Palaeobiogeographical Affinities Research Articles

Upper Cenomanian bivalves from the Guir Basin (southwestern Algeria): Order Veneroida

The Upper Cretaceous rocks are widely distributed and well exposed in south Algeria and consist in beds rich in macrofauna. For the first time, twenty veneroid species (Bivalvia) are systematically described from the upper Cenomanian deposits of the Guir Basin. While three species were reported since long before [Granocardium desvauxi (Coquand), G. productum (J. de C. Sowerby) and Glossus aquilinus (Coquand)]; Lucina fallax Forbes, Crassatella (Rochella) tenuicostata (Seguenza), Protocardia hillana (J. Sowerby), G. productum (J. de C. Sowerby) var. byzacenica (Pervinquière), Arctica cordata (Sharpe), A. humei (Cox), A. inornata (d’Orbigny), A. picteti (Coquand), Tenea delettrei (Coquand), Paraesa faba (J. de C. Sowerby), Meretrix desvauxi (Coquand) were previously unknown from the Cretaceous of Algerian Sahara. Because of reduced degree of preservation, Sphaera cf. corrugata J. Sowerby, Maghrebella cf. forgemoli (Coquand), Maghrebella sp., Granocardium cf. carolinum (d’Orbigny), Protocardia sp. and Meretrix sp. are tentatively determined. The studied material, found in the lower part of the “Calcaires de Sidi Mohamed Ben Bouziane” Formation, evidences palaeobiogeographic affinities occurring over a wide geographical area: from North Africa, southern Europe to Middle East and India. The present study provides new information to the knowledge of the upper Cenomanian palaeobiology of the studied region.

Llandovery (lower Silurian) graptolites from the Sepon Mine, Truong Son Terrane, central Laos and their palaeogeographical significance

Graptolites are described from the Llandovery of the Sepon mine area, central Laos, part of the Truong Son Terrane. The palaeobiogeographical affinities of the Rhuddanian graptolites are with peri-Gondwanan Europe and Arabia rather than equatorial regions such as South China and Laurentia (Arctic Canada). A review of previous palaeontological research on the middle Palaeozoic of the Indochina terranes reveals an often contradictory picture with vertebrates suggesting close proximity of South China to the Truong Son Terrane in the Devonian and invertebrates and radiolarians providing evidence for a palaeogeographical barrier between the two. Graptolites from the Mojiang area, Yunnan are typical of low latitude Silurian faunas and suggest that this area (Simao or Loei Terrane) was separate from the Truong Son Terrane.

Parahoplitid ammonites and narrowing down the Aptian/Albian boundary interval in northern Iran

Aptian and Albian parahoplitid ammonites from the Sanganeh- and Aitamir formations of the Koppeh Dagh Basin in northern Iran are described and illustrated, some taxa are recorded from Iran for the first time. The earlier established view of a close palaeobiogeographic affinities of the Koppeh Dagh Basin with the European faunal realm during the late Aptian–early Albian is consolidated by our data. The idea of an assumed faunal exchange particularly with Europe across the Russian Platform and Transcaspia is boosted by the new records of Parahoplites irregularis, Colombiceras (Colombiceras) tobleri, Protacanthoplites abichi and Diadochoceras sp. from Iran. The stratigraphic succession of the ammonite faunas is used for a biostratigraphic appraisal of the Sanganeh- and Aitamir formations and conform earlier ideas that both formations are diachronous. The Tutli section is particularly relevant in this respect since a high level in the Aitamir Formation is dated here as middle upper Aptian whereas the other sections investigated indicate a lower stratigraphic level, but are attributed to the underlying Sanganeh Formation. Most ammonites described indicate fairly long ranges in the upper Aptian according to the literature, except for those of the P. melchioris group characterising the middle part of the upper Aptian. We record the index of the eponymous P. melchioris Zone as well as the closely allied Parahoplites cf. transitans and Parahoplites cf. multicostatus. Only one species recorded, Hypacanthoplites elegans, probably indicates a level above the Aptian/Albian boundary.

