The hipparions (Mammalia,Perissodactyla) from the Turolian locality “Nikiti-2” (NIK), Macedonia,N. Greece

The hipparions from the late Miocene locality Nikiti-2 (NIK), Macedonia, Greece are described and compared with those from the other Greek and Eurasian localities. Two species have been determined, the medium-sized Hipparion dietrichi and the small-sized Hipparion macedonicum, while a third large-sized Hipparion is also recognized. The scanty material of the latter species indicates similarities with Hipparion proboscideum, as well as with Hipparion mediterraneum and it is referred to as Hipparion sp. The locality is dated to early Turolian as this is proved by the resemblance of the hipparions from “Nikiti 2” faunal assemblage with those from the neighbouring localities of “Ravin des Zouaves 5” and “Prochoma 1”, of Axios Valley, Greece. Interesting differences, which are inferred by the comparison of the studied material with those of Axios Valley, Samos and Turkey, are also discussed.     

Paleoclimatic trends in early and middle pliocene deep-sea sediments of the antarctic

Detailed micropaleontological investigation has established the distribution of major radiolarian assemblages in the Early to Middle Pliocene deep-sea sediments of the Antarctic region, with particular emphasis on the Gilbert Reversed Magnetic Epoch (t = 5.18 to 3.32 m.y. B.P.). Inter-core correlations, based on paleomagnetic stratigraphy and detailed radiolarian biostratigraphy, has provided a chronological framework for a detailed paleoclimatic investigation of the Gilbert Epoch. Early Gilbert sediments (t = 5.18 to 4.6 m.y. B.P.) contain a warm-Subantarctic assemblage marked by the presence of Anthocyrtidium ehrenbergi, “Eucyrtidium” spp., Carpocanium sp., Stylatractus universus and several collosphaerid species. Sediments of middle Gilbert age (t = 4.6 to 3.7 m.y. B.P.) contain a cool-Subantarctic assemblage marked by the presence of Stylodicta validispina, Cenosphaera cristata, Antarctissa longa, Triceraspyris pacifica and Lychnocanium grande rugosum. The late Gilbert—early Gauss sediments (t = 3.7 to 3.0 m.y. B.P.) contain an Antarctic assemblage marked by the presence of Antarctissa strelkovi, Antarctissa denticulata, Helotholus vema, Demospyris spongiosa and Eucyrtidium calvertense. The transition from a warm to a cold assemblage suggests a climatic deterioration occurring over a period of 1.6 m.y., significantly longer than the rapid climatic oscillations of the Pleistocene. Factor curves, produced by subjecting total faunal data to multivariate statistical analysis, have been interpreted in terms of paleoclimatic controls, resulting in a relative paleotemperature curve for the entire Gilbert Epoch. The maximum abundances of the Antarctic assemblage in the Gilbert and Gauss occurs between 3.7 and 3.2 m.y. ago coinciding closely with the 3.5 m.y. age of the first reported Patagonian glaciation in southernmost South America.     

Die Graptolithen des Ordoviziums von Rügen (Norddeutschland, Vorpommern)

Graptolite faunas from theHolmograptus lentus,Pterograptus elegans, Hustedograptus teretiusculus andNemagraptus gracilis Zones are identified in the Ordovician succession of Rügen. The well sections bear incomplete, often fault-bounded successions. Tectonic stacking is present in the Rügen 3h core. A sedimentological gap is expected in the Arenig. About twenty graptolite species are described and their local biostratigraphic ranges are documented. Most of the faunal elements are described for the first time from the Ordovician of northern Germany. The faunal associations belong to the Atlantic Faunal Province.     

Calcareous plankton biostratigraphy and biochronology of the Pliocene-Lower Pleistocene succession of the Capo Rossello area,Sicily

In the first part of this paper we present the calcareous nannofossil biostratigraphy of the Capo Rossello section (Sicily), which suggests that a sedimentary gap exists at the contact between the “Trubi” and the overlying Monte Narbone Formation, close to the top of the proposed Zanclean stratotype. This suggestion is supported by the planktonic foraminiferal results and field observations. In contrast, the transition from the “Trubi” to the Monte Narbone Formation is well exposed, gradational and biostratigraphically continuous in the nearby section of Punta Piccola. A composite of the Capo Rossello and Punta Piccola sections serves as a good biostratigraphic reference for the Pliocene of the Mediterranean.In a second part of this paper, we have attempted to update the Mediterranean Pliocene time framework by integrating all of the available biostratigraphic, biochronologic, chronostratigraphic, paleomagnetic and radiometric data.     

