Miocene Sentence Examples
The most widely spread of the sedimentary beds belong to the Miocene period.'
In Tertiary times the Central Plateau was the theatre of great volcanic activity from the Miocene, to the Pleistocene periods, and many of the volcanoes remain as nearly perfect cones to the present day.
The Miocene and Pliocene are absent.
It occurs in Miocene deposits and is also found washed up by the sea near Catania.
It is found in flat rolled pieces, irregularly distributed through a blue clay probably of Miocene age.Advertisement
This was accompanied in Europe by a drastic weeding out of Miocene types, ultimately leaving the flora pretty much as it now exists.
This, as will be explained, did not take place to anything like the same extent in North America, the vegetation of which still preserves a more Miocene facies.
In the Old World the boreal zone is almost sharply cut off and afforded no means of escape for the Miocene vegetation when the climate became more severe.
While it has been customary to describe the Miocene flora of Europe as of a North American type, it would be more accurate to describe the latter as having in great measure preserved its Miocene character.
While the tropics preserve for us what remains of the preTertiary or, at the latest, Eocene vegetation of the earth, which formerly had a much wider extension, the flora of the North Temperate region is often described as the survival of the Miocene.Advertisement
We must, however, agree with Starkie Gardner that it is only Miocene as regards its present position, which was originally farther north, and that its actual origin was much earlier.
Glacial elimination has been less severe, or rather there has been, at any rate on the Atlantic side, an unimpeded return of Miocene types.
It is remarkable that the characteristic features of the Miocene flora, which in other partm of the world have spread and developed southwards, are conspicususly absent from the African tropical flora.
It is no exaggeration to say that the genus, often even the species, can be determined from almost any recent bone, but in the case of Miocene, and still more, of Eocene fossils, we have often to deal with strange families, which either represent an extinct side branch, or which connect several recent groups with each other.
There were, for instance, trogons, secretary-birds, parrots, and other now Ethiopian forms in Miocene France.Advertisement
The Miocene has yielded by far the greatest number of bird-bones, including even eggs and imprints of feathers.
For instance, from the lower Miocene beds of Allier and Puy-de-Dome MilneEdwards has described about so species.
Pliocene remains are less numerous than those of the Miocene.
A collective polyphyletic or heterogeneous group, originally cosmopolitan; with certainty existing since the Miocene.
The sulphur occurs in Miocene marls and limestone, associated with.Advertisement
An important zone of sulphur-bearing Miocene rocks occurs on the east side of the Apennines, constituting a great part of the province of Forli and part of Pesaro.
Coming to the Tertiary we find the Oligocene beds of Aix, of east Prussia (amber) and of Colorado, and the Miocene of Bavaria, especially rich in remains of beetles, most of which can be referred to existing genera.
All these are involved in the earth movements to which the mountains of the island owe their formation, but the Miocene beds (with Clypeaster) and later deposits lie almost undisturbed upon the coasts and the low-lying ground.
Nummulitic limestone (Eocene) overlies the Cretaceous in Philistia, and north of Lebanon Eocene and Miocene deposits cover the greater part of the country.
In most cases the eruptions appear to be of Pliocene or later date, but in the extreme north some of the basalt seems to belong to the Miocene period.Advertisement
It is of Tertiary formation (Miocene), and has a chain of volcanic elevations along the axis, reaching a height of 2600 ft.
Finally, Tapirus itself, in which the last three upper premolars, makes its appearance in the Upper Miocene, and continues till the present day.
These Miocene strata have not been found farther north on the Greenland shore than the region mentioned; but in Lady Franklin Bay, on the Grinnell Land side of Smith Sound, they again appear, so that the chances are they will be found on the opposite coast, though doubtless the great disintegration Greenland has undergone and is undergoing has destroyed many of the softer beds of fossiliferous rocks.
On the east coast, more particularly in Hochstetter Foreland, the Miocene beds again appear, and we may add that there are traces of them even on the west coast, between Sonntag Bay and Foulke Fjord, at the entrance to Smith Sound.
Eocene nummulitic beds occur, but the deposits are mostly of Miocene age.
Five subdivisions may be recognised in the Miocene deposits, corresponding with five different stages in the evolution of southern Europe.
