Terrestrial Palaeoecology and Global Change

376 Valentin A. Krassilov. Terrestrial Palaeoecology
a
b
d
c
Fig. 150. An increase in betuloid remains (leaves, partial inflorescence,
a, b) relative to conifer remains (c, d) in the Early Palaeocene
of Zerkalnaya depression, Sikhote Alin suggests a downslope migration
of the birch woodland belt relative to its altitudinal position in
the Maastrichtian (Krassilov, 1999c).
Pterophyllum and Cycadites. The plant remains are coarsely preserved, oblique to the
bedding plane, apparently the result of an instantaneous burial by ash flow. The overlying
tuffaceous sequence contains nine sequential fossil plant assemblages. In the basal part,
a root-bed with horsetail remains is followed by a 50 cm thick fern-bed, a tuffaceous
shale with Woodwardia and Cladophlebis columbiana. Several leaf mats upsection
are dominated by Metasequoia occidentalis and Corylites protoinsignis (leaves and
husks), with Ginkgo, Trochodendroides arctica, Alnites protoschmalhausenii, Liriophyllum
sachalinense and Macclintockia kanei as the common species.