 13 graptolite biostratigraphy in the Marathon, Texas, standard succession and its bearing on Upper Ordovician graptolite biogeography

One of the long-standing problems in North American graptolite biostratigraphy is the distinct differences in assemblages of post-Climacograptus bicornis age between the classical graptolite sequences in the New York - Quebec and Marathon, west Texas, regions. These have been attributed either to faunal provincialism or to the presence of a major hiatus between the Woods Hollow and Maravillas formations in Texas. New collections from the key Marathon Picnic Grounds section contain diagnostic Late Ordovician graptolites that confirm the existence of a major stratigraphic gap below the Maravillas Formation. The lower Maravillas Formation (Zone 13) has a Late Ordovician, low-diversity Pacific Province graptolite fauna that includes the biostratigraphically diagnostic species Climacograptus nevadensis, C. tubuliferus, Orthograptus fastigatus and Dicellograptus ornatus. Zone 13 graptolite assemblages from the Marathon region correlate with the C. tubuliferus to D. ornatus zones in the Trail Creek, Idaho, succession, the Ea4-Bo2 interval in Victoria, the O. fastigatus Zone in the Canadian Arctic Islands, the O. quadrimucronatus to D. ornatus zones of the Canadian Cordillera, and the D. complanatus to D. anceps zones in Scotland. The hiatus between the Woods Hollow and Maravillas formations spans an interval corresponding to at least the Eal Ea3 interval in Australia, the C. americanus to upper A. manitoulinensis zones in the New York - Quebec succession, and the D. clingani and P. linearis zones in Scotland. These results agree with the magnitude of the hiatus previously indicated by conodont biostratigraphy. Late Ordovician graptolite distribution patterns in North America can be explained by an extension of Cooper, Fortey & Lindholm's (1991; Lethaia 24) Lower Ordovician graptolite biofacies model into the Upper Ordovician, which incorporates both lateral water-mass specificity and depth stratification. Using this model, we recognize in Laurentia two separate biofacies among tropical-zone Late Ordovician Pacific Province graptolite faunas, a cosmopolitan Oceanic biofacies, and a cratonic Laurentian biofacies. The lower Maravillas Formation graptolite fauna is clearly part of the Oceanic biofacies, whereas the coeval Appalachian faunas represent the Laurentian biofacies. □Graptolites, Ordovician, biostratigraphy, Texas, biofacies, biogeography.     

Horizon of the oldest known bryozoans (Ordovician)

Among the six species of fossil bryozoans described by Xia et al. [Xia, F.S., Zhang, S.G., Wang, Z.Z., 2007. The oldest bryozoans: new evidence from the late Tremadocian (Early Ordovician) of East Yangtze Gorges. Journal of Paleontology 81 (6), 1308–1326] from the Fenghsiang Formation of the Chenjiahe section of Yichang and the Guanzhuangping section, Liujiachang Town of Songzi, the Yangtze Gorges, Nekhorosheviella nodulifera occurs in the pristinus Conodont Subzone (lower Subzone of deltifer Conodont Zone) and the five other species are associated with the conodont Paltodus deltifer deltifer and the graptolites Acanthograptus sinensis and A. erectoramus. Based on the conodonts and graptolites, this bryofauna stratigraphically corresponds to the A. sinensis Graptolite Zone or P. deltifer Conodont Zone. The bryofauna is of Tremadocian Age (Early Ordovician) and represents the oldest bryozoans so far as known.     