There is an axial zone of Cretaceous and Lower Eocene, and this is flanked on each side by the Upper Eocene and the Miocene, while the valley of the Irrawaddy is occupied chiefly by the Pliocene.
Along the southern part of the Arakan coast the sea spreads over the western Miocene zone.
The Miocene beds are also marine and are characterized by an abundant molluscan fauna.
Flint chips, which appear to have been fashioned by hand, are said to have been found in the Miocene beds, but to prove the existence of man at so early a period would require stronger evidence than has yet been brought forward.
Intrusions of a serpentine-like rock break through the Miocene strata north of Bhamo, and similar intrusions occur in the western ranges.
The petroleum of Burma occurs in the Miocene beds, one of the best-known fields being that of Yenangyaung.
Jukes-Browne and Harrison ascribe the Scotland beds to the Eocene or Oligocene period, the Oceanic series to the Miocene, the Bissex Hill marls to the Pliocene, and the coral limestones partly to the Pliocene and partly to the Pleistocene.
The Oligocene and Miocene formations are present, but the Upper Miocene is confined to the coast.
Members of the group have existed in both east and west hemispheres since the beginning of the Miocene period; but in America they all became extinct before the end of the Pliocene period, and in the Old World their distribution has become greatly restricted.
The folding of this zone took place during the Miocene period.
The Lower Limestone probably belongs to the Tongarian stage of the Oligocene series, and the Upper Coralline Limestone to the Tortonian stage of the Miocene.
The most interesting genera are, however, the Upper Oligocene and Lower Miocene Gelocus and Prodremotherium, which have perfectly selenodont teeth, and the third and fourth metacarpal and metatarsal bones respectively fused into an imperfect cannon-bone, with the reduction of the lateral metacarpals and metatarsals to mere remnants of their upper and lower extremities.
Originally the family was an Old World type, but in the Miocene it gained access into North America, where the earliest form is Bothriolabis, an ancestral peccary showing signs of affinity with the European Miocene genus Palaeochoerus.
The genus has a very wide distribution, extending from Europe through Asia to North America, and occurring in strata which are of Oligocene and Miocene age.
In the above genera, so far as is known, the feet were four-toed, although with the lateral digits relatively small; but in Elotherium (or Entelodon), from the Lower Miocene of Europe and the Oligocene of North America, the two lateral digits in each foot had disappeared.
New Guinea was probably in Miocene times, if not later, united to the northern part of Queensland.
They are marine and probably Miocene; and range up to the height of 800 ft.
It appears to consist in the main of a continuation of an axis of old schists and slates, with granite intrusions, and flanked by coastal plains with Cretaceous or Jurassic, and Miocene beds, with Pleistocene sands and reefs and volcanic rocks.
Geologically the region is made up of Carboniferous limestones, clay slates and sandstones, containing anthracite and coal; of Cretaceous marls, chalk, sandstone and greensands - chalk cliffs, in fact, accompany the Don for 200 m.; and of Miocene limestones and clays.
Ameghino refers deposits in Patagonia, from which undoubted human bones and relics have been exhumed, to the Miocene.
Only a few lines can be devoted to extinct antelopes, the earliest of which apparently date from the European Miocene.
Gazelles are common in the Miocene and Pliocene of both Europe and Asia.
Tapirs are an ancient group with many of the original characters of the primitive Ungulates of the Oligocene period, and have undergone but little change since the Miocene.
Thus there is no difficulty in tracing the common origin in the Miocene tapirs of Europe of the now widely separated American and Asiatic species.
The Cainozoic system is represented by Oligocene, Miocene, Pliocene and Pleistocene beds.
The Miocene Pareora beds occur to the height of 3000 or 4000 ft.
In Westland the Miocene includes the Moutere gravels, which rest on the summit of Mount Greenland, 4900 ft.
The temperature of the lake varies greatly, in a manner resembling that of the sea, and many connect its origin with a sea of the Miocene period, the waters of which are said to have covered the Hungarian plain.
The strata in which it was found belong to the Miocene or Upper Pliocene.
The Miocene included a limestone with Clypeaster.
The Miocene formation obtains its greatest development in Oran and is much expanded in the Tell.
