See "On a Collection of Fossils from Madagascar," by R.
The fossils are sufficiently well preserved to admit of their genera, and in many instances even their species, being made out.
Some of the coastal sandstones may be of late Tertiary age, but Tertiary fossils have not been found except in a few small patches on the west coast, the most southerly being near Quilon in Travancore.
Over the years, hundreds of geologists described various rock layers and identified the fossils in them.
Thereby the metamorphic rock establishes a lower limit for the age of the intrusion: It must be younger than the fossils in the youngest of the metamorphic rocks it touched.
Some of these beds had fossils in them, and it was eventually realized that rocks with the same kinds of fossils are of the same age, even though they may differ in other respects—in color or composition, for instance.
Still, the measurements were repeated, the rocks were studied again, and the result did not change: The fossils were still about 2 million years old.
Illustration: Fossils of bird tracks in sandstone in Death Valley, California.
The relative age of almost any rock containing even poorly preservedfossils could be determined anywhere in the world with precision.
Some Precambrian fossils have been found, but they are so rare that they are useless for dating the strata containing them.
This new sediment may also contain fossils and thus furnish an upper limit for the age of the intrusion.
That the fossilshave been rolled on a sea-beach is plain to those who look at them.
Logan--who has since done such good work in Canada- -showed that every bed of coal had a bed of clay under it, and that that clay always contained fossils called Stigmaria.
The fossils in the slate are often distorted into quaint shapes, pulled out long if they lie along the plane of cleavage, or squeezed together, or doubled down on both sides, if they lie across the plane.
Fossils are very rare in these sands; it is not easy to say why.
There, between the Keuper above and the Bunter below, lies a great series of limestone beds, which, from the abundance of fossils which they contain, go by the name of Muschelkalk.
Footnote 97: The Permian Fossils of Britain are described by Professor King in the Monographs of the Palaeontographical Society (the Brachiopods by Dr Davidson in the Monographs of the same Society).
The announcement of the contemporaneity of ammonites with fossils regarded as exclusively palaeozoic was received with considerable doubt, but this contemporaneity is now clearly established, and need not be regarded as in any way anomalous.
It has been hinted above that no general rule as to the relative value of fossils as guides to the age of strata can be laid down, and that the ascertainment of their relative value is largely the result of actual experience.
Lenticular patches of Silurian rocks having the lithological characters of the Silurian strata are found in the Ordovician beds of that region, and they contain fossils specifically identical with those of the Silurian rocks.
Considerable misconception has arisen concerning the value of fossils as indices of age, and it is necessary therefore to discuss the significance of the law of identification of strata by their included organisms at some length.
A few fossils belonging to the Olenellus-fauna have occurred in the oldest Cambrian rocks of the Malvern district, and these rocks rest unconformably upon those of an old ridge which is therefore composed of Precambrian rocks.
Strictly speaking the term zone (a belt or girdle), when applied to distribution of fossils, should refer to the belt of strata through which a fossil or group of fossils ranges.
It is possible that some of the fossilsmentioned in that report belong to strata above that containing Olenellus.
The fossils of calcareous rocks are often very obvious, but difficult to extract, as they break across when the rock is fractured.
Most fossils belong to extinct species, but many of the later ones belong to species still living.
Defn: The science which treats of the ancient life of the earth, or of fossils which are the remains of such life.
To make hard; as, extreme heat indurates clay; some fossils are indurated by exposure to the air.
Some claim those fossils have been on the surface at one time, and were silted over.
But this allusion to fossils leads me to the next division of my subject--the argument from geology.
Lastly, as we come nearer to recent times, we find fossils of the existing horse, with the lateral toes shortened up to the condition of splint-bones.
Thus, in America we find fossils all presenting the characteristically American types of animals, in Australia the characteristically Australian types, and so on.
The champion who dealt it the deadly blow was Scilla, and his weapons were facts obtained by examination of the fossils of Calabria, (1670).
So now against geology it was urged that the scientific doctrine that the fossils represented animals which died before Adam was contrary to the doctrine of Adam's fall, and that death entered the world by sin.
The new position was that the fossils were produced by the deluge of Noah.
Plants constitute the chief fossils of the Ecca series; among others they include Glossopteris, Gangamopteris, Phyllotheca.
The hope that they will yield fossils has been held out but not yet fulfilled.
The third case (c) is filled with Brazilian fossilsof varieties of the megatherium, monkeys, &c.
The case marked F contains fossils of a higher order than the reptiles, as the bones and antlers of deer, found in later strata of the earth's crust; and on the top of the case are the horn and skull of a species of Texan bos.
Instead of employing the mixed assemblage of animals indicated as zone fossils in the table, A.
A chalcedonic deposit in the form of concentric rings, on fossils and fragments of limestone in S.
The whole of the fossils known to us certainly do not amount to a hundredth part of the remains that are really buried in the crust of the earth.