Igdabatis marmii sp. nov. (Myliobatiformes) from the lower Maastrichtian (Upper Cretaceous) of north-eastern Spain: an Ibero-Armorican origin for a Gondwanan batoid

Microvertebrate fossil assemblages (chondrichthyans, osteichthyans, lissamphibians and squamates) from the Campanian and Maastrichtian of south-western Europe include taxa with very different palaeobiogeographical affinities. However, most of these biogeographical histories remain unclear. As inhabitants of shallow marine waters, batoids are considered good palaeobiogeographical indicators that could reveal connections between continental platforms. Igdabatis is a stingray (Myliobatiformes) with an abundant Gondwanan fossil record, whereas its occurrence in the Ibero-Armorican landmass is intriguing. In this paper, a new species of Igdabatis – Igdabatis marmii sp. nov. – is reported from the lower Maastrichtian of Spain. Based on this new record, the phylogenetic relationships of Myliobatiformes are assessed, including Igdabatis taxa for first time. In addition, three new morphological characters are proposed based on the diagnoses of the different species and added to the dataset. The palaeobiogeographical events that these stingrays underwent during their speciation were explored through a Statistical Dispersal-Vicariance Analysis (S-DIVA) performed in RASP 2.1. The phylogenetic analysis suggests a highly nested position within Myliobatidae for the genus Igdabatis; and the new species was recovered as the most basal taxon in the clade. The S-DIVA results point to an Ibero-Armorican ancestral area for Igdabatis, from where its species diverged by a combination of vicariant and dispersal events. Both phylogenetic and palaeobiogeographical analyses were congruent with occurrences in the fossil record. Results and fossil evidence allow the proposal of a dispersal route between European and Gondwanan landmasses for these stingrays. The dispersal of Igdabatis between Ibero-Armorica and India during the Late Cretaceous was promoted by the proximity of the European and African continental platforms and then by the Kohistan-Ladakh island arc.http://zoobank.org/urn:lsid:zoobank.org:pub:F5C51029-2E26-48C6-8A87-A2D4310887EF

Foraminiferal biostratigraphy and facies analysis of the Permian Longge Formation in the Rongma Area, Tibet, China: implications for the palaeogeography of the South Qiangtang Block

Wang, Z-B., Gao, J-H., Wang, G-H. & Kang, Z-H., June 2018.2018. Foraminiferal biostratigraphy and facies analysis of the Permian Longge Formation in the Rongma Area, Tibet, China: implications for the palaeogeography of the South Qiangtang Block. Alcheringa XX, x–x.The Permian Longge Formation in the South Qiangtang Block, Tibet, is overwhelmingly composed of carbonate rocks with various skeletal (brachiopods, foraminifers, gastropods, echinoderms, ostracods, corals, bivalves, algae, and bryozoans) and non-skeletal (intraclasts and ooids) components. Three stratigraphic sections of the Longge Formation in the Rongma area of north-central Tibet—known as South Yibug Caka, Niushan and East Yibug Caka—were selected for this study, which examined both sedimentary facies and foraminiferal assemblages. The foraminifers in these sections consist of at least 38 species belonging to 18 genera. Based on the distribution of the foraminifers throughout the composite section, two foraminiferal assemblages were established, and the age of the Longge Formation was determined to be late Kungurian to Capitanian. During lithological studies, ten microfacies were identified using depositional textures, petrographic analysis and faunal content: mudstone, bioclast wackestone, bioclast perforated-foraminifera packstone, bioclast crinoid grainstone, intraclast wackestone, breccia, intraclast grainstone, ooid grainstone, fine crystalline dolostone and residual-grain dolostone. These microfacies are interpreted to represent four depositional environments—restricted lagoon, open marine, shoal and slope—which together suggest a shoal-rimmed carbonate platform. The non-fusuline foraminifers show transitional palaeobiogeographic affinities (Tethyan Cimmerian subregion), and the assemblage is considered to be influenced by the northward drift of the South Qiangtang Block, the climatic warming after the Late Paleozoic Ice Age and warm-water oceanic currents caused by the newly formed Neotethys Ocean. This indicates that the South Qiangtang Block was located in a relatively warm-water, low-latitude area during the middle Permian. The Permian depositional sequences in the Rongma area were also influenced by the palaeogeographic evolution of the South Qiangtang Block.Zhong-Bao Wang [zbwang@cugb.edu.cn] and Zhi-Hong Kang [kangzh98@cugb.edu.cn] School of Energy Resource, China University of Geosciences (Beijing), 29 Xueyuan Road, Beijing 100083, PR China; Jin-Han Gao* [wang_zhongbao@126.com] and Gen-Hou Wang [wgh@cugb.edu.cn] School of Earth Sciences and Resources, China University of Geosciences (Beijing), 29 Xueyuan Road, Beijing 100083, PR China.