At the close of the Lower Miocene period (beds with Ostrea crassissima) great modifications in the relief and limits of the Algerian formations took place.
Hitherto marine conditions were confined to the littoral; in Middle Miocene times (Helvetian) the sea broke in and spread in a south-east direction in the form of long ramified fjords but did not extend as far as the Sahara.
Among the Tertiary volcanic rocks those of acid types (granites, granulites) were the first to appear and are developed latitudinally; rocks of intermediate type (dacites, andesites) characterize the Miocene and early Pliocene periods; while the basic rocks (ophites, elaeolite syenites and basalts) attained their maximum in later Pliocene and Quaternary times.
To these divisions Lyell gave in 1833, the names Eocene, Miocene and Pliocene.
Fine examples of the spirit of the period as applied to extinct Mammalia are Gaudry's Animaux fossiles et geologie de l'Attique (1862) on the Upper Miocene fauna of Pikermi near Athens, and the remarkable memoirs of Vladimir Onufrievich Kowalevsky (1842-1883), published in 1873.
In1867-1872Milne Edwards published his memoirs en the Miocene birds of central France.
These horses are of the same geologic age (Upper Miocene) and 'were found in the same geographic region (South Dakota, U.S.A.).
Among land animals striking illustrations of this local polyphyletic law are found in the existence of seven or eight contemporary series of rhinoceroses, five or six contemporary series of horses, and an equally numerous contemporary series of American Miocene and Pliocene camels; in short, the polyphyletic condition is the rule rather than the exception.
It is displayed to-day among the antelopes and to a limited degree among the zebras and rhinoceroses of Africa, a continent which exhibits a survival of the Miocene and Pliocene conditions of the northern hemisphere.
In the Miocene period andesites of various kinds were erupted, while at the close of the Pliocene began the great eruptions of basalt which reached their maximum in Quaternary times and continue to the present day.'
A deposit of sinter and a calcareous sandstone, known as the Kalahari Kalk, considered by Dr Passarge to be of Miocene age, overlies a sandstone and curious breccia (Botletle Schnichten).
They occur in the Lower Chalk formations, and in Tertiary times were widely diffused; the genus is represented in the Eocene flora of Great Britain, and in the succeeding Miocene period was widely distributed in Europe and western Asia.
The Eocene beds are unconformable, generally, upon the Cretaceous, and unconformable beneath the Miocene.
The Miocene system, generally speaking, has a distribution similar to that of the Eocene.
The Miocene of the Atlantic and Gulf regions nowhere attains great thickness.
The oil of Texas and Louisiana is from the Miocene (or possibly Oligocene) dolomite.
The Miocene of California is oilproducing.
The terrestrial Miocene formations of the western part of the country are similar in kind, and, in a general way, in distribution, to the Eocene of the same region.
At the close of the Miocene, deformative movements were very widespread in the Rocky Mountains and between the principal development of the Coast ranges of California and Oregon, and mountain-making movements, new or renewed, were somewhat general in the west.
Subsequent erosion has changed the details of topography on an extensive scale, and subsequent deformative movements have renewed large topographic features where erosion had destroyed those developed by the close of the Miocene.
But in spite of these great changes since the Miocene, the great outlines of the topography of the present were probably marked out by the close of that period.
Volcanic activity and faulting on a large scale attended the deforijiation of the closing stages of the Miocene.
The Pliocene system stands in much the same stratigraphic relation to the Miocene as the Miocene does to the Eocene.
In origin and character, and to some extent in distribution, they are comparable with the Eocene and Miocene formations of the same region, and still more closely comparable with deposits now making.
Under these conditions sediments from the high lands were washed out and distributed widely over the plains, giving rise to a thin but widespread formation of ill-assorted sediment, without marine fossils, and, for the most part, without fossils of any kind, and resting unconformably on Cretaceous, Eocene and Miocene formations.
Geologically the anthracite and bituminous coals mainly belong to the same formation, the Carboniferous, and this is especially true of the better qualities; though it is stated by the United States Geological Survey that the geQlogic age of the coal beds ranges from Carboniferous in the Appalachian and Mississippi Valley provinces to Miocene (Tertiary) on the Pacific coast, and that the quality of the coal varies only to a very uncertain degree with the geologic age.
