A deep-sea agglutinated foraminifer tube constructed with planktonic foraminifer shells of a single species

Agglutinated foraminifera are marine protists that show apparently complex behaviour in constructing their shells, involving selecting suitable sedimentary grains from their environment, manipulating them in three dimensions, and cementing them precisely into position. Here we illustrate a striking and previously undescribed example of complex organisation in fragments of a tube-like foraminifer (questionably assigned to Rhabdammina) from 1466 m water depth on the northwest Australian margin. The tube is constructed from well-cemented siliciclastic grains which form a matrix into which hundreds of planktonic foraminifer shells are regularly spaced in apparently helical bands. These shells are of a single species, Turborotalita clarkei, which has been selected to the exclusion of all other bioclasts. The majority of shells are set horizontally in the matrix with the umbilical side upward. This mode of construction, as is the case with other agglutinated tests, seems to require either an extraordinarily selective trial-and-error process at the site of cementation or an active sensory and decision-making system within the cell

Taxonomy, Biostratigraphy and Phylogeny of Eocene Acarinina

The taxonomy, phylogeny and biostratigraphic ranges of 28 Eocene species of Acarinina are discussed together with detailed synonymies. The early Eocene is characterized by the radiation of two different groups - one characterized by rounded/inflated chambers and the other by anguloconical chambers - which are derived, in turn, from two late Paleocene lineages: the soldadoensis lineage (itself derived from Acarinina mckannai) and the esnaensis-wilcoxensis lineage (itself derived from Acarinina nitida). We interpret the genus Truncorotaloides as a synonym of Acarinina. Acarinina is regarded as paraphyletic, in that it gave rise to Morozovelloides Pearson and Berggren n. gen. in the upper part of the lower Eocene (see Pearson and Berggren Chapter 10, this volume). The following species are recognized in this chapter: Acarinina africana (El Naggar), Acarinina alticonica Fleisher, Acarinina angulosa (Bolli), Acarinina aspensis (Colom), Acarinina boudreauxi Fleisher, Acarinina bullbrooki (Bolli), Acarinina coalingensis (Cushman and Hanna), Acarinina collactea (Finlay), Acarinina cuneicamerata (Blow), Acarinina echinata (Bolli), Acarinina esnaensis (LeRoy), Acarinina esnehensis (Nakkady), Acarinina interposita Subbotina, Acarinina mcgowrani Wade and Pearson n. sp., Acarinina medizzai (Toumarkine and Bolli), Acarinina pentacamerata (Subbotina), Acarinina praetopilensis (Blow), Acarinina primitiva (Finlay), Acarinina pseudosubsphaerica Pearson and Berggren n. sp., Acarinina pseudotopilensis Subbotina, Acarinina punctocarinata Fleisher, Acarinina quetra (Bolli), Acarinina rohri (Brönnimann and Bermúdez), Acarinina sibaiyaensis (El Naggar), Acarinina soldadoensis (Brönnimann), Acarinina subsphaerica (Subbotina), Acarinina topilensis (Cushman), and Acarinina wilcoxensis (Cushman and Ponton)

Authenticating coins of the 'Roman emperor' Sponsian

The 'Roman emperor' Sponsian is known only from an assemblage of coins allegedly found in Transylvania (Romania) in 1713. They are very unlike regular Roman coins in style and manufacture, with various enigmatic features including bungled legends and historically mixed motifs, and have long been dismissed as poorly made forgeries. Here we present non-destructive imaging and spectroscopic results that show features indicative of authenticity. Deep micro-abrasion patterns suggest extensive circulation-wear. Superficial patches of soil minerals bound by authigenic cement and overlain by oxidation products indicate a history of prolonged burial then exhumation. These observations force a re-evaluation of Sponsian as a historical personage. Combining evidence from the coins with the historical record, we suggest he was most likely an army commander in the isolated Roman Province of Dacia during the military crisis of the 260s CE, and that his crudely manufactured coins supported a functioning monetary economy that persisted locally for an appreciable period

Taxonomy, biostratigraphy, and phylogeny of Oligocene Globigerinitidae (Dipsidripella, Globigerinita, and Tenuitella)

