Early Pleistocene

There were long intervals of temperate climate, similar to or even warmer than that of today during the later Pliocene and then during the Pleistocene interglacials, these alternated with a series of increasingly cold and then glacial periods. Before the more widely recognised glacial and interglacial periods a number of less well known periods have been described, namely:

Waltonian.

A landscape characterised by boreal forests comprising of pine (Pinus) and birch (Betula), with evidence also for species rich mixed oak forest comprising of oak (Quercus), fir (Abies), elm (Ulmus) and chestnut (Castanea). Sea temperatures may have been higher that today.

Ludhamian

Temperate conditions with Pine dominated forest and deciduous trees such as oak, alder (Alnus) and elm, and grassland heathland.

Thurnian

The vegetation evidence from this cool period suggests that the vegetation was much less diverse than during the Ludhamian, the forests were very much dominated by pine, with evidence for tracts of open grass and heathlands

Bramertonian/Antian

A temperate climate with mixed oak forest in southern England), distinguished from earlier stages by the presece of hemlock (Tsuga). Sea levels were higher than today.

Pre-Pastonian/Baventian

A cold stage with open grasslands and elements of boreal pine dominated woodlands in Southern England.

Pastonian - warm

A temperate period characterised by an expansion in mixed deciduous woodland, including hornbeam (Carpinus), elm , hazel (Corylus) and spruce (Picea). Towards the end of this stage there was a fall in sea level and an increase in grassland.

Beestonian - periglacial

This cold stage was characterised by an open grassland landscape.

During these poorly understood periods the fauna of Britain included two species of beaver (Trogontherium cuvieri and Castor fibia), extinct species of deer, gazelle, elephant, three toed and true horses, tapir, rhino, panda, clawless otter, hyaena and sabre-toothed cat. The European Beaver (C. fibia) is one of the only extant species to be represented in the British fauna of the time. The first mammoth (Mammuthus rumanus) and later the Ancestral (or Southern) Mammoth (M. meridionalis) roamed throughout Europe during the Late Pliocene to Early Pleistocene.

In Germany, and therefore probably also Britain, at this time occurred; Bison menneri, the earliest true bison from Europe, an early roe deer (Capreolus cusanoides), a moose (Alces carnutorum), the fallow deer sized Cervus s.l. nestii vallonnetensis, the comb-antlered Eucladoceros giulii, the very large hippo Hippopotamus amphibius antiquus, the Etruscan Rhino (Stephanorhinus etruscus). Predators included the Jaguar (Panthera onca gombaszoegensis), the large cheetah Acinonyx pardinensis pleistocaenicus, an Old World puma (Puma pardoides; syn. Viretailurus schaubi), the dirk-toothed cat Megantereon cultridens adroveri, the sabre-toothed cat Homotherium crenatidens, the bear Ursus dolinensis; syn. U. rodei, the large canid Canis (Xenocyon) lycaonoides and the medium-sized wolf C. lupus mosbachensis.

Jaguar

Conifer forests dominated the cold phases and broad-leaved forest the temperate phases. Several species of trees that occurred in Britain at the time are now only found in Asia or North America.

Such was the influence of the glacial periods that the courses of major rivers could be redirected and major drainage patterns altered. Before the commencement of the Cromerian Interglacial there was a switch in drainage pattern of a large part of southern England. The Bytham, which entered the North Sea through East Anglia, became the main river of southern England, draining much of Wales and the Midlands. The Bytham, had once been a tributary of the Thames but that river had moved southeast. The switch was either due to headwater extension of the Bytham in the Vale of Evesham and the lower Severn Valley, or erosion caused by advancing Welsh glaciers.