Nannoplankton-Based Biostratigraphic Subdivisions in the Reference Sections of the Taman Trough and Ciscaucasia

Paleontological Journal - Integrated paleomagnetic and biostratigraphic study of the Neogene sedimentary sequences in the reference sections of the Taman Trough and Ciscaucasia allowed...     

Paleomagnetism of the middle siwalik formations of northern Pakistan and rotation of the salt range decollement

Sampling for paleomagnetic study has been carried out at seven localities in the Potwar Plateau region of Pakistan in the vicinity of the Salt Range. In all, 253 sites, consisting of three samples per site, were studied. The sites were taken from the Chinji, Nagri, Dhok Pathan and Upper Siwalik formations which span the last 14 m.y. of Earth history. The formations have been deformed in the ongoing Himalayan orogeny and are exposed today in sections which dip at angles of from 10° to 90° in different directions.A characteristic direction of magnetization was isolated at all sections by thermal demagnetization at temperatures of from 550° to 650°C. The sediments have been folded within the last 2 m.y. and because of a positive fold test it can be shown that the characteristic magnetization of these sediments was acquired before folding. Four of the sections have directions of magnetization which have been rotated in a counter-clockwise fashion up to 40°; however, sections taken along the Indus River, the north flank of the Soan syncline and the south flank of the Salt Range show small counter-clockwise rotations of under 10°. These observations are in agreement with previous suggestions that strata in the Salt Range have been moved to the south and rotated in a counter-clockwise fashion. The observations reported here indicate that the paleomagnetic poles derived from Cambrian and Permian formations within the Salt Range have probably also suffered rotation and should be removed from consideration in Gondwanaland reconstruction of the Paleozoic.     

Miocene—pliocene sea-level changes and volcanic phases on gran Canaria (Canary islands) in the light of new K—Ar ages

Thirteen new K—Ar dates of stratigraphically important Pliocene and Pleistocene lava flows and intrusives from Gran Canaria (Canary Islands) permit a more precise definition of alternating periods of volcanic activity and erosional intervals. The Miocene erosional interval (Erosional Interval I) lasted from 9.6 to 4.4 m.y. B.P.; Roque Nublo volcanic activity (phase II in the magmatic history of the island) began 4.4 m.y. and ended 3.7 m.y. ago; Erosional Interval II lasted from 3.7 to 2.8 m.y. B.P.; volcanic activity resumed at 2.8 m.y. B.P. with the eruption of olivine nephelinite lavas. The subsequent alternation of phases of volcanic activity and erosional intervals is not yet precisely dated. Four regressions and three transgressions are recognized on Gran Canaria in the time interval 9.6-2 m.y. B.P. The famous marine sediments of the “Las Palmas Terrace” represent at least three distinct marine levels of different ages and only the oldest one may correspond to the age assignment “Helvetian or Tortonian” of Rothpletz and Simonelli (1890).Several causes for the marine transgressions are discussed such as eustatic changes in sea level, isostatic vertical movements of the island and movements in regional stress fields. None of the transgressions and regressions can be convincingly explained so far by either a single mechanism or a combination of several processes. However, we tentatively suggest that eustatic and, perhaps to a lesser degree, isostatic movements are the main causes. These uncertainties in the interpretation of the transgressions and regressions underscore the need for more precise dating of similar elevated marine sedimentary rocks on other Atlantic islands.     

Magnetic polarity stratigraphy and ages of Siwalik group rocks of the potwar plateau,Pakistan

Six magnetic polarity sections have been established over the Potwar Plateau region of Pakistan, including the major stratotypes of the Siwalik Group. In all six sections the dominant feature of the magnetic polarity stratigraphy is a long normal polarity zone, which is contained within the Nagri Formation. This conspicuous normal polarity zone has been radiometrically dated at 9.5 ± 0.6 m.y., which identifies it as magnetic Chron 9. Radiometric dates from the Upper Siwalik Formation have also been used to identify the Chron 2–3 boundary in two of the sections. The magnetic polarity stratigraphy of three of the sections has been correlated securely with the accepted magnetic polarity time scale, so that the ages of the local stratigraphy are indexed accordingly. Based exclusively on data from stratotype sections, the Chinji, Nagri and Dhok Pathan Formations have nominal age ranges of 10.1–13.1, 7.9–10.1 and 5.1–7.9 m.y. Age fluctuations on the order of 10⁵ years may be anticipated for these formational boundaries within radius of some 20 km of the designated stratotype. Mean sediment accumulation rates during the Chinji, Nagri and Dhok Pathan interval range from 13 to 52 cm/10³ yr.Essentially linear sediment accumulations are locally maintained over time intervals of several million years. The Chinji-Nagri lithofacies boundary marks a transition from slow to faster sediment accumulation over much of the Potwar Plateau, indicating a fundamental sedimentary-tectonic change at this time.     

