Pleistocene sentence example
The fossil shells, pottery and rude stone implements, found alike at the base and at the surface of these middens, prove that the habits of the islanders have not varied since a remote past, and lead to the belief that the Andamans were settled by their present inhabitants some time during the Pleistocene period, and certainly no later than the Neolithic age.
Although a few of the Pleistocene ground-sloths, such as Nothropus and Nothrotherium (= Coelodon), were of comparatively small size, in the Santa Cruz beds of Patagonia few of the representatives of the family much exceeded a modern sloth in size.
In the Pleistocene period many large lakes were formed within the Great Basin; especially, by the fusion of small catchment basins, two great confluent bodies of water - Lake Lahontan (in the Nevada basin) and Lake Bonneville (in the Utah basin).
The mammalian remains found in Pleistocene deposits are of exceptional interest.
Here may be noticed three genera of large extinct marsupials from the Pleistocene of Australia whose affinities appear to ally them to the wombat-group on the one hand and to the phalangers on the other.Advertisement
The whole of the great plain of Lombardy is covered by Pleistocene and recent deposits.
As the tench is of comparatively uncommon occurrence in unenclosed waters, its place among the indigenous fishes of Great Britain has been denied, and it has been supposed to have been introduced from the Continent; a view which, however, is not supported by any evidence, and is practically disposed of by the fact that fossil remains of the fish are found in the Pleistocene deposits of Great Britain.
The bones of Pleistocene mammals, the rhinoceros, mammoth, bison, hyaena, &c., have been found at numerous places, often in caves and fissures in the limestones, e.g.
As proved by the discovery of fossil remains, musk-oxen ranged during the Pleistocene period over northern Siberia and the plains of Germany and France, their bones occurring in river-deposits along with those of the reindeer, mammoth, and woolly rhinoceros.
They have also been found in Pleistocene gravels in several parts of England, as Maidenhead, Bromley, Freshfield near Bath, Barnwood near Gloucester, and in the brick-earth of the Thames valley at Crayford, Kent; while their remains also occur in Arctic America.Advertisement
In Pleistocene times, then, when there were prolonged glacial ages, the sea-level was lowered and at the same time there was a reduction in sea temperature, so that the rate of reproduction of the coral polypes, and so the growth of reefs, was diminished.
Of the Pleistocene and recent deposits the most interesting are the remains of extinct animals (Glyptodon, Mylodon, Megatherium, &c.) in the caves of the Sao Francisco.
In nearly all the other Pleistocene forms these teeth were subcylindrical in shape, with the summit of the crown (except sometimes in the first pair) forming a cup-like depression; enamel being in all cases absent.
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 mammoth belongs to the post-Tertiary or Pleistocene epoch and was contemporaneous with man.Advertisement
This deer inhabited Ireland, Great Britain, central and northern Europe, and western Asia in Pleistocene and prehistoric times; and must have stood 6 ft.
The Kevori grits, and the raised coral reefs are upper Cainozoic, and perhaps Pleistocene; but the reefs occur inland up to a height of 2000 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.
Scelidotherium is another genus of large South American Pleistocene ground-sloths, characterized, among other features, by the elongation and slenderness of the skull, which thus makes a decided approximation to the anteater type, although retaining the full series of cheek-teeth, which were, of course, essential to an herbivorous animal.
Another genus has been described from the Pleistocene of Nebraska, as Paramylodon; it has only four pairs of teeth, and an elongate skull with an inflated muzzle.Advertisement
Fossil remains of beavers are found in the peat and other superficial deposits of England and the continent of Europe; while in the Pleistocene formations of England and Siberia occur remains of a giant extinct beaver, Trogontherium cuvieri, representing a genus by itself.
Since 1880 organized institutions of anthropology have taken the spade out of the hands of individual explorers in order to know the truth concerning Glacial or Pleistocene man.
Hatcher, demonstrate the Pleistocene nature of the deposits, by which is not necessarily meant older Quaternary, for their horizons have not been differentiated and correlated in South America.
