Cretaceous amber insects

Abstract

Abstract Amber first became relatively abundant and widespread in the geological record during the Cretaceous period. It originated often as copious resin production by a variety of incompletely understood coniferous trees, generally under humid climates, but not excluding seasonal aridity. Study of insect and other organic inclusions only commenced in the twentieth century, but has expanded considerably since then, with several thousand taxa now described. Cretaceous amber insects can be exquisitely preserved in three dimensions, although tend to be biased towards smaller individuals that lived in the local forest environment. They are therefore complemented by the Cretaceous rock record, which sampled larger insects and other habitats. As well as the fine morphological detail exhibited by the amber insect inclusions, various behaviours and interactions unlikely to be otherwise preserved can be found frozen in time, such as brooding behaviour and the entrapment of insects in spiders’ webs. Insects in amber also provide important information about evolutionary changes over the course of the Cretaceous, including the rise of eusociality and angiosperm pollination.