02237nas a2200301 4500008004100000245018400041210006900225260001600294300001300310490000700323520126200330653001001592653001301602653001901615653002301634653001301657653002401670653001001694653002601704653001701730100001501747700002001762700001901782700002001801700002001821700001701841856007701858 2015 eng d00aExploring the Potential of Laser Ablation Carbon Isotope Analysis for Examining Ecology during the Ontogeny of Middle Pleistocene Hominins from Sima de los Huesos (Northern Spain)0 aExploring the Potential of Laser Ablation Carbon Isotope Analysi cApr-12-2016 ae01428950 v103 a

Laser ablation of tooth enamel was used to analyze stable carbon isotope compositions of teeth of hominins, red deer, and bears from middle Pleistocene sites in the Sierra de Atapuerca in northern Spain, to investigate the possibility that this technique could be used as an additional tool to identify periods of physiological change that are not detectable as changes in tooth morphology. Most of the specimens were found to have minimal intratooth variation in carbon isotopes (< 2.3‰), suggesting isotopically uniform diets through time and revealing no obvious periods of physiological change. However, one of the two sampled hominin teeth displayed a temporal carbon isotope shift (3.2‰) that was significantly greater than observed for co-occurring specimens. The δ13C value of this individual averaged about -16‰early in life, and -13‰later in life. This isotopic change occurred on the canine crown about 4.2 mm from the root, which corresponds to an approximate age of two to four years old in modern humans. Our dataset is perforce small owing to the precious nature of hominid teeth, but it demonstrates the potential utility of the intra-tooth isotope profile method for extracting ontogenetic histories of human ancestors.

10abears10ahominins10aLaser ablation10amiddle Pleistocene10ared deer10aSierra de Atapuerca10aSpain10astable carbon isotope10atooth enamel1 aGarcia, N.1 aFeranec, R., S.1 aPassey, B., H.1 aCerling, T., E.1 aArsuaga, J., L.1 aBondioli, L. uhttp://journals.plos.org/plosone/article?id=10.1371/journal.pone.014289502747nas a2200289 4500008004100000245013700041210006900178300001200247490000700259520185800266653002102124653002702145653001502172653001202187653002802199653002002227653001202247653001602259653001002275653002102285653002202306653002602328100001602354700001402370700001802384856005502402 2006 eng d00aDistinguishing Eustatic and Epeirogenic Controls on Lower-Middle Cambrian Boundary Successions in West Gondwana (Morocco and Iberia)0 aDistinguishing Eustatic and Epeirogenic Controls on LowerMiddle  a899-9180 v543 a

Major eustatic fall has been invoked to explain Lower–Middle Cambrian boundary sandstones and faunal replacements on a number of Cambrian palaeocontinents. This proposal has been tested on the Moroccan and Spanish margins of West Gondwana and found to be inadequate to explain stratigraphical developments. In these regions, sandstone intervals long presumed to be regressive and late Early Cambrian in age are now shown to be early Middle Cambrian, and composed of a lower regressive and an overlying transgressive sandstone separated by a regional unconformity. Only the lower tidalites (i.e. Tazlaft Formation in Morocco and lower Daroca sandstones in Spain) record the Hawke Bay eustatic regression in West Gondwana. The Tazlaft is overlain by a newly recognized, unconformably overlying sandstone (Talelt Formation) that onlapped southern Morocco with reactivation of a pull-apart or transcurrent regime. Up to 150 m of erosion on uplifted blocks in the High Atlas range and foundering of the Souss Basin to the south preceded onlap and deposition of the volcanic-rich Tatelt, the correlative and depositional analogue of the upper Daroca and lower Valdemides Formations in northern Spain. With folding and erosion, a type 1 depositional sequence boundary also caps the Tatelt at its contact with an overlying, lower Middle Cambrian mudstone-dominated succession. This unconformity probably occurs in Spain within the Valdemiedes Formation and corresponds to a faunal discontinuity called the ‘Valdemiedes geoevent’. The Iberian ‘Daroca regression’ and Moroccan ‘Asrir regression’ are misnomers, as the sandstones on which they are based are composite units with a lower regressive interval that records eustatic fall and an upper transgressive unit that records epeirogenically driven onlap.