The latter was a gigantic animal, especially during the Pleistocene period; the skulls and limbbones discovered in the brick-earths and gravels of the Thames valley and many other parts of England having belonged to animals that probably stood six feet at the shoulder.
The phosphate beds contain Eocene fossils derived from the underlying strata and many fragments of Pleistocene vertebrata such as mastodon, elephant, stag, horse, pig, &c. The phosphate occurs as lumps varying greatly in size, scattered through a sand or clay; they often contain phosphatized Eocene fossils (Mollusca, &c.).Advertisement
The Cainozoic system is represented by Oligocene, Miocene, Pliocene and Pleistocene beds.
The Pleistocene system in the South Island includes glacial deposits, which prove a great extension of the New Zealand glaciers, especially along the western coast.
The Pleistocene swamp deposits are rich in the bones of the moa and other gigantic extinct birds, which lived on until they were exterminated by the Maori.
The volcanic activity of the Taupo district lasted into the Pleistocene, and the last eruptions contributed many of its chief geographical features.'
Valley gravels .border the Thames, and Pleistocene mammalia have been found in fissures in the Hythe beds at Ightham, where ancient stone implements are common.
Unmolested by enemies (Harpagornis, a tremendous bird of prey, died out with the Pleistocene), living in an equable insular climate, with abundant vegetation, the moas flourished and seem to have reached their greatest development in specialization, numbers, and a bewildering variety of large and small kinds, within quite recent times.
Fossil bones and teeth, indistinguishable from those of existing leopards, have been found in cave-deposits of Pleistocene age in Spain, France, Germany and England.
Camper (1722-1789) contrasted (1777) the Pleistocene and recent species of elephants and Blumenbach (1752-1840) separated (1780) the mammoth from the existing species as Elephas primigenius.
This peculiar feature is explained as the result of displacement of the river from a better graded preglacial valley by the Pleistocene ice-sheet, which here overspread the plains from the moderately elevated Canadian highlands far on the north-east, instead of from the much higher mountains near by on the west.
In New Mexico, if glaciers were formed at all in the high valleys, they were so small as not greatly to modify the more normal forms. In central Colorado and Wyoming, where the mountains are higher and the Pleistocene glaciers were larger, the valley heads were hollowed out in well-formed cirques, often holding small lakes; and the mountain valleys were enlarged into U-shaped troughs as far down as the ice reached, with hanging lateral valleys oii the way.
Farther north in Montana, in spite of a decrease of height, there are to-day a few small glaciers with snowfields of good size; and, here the effects of sculpture by the much larger Pleistocene glaciers are seen in forms of almost alpine strength.
One of the most remarkable features of this province is seen in the temporary course taken by the Columbia river across the plains, while its canyon was obstructed by Pleistocene glaciers that came from the Cascade Mountains on the north-west.
C. Russell, have yielded evidence of past climatic changes second in importance only to those of the Pleistocene glaciated areas.
The duration of the Pleistocene lakes was, however, brief as compared with the time since the dislocation of the faulted blocks, as is shown by the small dimensions of the lacustrine beaches compared to the great volume of the ravine-heading fans on which the beaches often lie.
The Cascade Range is in essence a maturely dissected highland, composed in part of upwarped Colombian lavas, in part of older rocks, and crowned with several dissected volcanoes, of which the chief are (beginning in the north) Mts Baker (Io,827 ft.), Rainier (14,363 ft.), Adams (12,470 ft.) and Hood (11,225 ft.); the first three in \Vashington, the last in northern Oregon- These bear snowfields and glaciers; while the dissected highlands, with ridges of very irregular arrangement, are everywhere sculptured in a fashion that strongly suggests the work of numerous local Pleistocene glaciers as an important supplement to preglacial erosion.
In the north, the Strait of Juan de Fuca and the intricately branching waterways of Puget Sound between the Cascade and the Olympic ranges occupy trough-like depressions which were filled by extensive glaciers in Pleistocene times; and thus mark the beginning of the great stretch of forded coast which extends northward to Alaska.
