Secondary Epoch
Periods
T r i a s s i c— Large Monotreme-like reptiles, appear in Europe and North America.
J u r a s s i c — The origin of birds from. ^
C r e t a c e o u s— Chalk age and the age of reptiles. Appearance of Marsupials and
Monotremes, as well as; the first forms of Insectivores, Primates, and
Ungulates without horns.
Tertiary Epoch
E 0CENE_Advent of the true Mammalian families, such as the Cetaceans, Edentates,
Marsupials, Ungulates, Carnivores, Rodents, Insectivores, Cheiroptera, and
the Primates. Many existing types have altered but little since this period.1
Miocene— Mammalian order developing. Plant and animal life suggestive of a
tropical climate.
P l io c e n e— Main orders of Mammals finally developed. The climate still tropical,
and thé possible advent of Man to Britain and the northern world.
P l e i s t o c e n e— At the beginning of this period Britain was still more or less
tropical, the flora was abundant, and palm trees flourished as far north as
Greenland. Our fauna was then and immediately afterwards at its best,
and most óf the undetermined orders developed into specialised types of
the finest, description. Soon after the commencement of this period occurred
the first great Ice-sheet, carrying with it destruction and climatic change;
and thereupon these islands acquired an Arctic fauna, consisting of such
splendid species as the Mammoth, the Hairy Rhinoceros, the Elk, the
Gigantic Fallow Deer, a superior type of Red Deer, Fallow Deer, Roe,
Reindeer, Brown Bear, Cave-bear, Musk-ox, Saiga, Sabre-toothed Tiger,
Cave-lion, Hyaena, Glutton, Wolf, Wild Boar, and many other magnificent
creatures. At the close of this period came the second Glacial wave or
Ice-sheet, which destroyed the greater part of this splendid fauna.
■ 1 At the present day we are still unable to give a satisfactory answer to the question, In what part of the world did
Mammals first originate, and from what living creatures? They may have come from North America, the regions about the
North Pole, Persia. India, or even South Africa. All suggestions are alike supposititious, especially the last named,-for we
still know next to nothing of the geology and paleontology of Africa. What is more certain is that Mammals probably
evolved from Reptiles.