The Hipparion of the Rhone valley

A revision is given of the Rhone valley Hipparion. One new species is described from Montredon. It is noted that in the lower Vallesian localities one big heavily built Hipparion is present. In the late Vallesian a medium sized Hipparion with short limbs is found; in the Turolian a slender form of medium size and perhaps also a heavy form is present; finally in the Ruscinian two forms are found of which one has a very big size and has cabaloid characteristics.Some remarks are made about the paleoecology of Hipparion in general.     

New records of early Middle Jurassic belemnites in the French Subalpine Basin and their paleobiogeographic significance

A biostratigraphic and systematic study based on belemnites collected along with ammonites was performed on four sections in the Subalpine Basin (SE France): Lac du Castillon and La Baume (Castellane area), Galabrun and Grand Lara (Gap area). The specimens, originating from hemi-pelagic marl-limestone alternations in the lower part of the “Calcaires à Zoophycos” Formation, are dated from Middle Aalenian (Murchisonae Zone) to Lower Bajocian (Humphriesianum Zone). Five belemnite taxa (Megateuthis elliptica, Holcobelus munieri, H. trauthi, Pachybelemnopsis roettingensis, Hibolithes sp.) have been identified, and two more taxa are reported in an open nomenclature (Belemnitida incertae sedis sp. 1 and sp. 2). The biostratigraphic range of the belemnite fauna is established. The new findings contribute to a more detailed understanding of the paleobiogeography of holcobelid belemnites that flourished at the northern margin of the Tethys Ocean and formed a distinct sub-Mediterranean fauna. The association herein described is similar to the fauna of the Calabro-Peloritani Arc (Calabria, Italy), a further hint for the supposed paleogeographic position of the latter during the Middle Jurassic.     

Ammonite-benthic Foraminifera turnovers across the Lower-Middle Jurassic transition in the Lusitanian Basin (Portugal)

This paper describes and characterises the co-occurrence of ammonite and benthic foraminiferal assemblages across the São Gião outcrop (Central Portugal), a reference section for the Lower-Middle Jurassic boundary in the Lusitanian Basin. The upper Toarcian-lower Aalenian marls and marly-limestones in this section provide a precise and detailed ammonite-based biostratigraphic zonation, with a mixed assemblage of northwest European and Mediterranean faunal elements, associated with benthic foraminifera assemblages with northern hemisphere affinities, both correlatable with the Aalenian GSSP at the Fuentelsaz section (Iberian Cordillera, Spain). A total of 447 well-preserved ammonite specimens and 13.116 foraminifera have been studied; no evidence was detected of any taphonomic processes that could have changed the original assemblages. From a biostratigraphic point of view, the ammonite record has enabled four biostratigraphic units to be recognised (the Mactra and Aalensis subzones of the Aalensis Biozone in the upper Toarcian, and the Opalinum and Comptum subzones of the Opalinum Biozone in the lower Aalenian). With regard to the benthic foraminifera, the taxa identified have enabled the Astacolus dorbignyi Zone and 11 bioevents to be identified, most of which representing local biostratigraphic proxies. However, the increase in the relative abundance of Lenticulina exgaleata Dieni from the upper part of the Opalinum Subzone to the lower part of the Comptum Subzone has a regional value. The constant and continuous ammonite record of northwest European taxa, together with typical Mediterranean taxa – namely Grammoceratinae – throughout the section, the high relative abundance of Miliolina representatives – generally interpreted as foraminifers typical of shallow waters – and the absence of foraminiferal forms typical of cool waters, do not support the inference of cool seawater temperatures attributed to the Early Aalenian, or the global character of the “Comptum cooling event”, at least with reference to the Lusitanian Basin.     