Superimposed on these rocks are Pleistocene boulder clay, and clay and sand deposited in post-glacial lakes or an extension of the Gulf of St Lawrence.
Here it may be mentioned that Leithia, from the Pleistocene of Malta, originally regarded as a giant dormouse, seems near akin to Anomalurus.
The Upper Oligocene Cricetodon in Europe and Eumys in America are the earliest known forerunners of the cricetine Muridae; while at the same time primitive beavers appear in the form of Steneofiber, to be succeeded in the European Pleistocene by the gigantic Trogontherium.
The still larger North American Pleistocene Castoroides, known by one species of the size of a bear, and the allied West Indian Amblyrhiza, appear to be specialized beavers, although they have been referred to a family by themselves.
Platygonus is an aberrant type which died out in the Pleistocene.
Fossil remains of the badger have been found in England in deposits of Pleistocene age.
See GLACIAL PERIOD; PLEISTOCENE; BOULDER CLAY.
Deposits show that originally it formed part of the great inland sea that filled this depression in Pleistocene times.
In the Siebengebirge the little crater of Roderberg, with its lavas and scoriae of leucite-basalt, is posterior to some of the Pleistocene river deposits.
The Lake of Moeris, as a large body of fresh water, appears to have come into existence in Pleistocene times.
Remains of camels (C. thomasi) have also been found in the Pleistocene strata of Oran and Ouen Seguen, in Algeria; and certain remains from the Isle of Samos have been assigned to the same genus, although the reference requires confirmation.
The Algerian Pleistocene camel was doubtless the direct ancestor of the living African species, which it serves to connect with the extinct C. sivalensis.
In one species of Procamelus the metacarpals and metatarsals coalesced into canon-bones late in life; but when we come to the Pleistocene Camelops such union took place at an early stage of existence, and was thoroughly complete.
A lower jaw from the Pleistocene deposits of that continent has, however, been referred to the Old World Camelus.
Fossil remains of wombats, some of larger size than any now existing, have been found in caves and Pleistocene deposits in Australia.
The apparent absence of human remains in the beds yielding dingo teeth and bones (which are almost certainly not older than the Pleistocene) is of only negative value, and liable to be upset by new discoveries.
The true subterranean fauna may be regarded as chiefly of Pleistocene origin; yet certain forms are possibly remnants of Tertiary life.
The physiography of the surrounding country shows clearly that the basin occupied by Great Salt Lake is one of many left by the drying up of a large Pleistocene lake, which has been called lake Bonneville.
Captain Bonneville described the lake and named it after himself, but the name was transferred to the great Pleistocene lake.
In the earlier part of the Pleistocene period, England and Ireland were still incompletely severed, and the combined activity of certain extinct rivers and the sea had not yet cut through the land connexion with the continent.
The last well-marked lowering of the land took place in the Pleistocene period, when it was accompanied by glacial conditions, through which the greater part of northern England and the Midlands was covered by ice; a state of things which led directly and indirectly to the deposition of those extensive boulder clays, sands and gravels which obscure so much of the older surface of the country in all but the southern counties.
Mediterranean region, but more widely spread in Europe during the Pleistocene epoch, and also introduced into many European countries.
The Pleistocene forms, whose remains occur abundantly in the silt of the Buenos Aires pampas, are by far the largest, the skull and tail-sheath in some instances having a length of from 12 to 16 ft.
In the early Pleistocene epoch, when South America became connected with North America, some of the glyptodonts found their way into the latter continent.
All the above are of Pleistocene and perhaps Pliocene age, but in the Santa Cruz beds of Patagonia there occur the two curious genera Propalaeohoplophorus and Peltephilus, the former of which is a primitive and generalized type of glyptodont, while the latter seems to come nearer to the armadillos.
These Pleistocene deposits include bouldery drift, loess, terrace deposits and alluvium.
At Cambridge he obtained fossil shells from the Pleistocene deposit at Barnwell; in the Vale of Wardour he discovered in Purbeck Beds the isopod named by Milne-Edwards Archaeoniscus Brodiei; in Buckinghamshire he described the outliers of Purbeck and Portland Beds; and in the Vale of Gloucester the Lias and Oolites claimed his attention.
