In late Miocene coral reefs from the Fes area (Northern Morocco), bryo
zoans are the best represented group. An inventory of the bryozoan fau
na (59 species) was taken on two reefs with different organization and
palaeogeographical situation in a late Miocene seaway between the Atl
antic and the Mediterranean. A study of the bryozoans and their zoaria
l forms allows an improved reconstruction of reefal environments and a
vailable habitats. Membraniporiform (encrusting) colonies largely pred
ominate, whereas celleporiforms (nodular colonies) are more rare. Rigi
d erect (vinculariiform, adeoniform, and reteporiform) and rigid artic
ulated zoarial types (cellariiform and catenicelliform) are fairly wel
l represented. At depths of about 10 m and on the reef front encrustin
g bryozoans were well developed in cryptic habitats on living coral su
bstrates. Erect species lived in cavities provided by the cord framewo
rk, and plants offered flexible substrates for the attachment of epiph
ytal forms.