Carles Ferràndez-Cañadell

NEW PALEOCENE ORBITOIDIFORM FORAMINIFERA FROM THE PUNJAB SALT RANGE, PAKISTAN

The orbitoidiform foraminifers from the Paleocene of the Pakistan Salt Range, traditionally designated by “ Orbitosiphon ” or “ Actinosiphon ”, include two different genera, both with a concave-convex test shape. The first of these is characterized by a typically orbitoidal growth with lateral chamberlet layers on both sides of the equatorial layer, and corresponds to Lepidocyclina (Polylepidina) punjabensis Davies, the type species of the genus Orbitosiphon Rao. The second genus, named here Setia nov. gen., is characterized by orbitoidal chamberlet cycles and differentiated dorsal and ventral sides, with lateral chamberlets on the dorsal side and a canal system resembling that of miogypsinids on the ventral side. It includes two species, S. tibetica (Douville 1916) and a stratigraphically lower, structurally more simple new species, S. primitiva sp. nov. Both genera are found in the top of the Hangu Formation, the Lockhart Limestones, and at the base of Patala Formation from the Salt Range “Laki Beds”, which comprise the middle and upper parts of the Paleocene. The test of the new genus Setia shows a new morphostructural type, resembling that of miogypsinids, but with orbitoidal growth. Both Setia and Orbitosiphon became extinct before the arrival of orthophragminids ( Discocyclina and Orbitoclypeus ) to the basin (together with Nummulites , Assilina and Alveolina ), and therefore are never found together with the latter. The reports of orthophragminids from the Lockhart Limestones and the lower part of Patala Shales actually correspond to misidentified O. punjabensis or S. tibetica . On the other hand, the American Paleocene genus Actinosiphon cannot be related to either Orbitosiphon or Setia . Although it is similar to the former, it differs in several characters, such as the shape and arrangement of equatorial chamberlets and the stolon system.

La lámina orgánica en los foraminîferos orbitoidiformes complejos (Cretácico superior a Oligoceno)

Resumen Se presentan los resultados del estudio de la lamina organica en ocho generos de macroforaminiferosorbitoidiformes complejos pertenecientes a cinco familias distintas de diferentes edades: Lepidorbitoididae (Lepidorbitoides) y Orbitoididae (Orbitoides) del Cretacico Superior; Discocylinidae (Discocyclina, Nemkovella) y Orbitoclypeidae (Orbitoclypeus, Asterocyclina) del Paleoceno-Eoceno; y Lepidocyclinidae (Eulepidina, Nephrolepidina) del Oligoceno-Mioceno. En estos ocho generos, la lamina organica muestra las mismas caracteristicas: tiene una textura laminada; es mas gruesa en las primeras camaras, en el centro de la concha, adelgazandose progresivamente hacia la periferia; y cubre la boca de los poros, donde forma engrosamientos que penetran ligeramente en el poro. Dichas caracteristicas generales son similares a las descritas previamente en otros macroforaminiferos bilamelares como Heterostegina y Amphistegina, y difieren de las descritas en foraminiferos porcelanados como Sorites o Amphisorus. En Orbitoclypeus y Eulepidina, se observo la presencia de cocolitos entre las distintas capas de la lamina organica. Este hecho, juntamente con el incremento en el grosor de la lamina organica desde las camaras mas viejas a las mas recientes, sugiere una formacion aditiva de la lamina organica, en la que interviene probablemente material de excrecion.

LATE CHATTIAN LARGER FORAMINIFERA FROM THE PREBETIC DOMAIN (SE SPAIN): NEW DATA ON SHALLOW BENTHIC ZONE 23

Abstract: This study focuses on an Oligocene succession dominated by larger foraminifera and coralline algae in the Benitatxell Range (Prebetic Domain, southeastern Iberian Peninsula). The foraminiferal assemblage, studied in thin sections, and interpreted as Shallow Benthic Zone 23, late Chattian, includes: Austrotrillina asmariensis, Nephrolepidina spp., Eulepidina dilatata, E. elephantina, E. raulini, Amphistegina bohdanowiczi, A. mammilla, Operculina complanata, Nummulites cf. vascus, N. aff. kecskemetii, Heterostegina assilinoides, Spiroclypeus blanckenhorni, Cycloclypeus mediterraneus, Miogypsinoides formosensis, Postmiogypsinella aff. intermedia, Neorotalia viennoti, Risananeiza pustulosa, and Victoriella conoidea. The Rebaldí section, a succession of late Oligocene limestones 3 km north of the Benitatxell section, shows a similar association with Peneroplis thomasi, A. asmariensis, M. complanatus, Neorotalia viennoti, N. lithothamnica, Heterostegina aff. assilinoides, Spiroclypeus blanckenhorni, Cycloclypeus mediterraneus, A. bohdanowiczi, and Risananeiza pustulosa; it is interpreted as the early part of SBZ 23. This section also contains Praebullalveolina aff. oligocenica, described from the early Rupelian of Turkey, and Schlumbergerina alveoliniformis, previously interpreted as Burdigalian-Recent. Prior to this work, Cycloclypeus mediterraneus was considered to go extinct and be replaced by C. eidae at the SBZ 22B-23 boundary. However, its presence in the Benitatxell and Rebaldí sections extends its range to the late Chattian in the Eastern Betics and indicates an asynchronous extinction in the Tethys. The presence of Amphistegina mammilla Fichtel and Moll 1798 in late Chattian deposits from the western Tethys contradicts the currently accepted hypothesis that places its origin in the Indo-Pacific province in the early Miocene, from where it would have migrated into the Parathethys during the middle Miocene. In addition, the biogeographic range of P. thomasi, A. asmariensis, and P. oligocenica is extended to the westernmost part of the Tethys.