河北唐山下奥陶统牙形刺生物地层的新认识

本文作者在安太庠等(1983)研究过的唐山赵各庄剖面,对下奥陶统冶里组和亮甲山组较系统地采集了牙形刺样品,通过对所获牙形刺标本和安太库等(1983)所描述的牙形刺动物群仔细研究后,对包括分带和对比意见有新的认识。安太庠等(1983)把自寒武系凤山组顶部至下奥陶统亮甲山组这段地层,自下而上建立了Cordylodus proavus,Utahconus beimadaoensis-Monocostodus sevierensis,Cordylodus rotundatus-"Acodus"oneotensis,Scolopodus quadraplicatus-S.opimus,Scalpellodus tersus,Serratognathus bilobatus,S.extensus和Paraserratognathus paltodiformis等8带,其中Cordylodus proavus带为寒武系顶,Utahconus beimadaoensis-Monocostodus sevierensis至Scolopodus quadraplicatus-S.opimus等带为下奥陶统冶里组,其余则为下奥陶统亮甲山组,寒武系-奥陶系界线置于Utahconus beimadaoensis-Monocostodus sevierensis带之底。这一牙形刺序列和寒武系-奥陶系界线划分方案在国内被广泛引用至今(王志浩等,2011)。本文通过补充采集到的牙形刺标本和安太庠等(1983)报道的材料,根据一些重要分子在地层中的分布及公认的牙形刺分带原则,对安太庠等(1983)的牙形刺分带方案重新修订,自下而上修订为Cordylodus proavus,C.lindstromi,Iapetognathus jilinensis,Cordylodus angulatus,Chosonodina herfurthi-Rossodus manitouensis,Glyptoconus quadraplicatus,Scalpellodus tersus-Triangulodus aff.bifidus,Serratognathus bilobatus,S.extensus和Paraserratognathus obesus等10带,寒武系-奥陶系界线则置于Iapetognathus jilinensis带之底。根据这一修订后的牙形刺序列,寒武系顶至下奥陶统冶里组部分的牙形刺带可与国内、外相同层位的牙形刺带进行精细对比,而亮甲山组的牙形刺虽有明显的地方性特点,但除其顶部因更具地方性而不能直接对比外,其中下部仍可与华南区下奥陶统红花园组相对比。     

Early Tremadocian (Ordovician) graptolite biostratigraphy and correlation

A revision of the early Tremadocian graptolites of the genus Rhabdinopora shows that Rhabdinopora proparabola from the Xiaoyangqiao section, Dayangcha, North China is the oldest species of the genus. Early Tremadocian species of Rhabdinopora can be differentiated easily by the construction of their nemata. The earliest species, Rhabdinopora proparabola, lacks a nema, while a multibranched nema is present in Rhabdinopora campanulatum (= Rhabdinopora parabola). The Rhabdinopora proparabola, Rhabdinopora campanulatum, Rhabdinopora flabelliformis (Anisograptus matanensis Biozone) and Rhabdinopora anglica biozones can be correlated worldwide. A short interval at the base of the Ordovician System does not contain any planktic graptolites.     

内蒙古乌海大石门奥陶系牙形刺和Histiodella动物群发现的意义

本文描述了内蒙古乌海大石门剖面奥陶系的牙形刺动物群:下克里摩里组主要有Histiodella kristinae,H.holodentata,H.wuhaiensis sp.nov.,Polonodus newfoundlandensis和Paroistodus horridus等,应归属于中奥陶统达瑞威尔阶(Darriwilian)之Histiodella kristinae带,并在同一剖面上与笔石Pterograptus elegans带和Didymograptus murchisoni带下部相当;下克里摩里组顶部产Histiodella kristinae,Baltoplacognathus cf.reclinatus,Periodon aculeatus和Protopanderodus rectus等,所以大石门剖面的Histiodella kristinae带顶部可能已与北欧Pygodus serra带之底部相当;乌拉力克组底部的砾状灰岩透镜体产有牙形刺Pygodus anserinus?,Protopanderodus liripipus,Yangtzeplacognathus protoramosus和Dapsilodus viruensis等,其中Pygodus anserinus?Pa分子(器官种的一组成分子)的口面瘤齿列的瘤齿比较粗糙,与典型的Pygodus anserinus稍有不同,且在牙形刺十分丰富的样品中仅有一枚此种之Pa分子,所以本文尚有疑问地把这层砾状灰岩归入Pygodus anserinus带,同时不能排除把它归入Pygodus serra带顶部Yangtzeplacognathus protoramosus亚带的可能。由于此剖面牙形刺化石与丰富的笔石共生,为牙形刺带与笔石带的精确对比提供了直接证据。Histiodella动物群在此剖面的发现,不仅具有十分重要的地层意义,而且具有明显的岩相古地理意义。本文详细描述了新种Histiodella wuhaiensis并讨论了Histiodella属5个种之区别。     

The graptolite correlation of the North American Upper Ordovician Standard

The North American Upper Ordovician reference standard, the Cincinnatian Series, contains rich shelly microfossil faunas in its type area in the Cincinnati Region but graptolites are uncommon in most of its shallow-water calcareous sediments. Consequently, the graptolite correlation of this key sequence has remained uncertain, in part, even controversial. A review of both previously published recently discovered graptolite Occurrences in the type Cincinnatian, combined with data from the important graptolite successions in Oklahoma New York-Quebec, has not only clarified the graptolite correlation of the Cincinnatian but also added new data on the morphology taxonomy, the vertical horizontal distribution, of several taxa. The information now at hand indicates that the Edenian Stage correlates with the C. spiniferus Zone, the Maysvillian Stage with the C. pygmaeus lower middle P. manitoulinensis Zone, the Richmondian Stage with the upper P. manitoulinensis , the D. complanatus , possibly part of the C. inuiti Zone. Comparison between graptolite conodont biostratigraphic evidence reveals no apparent conflict. Correlations are proposed between Upper Ordovician North American stages, graptolite conodont zones, successions in Texas, Oklahoma, Sweden, European graptolite zones, British series.     