10aDaroca Sandstone10adepositional sequences10aepeirogeny10aeustasy10aJbel Wawrmast Formation10aMiddle Cambrian10aMorocco10aSouss Basin10aSpain10aTatelt Formation10aTazlaft Formation10aValdemiedes Formation1 aLanding, E.1 aGeyer, G.1 aHeldmaier, W. uhttp://dx.doi.org/10.1111/j.1365-3091.2006.00780.x05097nas a2200313 4500008004100000245007300041210006900114300001200183490000700195520426400202653001804466653002004484653001404504653001304518653002304531653002304554653002104577653001104598653001104609653001204620653001104632653001204643653001604655653001004671653001404681100001404695700001604709856005804725 2004 eng d00aA Unified Lower-Middle Cambrian Chronostratigraphy for West Gondwana0 aUnified LowerMiddle Cambrian Chronostratigraphy for West Gondwan a233-2730 v543 a

Similarities in biotic successions support a unified, composite chronostratigraphy for the Lower-Middle Cambrian of the Iberian and Moroccan margins of West Gondwana. The Cordubian Series (emended from an Iberian stage-level unit) comprises the sub-trilobitic Lower Cambrian of West Gondwana. This series represents ca. half of the Cambrian (ca. 25 m.y.), has a base defined at the lowest occurrence of diagnostic Cambrian ichnogenera in central Spain, and is comparable to the Placentian Series of Avalon. The overlying trilobite-bearing Lower Cambrian (ca. 9 m.y. duration), or Atlasian Series (new), of West Gondwana consists of two stages originally defined in highly fossiliferous (trilobites and archaeocyaths) Moroccan sections where they have great potential for precise U-Pb geochronology. The penultimate Lower Cambrian stage, the Issendalenian, with the near-joint lowest occurrence of trilobites and archaeocyaths, is approximately comparable with the sparsely fossiliferous, Iberian "Ovetian Stage" (designation abandoned). The "Ovetian" as currently revised is invalid because it is an objective homonym of SDZUY’s original “Ovetian.” The "Ovetian" is not a practically applicable unit as its basal stratotype horizon lacks any identified fossils, and its trilobites are so rare that it cannot serve as a standard for interregional correlation. By contrast, the Banian Stage as defined in Morocco is suitable as the terminal Lower Cambrian stage of West Gondwana. It is based on very fossiliferous successions that allow recognition of three successive trilobite zones and is similar in concept to the Iberian “Marianian Stage” (designation abandoned). The “Marianian” lacks a designated lower boundary stratotype locality, lacks a biostratigraphically defined base at a stratotype, and is so sparsely fossiliferous that no biostratigraphic zonation exists.

Long-term problems involving regional definition of the West Gondwanan Lower–Middle Cambrian boundary are resolved. The lowest occurrence of paradoxidid trilobites, the classic index for the base of the Middle Cambrian, is diachronous in West Gondwana and other regions, with the group showing a delayed appearance in Iberia, Sweden, and Bohemia, by comparison with Morocco. Taxonomic revision of Iberian trilobites and new documentation of their ranges in Morocco show that the Iberian terminal “Lower Cambrian” “Bilbilian Stage” (designation abandoned) correlates with the Moroccan upper Banian and lower and middle “Tissafinian” Stages and with the Siberian upper Toyonian (traditionally assigned to the Lower Cambrian in Siberia) and lower Amgan (assigned to the Middle Cambrian in Siberia) Stages. The “Bilbilian” thus includes Middle Cambrian strata in a traditional international concept. Faunas from the base of the Iberian “lowest” Middle Cambrian “Leonian Stage” (designation abandoned) correlate largely into the second trilobite zone of the “Tissafinian” and are now understood to appear above an intra-Middle Cambrian faunal break. This faunal break is still poorly understood and may be an artifact of collection failure immediately above the sparsely fossiliferous, problematical “Valdemiedes event” interval. The base of this “Middle Cambrian”, now termed Celtiberian Series (new designation), in West Gondwana is best defined by the base of the lower Middle Cambrian Agdzian Stage (new designation). The Agdzian includes the “Tissafinian” and overlying lower “Toushamian Stage” designations abandoned) of Morocco, and has its top defined by the base of the middle Middle Cambrian Caesaraugustian Stage, as defined in Spain at the lowest occurrence of Badulesia tenera. The Languedocian, originally defined at the lowest occurrence of Solenopleuropsis (Manublesia) thorali in the southern Montagne Noire of France comprises the third, and terminal stage of the Celtiberian Series. We suggest that the designations “Lower Cambrian” and “Middle Cambrian” be regarded as descriptive and nonchronostratigraphic terms in discussions of the Cambrian.

10aAgdzian Stage10aAtlasian Series10aAustralia10aCambrian10aCeltiberian Series10achronostratigraphy10aCordubian Series10aIsrael10aJordan10aMorocco10aPoland10aSiberia10aSouth China10aSpain10aTrilobita1 aGeyer, G.1 aLanding, E. uhttps://geojournals.pgi.gov.pl/agp/article/view/10274