From arid to humid - The Jurassic-Cretaceous boundary interval in northern Germany

In the Lower Saxony Basin, the late Jurassic-earliest Berriasian vegetation was dominated by cheirolepidiacean conifer forests growing under arid conditions along a coastal belt. A marked decline in cheirolepidiacean pollen and the spread of pioneering plants records an increase in seasonal humidity in the early-mid Berriasian. In the mid-late Berriasian the presence of highly diverse floras reflects even more humid and warm conditions. Fluvio-deltaic mixed swamp forests, which grew landwards behind the coastal belt were composed of conifers, ferns, lycopods, horsetails, bryophytes, ginkgos, cycads and Bennettitales. Cheirolepidiaceans, probably forming part of mangrove-type plant communities, remained an important component of the coastal flora. The climatic shift correlates to the upper Subcraspedites lamplughi-middle Heteroceras kochi ammonite zones of the marine Boreal zonation scheme and is synchronous to the early-mid Berriasian shift from arid to humid recorded from southern England.