The early Ludfordian leintwardinensis graptolite Event and the Gorstian–Ludfordian boundary in Bohemia (Silurian,Czech Republic)

The late Gorstian to early Ludfordian hemipelagic succession of the south‐eastern part of the Prague Synform preserves a rich fossil record dominated by 28 species of planktic graptoloids associated with pelagic myodocopid ostracods, pelagic and nektobenthic orthocerid cephalopods, epibyssate bivalves, nektonic phyllocarids, rare dendroid graptolites, brachiopods, crinoids, trilobites, sponges and macroalgae. Faunal dynamics have been studied with particular reference to graptolites. The early Ludfordian leintwardinensis graptolite extinction Event manifests itself as a stepwise turnover of a moderate diversity graptolite fauna rather than an abrupt destruction of a flourishing biota. The simultaneous extinction of the spinose saetograptids Saetograptus clavulus, Saetograptus leintwardinensis and the rare S. sp. B. at the top of the S. leintwardinensis Zone was preceded by a short‐term acme of S. clavulus. Cucullograptus cf. aversus and C. rostratus vanished from the fossil record in the lower part of the Bohemograptus tenuis Biozone. No mass proliferation of Bohemograptus has been observed in the postextinction interval. Limited indigenous speciation gave rise to Pseudomonoclimacis kosoviensis and Pseudomonoclimacis cf. dalejensis. Egregiograptus (the only novel element of cryptic origin) made its earliest occurrence in association with the latest cucullograptids. A postextinction graptolite assemblage of moderate diversity, composed for the most part of long‐ranging taxa, persisted through the middle and upper tenuis Biozone until new rediversification in the Neocucullograptus inexpectatus Biozone. Unlike the graptoloids, the planktic, epiplanktic, nektonic and nektobenthic shelly fauna did not suffer significant extinction in the early Ludfordian. The Gorstian–Ludfordian boundary is placed at the lowest occurrence of S. leintwardinensis in spite of the very modest graptolite record available from the Ludfordian GSSP where no graptolites occur below the basal bed of the Lower Leintwardine Formation. Elsewhere, the Gorstian–Ludfordian boundary has been placed at the base of the Saetograptus linearis Biozone which has been considered roughly correlative with the leintwardinensis Biozone. Indeed, our morphometric study places the worldwide biozonal index species S. linearis in synonymy with S. leintwardinensis and thus considerably enhances the biostratigraphical utility of the latter index species. Pseudomonoclimacis antiqua sp. nov. is described.     

华南特马豆克期笔石地层分带及全球对比

特马豆克阶是奥陶系底部第一个阶,笔石是特马豆克阶高分辨率地层划分与对比的重要化石类群。江南斜坡带是我国早奥陶世特马豆克期漂浮笔石分异度和丰度最高的相区之一,位于该区的湖南益阳南坝剖面,发育有完整的上特马豆克阶笔石地层,特马豆克阶-弗洛阶界线附近地层连续,上特马豆克阶笔石地层研究已取得较大进展,但下特马豆克阶地层缺乏系统研究。近年来,通过对该剖面笔石标本的不间断采集,新识别出下特马豆克阶笔石带Rhabdinopora flabelliformis parabola带。到目前为止,湖南益阳南坝剖面特马豆克阶可以识别出5个笔石带,自下而上依次为:Rhabdinopora flabelliformis parabola带、Adelograptus tenellus带、Aorograptus victoriae带、Araneograptus murrayi带以及Hunnegraptus copiosus带。基于目前已识别出的笔石带,参考国内外同期笔石地层资料,本文详细讨论华南特马豆克期笔石带序列,并与国内外同期地层进行精确对比。     

