Cardiotaxis heberti (Cotteau 1860) en Cardiaster granulosus (Goldfuss 1829) uit het onderste deel van de Formatie van Gulpen (Boven-Krijt): paleobiologie, voorkomen en systematiek.

Cardiotaxis heberti (Cotteau 1860) and Cardiaster granulosus (Goldfuss 1829) from the lower part of the Gulpen Formation (Upper Cretaceous; province of Liège): paleobiology, occurrence and systematics. On the basis of specimens of the holasteroid echinoids Cardiotaxis heberti and Cardiaster granulosus collected in situ in the CPL-quarry at Haccourt, municipality of Oupeye (Liege, Belgium) a rather extensive description of their skeletal morphology is given. Up to now, C.heberti has become known only from the basal part of the Zeven Wegen Member of the Gulpen Formation which is of early Late Campanian age. C.granulosus in its typical white chalk form is restricted to the Vijlen and Lixhe Members of this formation. Mention is made of related forms (probably from the same phylogenetic lineage) in the uppermost part of the Gulpen Formation (Lanaye Member) and the entire Maastricht Formation and the Vaals Formation (Lower Campanian). For both C.heberti and C.granulosus a palaeobiological reconstruction, based on the skeletal morphology, is worked out. The accompanying macrofaunal assemblages are also given particular attention, especially in the case of C.granulosus. It is concluded that C.granulosus was better adapted to an infaunal mode of life than C.heberti.