Herpetofaunas from the Upper Paleocene and Lower Eocene of Morocco

Two Upper Paleocene and one Lower Eocene localities from Morocco (Ouarzazate basin) have yielded terrestrial assemblages that stand among the rare herpetofaunas from the Paleogene of the African Plate. The collections include one of the rare frogs and the only lizards known from the Paleogene of Africa. One of the two Upper Paleocene localities, Adrar Mgorn 1, has produced an indeterminate anuran and the most diverse assemblage of squamates from the Mesozoic and Cenozoic of Africa. It has yielded the earliest known scolecophidian snake and the earliest Gekkonidae, amphisbaenians, Tropidophiidae, and perhaps Boidae from Africa. Moreover, a specimen represents either the last sphenodontian or the earliest acrodontan lizard from this continent. One of the amphisbaenians represents a very distinct new taxon, Todrasaurus gheerbranti gen. and sp. nov. Indeterminate scincomorphans, lacertilians, Madtsoidae, and Aniliidae are also present. The fauna from the Lower Eocene is less diverse than that from the Upper Paleocene, but some taxa are common to both levels. Contrary to nearly all other Paleogene herpetofaunas from the African Plate, these Paleocene and Eocene assemblages include taxa that were terrestrial, not aquatic.     

Biostratigraphy and stage boundaries of the upper Cretaceous–early Paleogene successions in southern Galala area,North-Eastern Desert,Egypt

The foraminiferal contents of three surface sections [Gebel Tarboul, Wadi Tarfa (WT) and Bir Dakhl (BD) sections] in southern Galala area, North-Eastern Desert, Egypt, have been studied in detail and used in biostratigraphy and chronostratigraphy of the upper Cretaceous–Paleogene successions. Sixty-nine planktonic foraminiferal species belonging to 23 genera have yielded 17 biozones. They are given in ascending order: Globotruncana aegyptiaca Interval Zone (IZ), Gansserina gansseri IZ, Contusotruncana contusa–Racemiguembelina fructicosa IZ, Abathomphalus mayaroensis IZ, P1c, P2, P3, P3a, P3b, P4, P4a, P4b, P4c, P5, E1, E2, E3, E4 and E5. Moreover, local and widespread regional hiatus was detected in the pelagic to hemipelagic sequence during Cretaceous–Paleogene boundary in southern Galala Sub-basin. This hiatus corresponds to the Early Maastrichtian–Early Eocene in Gebel Tarboul, the interval between Late Maastrichtian–Early Paleocene throughout WT sequences and Late Maastrichtian–Late Paleocene in BD section.     

Cretaceous and Cenozoic non-marine deposits of the Northern South Yellow Sea Basin, offshore western Korea: palynostratigraphy and palaeoenvironments

Palynological analyses of two wells (Haema-1 and Kachi-1) located in two sub-basins of the Northern South Yellow Sea Basin have been carried out in order to establish a palynostratigraphic breakdown of the sedimentary succession and to determine environments of deposition. Seven assemblage zones and two assemblage subzones have been erected on the basis of frequency variations in, and occurrences of, biostratigraphically significant palynomorphs as follows: Classopollis-Ephedripites Assemblage Zone (AZ): Barremian-Albian; Alisporites-Aquilapollenites-Penetetrapites AZ, which is subdivided into an Alisporites-Rugubivesiculites Assemblage Subzone: Cenomanian-Lower Maastrichtian, and an Aquilapollenites-Penetetrapites Assemblage Subzone: Upper Maastrichtian; Momipites-Coryluspollenites AZ: Paleocene; Caryapollenites-Inaperturopollenites AZ: Lower-Middle Eocene; Quercoidites-Pinuspollenites AZ: Upper Eocene; Liquidambarpollenites-Fupingopollenites-Magnastriatites AZ: Lower-Middle Miocene; Graminidites-Persicarioipollis AZ: Pliocene. The depositional environments represented by the well sections are considered to have been generally fluvio-lacustrine, and the climate to have varied between semi-arid and wet, and subtropical and warm temperate, except during the Late Eocene and Pliocene when a cool-temperate climate prevailed. Six stages in the development of the sub-basins are recognised. These are: (1) initial stage of rift or pull-apart basin-formation during the Late Jurassic?-Cretaceous; (2) subsidence from the Paleocene to Middle Eocene; (3) alternation of uplift and subsidence in the Late Eocene; (4) synrift inversion and erosion through the Oligocene; (5) uplift during the Early Miocene; and (6) widespread subsidence from the Middle Miocene onwards apart from during the Early Pliocene when the region was subjected to uplift once more.     

