The filling of the late Tertiary evaporation basins in North America with the sediments of the Green River Formation must have been accompanied by extremely effective processes to clear away the flora and fauna. Of the more than 60 woody plants whose leaves or seeds have been recorded in the Green River deposits, there are still 50 that are native in America in the same or a very similar form, but some have completely disappeared from the New World. Members of certain tree families – such as Ailanthus (Tree of the Gods), Pterocarya (Wing nut), and Zelkova (Zelkova) – have not survived the Tertiary clearances even as species. This is all the more remarkable since it concerns wind-dispersed and relatively undemanding trees. From the composition of this flora it may be consequently concluded that it in no way covered the entire surface of the present-day North American continent, but was confined along riverbeds and similar, at least occasionally undisturbed, landscapes. Such a pattern of dispersal makes their clearance by water easily conceivable.
The Ailanthus species are still widely dispersed in Eastern Asia today. Their characteristic flying seed fossils are known in Europe from, inter alia, the Siebengebirge and the Randecker Maar, which will be mentioned later. In somewhat milder climates than Germany, especially in Spain and North America, a planted “Tree of the Gods” has a tendency to run wild. Its regional extinction during the Tertiary period can, therefore, not have had a “normal” cause.
The Wing-nut, another tree extinct in America, is found as a fossil even in Iceland. Its present day occurrence in the Caucasus and eastwards from there forms only the remnant of a formerly circumpolar distribution. Further Pterocarya-species appear again only in the Far East.
The genus Zelkova became extinct in America during the Tertiary. The forms that grow in the remaining range of Crete, Cyprus, and in the Caucasus were still resident in southern Europe, e.g. in Italy, after the Ice Age. There they only fell victim to deforestation by the hand of man during historical times. In the Far East, however, the Zelkova tree remains common.
The water spruce Metasequoia has its last natural habitat in China. Conversely, the Bald cypress Taxodium is completely extinct in the Old World, and now survives in two populations, which differ completely from each other ecologically. they are swamps of Southeastern USA and the mountainous regions of Middle America.
In the above discussion, assignment of the date of the extinction of individual species to specific Tertiary period epochs has been intenionally avoided. The reason for this is that drawing the line is far too uncertain. For instance, the Eocene Green River flora and Oligocene flora of Florissant (Colorado) are so markedly similar in their species composition that doubt has even been expressed by supporters of Historical Geology as to whether they can be separated from each other by 5 or 10 million(!) years. This is a further reminder of the fact that – apart from predictable ecologically induced local deviations – no fundamental changes occur in the appearance ot the Tertiary flora from the Palaeocene to the Pliocene. The increasing genetic plasticity of the new growth after the Flood could have co-operated to produce the proliferation in the number of the presently living members of the respective tree genera – for instance, over 400 recent oak species have been recorded! This is, however, not the the certainty it seems. For example, the characteristic serrations of a giant leaved birch are unmistakably the same as today's Betula maximowicziana, which now only survives in a remnant region in Japan. Thus the birches were proliferated into varities in the Tertiary and were not about to start developing! The same applies to the species-rich genus of the Maple (Acer). Other types of trees like Liriodendron (Yellow Poplar), Sassafras, Platanus, Cercidiphyllum and Zizyphus, which are easily identified from their leaf form also prove to be “through-runners” from the entire duration of the Tertiary period.
That the post-Flood climax of the vegetation was reached in the Tertiary emerges from the intense disjunction (fragmentary distribution) of the present day distributions of many tree types. One can talk directly of species-pairs, where one species survived in North America and another in Eastern Asia. Some of these pairs are listed below:
The morphological differences between some of these pairs of species are very slight, often to the extent that they could as well be handled as races. So, for instance, in the case of Liriodendron, the main difference lies in the susceptibility to frost of the Asiatic species.
If we add to this list of species pairs those tree genera that have now become extinct in North America or Europe, such as Ginkgo, Paulownia, Pterocarya, Ailanthus, Koelreuteria, etc., the essential unity of the former circumpolar Tertiary period flora becomes even clearer. The former connection of Eurasia with the Americas fits thoroughly into this picture.
Therefore the term “Tertiary period survivors” does not mean some kind of geographically bounded refugees where some individual plant or animal species survive, which have stood still on the Tertiary period “evolutionary step” Much rather we obtain from within such survivor ranges, insights into the remainders of the climax-vegetation, which was reduced elsewhere to the verge of extinction by crustal movements of catastrophic proportion and the consequent icing-up these movements caused. In contrast, the monotonous forest picture of present day Central Europe so familiar to us is the result of a limited return of fewer species after the Ice Age that in no way represented its formerly abundant flora. It is different in Japan and Southern China: these flora can still be described today with full and entire justification as being “Tertiary”.
Species of very localized distribution are almost always suspected of being survivors. Wulfernia carinthiaca, the “Blue flower” from Nassfeld in Carinthia [Austria], grows nowhere else (except in botanical gardens). A second closely-related species is found primarily in Albania, a third in the Himalayas. The remarkable Gesneriaceae genus Ramonda thrives with two very similar species on shady rocks in the Pyrenees, as well as at dispersed sites in the Balkans. Thus the effects of the Tertiary catastrophe can be clearly read from such disjunctions (fragmentary distributions) even within the relatively circumscribed Mediterranean region. That catastrophic causes are responsible for the fragmentary distribution of these plants is not mere speculation. It is evidenly taught, amongst other things, by the unlikely appearance of fossils of tropical sea fish in the mountains of Bolca near Verona (Italy). What really happened there cannot be suitably described from our present day stock of experience.
