Early Cretaceous angiosperms of the Soviet Union based on leaf and fruit remains

Abstract

Five newly collected Early Cretaceous angiosperms from the Kolyma River in Siberia are described. There are two new species of leaf, Cinnamomoides ievlevii and Celastrophyllum serrulatus and a new genus of fruit, Kenella harrisiana together with two leaves, Nelumbites aff. minimus Vachrameev and Celastrophyllum aff. hunteri Ward. Early Cretaceous angiosperm records for the Soviet Union are given in a table and their significance is discussed. It is argued that by the end of the Early Cretaceous whon the flora underwent a substantial change angiosperms were already distinguished by their high state of morphological development judging by leaf form and systematic composition. They were widely spread occurring in regions of both temperate and warm humid climates. They appear to have been plants of mountains, including trees and herbs, terrestrial and aquatic. With the advent of physical and climatic changes these angiosperms were ready for rapid expansion. Their domination of the vegetation of the Late Cretaceous was not as inexplicable as previously thought.