Découverte d’un micro-organisme commensal impliqué dans une crise biologique chez les gilianelles du Crétacé de Tercis (Landes, France) : Convictorella pusula, nov. gen. nov. sp. (microproblematica)

The recently discovered gilianelles commonly show attached microspheres. The morphological relationships indicate that this association is of biological origin with benefit for the microspheres but not for the gilianelles. A local bloom of the commensal microspheres (age estimate: about 73 Ma) coincides with a biological crisis in the evolutionary pattern of the gilianelles. The group convictorelles (microproblematica) and the species Convictorella pusula n. gen. n. sp. are created for this original ethological relationship.