Chronostratigrahy of Acritarchs and Chitinozoans from upper Ordovician Strata from the Robat-e Gharabil Area, NE Alborz Mountains, Northern Khorassan Province: Stratigraphic and Paleogeographic Implications

The Palaeozoic rock units mainly, Ghelli, Niur, Padeha, Khoshyeilagh and Mobark formations are well-exposed in the north of Robat-e Gharabil village. 116 out of 157 surface samples were analyzed to determine aged relationships of Ghelli Formation. The samples of Ghelli Formation are dominated by acritarchs (42 species belonging to 23 genera) and chitinozoans (26 species distributing among 15 genera). Two new acritarch species are introduced, consisting of Goniosphaeridium iranense n.sp., and Goniosphaeridium persianense n. sp. Based on the restricted stratigraphic range of chitinozoan species, Late Ordovician (Ashgill) age is assigned to the Ghelli Formation. On the other hand, the presence of diagnostic chitinozoan taxa in the Ghelli Formation consisting of Armoricochitina nigerica, Ancyrochitina merga, and Spinachitina oulebsiri chitinozoan biozones, suggest a clear palaeobiogeographic affinity between NE Alborz Mountain and North Gondwana Domain. The presence of some chitinozoan and acritarch taxa from the Baltic and Laurentia in Gondwanan chitinozoan biozones of the Robat-e Gharabil area suggests the existence of counter-clockwise marine currents that resulted in bringing planktonic organisms (acritarchs and chitinozoans) from lower latitudes (Baltica) to higher latitudes (Northern Gondwanan Domain) settings.

Aalenian-Bajocian belemnites from the Middle and High Atlas, Morocco: taxonomy, biostratigraphy and palaeobiogeographical affinities

Aalenian-Bajocian belemnites from the Middle and High Atlas, Morocco: taxonomy, biostratigraphy and palaeobiogeographical affinities

The upper Palaeozoic Godar-e-Siah Complex of Jandaq: Evidence and significance of a North Palaeotethyan succession in Central Iran

The Upper Palaeozoic Godar-e-Siah Complex of Jandaq, Central Iran, comprises three isolated, fault-bounded outcrops exposing Palaeozoic fossiliferous carbonates, volcanics and siliciclastics, which are markedly distinct from the surrounding sedimentary successions. The three outcrops, that emerge below Cretaceous and younger sediments, are the Chah Rizab outcrop, the Godar-e-Siah northern outcrop, and the Godar-e-Siah central outcrop. Their sedimentary successions strongly differ from the typical passive margin successions of Gondwanan affinity that characterize the Yazd, Lut and Tabas blocks of Central Iran and the Alborz in North Iran. To understand the origin of these profound differences, we first calibrated the age of the Jandaq successions: U-Pb radiometric zircons ages, obtained from granitoid boulders in the conglomerates at Chah Rizab and in the Godar-e-Siah northern outcrop, gave a Late Devonian to Mississippian age. Biostratigraphic data from brachiopods and fusulinids from the Godar-e-Siah northern and central outcrops indicate a Pennsylvanian age. The age of the successions is thus post-Visean to Pennsylvanian. The petrographic composition of the siliciclastic deposits indicates the erosion of a magmatic arc. To understand where the Jandaq complex could have been located at that time, we have assessed the palaeobiogeographic affinity of the faunas. The collected brachiopods and fusulinids assemblages are mostly similar to coeval faunas from Spain, Donbass, Urals, and Yukon Territory (Canada) and have a North-Palaeotethyan affinity. The Godar-e-Siah Complex of Jandaq likely represents part of the southern active margin of Eurasia (northern margin of the Palaeotethys), in contrast to the surrounding Central and North Iran blocks, which were at that time located along the southern margin of the Neotethys.Our investigations confirm a complex palaeogeographic evolution for the studied outcrops, suggesting that they represent fragments of the southern Eurasian active margin - today preserved in NE Iran - displaced by crustal-scale wrench motions related to the opening and closure of the Sabzear Ocean and to the Cenozoic activity of the Great Kavir-Doruneh Fault and its possible precursors.