This last elevation led to the formation of numerous lakes which are now filled up by Pleistocene deposits.
In the Pleistocene of India occurs a large ox (Bos namadicus), possibly showing some affinity with the Bibos group, and in the same formation are found remains of a buffalo, allied to, but distinct from the living Indian species.
His chief distinctions, however, were won in the realms of anthropology by his researches into the lives of the cave-dwellers of prehistoric times, labours which have borne fruit in his books Cave-hunting (1874); Early Man in Britain (1880);(1880); British Pleistocene Mammalia (1866-1887).
By some authorities the term Tertiary is made to embrace in addition to the foregoing periods those of the Quaternary (Pleistocene and Holocene), i.e.
In the Pleistocene period the whole of this depression was filled with water forming a lake about 200 m.
It is most intimately connected with Victoria, from which it was only separated by the foundering of Bass's Strait in late Pliocene or early Pleistocene times.
North-western Tasmania in Pleistocene times had an._ extensive series of glaciers, of which the lower moraines were deposited only about 400 feet above sea level.
The discovery of great Pampean mammals in the Pleistocene beds of that region shows that this upheaval of the latter is very recent, for in the heart of the Cordillera, as well as on the west coast of Bolivia and Peru, there have been discovered, in very recent deposits, the remains of some mammals which cannot have crossed the high range as it now exists.
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.
The true brick-clays, however, are superficial deposits of Pleistocene or Quaternary age, and occur in hollows, filled-up lakes and deserted stream channels.
The allied Argentine Onohippidium, which is also Pleistocene, has still longer nasal bones and slits, and a deep double cavity in front of the orbit, part of which probably contained a gland.
This would appear to date man in Washington to a time before the Pleistocene epoch, which scientists are reluctant to do.
Similar conclusions concerning the late survival of the Pleistocene fauna were drawn by various field workers in many parts of the American continent.
The pit also has glacial gravels at the top from the Pleistocene.
This suggests that most Mode 1 assemblages are a result of environmental adaptations by Pleistocene hominids in the region.
Some gravel and coarse sand may derive from erosion of sediment infills of earlier (Pleistocene) buried channels and valley terrace deposits.
It is also a Pleistocene refugium, all of which have resulted in extremely high biodiversity.
In addition to remains referable to the existing genus, the Pleistocene deposits of Australia have yielded evidence of an extinct giant wombat constituting the genus Phascolonus (Sceparnodon).
Extinct Marsupials Reference has been made to the Australasian Pleistocene genera Phascolonus, Diprotodon, Nototherium and Thylacoleo, whose affinities are with the wombats and phalangers.
As to the loess, the usual view is that it was a steppe-deposit due to the drifting of fine sand and dust during a dry episode in the Pleistocene period.
Possibly the Arctic musk-ox (Ovibos) may be connected with the takin by means of certain extinct ruminants, such as the North American Pleistocene Euceratherium and the European Pliocene Criotherium (see Chamois, Goral, Serow, Rocky Mountain Goat and Takin).
These irregular features are wanting south of the limits of Pleistocene glaciation; there the rivers have had time, in the latest cycle of erosion into which they have entered, to establish themselves in a continuous flow, and as a rule to wear down their courses to a smoothly graded slope.
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.
The consequence of the ancient evaporation, by which the great Pleistocene lake was reduced to its present modest dimensions, and of the ceaseless modern daily evaporation, is the impregnation of the waters of the lake with salts and other mineral substances to a remarkable degree.
It may be added that fossil remains of the African elephant have been obtained from Spain, Sicily, Algeria and Egypt, in strata of the Pleistocene age.
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.
Most Pleistocene birds are generically, even specifically, identical with recent forms; some, however, have become extinct, or they have become exterminated by man.
To the Ratitae belong possibly also the imperfectly known Diatryma, Eocene of New Mexico, Gastornis and Dasornis, Eocene of Europe, Genyornis, Pleistocene of Australia.