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Produced by Tom Cosmas and the Online Distributed | |
Proofreading Team at http://www.pgdp.net (This file was | |
produced from images generously made available by The | |
Internet Archive) | |
[Illustration: Slab with fossil impressions] | |
REMARKS | |
ON SOME | |
FOSSIL IMPRESSIONS | |
IN | |
THE SANDSTONE ROCKS OF CONNECTICUT RIVER. | |
BY | |
JOHN C. WARREN, M.D. | |
PRESIDENT OF THE BOSTON SOCIETY OF NATURAL HISTORY. | |
[Illustration: Logo] | |
BOSTON: | |
TICKNOR AND FIELDS, | |
135, Washington Street. | |
1854. | |
BOSTON: | |
PRINTED BY JOHN WILSON AND SON, | |
22, School Street. | |
The principal part of these remarks were made at the meetings of | |
the BOSTON SOCIETY OF NATURAL HISTORY. A portion of them also | |
have been printed in the Proceedings of the Society. | |
The object of this publication is to afford to those who are not | |
members of the Society an opportunity of obtaining some knowledge | |
of Fossil Impressions, which they might not be able to obtain | |
elsewhere so conveniently. | |
Some account of the Epyornis seems to be very properly connected | |
with Ornithichnites. | |
The first of these papers was written in October, 1853; the others | |
in the earlier part of the present year. | |
[Illustration: Epyornis] | |
THE EPYORNIS; | |
OR, | |
GREAT BIRD OF MADAGASCAR, AND ITS EGGS. | |
In the course of the year 1851, an account was circulated of the | |
discovery of an immense egg, or eggs, in the Island of Madagascar. The | |
size of the eggs spoken of was so disproportionate to that of any | |
previously known, that most persons received the account with | |
incredulity; and, I must confess, I was one of this number. Being in | |
Paris soon after hearing of this report, I made inquiry on the | |
subject, and was surprised to learn, that the great egg was actually | |
existing in the Museum of Natural History in Paris. In a few days I | |
had an opportunity of seeing a cast of it in the hands of the artist, | |
M. Strahl, of whom I solicited one. He informed me that it could not | |
be obtained at that moment; but that, if my request were made known to | |
the Administration of the Museum, he had no doubt they would accede to | |
it. I accordingly did apply, and also presented them with the cast of | |
a perfect head of Mastodon Giganteus; and they very liberally granted | |
my request. | |
The distinguished naturalist, Professor Geoffroy St. Hilaire, the | |
second of that honorable name, has made a statement to the Academy of | |
Sciences, which, though only initiatory, contains many facts of a very | |
interesting nature, some of which I have had an opportunity of | |
verifying; and to him we are indebted for a greater part of the | |
others. | |
The eggs sent to me are, in number, two; one of which was purchased by | |
M. Abadie, captain of a French vessel, from the natives. Another was | |
soon afterwards found, equal in size. A third egg was discovered in an | |
alluvial stratum near a stream of water, together with other valuable | |
relics of the animal which had probably produced them; but, | |
unfortunately, it was broken during transportation. Of the two eggs, | |
one is of an ovoid form, having much the shape of a hen's egg; and the | |
other is an ellipsoid. | |
The ovoid egg is of enormous size, even when compared with the largest | |
egg we are acquainted with. Its long diameter exceeds thirteen inches | |
of our English measure, its short diameter eight, and its long | |
circumference thirty-three inches. Its capacity is thought to be equal | |
to eighteen liquid pints, or to be six times greater than that of the | |
largest egg known to us (the ostrich), although but twice its length. | |
It is said to be equal to a hundred and forty-eight hen eggs. The | |
ellipsoid egg has its longest diameter somewhat less than that of the | |
ovoid; its short diameter nearly equals that of the other egg, being | |
more than eight inches. The third egg, although broken, has been very | |
useful to science, by displaying the thickness of the shell, which is | |
about one-tenth of an inch. | |
The bones, of which I have received the casts, are three in number, | |
and of great interest. One of them is a characteristic fragment of the | |
upper part of a fibula; the other two, still more interesting, as | |
enabling us to determine the class and genus of the animal to which | |
they belong, exhibit the extremities of the right and left | |