In the European Miocene we have Hyotherium and Palaeochoerus, and in the Upper Oligocene Propalaeochoerus, which have square molars without any tendency to a selenodont structure in their cusps.
In the European Miocene Listriodon, which also occurs in the Indian Tertiaries, the molars have a pair of transverse ridges, like those of the proboscidean Dinotherium; but the genus is believed to be related to the Oligocene Doliochoerus and Choerotherium, in which these teeth show a more normal type of structure.
For the genus Elotherium, of the Lower Miocene and Upper Oligocene of both hemispheres, which is often placed next the Suidae, see ARTIODACTYLA.
The Plecoptera are world-wide in their range and fossils referable to them have been described from rocks of Eocene, Miocene and Jurassic age, while C. Brongniart states that allied forms lived in the Carboniferous Period.
Geologically and structurally Cyrenaica is a mass of Miocene limestone tilted up steeply from the Mediterranean and falling inland by a gentle descent to sea-level again at the line of depression, which runs from the gulf of Sidra through Aujila to Siwa.
Near akin is the North American Miocene family Mylagaulidae, typified by Mylagaulus, but including Mesogaulus and Protogaulus.
To discuss the remaining Miocene and later.
As regards the Duplicidentata, it appears that the families Ochotonidae and Leporidae had become differentiated as early as the Lower Miocene.
Titanomys is the earliest form, from the Middle Miocene, succeeded by Lagopsis, and then by the modern Ochotona.
These sudden appearances of vast bodies of lemmings, and their singular habit of persistently pursuing the same onward course of migration, have given rise to various speculations, from the ancient belief of the Norwegian peasants, shared by Olaus Magnus, that they fall down from the clouds, to the hypothesis that they are acting in obedience to an instinct inherited from ancient times, and still seeking the congenial home in the submerged Atlantis, to which their ancestors of the Miocene period were wont to resort when driven from their ordinary dwelling-places by crowding or scarcity of food.
The fossil remains of three species have been described by Professor Marsh - one from the Miocene of Colorado, and two, one much taller and the other smaller than the existing species, from the post-Pliocene of New Jersey.
Of the extinct North American peccaries, the typical Dicotyles occur in the Pliocene while the Miocene Bothriolabis, which has tusks of the peccary type, approximates in the structure of its cheek-teeth to the European Miocene genus among the Suinae.
The depression is filled by Miocene and later beds, which for the most part lie flat and undisturbed as they were laid down.
The Molasse, in the neighbourhood of the mountains, consists chiefly of conglomerates and sandstones, and the Flysch consists of sandstones and shales; but the Molasse is of Miocene and Oligocene age, while the Flysch is mainly Eocene.
The most conspicuous folding, that of the Mesozoic and Tertiary belts, must have occurred in Tertiary times, and it was not completed till the Miocene period.
The Miocene consists chiefly of marls, with occasional beds of lignite and limestone.
Except in Limburg, where, in the neighbourhood of Maastricht, the upper layers of the chalk are exposed and followed by Oligocene and Miocene beds, the whole of Holland is covered by recent deposits of considerable thickness, beneath which deep borings have revealed the existence of Pliocene beds similar to the " Crags " of East Anglia.
The Oligocene forms a band stretching from Antwerp to Maastricht, and this is followed towards the north by a discontinuous strip of Miocene and a fairly extensive area of Pliocene.
This communication began to fail, or close up presumably in the Miocene period; and before the dawn of Pliocene times the Sarmatian Ocean was broken up or divided into sections, one of which was the Aralo-Caspian sea already discussed.
The Eoccne system is unknown in Germany except in the foothills of the Alps; but the Oligocene and Miocene are widely spread, especially in the great plain and in the depression of the Danube.
Marine Miocene occurs in N.W.
Germany and the Miocene of the Danube valley is also in part marine, but in central Germany it is of fluviatile or lacustrine origin.
The very much broader depression of the Danube is associated with the formation of the Alps, and was flooded by the sea during a part of the Miocene period.
Miocene and Pliocene deposits cover nearly the whole of the country south of a line drawn from Etna to Marsala; and there is also a considerable Miocene area in the north about Mistretta.
Miocene strata are absent in the southern Tertiary areas, but are present at Moghara and in the north.