The taxonomy, biostratigraphy, and phylogeny of the Oligocene Globigerinitidae (comprising the genera Dipsidripella, Globigerinita and Tenuitella) is reviewed. This family is here included in the Superfamily Globigerinitoidea based on the distinctive wall texture. The group is united by possessing a ‘radially crystalline’ wall texture (the glutinata-type wall) which typically bears pyramidal pustules and in most species is microperforate (pores <1 µm in diameter). The genus Dipsidripella is included in the family here for the first time. In Dipsidripella the wall is often medioperforate (pores 1-2 µm in diameter; danvillensis-subtype). The following species are recognized as valid and occurring in the Oligocene: Dipsidripella danvillensis (Howe and Wallace), Dipsidripella liqianyui Huber and Pearson, Globigerinita glutinata (Egger), Globigerinita uvula (Ehrenberg), Tenuitella angustiumbilicata (Bolli), Tenuitella gemma (Jenkins), Tenuitella munda (Jenkins), and Tenuitella praegemma (Li)

Oligocene chronostratigraphy and planktonic foraminiferal biostratigraphy: Historical review and current state-of-the-art

We review past and recent advances in Oligocene chronostratigraphy (and its internal subdivisions) and geochronology, the so-called “missing” Oligocene debate of the 1960s, and planktonic foraminiferal biostratigraphies of (sub)tropical and austral biogeographies. The Oligocene spans the interval from Chron C13r.0.14 to Subchron C6Cn.2n(o), corresponding to astronomical cycles 84Ol-C13n to 58OlC6Cn. It is currently subdivided into two (Rupelian and Chattian) ages/stages. The planktonic foraminiferal biostratigraphy is characterized by a 7-fold (sub) tropical and 4-fold austral zonation, respectively

The mapping class group and the Meyer function for plane curves

For each d>=2, the mapping class group for plane curves of degree d will be defined and it is proved that there exists uniquely the Meyer function on this group. In the case of d=4, using our Meyer function, we can define the local signature for 4-dimensional fiber spaces whose general fibers are non-hyperelliptic compact Riemann surfaces of genus 3. Some computations of our local signature will be given.Comment: 24 pages, typo adde

What the geological past can tell us about the future of the ocean’s twilight zone

Paleontological reconstructions of plankton community structure during warm periods of the Cenozoic (last 66 million years) reveal that deep-dwelling ‘twilight zone’ (200–1000 m) plankton were less abundant and diverse, and lived much closer to the surface, than in colder, more recent climates. We suggest that this is a consequence of temperature’s role in controlling the rate that sinking organic matter is broken down and metabolized by bacteria, a process that occurs faster at warmer temperatures. In a warmer ocean, a smaller fraction of organic matter reaches the ocean interior, affecting food supply and dissolved oxygen availability at depth. Using an Earth system model that has been evaluated against paleo observations, we illustrate how anthropogenic warming may impact future carbon cycling and twilight zone ecology. Our findings suggest that significant changes are already underway, and without strong emissions mitigation, widespread ecological disruption in the twilight zone is likely by 2100, with effects spanning millennia thereafter

Correspondence: No substantial long-term bias in the Cenozoic benthic foraminifera oxygen-isotope record

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Chromosome assignment of two cloned DNA probes hybridizing predominantly to human sex chromosomes

In situ hybridization experiments were carried out with two clones, YACG 35 and 2.8, which had been selected from two genomic libraries strongly enriched for the human Y chromosome. Besides the human Y chromosome, both sequences strongly hybridized to the human X chromosome, with few minor binding sites on autosomes. In particular, on the X chromosome DNA from clone YACG 35 hybridized to the centromeric region and the distal part of the short arm (Xp2.2). On the Y chromosome, the sequence was assigned to one site situated in the border region between Yq1.1 and Yq1.2. DNA from clone 2.8 also hybridized to the centromeric region of the X and the distal part of the short arm (Xq2.2). On the Y, however, two binding sites were observed (Yp1.1 and Yq1.2). The findings indicate that sex chromosomal sequences may be localized in homologous regions (as suggested from meiotic pairing) but also at ectopic sites

The Milliarcsecond Structure of Radio Galaxies and Quasars

Hybrid maps of the nuclei of radio galaxies and quasars show a variety of morphologies. Among compact sources, two structures are common: an asymmetric, “core-jet” morphology (eg, 3C 273), and an “equal double” morphology with two separated, similar components (eg, CTD 93). The nuclei of extended, double radio galaxies generally have a core-jet morphology with the jet directed toward one of the outer components