The pliocene species of Hipparion andtheir biostratigraphical meanings

During the Pliocene, the «Hipparion fauna in the Mediterranean area decreased sharply in comparison with the Upper Miocene. Nevertheless, this species can be used to represent the Hipparion biozones in order to compare them with the mammal units. H. gromovae characterizes the Ventian or MN 13 mammal unit; H. crassum the Ruscinian or the Lower Pliocene or MN 14 unit; H. fissurae the Upper Ruscinian or the Lower Pliocene, MN 15; H. rocinantis, the Middle Pliocene or Lower Villafranchian, MN 16a. This distribution can be correlated in most of the Eurasian region.     

A new genus and species of triggerfish from the Middle Eocene of the Northern Caucasus,the earliest member of the Balistidae (Tetraodontiformes)

Until now, the earliest known members of the triggerfish family Balistidae have been two genera from the Oligocene. Herein is described the new balistid Gornylistes prodigiosus gen. et sp. nov. from the uppermost Middle Eocene (Kuma Horizon) of the Northern Caucasus (Gorny Luch locality); it is as thoroughly modern in its bauplan as the taxa of balistids from the Oligocene and more recent periods, and far more advanced morphologically than the several stem taxa of the balistoid + ostracioid clade known from earlier in the Middle and Lower Eocene and from the Upper Paleocene.     

Integrated biostratigraphy based on planktonic foraminifera and dinoflagellates across the Cretaceous/Paleogene (K/Pg) transition at the Izeh section (SW Iran)

The present work is based on semi-quantitative study carried on detailed sampling (samples are spaced by 5, 10 and 15 cm close to the boundary) of an essentially continuous and expanded section crossing the Cretaceous–Paleogene (K/Pg) boundary in Iran. By this work, we attempt to detail biostratigraphy based on planktonic foraminifera biozones and correlate biozones and subzones with dinocyst events. The entire Cretaceous–Paleogene interval contains rich, diversified and well-preserved planktonic foraminifera and dinoflagellate cyst assemblages. Four planktonic foraminiferal biozones have been recognized across the Cretaceous–Paleogene transition (K/Pg): Abathomphalus mayaroensis Biozone including Plummerita hantkeninoides Subzone from the Late Maastrichtian and Guembelitria cretacea (including Hedbergella holmdelensis and Parvularugoglobigerina longiapertura subzones), Parvularugoglobigerina eugubina Biozone and Parasubbotina pseudobulloides Biozone belonging to the Early Danian. These biozones have been correlated with four dinocyst biozones: the Manumiella seelandica Biozone belonging to the Late Maastrichtian and the Alisocysta reticulata, Senoniasphaera inornata and Damassadinium californicum biozones from the Early Danian. At this section, like at the El Kef section (GSSP for the K/Pg) and the auxiliary sections, an Ir anomaly is detected indicating the K/Pg boundary. This geochemical anomaly coincides also with mass extinctions of planktonic foraminifera species. The extinct species are in particular the large, complex tropical and subtropical taxa dwelling in subsurface and lower photic water. The mass extinctions at the Izeh section occurred over a succinct period of time similar to the K/Pg type section at El Kef (Tunisia). These sudden mass extinctions indicate a catastrophic pattern event occurring at the Maastrichtian/Danian boundary. In contrast the organic-walled dinocysts were less affected by the mass extinction and most species crossed the K/Pg boundary without showing mass and sudden extinctions. Nevertheless, they showed changes in their assemblages’ structure beyond the K/Pg boundary. Especially, Manumiella seelandica and M. druggii, typical species of Antarctic Maastrichtian dinocysts assemblages, occur in coeval deposits at the Izeh section; they persist through the Lower Danian and, like in Tunisia (e.g., El Kef section, Ellès section) show an obvious increase in relative abundance.     