A Kungurian (early Permian) Brachiopod Fauna from Ogama, Kuzu Area, Central Japan, and Its Palaeobiogeographical Affinity with the Wolfcampian—Leonardian (early Permian) Brachiopod Fauna of West Texas, USA

Abstract. This paper describes a Kungurian (early Permian) brachiopod fauna consisting of 16 species in 16 genera from the lower part of the Nabeyama Formation of Ogama in the Kuzu area, Ashio Mountains (Mino Belt), central Japan. The fauna includes a new species, Acritosia ogamensis. The Ogama fauna is a tropical Panthalassan fauna showing strong affinity with the Wolfcampian—Leonardian (early Permian) fauna of West Texas, USA.

Middle Miocene ostracods from Wadi Sudr, westcentral Sinai, Egypt: systematic, biostratigraphy and palaeobiogeographic affinity with the Mediterranean realm

The investigation of the exposed middle Miocene strata from Wadi Sudr yielded well-preserved ostracod carapaces. Detailed taxonomic and paleontological studies led to the recognition of 36 ostracod species belonging to 25 genera, 4 species of them were considered new which fully described. Three assemblage biozones were recorded as follows: Actinocythereis spinosa–Actinocythereis hystrix zone, Chrysocythere cataphracta muricata-Cytheretta africana zone, and Disopontocypris schweijeri-Bythocypris tripolensis zone. The recorded biozones were calibrated with the previously studied middle Miocene planktonic foraminiferal biozones on the same samples and also correlated with the Miocene ostracod biozones from the neighboring countries. Our ostracod assemblages present in the lower and upper parts of the studied section (section II) indicated an inner neritic marine environment of moderate energy of currents and rapid sedimentation, while the assemblages in the middle part showed more deeper (outer neritic) environments with low energy of currents and low rate of sedimentation. The palaeobiogeographic distribution of the studied ostracods showed high affinity with the ostracod assemblages of the southern Mediterranean and moderate to low affinities with that of the northern and eastern Mediterranean respectively. The highly ornamented ostracod species with structures on the carapace were recorded from both Northern and Southern Mediterranean, while the smooth ones were found in the Southern Mediterranean only. The highly ornamented species are more widely distributed in both Southern and Northern Mediterranean than the smooth species. This may indicate that the ornamented species are more able to migrate than the smooth ones.

Diversity patterns and palaeobiogeographical relationships of latest Devonian–Lower Carboniferous foraminifers from South China: What is global, what is local?