Two Deciduous Human Molars from the Early Pleistocene Deposits of Barranco León (Orce, Spain)

Recently Toro-Moyano et al. (2013) reported a deciduous tooth from Barranco León (Spain; BL02-J54-100) and claimed it to be the oldest human fossil in Europe. In that paper, the authors suggest that a previously reported human molar fragment from the same site (BL5-0) was not human but a deciduous molar of Hippopotamus found out of stratigraphic context. Here, we show the stratigraphic and spatial position of BL5-0, and we separate it from deciduous teeth of Hippopotamus. We conclude that two human deciduous molars have been discovered at the Barranco León site. Both teeth were found 9 meters apart, have a similar size, are heavily worn on the occlusal surface, have a nearly identical interstitial contact facet, and in both cases the roots are practically missing due to resorption. These similarities and the proximity of the finds suggest that both molars probably belonged to the same individual.

The foraminiferal genus Lakadongia Matsumaru and Jauhri 2003, a re-evaluation

Abstract Lakadongia indica n. gen., n. sp. erected by Matsumaru and Jauhri (2003) is a junior synonym of Setia tibetica Ferràndez-Cañadell 2002. The genus Lakadongia is based on ambiguous characters and misinterpretation of oblique sections, and it is considered invalid. The postulated evolutionary relationship of these Paleocene orbitoidiform foraminifera with those of Cretaceous age is not justified by structural similarities and inconsistent with the stratigraphical record.

LATE CHATTIAN PLATFORM CARBONATES WITH BENTHIC FORAMINIFERA AND CORALLINE ALGAE FROM THE SE IBERIAN PLATE

Abstract: The carbonate system studied represents an under-investigated sedimentary record formed in the western end of the Tethys during the Chattian relatively warm climate regime. These platform carbonates are examined with respect to rock fabrics, biostratigraphy, biostratinomy, paleoecology, and sequence stratigraphy. Dominant carbonate producers include scleractinian corals and echinoids, but the most prolific were symbiont-bearing benthic foraminifera and coralline algae. The presence of Miogypsinoides complanatus and Miogypsinoides formosensis indicates a late Chattian age (Shallow Benthic Zone 23). The depositional profile is consistent with a homoclinal ramp. The absence of a barrier margin and thus, of a lagoon, facilitated the transport and re-working of biogenic components throughout the platform. As a result, facies are rather homogeneous corresponding to a rudstone mainly formed by benthic foraminifera and coralline algae, which passes basinwards to deeper ramp to hemipelagic deposits rich in echinoids and planktonic foraminifera. Within this dominant facies, only subtle and gradual lateral variations on the relative abundance or absence of certain skeletal components or species are recognized, comprising two end members. A proximal biofacies of benthic foraminifera and coralline algae including corals in growth position, fragments of green algae, and seagrass dwellers where Eulepidina, Nummulites, and Operculina are absent, and a distal biofacies where corals, green algae, and seagrass dwellers are not present, but Eulepidina, Nummulites and Operculina are common. Carbonate deposition was controlled by long-term relative sea-level fluctuations including a Rupelian?–late Chattian transgression, a late Chattian regression, which ended in subaerial exposure of proximal ramp carbonates, and a latest Chattian to early Miocene transgression. The Chattian carbonate platform was finally drowned around the Oligocene/Miocene transition.

Geology of the Falcón Basin (NW Venezuela)

ABSTRACT This paper presents a geological map and cross-section of the Falcón Basin based both on published and unpublished work and on new data collected in the northern and southern basin margins. The geological map covers an area of 4600 km2 at 1:100,000 scale. The cross-section is oriented NNW-SSE, traversing perpendicular to the main structures. In general, the structure of the study area results from the inversion of a graben (Oligocene-early Miocene back-arc basin), that started in the middle Miocene due to the convergence between the Caribbean and South American plates. The map, the cross-section and the observations made in the field have been used to generate a tectonostratigraphic reconstruction of the Falcón Basin. The Oligocene-early Miocene sedimentary succession mapped and described is relevant to the hydrocarbon exploration in the Caribbean and in the Gulf of Venezuela, where new hydrocarbon resources have recently been discovered (i.e. Perla gas field).

Morphostructure and systematics of Linderina brugesi Schlumberger, 1893 (Foraminifera, Eocene)

Abstract The morphostructure of the genus Linderina Schlumberger , 1893 is revised relying on a structural studyof the type species L. bruguesi, Schlumberger . Its test is lamellar-involute, with annular-cyclic growth of ornitoidal type. It has only one kind of stolons which are crosswise-oblique, alternately arranged in axial rows, and correspond with the apertures in the last chamber. The lateral thickenings of the test are formed by the superposition of the successive involute outer lamellae of the different chambers, lacking piles and granules, and the irregularity of the lateral surfaces is due to the lateral rounded reliefs of the alternate chamberlets. The embryonic apparatus is quadrilocular, with three subspherical initial chambers forming a triconch, and a fourth larger, arcuate chamber with rows of apertures in both sides from which the orbitoidal growth starts. An explanation is given for the morphogenesis of embryos in triconch, observed in a number of foraminiferal genera. L. brugesi shows a close similarity to American Eocene species Caudriella ospinae ( Caudri ), which differs from Linderina in that it has lateral chamberlets. Because of this affinity, Caudriella is included in the Linderinidae. A redefinition of the genus Linderina and of the family Linderinidae is performed. The genera Eoannularia and Epiannularia, previously classified into the Linderinidae, do not fit into the new characterization of the family and are thus grouped into a new family, named Eoannularidae.