tarso-metatarsal bones. The former is somewhat broken; the latter is | |
nearly perfect, and exhibits the triple division of the inferior | |
extremity of the bone into the three trochleae or pulley-shaped | |
processes of the struthious birds. It might be mistaken for a bone of | |
the great Dinornis, but is distinguished from this by the flatness of | |
the portion above the trochleae. Still less is it one of the bones of | |
the ostrich, its three pulleys being separated from each other by | |
distinct intervals; whereas the pulleys of the ostrich have only one | |
such separation, constituting two distinct eminences. | |
M. Geoffroy St. Hilaire considered himself justified, from these and | |
other facts, in deciding this bone to belong to a bird of a new genus, | |
to which he gives the name of EPYORNIS, from _aipys_, _high_, | |
_tall_, and _ornis_, _bird_; and, as probably it is a specimen of the | |
largest animal of the family, he affixes the specific name of | |
_maximus_. | |
The size of this bird, inferred from that of its egg, would be vastly | |
superior to that of the ostrich. But if we notice the comparative size | |
of the trochleated extremity of the tarso-metatarsal bone, we shall | |
see that its height would be greatly exaggerated by adopting such a | |
basis for its establishment; in fact, it would not probably exceed a | |
height double that of the ostrich. And, though it must have been | |
superior to that of the Dinornis maximus of Prof. Owen, it might | |
perhaps excel it only by the difference of two or three feet. A bird | |
of twelve or thirteen feet in height would, however, if we stood in | |
its presence, appear enormous, and must have greatly astonished and | |
terrified the natives of Madagascar. Whether it now exists is | |
uncertain, as it may possibly have a habitation in the wild recesses | |
of the island, which have never yet been visited by any European | |
traveller. | |
The credit of most of the observations and discoveries relating to | |
this remarkable bird is attributable to French naturalists;[A] and it | |
seems to be a duty devolving on English and American navigators to | |
complete the history thus happily begun, and to tell us whether the | |
Epyornis still exists in the mountain-forests of Madagascar, or at | |
least present us with its extraordinary relics. | |
[Footnote A: The following are the names of French travellers, who | |
have been supposed to have seen the eggs of the Epyornis in the | |
Island of Madagascar: M. Sganzin, in 1831; M. Goudot, in 1833; M. | |
Dumarele, in 1848; and M. Abadie, in 1850.] | |
FOSSIL IMPRESSIONS.--I. | |
Ichnology, a newly created branch of science, takes its name from the | |
Greek word _ichnos_, a _track_ or _footstep_, and the tracks | |
themselves have been denominated Ichnites, or, when they refer to | |
birds only, Ornithichnites, from _ornis_, a _bird_. And this last term | |
has by custom been generally applied to ancient impressions, though | |
not correctly. | |
Geology has revealed to us not only the remains of animals and | |
vegetables, but the impressions made by them during their lives, and | |
even the impressions of unorganized bodies. The first notice of these | |
appearances was, as often happens, regarded with indifference or | |
scepticism; but their number and variety enlightened the public mind, | |
and opened a new source of information and improvement. | |
The first remarkable observation made on fossil footsteps was that of | |
the Rev. Dr. Duncan, of Scotland, in 1828. He noticed, in a _new red | |
sandstone_ quarry in Dumfriesshire, impressions of the feet of small | |
animals of the tortoise kind, having four feet, and five toes on each | |
foot. They were seen in various layers through a thickness of forty | |
feet or more. | |
Sandstone, in which these impressions are principally discovered, is a | |
rock composed chiefly of siliceous and micaceous particles cemented | |
together by calcareous or argillaceous paste, containing salt, and | |
colored with various shades of the oxide of iron, particularly the | |
red, gray, brown. It has been remarked by Prof. H. D. Rogers, that the | |
perfection of the surface containing fossil footmarks is often | |
attributable to a micaceous deposit. The layers of sandstone have been | |
formed by deposits from sea-water, dried in succession; such layers | |
are also seen in the roofing slate. These deposits on the shores of | |