Paleocene and Lower Eocene shallow-water limestones of Tibet: Microfacies analysis and correlation of the eastern Neo-Tethyan Ocean

Microfacial investigations of the Lower Paleogene sediments were based on four sections of the passive Indian (Ladakh, Tingri County, Gamba County and Yadong County) and one of the active Asian continental margin (Zhongba County). Eleven microfacies from the Tethyan Himalaya (prefixed with P for passive continental margin) and four from the Xigaze forearc basin (prefixed with A for active continental margin) were observed. The distribution of fossil assemblages in the environment ranges from the tidal flat and restricted lagoonal part of the inner carbonate ramp to the outer carbonate ramp: (P1) green algae pack-/grainstone with small miliolids, (P2) bioclast grainstone, (P3) Rotaliidae packstone, (P4) Miscellaneidae-Rotaliidae-Nummulitidae pack-/grainstone, (P5) laminated and bioturbated mud- and grainstone, (P6) Alveolina wacke-/packstone with Soritidae, (P7) Nummulites-Alveolina-Orbitolites pack-/floatstone, (P8) Discocyclinidae-Nummulitidae pack-/floatstone, (P9) Rhodolith wacke-/packstone, (P10) mudstone with anhydrite nodules, (P11) planktonic foraminiferal wackestone, (A1) molluskan float-/rudstone, (A2) Nummulitidae wacke-/packstone, (A3) rhodolith wacke-/packstone, (A4) Discocyclinidae-Nummulitidae float-/rudstone. The correlation of our observations provides a detailed overview of the paleoenvironmental development and the sedimentary history of the eastern Neo-Tethyan Ocean, showing a deepening trend in two stages from Lower Paleocene to Lower Eocene.     

Le Paléocène supérieur a Ranikothalia bermudezi et l'Éocène inférieur (Ilerdien basal) a Nummulites fraasi et N. Deserti du Tadémait-E et Tinrhert-W

The Upper Paleocene of E-Tademaït and W-Tinrhertis characterized by a new macrofauna and the appearance of Ranikothalia bermudezi. This is followed by Lower Eocene (Lowermost Ilerdian) Nummulites fraasi and N. deserti, in E-Tademaït.We note in relation with the uplifting of Saharo-Nubianshelf a regressive evolution towards the North, where successively later Nummulites species (deserti, globulus, rollandi, gizehensis) appear during the Lower Eocene.     

Three new dinoflagellate cysts from the Moroccan Paleocene-Eocene phosphates

Moroccan phosphate deposits from the Phosphate Plateau (Oulad Abdoun basin, near Khouribga) contain varied and well preserved dinoflagellate cysts. Among them, a new genus: Bitubericysta and three new species: B. boroujiana, Liesbergia abdounensis and Spinidinium stellatum are described in this paper. The two gonyaulacoid cysts have been found in Upper Paleocene (Thanetian) and Lower Eocene (Ypresian) sediments, the peridinioid cyst has been observed in Upper Paleocene (Thanetian) and basal Eocene (basal Ypresian) material.     