Other survivors are those species normally found only in the rain forest on the Usambara mountain range which, in part, show their close relationship with those of the Congo Basin and Equatorial West Africa. Their genetic isolation has led especially to the development of very noticeable local races of insects. One other obvious survivor is the mighty “Msoo” tree (Oxystigma msoo) whose East-African area of distribution near Moshi does not even reach a square kilometre. A further isolated location of this tree species occurs in the lowland east of the Pare Mountains. The “Amber-tree” Hymenaea verrucosa, a close relative of the producer of the Caribbean amber, which has scattered occurrences along the tropical lowlands of East Africa and Madagascar, may also be considered as one of these survivors.
Many inland waters understandably also harbour surviving relict species. In the rain-water marshes of the Munene forest and of the Minziro forest on both sides of the Kagera River, a tributary of the White Nile, there lives during the rainy season the splendidly coloured seasonal fish Nothobranchius. After laying, its eggs only develop after a complete drying out of the clay soil. The species does not migrate at all. The populations of both marsh forest have been separated from each other by the mighty Kagera at least since the beginning of the Pleistocene. They are, therefore, older than the present landscape on the western bank of Lake Victoria. Neverthless, both parts of the population are completely alike in appearance; their genetic potential for the development of races was evidently already exhausted before their separation. Genuine Nothobranchius races (sometimes also regarded as species) are, however, found dispersed over large parts of East Africa, in the drier parts of West Africa, in the southern Congo region, on the islands of Mafia and Zanzibar and even on the Seychelles! Between there and the African east coast lie 1400 km of Indian Ocean which is 4-5 km deep! The distribution of these extremely specialized little fish whose populations die out every year and begin anew with the rain, can therefore only have been established before the completion of the development of the present day geographic situation. What powerful geological mechanisms of geographical dispersal we must be reckoning with here!
Many large lakes on the earth harbour animal survivor forms, about which only a little is known. Lake Titicaca in Peru/Bolivia, Lake Victoria and Lake Tanganyika, Lake Ochrida in Albania, the Caspian Sea, the Baikal and other lakes in Central Asia amaze by the unexpected presence of certain shellfish, snails, fish, amphibians or seals, which presuppose a very wide-ranging redistribution of the water-covered areas during the Tertiary period. The occurrence of Baikal seals in the lakes of Central Asia, given the complete isolation of these stretches of water from the world's oceans is only explicable by unusual geological changes. Likewise, the jellyfish in Lake Tanganyika – typically animals of the open sea – are odd!
In the Central European regions, in addition to the geological processes, the closing in of the Ice Age also played an important role in the retreat of the living communities of the Tertiary climax. One “Tertiary” salamander genus, Pleurodeles (Rib salamander), which today inhabits only the southwestern half of the Iberian peninsula and the coastal region of Morocco, has been found as several fossil specimens in the Randecker Maar in southwestern Germany. The giant salamander Andrias scheuchzeri, remains of which from Ohningen on Lake Constance (Bodensee) were initially wrongly publicised as human remains from the Flood by the Swiss scientist J.J. Scheuchzer (1672-1733) and must have been cited again and again in geological textbooks as means of scorning Flood Geology, was evidently once dispersed over the whole Palaearctic region. It now survives only in cold mountain streams in China and Japan (and in zoos). Naturally the fossilized representatives are specimens that were washed down by water. In the eastern Asiatic and somewhat warmer refuges is found the crocodile salamander (Tylototriton). These, too, were dispersed widely in Europe during the Tertiary.
There are also relationships from Europe to the New World. The cave-dwelling proteid salamander Proteus anguineus, which only inhabits the stream system of the Adelsberg Grotto (formerly Yugoslavia) is closely related to the North American mud puppy Necturus maculosus and its relatives, which live in surface waters. It seems obvious that both these species, which are separated by the Atlantic, are in reality only genetically separated populations of a single created kind. A proteid salamander intermediate beween the two types is found in the lignite of the Geisel valley. The mud minnow Umbra krameri occurs in the eastern USA. If the bowfin (Amia), gar (Lepisosieus or Atractosteus) and snapping turtles (Chelydra or Chelydropsis), still surviving in North America but extinct in Europe, are included, then the drastic impact of the Tertiary events on the aquatic creatures of pre-Ice Age “Old Europe” becomes impossible to ignore.
Lastly, the just recently discovered distribution-ranges of two non-migratory moths must be reckoned as Tertiary survivors. Acanthobrahmaea europaea from Mt. Vulture in Southern Italy and Graellsia isabella with the local race galliaegloria in the French Southern Alps. The Graellsia, which is widely dispersed in North-eastern Spain, lives as a caterpillar on pines which are abundant everywhere. The isolated occurrence of the French population is, therefore, all the more astonishing. The occurrence of Acanthobrahmaea is even limited to just one point on the Atlas. Such species at one time certainly inhabited a very much more extensive region. Moreover, their astonishingly restricted distribution cannot be explained by Ice-Age influences because these played no role in the Mediterranean region. All these survivors remind us of the fact that the post-Flood successions must have already reached their peak in the Tertiary and that the diversity of living creatures on the earth has continually receded since then. Without reference to the geological information in the Bible, the riddle provided by the present distribution of the animals and plants will remain totally obscure.