A la recherche de la vie dans l’univers

Article for general public (2004)

ILLUSTRATION OF MODERN BENTHIC FORAMINIFERA FROMBERMUDA AND REMARKS ON DISTRIBUTION IN OTHER SUBTROPICAL/TROPICAL AREAS

in Palaeontologia Electronica (2003), 6(4), 1-29

A scanning light microscope (SLM) is used to illustrate recent benthic foraminiferal species from surface sediment samples collected in Bermuda subtropical environments. Species illustrated here are the ... [more ▼]

A scanning light microscope (SLM) is used to illustrate recent benthic foraminiferal species from surface sediment samples collected in Bermuda subtropical environments. Species illustrated here are the main foraminiferal species found in Bermuda lagoons, reefs, caves, mangroves, and ponds, but also occur in most subtropical and tropical areas. The SLM permits photography of specimens without coating and gives pictures most similar to specimens that micropaleontologists see under a dissecting reflected light microscope in a petri dish with water, in contrast to images made with scanning electron microscopes. These pictures are the first SLM illustrations of subtropical/tropical species of benthic foraminifera and will be very useful for their identification. Bermuda recent sediment hosts a benthic foraminifera fauna as diverse as in other subtropical and tropical areas, and the general trends of foraminiferal distribution and morphology are similar. Remarks on foraminiferal distribution in Bermuda and other subtropical/tropical areas are also presented. [less ▲]

L’astrobiologie

Scientific conference (2003)

Recognizing and interpreting the fossils of early eukaryotes.

Conference (2002, October)

Cytological and ecological complexity in the Early Mesoproterozoic.

Conference (2001, November)

Morphological and ecological complexity in early eukaryotic ecosystems

in Nature (2001), 412(6842), 66-69

Molecular phylogeny and biogeochemistry indicate that eukaryotes differentiated early in Earth history. Sequence comparisons of small-subunit ribosomal RNA genes suggest a deep evolutionary divergence of ... [more ▼]

Molecular phylogeny and biogeochemistry indicate that eukaryotes differentiated early in Earth history. Sequence comparisons of small-subunit ribosomal RNA genes suggest a deep evolutionary divergence of Eukarya and Archaea(1); C-27-C-29 steranes (derived from sterols synthesized by eukaryotes) and strong depletion of C-13 (a biogeochemical signature of methanogenic Archaea) in 2,700 Myr old kerogens independently place a minimum age on this split(2,3). Steranes, large spheroidal microfossils, and rare macrofossils of possible eukaryotic origin occur in Palaeoproterozoic rocks(4-6). Until now, however, evidence for morphological and taxonomic diversification within the domain has generally been restricted to very late Mesoproterozoic and Neoproterozoic successions(7). Here we show that the cytoskeletal and ecological prerequisites for eukaryotic diversification were already established in eukaryotic microorganisms fossilized nearly 1,500 Myr ago in shales of the early Mesoproterozoic Roper Group in northern Australia. [less ▲]

. Distribution of benthic foraminifera in modern sediments of Bermuda: implications for Holocene sea-level studies

Doctoral thesis (1999)

Late Holocene sea-level curve for Bermuda: a proxy for the past and the future?

Poster (1998)

Benthic foraminifera in Bermudan mangrove swamp; implications for Holocene sea level studies

Poster (1996)

Benthic foraminiferal assemblages from Bermudan marine caves.

Poster (1995)