During latest Devonian and early Carboniferous times, calcareous foraminifers were abundant, widely distributed, and showed the most rapid rate of evolution in the shallow-sea deposits. These factors, especially their fast phylogenetic changes, make them an essential element in biostratigraphic schemes of this time interval. However, the distribution patterns of calcareous foraminifers depend on a series of biological and non-biological factors, such as population sizes, dispersion, oceanic currents and temperatures, and substrate types, which are not always well-controlled when interpreting spatial and temporal distribution patterns.For this study, a dataset of calcareous foraminifers was compiled containing the temporal distribution (biozone level) of 420 species belonging to 155 genera currently described from Strunian (latest Devonian) to basal Serpukhovian (Lower Carboniferous) key sections in southern China, and the presence of those species in eleven palaeobiogeographical units. The comparison of the regional Chinese diversity curve, which has a bell-shaped form with a double peak in the Ivorian, to a global curve shows the influence of local and regional factors. Minimum values in the Chinese Strunian, basal Tournaisian and early late Visean can be explained by the small number of studied outcrops, unfavourable facies and depositional gaps in these stratigraphic intervals in South China. This is especially obvious in the late Visean and Serpukhovian, which is a peak time of global diversity. The fall observed at that time interval in southern China is easily explained by the fact that this time peried is far less intensively studied and thus fewer data are present in the database. The opposite situation is seen around the Tournaisian–Visean boundary. Here, a peak is found in both regional and global curves, but that up to 87% of all known species are found in southern China seems to be unlikely, especially when the normal average value are 35%–40%. This anomalously high percentage is a consequence of the work undertaken on the Global Stratotype Section and Point (GSSP), and it shows that a species deficit may exist in the global curve.Cluster, hierarchical cluster and Nonmetric multidimensienal Scalingel (NMDS) analyses have been calculated to study the palaeobiogeographical affinities of the southern Chinese calcareous foraminifers. The palaeobiogeographical patterns for the complete studied interval or parts of it (substages) are comparable on the genus and species level and stable through time. The assemblages found in southern China are well connected to other palaeo(bio)geographical entities supporting the idea of relatively abundant widespread and cosmopolitan taxa in the studied interval. A cluster of South China, Europe and the Russian Platform is found in all analyses. This cluster often attached to the units Far-East Russia and Turkey represents the northern Palaeotethyan Realm. The relatively close affinities between South China and North America cannot be well discussed yet. Chinese data for endemicity, geographical spread and biodiversity in the Tournaisian–Visean boundary interval can be roughly correlated to 3rd-order sea-level fluctuations. Migration patterns into and out of South China can only be suspected, but not yet quantified.

A review of Ordovician crinoids from France: New data from the Darriwilian of the Armorican Massif and palaeobiogeographic implications

All known occurrences of crinoids in the Ordovician of France (Armorican Massif, Montagne Noire, Corbières and Pyrénées) are reviewed and replaced stratigraphically. Fully articulated crinoids are described for the first time in the Darriwilian (Middle Ordovician) of the Armorican Massif. The disparid crinoid Heviacrinus melendezi is reported from the middle and late Darriwilian (artus and teretiusculus zones) of both Brittany and Normandy, which extends both its geographic distribution and its temporal range. In addition, a new species of Heviacrinus, H. tromelini is described from the late Darriwilian (teretiusculus zone) of both Brittany and Normandy. Finally, three successive French Ordovician crinoid faunas are identified. They show strong palaeobiogeographic affinities with other Gondwanan and peri-Gondwanan assemblages, and in particular with those of the Mediterranean Province.

Late Cenomanian oysters from Egypt and Jordan

Late Cenomanian oysters occur in great numbers, wide distribution, usually as original shells, and can be used as guide fossils in northeastern Egypt and Jordan. Six genera including seven species of typical Tethyan palaeobiogeographic affinity have been recorded from two sections, Wadi Al-Atashieh in central Jordan and west Saint Anthony in north eastern Egypt. The oyster assemblages exhibit a similar stratigraphic trend in Egypt and Jordan. As a result, four oyster zones can be recognized in the upper Cenomanian succession i.e., Ceratostreon flabellatum, Ilymatogyra africana, Costagyra olisiponensis, and Pycnodonte (Phygraea) vesicularis vesiculosa. These zones are correlated with the equivalent ammonite zones. Extinction of some species of these oysters toward the Cenomanian/Turonian (C/T) boundary may be linked to the eustatic sea level rise.

