ABSTRACT
Amongst the 21 regular echinoid species known to date from the early Palaeocene Geulhem Member as exposed in NE Belgium, two (Goniopygus minor Sorignet, 1850 and ? Arbacina sp.) are marsupiate. Their presence is assumed to be a function of adaptation to a very specific habitat as expressed in a reduction or avoidance of larval dispersal, rather than of a prevalence of cold-water oceanic conditions during deposition of this unit.
