Skip to content Skip to navigation

Article: Gilianelles: Late Cretaceous microproblematica from Europe and Central America

Publication: Palaeontology
Volume: 54
Part: 1
Publication Date: January 2011
Page(s): 133 144
Author(s): Gilles Serge Odin
Addition Information

How to Cite

ODIN, G. 2011. Gilianelles: Late Cretaceous microproblematica from Europe and Central America. Palaeontology54, 1, 133–144.

Online Version Hosted By

Wiley Online Library
Get Article: Wiley Online Library [Pay-to-View Access] |


During the last two decades, a range of microfossils have been collected from strata of Late Cretaceous (Coniacian–Maastrichtian) age. The name gilianelles has been coined to accommodate these microproblematica. On the basis of many thousands of specimens, typical features of this group have now been assessed. Distinctive traits are calcareous unilocular, basically axially symmetrical test, in the size range 80–200 ?m, with a single-layered wall of radially arranged crystals, 15 ?m thick, the outer surface with a crochet-like nanostructure, a small-sized aperture (one tenth of test diameter), situated on the upper surface in vivo. Secondary criteria include modification of axial test symmetry into radial or bilateral symmetry, development of expansions, either spiny or laminar and presence of longitudinal and latitudinal ornament. To date, 60 taxa have been described from northern Spain to northern Germany and from Central America. Evolutionary patterns of gilianelles are diverse, with both short- and long-ranging forms, some of which comprise lineages that were affected by a marked crisis dated at about 73 Ma. This event is here illustrated by the tribe Coraliellini, of which a key taxon, Coraliella cognatio, is described as new. Previous interpretations of Gilianelles as dinoflagellate cysts are discussed and rejected.
PalAss Go! URL: | Twitter: Share on Twitter | Facebook: Share on Facebook | Google+: Share on Google+