Restoration of Aegiceras corniculatum mangroves in Jiulongjiang Estuary changed macro-benthic faunal community

Macro-benthic faunal communities were compared between non-vegetation mudflat and Aegiceras corniculatum mangroves with different ages in Jiulongjiang Estuary, China. Faunal species number was highest in the mature mangrove and was higher in mangroves than in the mudflat, as snails and some crustaceans species were only collected in mangroves. The 5-year-old mangrove had the highest infaunal abundance and crustacean biomass. Snails had more abundance in the young mangroves. Uca arcuata was the dominant crab species in the non-vegetation mudflat and 5-year-old mangrove. Mangrove vegetation and sediment characteristics analyses indicated different habitats due to A. corniculatum mangrove restoration. However, overall poor correlations between faunal assemblage and sediment properties indicated that sediment properties were not the major factors influencing faunal distribution.     

Faunal turnover at the end of the Cretaceous in the North Pacific region: Implications from combined magnetostratigraphy and biostratigraphy of the Maastrichtian Senpohshi Formation in the eastern Hokkaido Island,northern Japan

A combined magnetostratigraphic and biostratigraphic study has been performed on the Maastrichtian Senpohshi Formation in eastern Hokkaido Island, northern Japan, which is an approximately 1300 m thick section mainly composed of hemipelagic mudstone. The identification of magnetic polarity was possible at 51 horizons, whereby four magnetozones were recognized. These magnetozones were correlatable to geomagnetic polarity chrons C31r to C30n, suggesting that the age of the Senpohshi Formation is spanning from middle to upper part of the Maastrichtian (ca. 69–67 Ma).The magnetostratigraphy of the Senpohshi Formation established in this study enables a direct age correlation to the Maastrichtian successions in other regions. Thus, this detailed chronology of the formation contributes to paleontological studies of the Maastrichtian in the North Pacific region. For instance, this magnetostratigraphic age assessment implies the following: (1) the stratigraphic range of the ammonite Pachydiscus flexuosus contains polarity chrons from the lower part of C31r to the lower part of C31n, (2) the first occurrence (FO) of the calcareous nannofossil Nephrolithus frequens in the North Pacific region is correlatable to polarity chron C30n or below, and (3) the FO of the bivalve “Inoceramus” awajiensis is located within polarity chrons from C31r to the upper part of C31n. This suggests that the inoceramid extinction event in the North Pacific region might have occurred during polarity chrons from C31r to the upper part of C31n (ca. 70.5–67.8 Ma), which is 2.3–5.0 Myr prior to the Cretaceous/Paleogene boundary. The trend of the Maastrichtian faunal turnover in the North Pacific is well consistent with those of other regions, brings a new evidence for understanding the global faunal turnover in the Maastrichtian, just before Cretaceous/Paleogene mass extinction.     

The Guadalupian–Lopingian boundary (Permian) in a pelagic sequence from Panthalassa recognized by integrated conodont and radiolarian biostratigraphy

Guadalupian–Lopingian sedimentary rocks are widely distributed in accretionary complexes in Japan, but the Guadalupian–Lopingian boundary (G–LB) is not well documented from these pelagic sediments. To identify the G–LB and to better correlate an extinction event that occurred around the Guadalupian–Lopingian boundary, we examined the conodont biostratigraphy from a Permian pelagic chert sequence in the Gujo-hachiman section, Gifu, southwest Japan. Age-diagnostic conodonts, including Clarkina postbitteri postbitteri, were found in this section. The biostratigraphic occurrences of these age-diagnostic conodonts can pinpoint the “G–L transitional zone” in the Gujo-hachiman section by comparison with well-studied sections from south China, including the GSSP section. The transitional zone was recognized by the first occurrence horizons of both Clarkina postbitteri hongshuiensis and C. p. postbitteri. The G–LB has been placed at or above the first occurrence horizon of the radiolarians Albaillella yamakitai or Albaillella cavitata in previous studies from China and Japan. We detected the first occurrence horizon of A. yamakitai below the base of the “G–L transitional zone,” in the Upper Capitanian. The conodont biostratigraphy is consistent with the radiolarian biostratigraphy in this section, which can be correlated to relevant sections in China.     