Palaeobiogeographical affinity of the early Pliensbachian (Early Jurassic) brachiopod assemblage of the Northern Caucasus (Russia): A new evidence

Brachiopods are useful in detecting the Mesozoic palaeobiogeographical affinity of European terranes. Numerous representatives of this fossil group known from the lower Pliensbachian deposits of the Northern Caucasus (southwestern Russia) allow quantitative assessment of their palaeobiogeographical affinity. A total of 175 brachiopod species from the Northern Caucasus and several other regions (Bakony, Germany without the Alps, Hallstatt, the Pyrenees, Switzerland without the Southern Alps, the Swiss Southern Alps, and western Algeria) are considered for the purposes of the present study. The relationships between the regional assemblages were examined with three similarity indices, namely the Jaccard Index, the Czekanowski's Quantified Coefficient, and the Gower index. The results indicate the relatively strong similarity of the early Pliensbachian brachiopods of the Northern Caucasus to those of Germany, the Pyrenees, Switzerland, and western Algeria and the strong dissimilarity from the assemblages of the Bakony, Hallstatt, and the Swiss Southern Alps. These results reveal the affinity of the early Pliensbachian brachiopod assemblage of the Northern Caucasus to the Boreal biochore. However, there are Tethyan taxa in this assemblage, and, thus, the latter is of transitional nature. Palaeogeographical and plate tectonic configurations, eustatic fluctuations, differences between the regional depositional environments, etc. may explain the palaeobiogeographical patterns registered in the present study. The regional factors might have been especially important because of the moderate-to-weak global palaeobiogeographical differentiation in the early Pliensbachian. The concept of the Mediterranean microcontinent seems to be also useful for explanation of the early Pliensbachian brachiopod provinciality.

Devonian palaeobiogeographic affinities of Afghanistan and surrounding areas (Iran, Pakistan)

Palaeozoic (Devonian) outcrops in Afghanistan and neighbouring countries (Iran, Pakistan) are numerous but very sparsely distributed, and poorly known. The first interpretation, based on rare or poor data considered these North Gondwanan terranes as poorly connected and some authors have suggested the presence of large oceanic domains in palaeogeographical models. Increase in knowledge, especially of the distribution of main fossils groups, and also some lithological similarities, allow a review of the preliminary models and the identification of connections between the different terranes. For example the presence of Fistuliporid Bryozoan beds or rich Receptaculites levels in different sections of the three countries, especially in the Dasht-e Nawar and Central Iran areas, allows the preliminary models to be reviewed and the connections among the different terranes to be clarified.

Late Albian ammonites from the Aitamir Formation (Koppeh Dagh, northeast Iran)

Late Albian ammonite faunas from the Aitamir Formation of the Koppeh Dagh Basin in northeast Iran are described and illustrated. These comprise 14 taxa, several of which are recorded from Iran for the first time, namely Anahoplites planus (formerly recorded from central Iran in open nomenclature only), Semenoviceras solidus, Epihoplites (Metaclavites) iphitus, Hysteroceras orbignyi and Pseudhelicoceras robertianum. New records of Placenticeras grossouvrei extend the stratigraphic range of this species downwards into the Late Albian; previously it was known from the Early and Middle Cenomanian only. The record of the rare E. (M.) iphitus fills a palaeobiogeographic gap between Crimea and Tajikistan, and the holotype of Spath is re-illustrated here. Additionally, Epihoplites trapezoidalis, from the Late Albian of Tajikistan, is relegated into the synonymy of Spath's species. A large number of taxa typical of the Late Albian (upper part of the Gault Clay Formation) of northwest Europe indicate close palaeobiogeographic affinities with the Koppeh Dagh Basin and faunal exchange across the Russian Platform and Transcaspia. The stratigraphic succession of the ammonite faunas is used for a biostratigraphic subdivision of the upper Aitamir Formation.

