The distribution of conodonts in the early Silurian successions of the Oslo Region is assessed with respect to water depth and energy level changes. Although there is no strong lateral segregation nor increase in diversity in deeper waters, species seem to be selective in their preference for environments. A few
exhibited anomalies in the near-shore, high energy environments, others in the off-shore, lower energy environments. The distributional trends of the main zonal indices Distomodus kentuckyensis and lcriodella discreta - lcriodella deflecta suggest that there are some interactions between these species.
Generally, the distribution patte ms of the coniform apparatuses indicate that they are least tolerant of the shallow water, high-energy environments.