As we descend in the geological series the deer have simpler antlers, as in the European Miocene Dicrocerus; while in the Oligocene Amphitragulus, Dremotherium and Palaeomeryx, constituting the family Palaeomerycidae, antlers were absent, and the crowns of the molars so low that the whole depth of the hollows between the crescentic columns is completely visible.
The clays, which contain layers of good coal and an abundant fossil vegetation, show that during the Miocene period Sakhalin formed part of a continent which comprised north Asia, Alaska and Japan, and enjoyed a comparatively warm climate.
Fossil remains of flamingos have been described from the Lower Miocene of France as P. croizeti, and from the Pliocene of Oregon.
Although it has the deciduous dentition, Mme Pavlow considers herself justified in referring the Kherson skull to the genus Procamelus previously known only from the Lower Pliocene or Upper Miocene strata of North America, and differing from modern camels, among other features, by the retention of a fuller series of premolar teeth.
In the Lower Miocene occurs Protomeryx or Gomphotherium, in which there is a considerable increase in the matter of bodily size, the two metacarpal and metatarsal bones (or those which unite in the latter forms to constitute the cannon-bones) being double the length of the corresponding elements in Protylopus.
In Protolabis of the Middle Miocene, while no cannon-bone is formed, the first and second pairs of incisor teeth are retained, and the limbs and feet are short and disproportionately small.
In the Upper Miocene we come to a distinct type - Procamelus - which is entitled to be regarded as a camel, and approximates in size to a small llama.
In addition to the above there is an extraordinary North American Miocene giraffe-necked camel (Alticamelus), a creature of the size of a giraffe, with similarly elongated neck and limbs, and evidently adapted for browsing on trees.
The family ranges in North America from the Upper Eocene to the Lower Miocene, but Oreodon (or Merycoidodon), which is typified by an animal of the size of a sheep, is Oligocene.
In the Miocene Agriochoerus, which typifies a second sub-family (Agriochoerinae), there is no gland-pit in the skull, of which the orbit is open behind; while the upper incisors are wanting in the adult and the terminal toe-bones are claw-like rather than of the hoofed type.
Miocene beds are found in Corfu and Zante, and Pliocene deposits cover much of the low-lying ground.
The lower part of the Miocene is marine in Herat and Afghan Turkestan; but the upper Miocene is usually of freshwater or estuarine origin.
In Afghanistan, as in other regions near the great Eurasian system of folds, the Miocene includes extensive deposits of gypsum and salt.
Fossil remains of extinct civets are found in the Miocene strata of Europe.
The Tertiary system includes conglomerates, sandstones, limestones and marls, which appear to be of Eocene, Oligocene and Miocene age.
The folding of the Anti-Taurus affects the Eocene but not the Miocene, while in the Taurus the Miocene beds have been elevated, but without much folding, to great heights.
The Pliocene is of marine origin, and rests unconformably upon all the older beds, including the Post-oligocene igneous rocks, thus proving that the final folding and the last volcanic outbursts were approximately of Miocene age.
The Tertiary beds include both marine and terrestrial deposits, and appear to be chiefly of Miocene and Pliocene age.
The genus was represented in the Tertiary flora of Europe, when it extended into the polar regions; nineteen species have been recorded from the Miocene strata of Oeningen in Switzerland.
Where this intervening band is not covered by recent gravel deposits, it exhibits beds of limestone, clays and sandstone with fossils, which, in age, range from the Lower Eocene to the Miocene.
It shows few traces of dynamic disturbance, but has been carved, mainly by erosion since the Miocene epoch, into many caverns, of which the Mammoth Cave is the largest.
It was, therefore, during the Miocene period that the elevation of this part of the chain began, while the disturbance of the Siwalik-like sandstone indicates that the folding continued into the Pliocene period.
The Siwalik fossils contain 84 species of mammals of 45 genera, the whole bearing a marked resemblance to the Miocene fauna of Europe, but containing a larger number of genera still existing, especially of ruminants, and now held to be of Pliocene age.
The volcanic rocks then formed are followed by marine deposits of Oligocene and Miocene age.
Thick Tertiary deposits, probably Miocene, overlie the middle portions of the west coast.