European ornithomimosaurs (Dinosauria, Theropoda): an undetected record

Early Cretaceous ornithomimosaurian theropod dinosaurs have been reported from various localities in Asia, whereas they remain poorly represented and extremely rare in North America, Africa and Europe. So far, the only known European ornithomimosaur is Pelecanimimus from the Barremian of Spain. The recent discovery in southwestern France of the Angeac bone bed, which has yielded several hundred ornithomimosaur bones, sheds new light on the ornithomimosaurian fossil record. Based on this new material, we re-evaluate here the systematic position of various isolated theropod bones from the Wealden of England, including historical taxa of uncertain affinities. Based on a unique combination of derived characters, Thecocoelurus and Valdoraptor are linked to the Angeac taxon but are considered to be nomina dubia . Valdoraptor from the Valanginian of West Sussex appears to be the oldest known ornithomimosaur together with the contemporaneous Nqwebasaurus from South Africa. Ornithomimosaurs were a common component of the Early Cretaceous European dinosaur fauna. Their presence in Spain, France and England further strengthens the palaeobiogeographic affinities of the European fossil biota with that of Asia during this period.

Early Devonian fishes from coastal De Long Strait, central Chukotka, Arctic Russia

ABSTRACT Calcareous and sandy deposits from the basal members of the Enmakaj and Pil'hikaj formations in coastal exposures along the De Long Strait in central Chukotka, Arctic far-eastern Russia, have yielded two assemblages of fossil fish comprising heterostracan plate fragments, turiniid and other thelodont scales, acanthodian scales and a partial tooth, typical of the Old Red Sandstone facies. Exceptional are acanthothoracid placoderm platelets characteristic of marine facies. In addition a sarcopterygian fragment have been found in Member 1 of the Enmakaj Formation. Some scale surfaces show an unusual, scoured preservation. A Lochkovian age, and most probably basal Lochkovian, is supported for the Enmakaj assemblage, and a somewhat later Lochkovian age is supposed for the Pil'hikaj assemblage. The palaeobiogeographic affinities of these assemblages based on the heterostracans and thelodonts are with other Lochkovian occurrences in Arctic regions such as Severnaya Zemlya, Spitsbergen and the northern a...

MIDDLE JURASSIC BELEMNITES AND AMMONITES (CEPHALOPODA) FROM TELMA-DAREH, NORTHERN IRAN

Ammonites and belemnites from a Middle Jurassic section at Telma-Dareh (Alborz Mountains, northern Iran) are described. The lithology of the studied section consists of an alternation of marls and limestones attributed to the Dalichai Fm., overlying the top of the Shemshak Fm. (sandstones) and underlying the Lar Fm. (limestones). Fossils are rather abundant but concentrated in ten scattered levels, ranging from the Aalenian (Scissum-Murchisonae zones) up to the Bajocian. Ammonites ( Tmetoceras scissum , Leioceras cf. comptum , Ludwigia cf. murchisonae , Onychoceras ? sp., and Leptosphinctes sp.), belemnites ( Brevibelus breviformis , Holcobelus cf. munieri ) and bivalves are the most abundant and well-preserved fossils; accessory elements are scarce brachiopods and gastropods. The palaeobiogeographic affinities of the belemnite fauna is Subboreal-Submediterranean, whereas the ammonites have Submediterranean-Tethyan affinities. The Aalenian age of the lower part of the Dalichai Fm. at Telma-Dareh differs from the Bajocian age attributed by other authors to this formation in other localities.

Kubergandian (Roadian, Middle Permian) of the Lycian and Aladağ Nappes (Southern Turkey)

The Nişangahtepe Formation (Teke Dere unit) in the Lycian Nappes, and reworked pebbles and blocks from the Late Triassic Gevne Formation in the Aladağ unit (both in Southern Turkey), present a well-developed Kubergandian microfauna and microflora found for the first time in this area. The following cyanobacterial and algal taxa are newly established: Clinortonella nov. gen., Ramovsia lyciana nov. sp., and Kantia? guevenci nov. sp.; some Cancellina and Armenina are revised. These Kubergandian faunas and floras present strong palaeobiogeographical affinities with the Eurasian southern margin (northern Palaeotethyan border). The Teke Dere unit represents an accretionary prism/fore-arc sequence containing different parts of the Palaeotethyan succession. The Late Triassic Gevne Formation marks the Eo-Cimmerian unconformity related to the closure of the Palaeotethys between the Taurus and Anatolian terranes.