A Late Cenomanian bryozoan biostrome from north-eastern Nigeria

摘要: Abstract Bryozoans are present in rock-forming abundance throughout a 30-cm thickness of the Late Cenomanian Pindiga Formation at its type locality north-eastern Nigeria. In addition to representing rare record Cretaceous bryozoans from African continent, bryozoan biostrome provides an exception general rule that post-Palaeozoic bryozoan-rich deposits formed only outside palaeotropics. A single species is present, anascan cheilostomeHeteroconopeum janieresiense (Canu, 1897), originally described French Turonian. Colonies preserved as para-authochthonous branch fragments derived bushy colonies. The ancestrula and early budding pattern for first time this genus. attached to, themselves encrusted by, small oysters. Unlike most cheilostomes, malacostegan H. probably had long-lived, planktotrophic larva was tolerant variable salinities. These factors may explain occurrence upper Benue Trough, area intermittent hyposalinity far distant main contemporaneous populations.