They include some Miocene, or perhaps Oligocene marine sands, formed in the northern part of an inland sea, which occupied the basin of the Lower Murray.
The fact that every known geological formation (except the Miocene) is represented, proves of itself how long the history has been, and how multifarious the changes.
On the south the corresponding zone is affected by numerous secondary folds which involve the Sarmatian or Upper Miocene deposits.
Fournier north are nearly horizontal but on the south are in part included the folds - the Eocene and Miocene being folded, while the later beds, though sometimes elevated, are not affected by the folding.
The final folding of the chain undoubtedly occurred at the close of the Miocene period.
In 1854 he proposed the term Oligocene for certain Tertiary strata intermediate between the Eocene and Miocene; and the term is now generally adopted.
Along the foot of the Carpathians lies a broad trough of Miocene salt-bearing beds, and in this trough the strata are sometimes horizontal and sometimes strongly folded.
Outside the band of Miocene beds the Sarmatian, Pontian and Levantine series, often concealed by Quaternary deposits, cover the great part of the Danube plain.
Remains referred to Chalicotherium have been also obtained from the Lower Pliocene and Upper Miocene strata of Greece, Hungary, India, China and North America.
Macrotherium, which is typically from the Middle Miocene of Sansan, in Gers, France, may indicate a distinct genus.
Elsewhere they occur in South America and throughout a large part of the northern hemisphere, where they appear to have survived in India to the later Oligocene or Miocene.
Be this as it may, the Apennines, excepting in Calabria, are formed chiefly of Triassic, Jurassic, Cretaceous, Eocene and Miocene beds.
The folding and consequent elevation went on until the close of the Miocene period when a considerable subsidence took place and the Pliocene sea overspread the lower portions of the range.
Volcanic activity may have extended into Miocene times; but the only fossiliferous relics of Cainozoic periods later than the Eocene are the pale clays and silicified lignites on the south shore of Lough Neagh, and the shelly gravels of pre-glacial age in county Wexford.
In the neighbourhood of Vienna a gap in the folded belt - the gap between the Alps and the Carpathians - has formed a connexion between these two regions since the early part of the Miocene period.
Beyond this, in Russia and Galicia, lies an extensive plateau, much of which is covered by flat-lying Miocene and Pliocene beds; but in the deep valleys of the Dniester and its tributaries the ancient rocks which form the foundation of the plateau are laid bare.
Most of the eruptions took place during the Miocene and Pliocene periods.
The great salt mines of Galicia are in Miocene deposits; but salt is also worked largely in the Trias of the Alps.
The Pyrenees are therefore contemporaneous with the Alps; but they appear to have escaped the Miocene disturbances which affected the latter.
Marine Miocene deposits occupy some small tracts, especially on the coast of Valencia, But most of the sandy Tertiary rocks of that district are Pliocene.
But the most extensive and interesting Tertiary accumulations are those of the great lakes which in Oligocene and Miocene time spread over so large an expanse of the table-land.
The superficial Miocene and Pliocene deposits in the west, above referred to, are underlaid by the White river groups of the Oligocene, whose outcrops of Brule clay and Chadron formation also have been mentioned.
The precise date of the separation is fixed as later than the Miocene, since the fringe of the marine Miocene deposits along the southern coast of Victoria is broken, from Flinders to Alberton; and this gap was no doubt due to the subsidence of the land; of which the islands in the Bass Strait are remnants, which then connected Tasmania with the continent.
The Tertiary formations have been assigned to six periods; these are termed - Paleocene, Eocene, Oligocene, Miocene, Pliocene, Pleistocene, and each has its own botanical peculiarities.
These also, like the lignites of Bovey Tracey, have been referred to the Miocene period, on the supposed evidence of the plants; but more recent discoveries by Gardner tend tb throw doubt on this allocation, and suggest that, though of various ages, the first-formed of these deposits may date back to early Eocene times.
The lignite deposits and pipe-clays of Bovey Tracey in Devon, referred by Heer and Pengelly to the Miocene period, were considered by Gardner to be of the same age as the Bournemouth beds (Middle Eocene).
The flora of Bovey is like that of the lignite of the Wetterau, which is either highest Oligocene or lowest Miocene.