the ocean, having in a soft condition received the impressions of the | |
feet of birds, other animals, vegetables, and also of rain-drops, | |
under favorable circumstances dried, hardened, and formed a rock of | |
greater or less solidity. Our colleague, Dr. Gould, has exhibited to | |
us a specimen of dried clay from the shores of the Bay of Fundy, | |
containing beautiful impressions, recently made, of the footsteps of | |
birds. The particles brought by the waves, and deposited in the manner | |
described, were derived from the destruction of other rocks previously | |
existing, particularly granite and flint, or silex, the shining atoms | |
of which compose no small part of the sandstone rock. | |
It is easy to conceive, that, while these deposits were taking place | |
in the soft condition, portions of vegetable matters might become | |
intermixed; and that these, with the impressions of the feet and other | |
parts of animals and unorganized substances, might be preserved by the | |
process of desiccation. The agency of internal heat may have also been | |
employed in some cases in baking and hardening these crusty layers. | |
The sandstone rock, though in some places actually in a state of | |
formation at the present time, lies in such a manner in the earth's | |
crust as to indicate an immense antiquity. The age of these beds | |
varies in different situations. The sandstone rocks which contain the | |
greater part of the impressions are called _new red sandstone_, to | |
distinguish them from the _old red_, which is of a greater age. The | |
deposits on Connecticut River may not be attributed to the action of | |
this river, but are of higher antiquity, probably, than the river | |
itself, and proceeded from the waves of an ancient sea, existing in a | |
state of the surface of the globe very different from that of the | |
present day. | |
In 1834, tracks were discovered near Hildberghausen in Saxony, to | |
which Prof. Kaup, of Darmstadt, gave the name of Chirotherium, from | |
the resemblance to the impressions of the human hand. On a subsequent | |
examination, Prof. Owen preferred the name of Labyrinthodon, from the | |
resemblance of the folds in the teeth to the convolutions of the | |
brain. | |
Various other instances of impressions were seen; and, in the year | |
1835, Dr. Deane and Mr. Marsh, residents of Greenfield, noticed | |
impressions resembling the feet of birds in sandstone rocks of that | |
neighborhood. These observations having come to the knowledge of | |
President Hitchcock, of Amherst College, that gentleman began a | |
thorough investigation of the subject, followed it up with unremitted | |
ardor, and has, since 1836 (the date of his first publication), laid | |
before the public a great amount of ichnological information, and | |
really created a new science. Dr. Deane, on his part, has not been | |
idle: besides making valuable discoveries, he has written a number of | |
excellent papers to record some portion of his numerous observations. | |
In 1837, at the request of my friend Dr. Boott, I carried to London, | |
for the Museum of the Royal College of Surgeons, various scientific | |
objects peculiar to this country; among which were a number of casts | |
of Ornithichnites. | |
These casts were kindly furnished me by President Hitchcock, and the | |
Government of the Royal College thereon voted to present to President | |
Hitchcock and Amherst College casts of the skeleton of the famous | |
Megatherium of South America. These casts were packed, and sent to be | |
embarked in a ship destined for Boston, but were unluckily delivered | |
to a wrong shipping house in London, and I lost sight of them for some | |
time. They were at length discovered. After remaining in this | |
situation for more than a year, they were sold at public auction; and, | |
notwithstanding many efforts on my part, I was unable to obtain and | |
transmit them to Amherst College. | |
The fossil impressions which have been distinguished in various places | |
in the new red sandstone are those of birds, frogs, turtles, lizards, | |
fishes, mollusca, crustacea, worms, and zoophytes. Besides these, the | |
impressions made by rain-drops, ripple-marks in the sand, coprolites | |
or indurated remains of faeces of animals, and even impressions of | |
vegetables, have been preserved and transmitted from a remote | |
antiquity. No authentic human impressions have yet been established; | |