Synthèse biostratigraphique du plio-pléistocène de Guadix-Baza (Province de Granada,Sud-Est de l'Espagne)

In the Guadix-Baza basin, a continental sequence 0214 ranging from the Upper Miocene (Upper Turolian) to the Middle Pleistocene (Cromerian) has been established. An essay of biozonation by means of the Rodent succession is proposed, based on the following biozones: Trilophomys castroi, Mimomys occitanus, Mimomys cappetai, Mimomys cf. reidi, Mimomys ostramosensis, Allophaiomys pliocaenicus, Mimomys savini and Arvicola cantiana.     

Upper jurassic to lower cretaceous carbonate facies of african affinities in a Peri-European area: Chalkidiki Peninsula, Greece

Summary The Epanomi-New Iraklia area (West coast of the Chalkidiki peninsula) is considered to belong to the Prepeonias subzone (or Gevgeli unit), with a palaeogeographic position near the European margin, represented by the Serbo-Macedonian massif, and at a considerable distance from the fragmented African plate, the marginal block of which is here the Pelagonian Domain. In some boreholes in the area an Upper Jurassic to Lowei Cretaceous limestone sequence has been observed, ending with an unconformity and followed by an Upper Middle-Lower Upper Eocene transgressive bioclastic limestone, an Upper Eocene to Lower Oligocene clastic series and Neogene deposits. This Upper Jurassic to Lower Cretaceous carbonate platform sequence and probably the Upper Jurassic limestones with bauxites of the nearby Mt. Katsika, show African affinities, viz: the presence of the essentially Aptian algal speciesSalpingoporella dinarica, an African plate marker; the chlorozoan type association and the bauxite formation during the Late Jurassic indicating tropical conditions; finally, the chloralgal type association and the sporadic presence of radial-fibrous ooids during the Early Cretaceous indicating peritropical conditions. Lower Cretaceous limestones are apparently missing in the innermost Hellenides. In the Pelagonian Domain s.l., on the other hand, Upper Jurassic to Lower Cretaceous limestones are found in some places, with same characteristics as in the Epanomi-New Iraklia boreholes. On the contrary, the Upper Eocene to Lower Oligocene clastic series of the boreholes can be correlated with the Axios (=Vardar) molassic basin, inline with its present situation. During the Mesozoic, the Epanomi area therefore belonged to a micro-block, next to the NE margin of the Pelagonian Domain, in contrast to earlier interpretations. Its present time position results from Early Cenozoic tectonic phases.     

On the early biogeographical history of the African placentals

The Paleocene Adrar Mgorn local fauna recently discovered in the Ouarzazate basin (Morocco) along with several significant Eocene North African faunas, has yielded the oldest known placental mammals of Africa. Contrary to those from the Eocene which are basically endemic, the Adrar Mgorn placentals display affinities with taxa from North‐Tethyan continents and indicate active faunal interchanges between Africa and Europe (and perhaps Asia) during the Cretaceous/Paleogene times. On biogeographical grounds, two dispersal events are suggested as a working hypothesis. The oldest one, exemplified by the presence of paleoryctid and adapisoriculid “insectivores”; in the Moroccan locality, possibly took place by the K/T boundary. The second dispersal event exemplified by the discovery of an omomyid primate and possible hyaenodontid creodonts may have been contemporaneous with the Paleocene/Eocene boundary during which a marine regression is also known.     

New data on the Dyrosauridae (Crocodylomorpha) from the Paleocene of Togo

Following our fieldwork in Paleogene deposits of Togo, we herein report cranial as well as postcranial elements belonging to the family Dyrosauridae. This assemblage is dated to the Late Paleocene (Thanetian) from two quarries in southern Togo. The specimens include a partial skull presenting two large supratemporal fossae and a massive occipital condyle; long and slender isolated teeth; amphicoelous vertebrae including several articulated ones; and two osteoderms devoid of carina. The morphology of the partial skull reveals similarities with some African longirostrine forms such as Rhabdognathus spp., although this attribution cannot be confirmed. Longirostrine forms, known in the late Paleocene and early Eocene of the Iullemmeden basin (Nigeria, Niger, Mali, Algeria) and in the phosphates of Morocco and Tunisia, is only represented in Thanetian levels in Togo. Different palaeoenvironmental settings seem to have characterized the various African basins during the lower Eocene, with consequences for the geographic distribution of dyrosaurids. These dyrosaurid remains confirm the presence of the family in Togo during the Paleocene and underline the fossiliferous potential of the coastal sedimentary basin in Togo and in the bay of Benin.     