Hence it has not yet been possible to arrange these important fossils with any confidence in the ancestral series that descend from the Protamniotes to the Sauropsids on the one side and the Mammals on the other.
We have only a few specimens of the innumerable fossils that are buried in the vast mountain ranges of Asia and Africa.
We know that all the fossils yet discovered are only an insignificant fraction of the plants and animals that have lived on our planet.
The numerous fossils that we have from the first two geological sections, the Laurentian and Cambrian periods, belong exclusively to aquatic plants and animals.
Immediately above the Tertiary beds is a hard greenish clay, full of derived Tertiary fossils and Pleistocene shells with large flints and erratic blocks, some of the latter weighing several tons.
Among thefossils brought in 1858 by Mr. Hayden from the Niobrara Valley, Dr.
I have examined the site of this older drift, and the fossils have been determined by Dr.
The fossils were lighter than fresh bones, except such as had their pores filled with carbonate of lime, in which case they were often much heavier.
No geologist will deny that the distance of time which separates some of the eras above alluded to, or the dates of the earliest and latest appearances of some of the fossils above mentioned, must be reckoned by millions of years.
No fossils have been found in the Spearfish formation in the Devils Tower region, but elsewhere in Wyoming, stratigraphically equivalent rocks contain land vertebrates of Triassic age.
Hitherto no fossils have been obtained from these beds save some obscure plant-like markings, but they are evidently a continuation southwards of the sandstones of Hoy, which there rest unconformably on the flagstone series of Orkney.
Gneiss and granite occur; Ordovician fossils have been found in the Upper Shan States, and Carboniferous fossils in Tenasserim and near Moulmein.
Apart from the shell fragments, many of which are striated, the deposit contains blocks foreign to the county, as for instance chalk and chalk-flints, fragments of Jurassic rocks with fossils and pieces of jet.
Fossils in the Bunter are very scarce; in addition to the footprints of Cheirotherium, direct evidence of amphibians is found in such forms as Trematosaurus and Mastodonsaurus.
In his Climates of Geologic Times, Schuchert states that the fossils give almost no warning of an approaching catastrophe.
Proterozoic fossils have been found in places where the present average temperature approaches 0 deg.
Zooelogists who see these wonderful fossils are at once struck with their modernity and the little change that has taken place in certain stocks since that far remote time.
The Proterozoic fossils thus far discovered include not only microscopic radiolarians such as still form the red ooze of the deepest ocean floors, but the much more significant tubes of annelids or worms.
The marine fossils of the Permian, however, do not indicate any such condition.
If so, the change from paucity to abundance must have occurred before fossils were numerous enough to give much clue to climate.
The mammalian fossils seem to him to prove that the loess was formed while boreal animals occupied the region, for they include remains of the hairy mammoth, woolly rhinoceros, and reindeer.
Back of the Paleozoic, little can be said of life from the generic standpoint, since so few fossils have been recovered, but what is at hand suggests that the marine environment was similar to that of today.
The limestone in this ridge is rich in fossils of Bala age, and has been compared with that at Portrane in county Dublin.
His geological work was marred by an implicit belief in the universal deluge, and through finding fossils associated with the trap rocks near Portrush he maintained basalt was of aqueous origin.
Thus fossils can give a clue to the age of the rock strata.
A Word On Fossils Perhaps you'll find rocks containing fossils--or evenfossils by themselves.
Fossils are the remains--or the outlines--of former plant or animal life buried in rock.
It is one of the water-made rocks, in which so many fossils have been found; while in the fire-rocks there are no remains of anything which ever lived.
The fossils demonstrate the time to have been long, though we cannot say how long.
In interpreting this geological history, he laid great stress on the evidence of the fossils contained in the rocks.
When the typical fossils of a formation are known, they serve to identify that formation in its progress across a country.
The relative importance of these breaks, and therefore, probably, the comparative intervals of time which they mark, may be estimated by the difference of the facies or general character of the fossils on each side.
In limestones containing abundant encrinites, shells, or other organic remains, the weathered surface commonly presents the fossilsstanding out in relief.
We should naturally expect that these changes would have had a marked influence; that, for instance, a difference should be perceptible between the character of the fossils in a limestone and that of those in a shale or a sandstone.
Although the authors supposed their fossils to be relics of Noah's flood, their work must be acknowledged to mark a distinct onward stage in the palaeontological department of geology.
A group of strata having the same general lithological characters throughout may be marked by a great discrepance between the fossils above and below a certain line.
He thought that many of the fossils must be as old as the time of the general deluge, but he was careful not to indulge in any speculation as to the antiquity of the earth.
But the occurrence of fossils embedded in the heart of the solid rocks of the mountains offered much greater difficulties of explanation, and further progress was consequently slow.
Steno's anatomical training peculiarly fitted him for dealing authoritatively with the question of the nature and origin of the fossils contained in the rocks.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "fossils" in a variety of sentences. We hope that you will now be able to make sentences using this word.