It forms a perfectly gradual transition to the still newer Miocene period, the newer species slowly appearing and increasing in number.
Saporta considers that in central and southern Europe the alternate dry and moist heat of the Eocene period gave place to a climate more equally and more universally humid, and that these conditions continued without material change into the succeeding Miocene stage.
The Miocene flora, which succeeds to that just described, is well represented in Europe; but till recently there has been an unfortunate tendency to refer Tertiary floras of all dates to the Miocene period, unless the geological position of the strata was so clear as obviously to forbid this assignment.
Thus plant-beds in the basalt of Scotland and Ireland were called Miocene; and in the Arctic regions and in North America even plant-beds of Upper Cretaceous age were referred to the same period.
The reason for this was that some of the first Tertiary floras to be examined were certainly Miocene, and, when these plants had been studied, it was considered that somewhat similar assemblages found elsewhere in deposits of doubtful geological age must also be Miocene.
It may appear absurd to a geologist that any one could mistake a Cretaceous flora for one of Miocene date, since the marine animals are completely different and the differences are striking.
The Miocene period is unrepresented by any deposits in Great Britain, unless the Bovey lignite should belong to its earliest stage; we will therefore commence with the best known region - that of central Europe and especially of Switzerland, whence a prolific flora has been collected and described by Oswald Heer.
The Miocene lacustrine deposits are contained in a number of silted-up lakebasins, which were successively formed and obliterated during the uprise of the Alps and the continuous folding and bending of the earth's crust which was so striking a feature of the period.
We thus find preserved in the Upper Miocene lacustrine deposits of Switzerland a larger flora than is known from any other period of similar length; in fact, an analysis of its composition suggests that the Miocene flora of Switzerland must have been both larger and more varied than that now living in the same country.
The best known locality for the Upper Miocene plants is Oeningen, on the Lake of Constance, where have been collected nearly 500 species of plants, the total number of Miocene plants found in Switzerland being stated to be now over 900.
Among the characteristics of this Miocene flora are the large number of families represented, the marked increase in the deciduous-leaved plants, the gradual decrease in the number of palms and of tropical plants, and the replacement of these latter by Mediterranean or North American forms. According to Heer, the tropical forms in the Swiss Miocene agree rather with Asiatic types, while the subtropical and temperate plants are allied to forms now living in the temperate zone in North America.
Monocotyledons form one-sixth of the known Miocene flora, 25 of them being grasses and 39 sedges; but most of these need further study, and are very insufficiently characterized.
It is obvious that many of these Swiss Miocene plants will need more close study before their specific characters, or even their generic position, can be accepted as thoroughly made out; still, this will not affect the general composition of the flora, with its large proportion of deciduous trees and evergreens, and its noticeable deficiency in many of our largest living families.
This difficulty in migration is probably the reason why the existing European flora is so poor in large-fruited trees compared with what it was in Miocene times or with the existing flora of North America.
These were described by Heer, who referred them to the Miocene period; he recognized, Arctic in fact, two periods during which Angiosperms flourished within the Arctic regions, the one Upper Cretaceous, the other Miocene.
To this view of the Miocene age of the plant-bearing strata in Greenland and Spitsbergen there are serious objections, which we will again refer to when the flora has been described.
Among the plants from Disco, more than a quarter are also found in the Miocene of central Europe.
But if this process is continuous from latitude to latitude, then we ought not to look for a flora of equivalent age in the warm-temperate Miocene deposits of central Europe, but should rather expect to find that the temperate plants of Greenland were contemporaneous with a tropical flora in central Europe.
Mr Gardner suggests, therefore, that the plant-beds of Greenland and Spitsbergen represent the period of greatest heat, and are therefore wrongly referred to the Miocene.
At present the evidence is scarcely sufficient to decide the question, for if this view is right, we ought to find within the Arctic circle truly Arctic floras equivalent to the cool Lower Eocene and Miocene periods; but these have not yet been met with.
There is also a decided resemblance to the earlier Miocene flora.
The only mammal actually associated with the plants appears to be a species of tapir, a genus which in Europe seems to be characteristically Miocene and Older Pliocene.
The plants of the Val d'Arno have been described by Ristori; they consist mainly of deciduous trees, a large proportion of which are known Miocene and early Pliocene forms, nearly all of them being extinct.