Bird evolution in the Eocene: climate change in Europe and a Danish fossil fauna

The pattern of the evolutionary radiation of modern birds (Neornithes) has been debated for more than 10 years. However, the early fossil record of birds from the Paleogene, in particular, the Lower Eocene, has only recently begun to be used in a phylogenetic context to address the dynamics of this major vertebrate radiation. The Cretaceous-Paleogene (K-P) extinction event dominates our understanding of early modern bird evolution, but climate change throughout the Eocene is known to have also played a major role. The Paleocene and Lower Eocene was a time of avian diversification as a result of favourable global climatic conditions. Deteriorations in climate beginning in the Middle Eocene appear to be responsible for the demise of previously widespread avian lineages like Lithornithiformes and Gastornithidae. Other groups, such as Galliformes display replacement of some lineages by others, probably related to adaptations to a drier climate. Finally, the combination of slowly deteriorating climatic conditions from the Middle Eocene onwards, appears to have slowed the evolutionary rate in Europe, as avian faunas did not differentiate markedly until the Oligocene. Taking biotic factors in tandem with the known Paleogene fossil record of Neornithes has recently begun to illuminate this evolutionary event. Well-preserved fossil taxa are required in combination with ever-improving phylogenetic hypotheses for the inter-relationships of modern birds founded on morphological characters. One key avifauna of this age, synthesised for the first time herein, is the Lower Eocene Fur Formation of Denmark. The Fur birds represent some of the best preserved (often in three dimensions and with soft tissues) known fossil records for major clades of modern birds. Clear phylogenetic assessment of these fossils will prove critical for future calibration of the neornithine evolutionary timescale. Some early diverging clades were clearly present in the Paleocene as evidenced directly by new fossil material alongside the phylogenetically constrained Lower Eocene taxa. A later Oligocene radiation of clades other than Passeriformes is not supported by available fossil data.     

New Paleocene Sepiid Coleoids (Cephalopoda) from Egypt: Evolutionary Significance and Origin of the Sepiid ‘Rostrum’

New coleoid cephalopods, assignable to the order Sepiida, are recorded from the Selandian/Thanetian boundary interval (Middle to Upper Paleocene transition, c. 59.2 Ma) along the southeastern margin (Toshka Lakes) of the Western Desert in Egypt. The two genera recognised, Aegyptosaepia n. gen. and ?Anomalosaepia Weaver and Ciampaglio, are placed in the families Belosaepiidae and ?Anomalosaepiidae, respectively. They constitute the oldest record to date of sepiids with a ‘rostrum-like’ prong. In addition, a third, generically and specifically indeterminate coleoid is represented by a single rostrum-like find. The taxonomic assignment of the material is based on apical parts (as preserved), i.e., guard, apical prong (or ‘rostrum-like’ structure), phragmocone and (remains of) protoconch, plus shell mineralogy. We here confirm the shell of early sepiids to have been bimineralic, i.e., composed of both calcite and aragonite. Aegyptosaepia lugeri n. gen., n. sp. reveals some similarities to later species of Belosaepia, in particular the possession of a distinct prong. General features of the phragmocone and protoconch of the new form are similar to both Belocurta (Middle Danian [Lower Paleocene]) and Belosaepia (Eocene). However, breviconic coiling and the presence of a longer ventral conotheca indicate closer ties with late Maastrichtian–Middle Danian Ceratisepia. In this respect, Aegyptosaepia n. gen. constitutes a link between Ceratisepia and the Eocene Belosaepia. The occurrence of the new genus near the Selandian/Thanetian boundary suggests an earlier origin of belosaepiids, during the early to Middle Paleocene. These earliest known belosaepiids may have originated in the Tethyan Realm. From northeast Africa, they subsequently spread to western India, the Arabian Plate and, probably via the Mediterranean region, to Europe and North America.     