MIDDLE LLANDOVERY (AERONIAN) GRAPTOLITES OF THE WESTERN MURZUQ BASIN AND AL QARQAF ARCH REGION, SOUTH-WEST LIBYA

Abstract:  The taxonomy and biostratigraphy of the Aeronian graptoloid graptolites of the Tanezzuft Formation (Murzuq Basin and Al Qarqaf Arch area) is presented and discussed with respect to their palaeoenvironmental setting and palaeobiogeographical links. The gregarius-libycus , ' leptotheca ', convolutus and sedgwickii assemblage biozones and tenuis Subzone are recognized and correlated with the generalized zonal scheme and with graptoloid successions in peri-Gondwanan Europe. The Rhuddanian/Aeronian boundary is tentatively placed at the base of the gregarius-libycus Biozone. Telychian faunas have not been identified. Fourteen of the 23 species recorded herein belong to the middle Aeronian convolutus Biozone assemblage. The overall low diversity may be the result of inhabiting unstable, occasionally turbulent and/or oxic environments. The lowest diversity, but with abundant graptoloid rhabdosomes, is observed in proximal silty and sandy deposits. The presence of ' Paraclimacograptus' libycus suggests biogeographical links to Aeronian graptolite faunas of Jordan and South America. The convolutus Zone assemblage is very similar to the coeval faunas of the Saudi Arabian Qusayba shales. The occurrence of several species endemic to northern and north-western Gondwana and peri-Gondwana provides further evidence for a distinct palaeoclimatic/palaeolatitudinal control on graptolite distribution.     

Funsulinid assemblages and facies of the Bombaso Fm. and basal meledis Fm. (Moscovian-Kasimovian) in the central Carnic Alps (Austria/Italy)

Summary The Bombaso Formation and basal Meledis Formation in the central Carnic Alps near Straniger Alm and Zollnersee (Austria/Italy) unconformably overlie the folded Variscan basement and consist of shallow marine clastic and carbonate sediments which are arranged to form two fining and deepening upward sequences. Particularly limestones and even breccias of the Bombaso Formation yielded a rich fusulinid fauna composed of 34 species which are attributed to the following zones:Quasifusulinoides quasifusulinoides-Protriticites ovatus; Protriticites pseudomontiparus, andMontiparus montiparus. Breccias of the Bombaso Formation west of Straniger Alm contain the oldest fusulinid fauna of the Carnic Alps, belonging to theQuasifusulinoides quasifusulinoides —Protriticites ovatus zone. The fauna is composed ofQuasifusulinoides quasifusulinoides, Q. fallax, Q. intermedius, Protriticites cf.ovoides, andPr. ovatus. This assemblage is most similar to that of the Peskovskaya Formation of the Myachkovian Horizon in the Moscow Basin indicating uppermost Moscovian age. Limestones from depositional sequence 1 at Zollnersee also contain fusulinids of the uppermost Moscovian which are characterized by a more diverse assemblage:Schubertella donetzica, Fusiella lancetiformis, Beedeina ulitinensis, B. consobrina, B. nytvica, B. siviniensis, Quasifusulinoides pakhrensis, Q. fallax, Q. kljasmicus, Q. quasifusulinoides, Fusulinella rara, andProtriticites ovatus. Limestones and calcareous sandstones-siltstones of the basal Meledis Formation of depositional sequence 2 near Zollnersee and at Cima Val di Puartis are characterized by fusulinids of theProtriticites pseudomontiparus zone (Protriticites globulus, Pr. pseudomontiparus, Pr. sphaericus, Pr. rotundatus, Pr. ovoides, Pr. lamellosus, andPraeobsoletes burkemensis) and byMontiparus paramontiparus zone (Praeobsoletes pauper, P. burkemensis, Obsoletes timanicus, O. obsoletes, Montiparus paramontiparus, M. umbonoplicatus, M. montiparus, M. likharevi, M. rhombiformis andM. priscus) indicating lower to middle Kasimovian age (Krevyakinskian and Khamovnicheskian Horizons of the Russian Platform). In memoriam FranzKahler (1900–1995)     

Discovery of Anticostia uniformis from the Xiazhen Formation at Zhuzhai,South China and its stratigraphic implication

The Xiazhen Formation is an Upper Ordovician lithostratigraphic unit in the Jiangshan-Changshan-Yushan (JCY) area, which contains series of Late Ordovician reef successions. The reef successions of the Xiazhen Formation at Zhuzhai are critical for evaluation of the Late Ordovician marine diversity and palaeoecology. However, their age has long been uncertain and generally is regarded as of upper Katian, based on the occurrences of shelly fossils and correlation with the stratigraphic equivalent Changwu Formation. The newly discovered graptolite species Anticostia uniformis, in the Xiazhen Formation, together with the combined evidence of brachiopods and sedimentology, indicates an age range for the graptolite locality from the Dicellograptus complanatus Biozone to the Diceratograptus mirus Subzone of late Katian, but the graptolites do not rule out the possibility that it is Hirnantian.     