and none of the mammalia, except the marsupials.(?) We must, however, | |
remember that, although the early paleontology contains no record of | |
birds, the ancient existence of these animals is now fully | |
ascertained. Remains of birds were discovered in the Paris gypsum by | |
Cuvier previous to 1830. Since that time, they have been found in the | |
Lower Eocene in England, and the Swiss Alps; and there is reason to | |
believe that osseous relics may be met with in the same deposits which | |
contain the foot-marks. Most of the bird-tracks which have been | |
observed, belong to the wading birds, or Grallae. | |
The number of toes in existing birds varies from two to five. In the | |
fossil bird-tracks, the most frequent number is three, called | |
tridactylous; but there are instances also of four or tetradactylous, | |
and two or didactylous. The number of articulations corresponds in | |
ornithichnites with living birds: when there are four toes, the inner | |
or hind toe has two articulations, the second toe three, the third toe | |
four, the outer toe five. The impressions of the articulations are | |
sometimes very distinct, and even that of the skin covering them. | |
President Hitchcock has distinguished more than thirty species of | |
birds, four of lizards, three of tortoises, and six of batrachians. | |
The great difference in the characters of many fossil animals from | |
those of existing genera and species, in the opinion of Prof. Agassiz, | |
makes it probable that in various instances the traces of supposed | |
birds may be in fact traces of other animals, as, for example, those | |
of the lizard or frog. And he supports this opinion, among other | |
reasons, by the disappearance of the heel in a great number of | |
Ornithichnites. | |
D'Orbigny, to whom we are indebted for the most ample and systematic | |
work on Paleontology ("Cours Elementaire de Paleontologie et de | |
Geologie," 5 vols. 1849-52), does not accept the arrangement of | |
President Hitchcock. He objects to the term Ornithichnites, and | |
proposes what he considers a more comprehensive arrangement into | |
organic, physiological, and physical impressions. _Organic | |
impressions_ are those which have been produced by the remains of | |
organized substances, such as vegetable impressions from calamites, | |
&c. _Physiological impressions_ are those produced by the feet and | |
other parts of animals. _Physical impressions_ are those from | |
rain-drops and ripple-marks; and to these may be added coprolites in | |
substance. This plan of D'Orbigny seems to exclude the curious and | |
interesting distinctions of groups, genera, and species; in this way | |
diminishing the importance of the science of Ichnology. | |
Fossil impressions have been found on this continent in the | |
carboniferous strata of Nova Scotia, and of the Alleghenies; in the | |
sandstone of New Jersey, and in that of the Connecticut Valley in a | |
great number of places, from the town of Gill in Massachusetts to | |
Middletown in Connecticut, a distance of about eighty miles. | |
A slab from Turner's Falls, obtained for me by Dr. Deane in 1845, | |
measuring two feet by two and a half, and two inches in thickness, | |
contains at least ten different sets of impressions, varying from five | |
inches in length to two and a half, with a proportionate length of | |
stride from thirteen inches to six. All these are tridactylous, and | |
represent at least four different species. In most of them the | |
distinction of articulation is quite clear. The articulations of each | |
toe can readily be counted, and they are found to agree with the | |
general statement made above as to number. The impressions are | |
singularly varied as to depth; some of them, perfectly distinct, are | |
superficial, like those made by the fingers laid lightly on a mass of | |
dough, while others are of sufficient depth nearly to bury the toes; | |
some of the tracks cross each other, and, being of different sizes, | |
belong to animals of different ages or different species. There is one | |
curious instance of the tracks of a large and heavy bird, in which, | |
from the softness of the mud, the bird slipped in a lateral direction, | |
and then gained a firm footing; the mark of the first step, though | |
deep, is ill-defined and uncertain; the space intervening between the | |
tracks is superficially furrowed; in the settled step, which is the | |
deepest, the toes are very strongly indicated. On the same surface are | |