A contribution to the chronology of some Old World miocene faunas based on hipparionine horses

The Maragheh Formation, northwestern Iran,provides a local biostratigraphic base upon which to build a biochronology of hipparionine horses that has potential regional importance in ordering faunas of Vallesian and Turolian age in other areas of the Old World. This, as well as faunal and radiometric analysis of the Maragheh sequence, is compared with those aspects of other districts. The radiometric age of the so-called «Hipparion Datum» is 12 Ma, if not slightly older, and more than one species of «Hipparion» may be associated with it. Based on cranial morphology, hipparionine horses of Vallesian age consist of a single group; faunas of Turolian age contain four hipparionine groups by these criteria. A group composed of Hipparion prostylum and later members appears to be the most useful in compiling a possible biochronology. This group may have had an endemic European rather than allochthonous (American) origin. Based on the various assessments discussed here the following temporal sequence of certain faunal localities is proposed (oldest to youngest): Vallesian-Höwenegg (Germany), Bou Hanifia I (N. Africa) and Hostalets de Pierola (Spain). Early Turolian-Kopran, Lower Maragheh (Iran). Medial Turolian-Mont Luberon (France), Kerjabad or Ketschawa, Middle Maragheh (Iran), Saloniki (Macedonia), Pikermi (Greece), Shol'avand, Upper Maragheh (Iran), Samos (Greece). Our assessment of the age of the Mont Luberon and Samos faunas differs from conventional assignments.     

Pleistocene biostratigraphy,chronostratigraphy and paleocirculation of the southeast pacific central water core RC 11-220

An 11-m core, RC 11-220, raised from a depth of 2,950 m in the unstudied Southeast Pacific Central Water of the Tuamotu Ridge (14° 49′S 139° 58′W) received paleontologic and paleoecologic analysis. Eight biostratigraphic horizons were recognized (6 planktonic foraminiferal, 1 coccolithophorid and the discoaster extinction) defining the core as continuous through the basal Pleistocene. The Globorotalia truncatulinoides (d'Orbigny) datum was approached but not encountered. The core has an estimated average sedimentation rate of 0.60 cm/10³ years. Extrapolation from two paleomagnetic datums (Brunhes/Matuyama, ca. 0.69 Ma and the top of the Olduvai, ca. 1.61 Ma) indicates the age of the core bottom to be ca. 1.87 Ma.Based on the evidence recorded in RC 11-220 and our knowledge of the circulation patterns at the core site today, the following paleocirculation model is proposed. The total carbonate and coarse fraction data indicate a relatively constant depositional pattern and productivity. In addition, judging from the faunal dominance and the distributional pattern of key species such as Globigerinoides ruber (d'Orbigny), Globigerinoides sacculifer (Brady) and Globigerinita glutinata (Egger), a minor shift in the salinity regime is suggested while temperature remained relatively constant. On the average, salinity was slightly higher during the first approximate million years and was somewhat reduced during the last million years B.P. The major conclusion of this study however is that the character of the surface South Central Pacific Waters remained relatively constant throughout the Pleistocene.     

Bathymetric distribution of benthic foraminifera on the Australian-Irian Jaya continental margin,eastern Indonesia

We identified 164 taxa of benthic foraminifera in 35 selected box-core top samples collected on the Australian-Irian Jaya continental margin in waterdepths between 60 and 2119 m, along three systematically sampled transects across the Banda Arc. The bathymetric distribution pattern of the benthic foraminiferal faunas is related to the oceanographic situation of this area, where the watermasses of the Indian Ocean collide with the watermasses of the Pacific Ocean. With the results of cluster analyses and empirical depth-ranges of “isobathyal” taxa, four faunal depth-zones and four subzones can be distinguished:

• 1.(A) The Outer Shelf Biofacies (60–150 m), corresponding to the photic oxycline-zone of the Indonesian Surface Waters, and inhabited by a benthic foraminiferal association dominated by Amphistegina lessonii, Operculina ammonoides, Heterolepa dutemplei and various miliolids.
• 2.(B) The Upper Bathyal Biofacies (150–400 m), reflecting the aphotic, deeper Indonesian Surface Waters, dominated by Bolivina robusta, Heterolepa mediocris, Hanzawaia nipponica and Lenticulina spp. A major faunal break is situated at the lower boundary of this depth-zone.
• 3.(C) The Middle Bathyal Biofacies (400–1500 m), representing the Indonesian Intermediate Waters with minimum oxygen-contents, dominated by Bolivina robusta, Cassidulina carinata, Gavelinopsis lobatulus and Sphaeroidina bulloides. In this depth-zone many taxa occur with only limited depth-ranges, on which four subzones (C1–4) could be identified, allowing for a local (paleo)bathymetric resolution of a few hundred meters.
• 4.(D) The Lower Bathyal Biofacies (1500–2120 m) corresponds with the Indonesian Deep Waters. It is dominated by Pullenia bulloides and other cosmopolitan deep water indicators, such as Epistominella exigua, Laticarinina pauperata, Oridorsalis umbonatus and Planulina wuellerstorfi.