Fossil remains are few in the Upper Eocene and Miocene of Europe and the Upper Cretaceous of North America.
Apart from a few unsatisfactory remains from the Eocene of Wyoming, fossil tailless batrachians are otherwise only known from the Oligocene, Miocene and Pliocene of Europe and India.
Palaeobatrachus (26), of which a number of species represented by skeletons of the perfect form and of the tadpole have been described from Miocene beds in Germany, Bohemia and France, seems to be referable to the Pelobatidae; this genus has been considered as possibly one of the Aglossa, but the absence of ribs in the larvae speaks against such an association.
The Miocene contains an Orbitoides limestone.
It is held that in the Miocene and Pliocene periods there were land connexions with the Philippines, Java and the Moluccas, and through the last with Australasian lands to the east and south-east.
In any case the number of distinct sea-beaches seems to imply a succession of convulsive changes, more recent than the great Miocene upheaval, which are responsible for the shrinkage of the water into the three isolated pans now found.
Species from the Pliocene of Texas and the Upper Miocene (Loup Fork) of Oregon were at one time assigned to Hippidium, but this is incorrect, that genus being exclusively South American.
Be this as it may, the next North American representatives of the family constitute the genera Protohippus and Merychippus of the Miocene, in both of which the lateral digits are fully developed and terminate in small though perfect hoofs.
Between this subfamily and the second subfamily, Hyracotheriinae, a partial connexion is formed by the North American Upper Miocene genera Desmatippus and Anchippus or Parahippus.
The longest-known genus and the one containing the largest species is Anchitherium, typically from the Middle Miocene of Europe, but also represented by one species from the Upper Miocene of North America.
Nearly allied is the American Mesohippus, ranging from the Lower Miocene to the Lower Oligocene of the United States, of which the earliest species stood only about 18 in.
Gidley, Proper Generic Names of Miocene, Horses, p. 191; and the article PALAEONTOLOGY.
The Seriema must be regarded as the not greatly modified heir of some very old type, such as one may fairly imagine to have lived before many of the existing groups of birds had become differentiated, and it is probable that the extinct birds known as Stereornithes, and in particular the fossil Phororhachos from the Miocene of Patagonia, were closely allied to its ancestors.
The extinct members of the family are represented by the genera Epanorthus, Acdestis, Garzonia, &c. In a second family - Abderitidae - also from the Patagonian Miocene, the penultimate premolar is developed into an enormous tooth, with a tall, secant and grooved crown, somewhat after the fashion of the enlarged premolar of Plagiaulax.
Heer has described such Australian genera as Banksia, Eucalyptus, Grevillea and Hakea from the Miocene of Switzerland.
This genus was already typically developed in late Miocene times, and with a very wide geographical distribution (see Bird, Fossil), but of the affinities of the other midand early tertiary flightless birds we know nothing, and it must be emphasized that we should probably not be able to classify a truly ancestral Ratite, namely, a bird which is still to a certain extent carinate and not yet ratite.
The deposits of the actual valley here, belonging to the Miocene group of the Tertiary system, are older than the deposits either farther up or farther down the river; but they are contemporaneous with the basalts of the Rhine, which at Coblenz and in the peaks of the Seven Mountains also contribute to the scenic charm of the river.
It is built up of Tertiary deposits, belonging to the Sarmatian division of the Miocene period and covered with loess and black earth, and its escarpments represent the old shore-line of the Caspian.
In many respects, especially the form of the lower jaw, Anthracotherium, which is of Oligocene and Miocene age in Europe, and typifies the family Anthracotheriidae, is allied to the hippopotamus, of which it is probably an ancestral form.
The large area which is enclosed within the curve of the Carpathians is for the most part covered by loess, alluvium and other modern deposits, but Miocene and Pliocene beds appear around its borders.
The eastern part of the state is covered with a thick mantle of Quaternary (Pleistocene), and the greatest part of the western portion with very thick deposits of Miocene and Pliocene (Tertiary) To the Pleistocene belong the alluvium, loess and glacial drift, and in part the sand-hills.
We have applied this UV laser system to the analysis of single shards from Miocene tephra deposits from the Ruby Range in southwest Montana.