Fossil wood Sequoioxylon dimyense sp. nov. (Cupressaceae) from the upper cretaceous of Zeya-Bureya basin, Russian Far East

A new species Sequoioxylon dimyense (Cupressaceae) is described from the Middle Maastrichtian (Upper Cretaceous) deposits of the Zeya-Bureya basin (Russian Far East) based on the fossil wood anatomy. The new species is characterized by combination of anatomical wood characters of the modern representatives of the subfamily Sequoioideae.     

Foraminiferal paleoecology of the Montpelier and lower coastal groups (eocene-miocene), Jamaica,West Indies

Two domains of carbonate deposition characterized mid-Tertiary Jamaica. After latest Cretaceous to Paleocene orogeny, submergence of insular paleo-Jamaica accompanied the strike-slip or extensional faulting associated with the formation of the Cayman Trench to the north. Differential subsidence along a series of peripheral subsea escarpments (Duanvale-Wagwater escarpment) produced relief in excess of 2000 m by the Late Eocene. Shoalwater limestones covered the slowly subsiding Cornwall-Middlesex platform, thus ending the supply of clastics to deep-sea bottoms north and east of the escarpment where contemporaneous planktonic-foraminiferal pelagites accumulated. Middle Eocene to Middle Miocene carbonate rocks deposited in the deep-sea represent a distinctive lithogenetic unit termed the Montpelier Group.A preponderance of globigerinacean and radiolarian tests characterizes lower Montpelier microfossil assemblages. Dominant benthonic forms include Melonis pompilioides, Fontbotia wuellerstorfi and species of Stilostomella and Pleurostomella. Available faunal criteria including the assemblage composition, depth preferences of extant species and recurrent morphologic-ecologic patterns suggest abyssal (2000 m) paleo-depths at the site of accumulation on a sediment apron near the base of the Duanvale-Wagwater escarpment. Computed from inferred paleodepth and estimated sedimentary thickness, Middle Eocene to Lower Miocene subsidence totals 2800 m. Biostratigraphic and paleoecologic data do not support the prevalent concept of a regional unconformity within the Montpelier.In the Middle Miocene, regional uplift led to the emergence of the Cornwall-Middlesex platform and to pronounced shoaling of marginal sea bottoms. Here, hemipelagic sedimentation resumed during the later Middle Miocene after the carbonate veneer on the adjacent platform was sufficiently eroded so as to expose noncarbonate rocks. See NAPS document No. 02395 for 67 pages of faunal reference lists, maps of sample locations and tables of foraminiferal occurrences. Order from ASIS/NAPS, c/o Microfiche Publications, 305 East 46th St., New York, N.Y., U.S.A. 10017. Remit with order $9.05 for photocopies or $5.55 for microfiche. Make checks payable to Microfiche Publications.     

Vertebrae of sea snakes from the Eocene of the Crimea

A sea snake vertebra from the Middle Eocene (Kuma Horizon) of the vicinity of the town of Bakhchisarai (Crimea) is referred to Palaeophis nessovi Averianov, 1997, which was previously recorded in the Middle and Upper Eocene of northern and western Kazakhstan. P. udovichenkoi Averianov, 1997 described from the Crimea based on the material from the Prolom locality (Bartonian-Priabonian?) is a junior subjective synonym of P. nessovi. A vertebra from the Belaya Skala locality (Middle Eocene, outskirts of the town of Belogorsk) is determined as Palaeophis sp.     