The sample fraction > 250 μm can be used to readily delineate the major faunal trends. Paleobathymetric resolution improves when the sample portion > 125 μm is used.     

Wilkes Land Late Pleistocene diatom age model: From bio-events to quantitative biostratigraphy

A new method merges conventional and quantitative biostratigraphic approaches, supported by magnetic polarity data, to develop a chronological framework for sediment core MD03-2595 retrieved on the continental rise off Wilkes Land, East Antarctica before proceeding to paleoceanographic and paleoclimatic analysis. This combined method helped to identify climatic cycles, highlight stratigraphic discontinuities and reworking, and assess regional sedimentological and diatom biostratigraphic evolution. Core MD03-2595 spans the last 0.8 Ma, from the Mid Pleistocene Transition (MPT) to the Early Holocene. A hiatus including Marine Isotope Stages (MIS) 19, 18 and 17 was identified, and a decreasing trend in sediment accumulation rates from MIS 16 to the Holocene was observed. This quantitative diatom biostratigraphic dataset, placed in its own sedimentological and paleomagnetic context, provides new information regarding the paleobiogeographic distribution and ecological responses of biostratigraphically significant diatom species, such as Thalassiosira elliptipora and T. fasciculata, for the Matuyama–Brunhes (M–B) transition, and Actinocyclus ingens, Hemidiscus karstenii and Rouxia spp. for the middle and late Pleistocene diatom biozonation.     

Danian/Selandian boundary stratigraphy,paleoenvironment and Ostracoda from Sidi Nasseur,Tunisia

Two detailed records (NSF and 05NSC, Sidi Nasseur, Tunisia) across the Danian/Selandian (D/S) boundary were investigated for their micropaleontological content. Calcareous nannofossils and planktic foraminifera provided a biostratigraphic framework. The interval spans part of planktic foraminiferal Zone P2, Subzone P3a and part of Subzone P3b. This corresponds to calcareous nannoplankton Zone NP4. Using a more detailed nannofossil zonation the studied section spans part of Zone NTp6, Zone NTp7a and part of NTp7b. Quantitative ostracod and qualitative benthic foraminiferal data were used to characterize environmental changes across the D/S boundary. The two subsections have yielded a total of 50 ostracod taxa. The ostracod assemblage of the entire section belongs to the Southern Tethyan Type showing subtle but distinct changes up section. Based on statistical analysis of the quantitative ostracod data, faunal changes at a glauconitic maker bed (P3a/P3b boundary) were demonstrated. The local Reticulina proteros assemblage, with the typical species R. proteros, Oertliella vesiculosa and Cytheroptheron lekefense, is gradually replaced by the Protobuntonia nakkadii assemblage, with the typical species Cristaeleberis arabii, Xestoleberis tunisiensis, Cytheropteron sp. and P. nakkadii, across the glauconitic bed. The benthic foraminifera also demonstrated distinct changes at this marker bed. The changes in ostracods and foraminifera are related to changes in paleoproductivity and an overall relative sea-level fall.The lithological and faunal changes at the P3a/P3b zone boundary within the Sidi Nasseur sections seem to correspond to the D/S boundary in the type region in Danmark and are characterized by a significant hiatus, yielding this section not suitable as a GSSP candidate for this boundary.     

Lower Emsian biostratigraphy and event stratigraphy of Ha Giang Province,northern Vietnam

A new species of rugose coral, Sanidophyllum dubium n. sp., and the typical Emsian (Early Devonian) rugose coral Xystriphylloides nobilis are described from the Mia Le Formation in northern Vietnam. The lower Emsian index conodonts ranging from the Polygnathus excavatus zone to the P. nothoperbonus zone are illustrated. The biostratigraphic correlation between northern Vietnam and South China shows that the Mia Le Formation in northern Vietnam is early Emsian in age, and its upper part can be correlated with the lower part of the Shizhou Member of the Yukiang Formation in Liujing, Guangxi and its equivalents in South China. Based on the study of the lower Emsian biostratigraphic sequence, the disappearance of Xystriphylloides nobilis fauna in the overlying bed of the uppermost Mia Le Formation and the extinction of the “tonkinensis fauna” (sensu lato) in the interval between the basal Si Phai Formation and the uppermost Mia Le Formation demonstrate the influence of the Yujiang Event in northern Vietnam.