EARLY ORDOVICIAN CONODONTS FROM TARUTAO ISLAND,SOUTHERN PENINSULAR THAILAND

Abstract: Early Ordovician conodont faunas of the Thung Song Formation on Tarutao Island, southern peninsular Thailand, consist of 14 known species belonging to 17 genera, and eight undescribed species. Utahconus tarutaoensis and Filodontus tenuis are new species. Three conodont zones: the Rossodus manitouensis Zone, the Utahconus tarutaoensis Zone and the Filodontus tenuis Zone, in ascending order, are defined in the study sections. These are coeval with the interval from the Rossodus manitouensis Zone to the Acodus deltatus‐Oneotodus costatus Zone of the standard zonation in the North American Midcontinent. Based on the conodonts studied here and fossils previously reported from Tarutao Island, the Thung Song Formation is early Tremadocian to middle Arenig (Ibexian) in age. This formation is lithostratigraphically subdivided into the S1 to S5 members, and our study sections consist of the S1 to S3 members. These strata accumulated on a shelf in the Early Ordovician. The depositional environments of the limestones making up the S1 and S3 members were in deeper‐shelf conditions. Limestone and shale of the S2 member formed in a shallow‐water, high‐energy environment.     

Ichnology and sedimentology of the early Permian deep-water deposits from the Lercara-Roccapalumba area (Western Sicily,Italy)

Summary Diverse and abundant trace fossils of the deep-waterNereites ichnofacies have been found in well-dated Early Permian deep-water turbidites (Lercara Formation) of western Sicily (Italy). Conodonts indicate a latest Artinskian to Cathedralian (late Early Permian) age. Microfossils (pelagic conodonts, albaillellid Radiolaria, paleopsychrospheric ostracods, foraminiferal associations dominated byBathysiphon), trace fossils (deep-bathyal to abyssalNereites ichnofacies) and sedimentologic data collectively indicate a deep-water environment for the Early Permian turbidites of the Lercara Formation. The dominance ofAgrichnium and of thePaleodictyon subichnogeneraSquamodictyon andMegadictyon suggests that this icnofauna is closely related in ichnotaxonomic composition to other late Paleozoic deep-water ichnofaunas. The occurrence ofAcanthorhaphe. Dendrotichnium andHelicoraphe, to date only reported from Cretaceous or Tertiary flysch deposits, suggests that the entire ichnofauna corresponds well to previously documented Silurian-Tertiary flysch ichnofaunas. Eight new ichnospecies and a new ichnosubgenus,Megadictyon, are described.     

Devonian and Carboniferous dendroid graptolites from Belgium and their significance for the taxonomy of the Dendroidea

Devonian and Carboniferous dendroid graptolites from Belgium are evaluated and partly revised. New finds in two different stratigraphic intervals of the ‘Carrière de Lompret’, an active quarry exploiting Frasnian limestones and shales east of Frasnes-lez-Couvin, allow the identification of Callograptus sp. and Dictyonema fraiponti, both belonging to the dendroid family Acanthograptidae. The relatively high diversity of the dendroid graptolite fauna from the Viséan Marbre noir de Denée, one of the few Carboniferous graptolite faunas in the world, can be shown to be based on astogenetic and preservational aspects. Nearly all known specimens can be included in the highly variable Dictyonema fraiponti, a fan-shaped large dendroid species with complex stipes formed from tubular thecae, possessing simple to complex bridges connecting adjacent stipes. Some of the graptolite material is well preserved and provides important information on the tubarium construction of Devonian to Carboniferous dendroid graptolites and, thus, is highly significant for a taxonomic and phylogenetic understanding of the youngest dendroid graptolite faunas worldwide. The genera Callograptus and Ptiograptus are revised based on their type species (Callograptus elegans from Quebec, Canada; Ptiograptus percorrugatus from the Silurian or Devonian of Kentucky, USA) and referred to the Acanthograptidae.     

A new species of Caprellinoides (Crustacea: Amphipoda: Phtisicidae) from the Antarctic

A new caprellid species, Caprellinoides singularis, is described and illustrated based on the material collected on the Polarstern Cruise ANT XVII/3 from the Branfield Strait. The most striking characteristic of this species is the presence of bilobed gills on pereonites 3 and 4. The genus Caprellinoides is revised. Caprellinoides antarctica Schellengerg, 1926 and Caprellinoides spinosus Barnard, 1930 are considered junior synonyms of Caprellinoides tristanensis Stebbing, 1888 and Caprellinoides mayeri (Pfeffer, 1888), respectively. The new species, C. singularis, is compared with the remaining species in the genus Caprellinoides: C. tristanensis and C. mayeri, which are illustrated in detail. Received in revised form: 4 June 2001 Electronic Publication