Ostracods from the Upper Cretaceous–Paleocene Jiaozhou Formation of Jiaozhou,Shandong, China and their biostratigraphic significance

Late Mesozoic–Cenozoic non-marine deposits are well developed in the Jiaolai Basin, eastern Shandong Province, China, yielding abundant fossils including ostracods. In order to further understand the geological settings of the basin during the Late Cretaceous–Paleogene, three boreholes (JK-1, JZK-01 and JZK-02) were drilled in the city of Jiaozhou. Nine genera and sixteen species (including six indeterminate species) of ostracods are described from the Jiaozhou Formation in the three boreholes, including Cypridea, Mongolocypris, Talicypridea, Candona, Eucypris, Cyprois, Porpocypris, Sinocypris and Timiriasevia. Of these, Porpocypris sphaeroidalis Guan, 1978 is reported from northern China for the first time, indicating that this species has great potential to be an indicator of the K/Pg boundary. Correlation of these species with the known Cretaceous–Paleogene ostracod assemblages suggests that the age of the Jiaozhou Formation could be latest Cretaceous–Paleocene in borehole JK-1, Campanian–Maastrichtian in borehole JZK-01, and Maastrichtian–Danian in borehole JZK-02. The exact position of K/Pg boundary, however, is unavailable for the present in the Jiaozhou Formation from boreholes JK-1 and JZK-01.     

Les foraminifères du Paléocène et de l'Éocène basal du sillon nord-pyrénéen (Aquitaine, France)

This paper presents for the first time the inventory of the Paleocene and Lower Eocene foraminifers located in the North Pyrenean trough, between the Atlantic Ocean and the neighbourhood of the town Pau. They have been studied from three outcrops. The Bidart Beach section shows the Lasseube Formation from the Cretaceous/Paleogene boundary to the base of the P 3a zone. The Loubieng Quarry section, near Orthez, represents the upper P 3a zone and the lower P 3b zone as well as the Lasseube Formation / Pont Labau Formation boundary. The interval between the upper part of the P 3b zone and the upperest part of the P 5 zone crops out along the Gan - Rébénacq road with a hiatus located at the Paleocene / Eocene boundary, the whole interval belonging to the Pont Labau Formation. 394 taxons of foraminifers are present in this formations: 349 benthic and 45 planktonic species. The Velasco type benthic foraminifers show a middle bathyal depositional environment, with a paleobathymetry included between 500-600 m and 1000 m: Nuttallides truempyi, Osangularia velascoensis, Bulimina trinitatensis. The Midway type species which were transported by the turbidite currents from the lower to middle neritic environments are frequent as well as the Cretaceous reworked species. The species number is low: 29 in the iridium layer of the Cretaceous/Paleogene boundary (P 0 zone). Fauna grows rich quickly in the Pα zone reaching 129 species. The diversity grows up progressively from P α to the P 4a zone (NP 8). The disappearances are rare until his horizon, but their number is bigger than the number of appearances from the P 4b zone. It reaches their maximum between the P 4c zone and the P 5 zone. It shows that the decline of the Paleocene fauna begins around 2 million years before the thermal event of the Paleocene / Eocene boundary in the Aquitaine sections. The disappearances stay important in the Lower Eocene - Ypresian, but the appearance of lots of Eocene species show that the fauna renewal is located in this stage. The Cretaceous taxa dominate in the Paleocene benthonic fauna. The appearance or the disappearance of some species has a stratigraphic value in the Aquitaine region: the disappearance of Coryphostoma incrassata in the P 1b zone, the appearances of Plectina dalmatina, Elongobula grata (P α); Bulimina tuxpamensis (P 2); Tritaxilina cubensis, Thalmannita madrugaensis (P 3a); Svenia bulbosa (P 3b); Discorbis perovalis (P 4a/NP 7); Elongobula pulchra, E. pupa, Asterigerina bartoniana, Neorotalia gr. tuberculata (P 4a/NP 8); Bigenerina pannonica, Pentellina pseudosaxorum (P 5/NP 9-10).