impressions of nails, which may have belonged to birds or chelonians. | |
The inferior surface of the same slab exhibits appearances more | |
superficial, less numerous, but generally regular. There are three | |
sets of tracks entirely distinct from each other; two of them | |
containing three tracks, and one containing two,--the latter being | |
much the largest in size. In addition, there is one set of tracks, | |
which are probably those of a tortoise. These marks present two other | |
points quite observable and interesting. One is that they are | |
displayed in relief, while those on the upper surface are in | |
depression. The relief in this lower surface would be the cast of a | |
cavity in the layer below; so the depressions in the upper surface | |
would be moulds of casts above. The second point is the | |
non-correspondence of the upper and lower surfaces; i.e. the | |
depressions in the upper surface have not a general correspondence | |
with the elevations on its inferior surface. The tracks above were | |
made by different individuals and different species from those below. | |
This leads to another interesting consideration, that in the thickness | |
of this slab there must be a number of different layers, and in each | |
of them there may be a different series of tracks. | |
To these last remarks there is one exception: the deep impression in | |
which the bird slipped in a lateral direction corresponds with an | |
elevation on the lower surface, in which the impression of these toes | |
is very distinctly displayed, and even the articulations. Moreover, | |
one of the tracks on the inferior surface interferes with the outer | |
track in the superior, and tends in an opposite direction, so that | |
this last-described footstep must have been made before the other. It | |
is also observable, that, while all the other tracks are superficial, | |
this last penetrates the whole thickness of the slab; thus showing | |
that the different deposits continued some time in a soft state. | |
On the surfaces of this slab, particularly on the upper, there are | |
various marks besides those of the feet, some of which seem to have | |
been made by straws, or portions of grass, or sticks; and there is a | |
curved line some inches in length, which seems to have arisen from | |
shrinkage. | |
In the collection of Mr. Marsh,[B] there were two slabs of great size, | |
each measuring ten by six feet, having a great number of impressions | |
of feet, and about the same thickness as the slab under examination. | |
One of these presented depressions; and the other, corresponding | |
reliefs. These very interesting relations were necessarily parted in | |
the sale of Mr. Marsh's collection; one of them being obtained for the | |
Boston Society of Natural History, and the other for the collection of | |
Amherst College. | |
[Footnote B: Mr. Marsh was a mechanic of the town of Greenfield, | |
and procured his subsistence by his daily labor. Being employed by | |
Dr. Deane in obtaining the sandstone slabs of Ornithichnites, he | |
acquired a taste for the pursuit, entered into it with | |
extraordinary ardor, and accumulated by his own labors a great | |
collection of fine specimens. He unfortunately fell into a | |
consumption, and died in 1852. The collection was sold at public | |
auction for a sum between two and three thousand dollars. The | |
specimens were purchased by the Boston Society of Natural History, | |
by Amherst College, and by varioud colleges and scientific | |
associations in this country.] | |
The _Physical Impressions_, according to Professor D'Orbigny, are | |
of three kinds, viz.: 1st, Rain-drops; 2d, Ripple-marks; and 3d, | |
Coprolites. I have a slab which exhibits two leptodactylous | |
tracks very distinct, about an inch and a half long, surrounded | |
by impressions of rain-drops and ripple-marks. Another specimen | |
exhibits the impressions of rain in a more distinct and remarkable | |
manner. The imprints are of various sizes, from those which might | |
be made by a common pea to others four times its diameter; some | |
are deep, others superficial and almost imperceptible. They are | |
generally circular, but some are ovoid. Some have the edge equally | |
raised around, as if struck by a perpendicular drop; and others | |
have the edge on one part faintly developed, while another part is | |
very sharp and well defined, as if the drop had struck obliquely. | |
It has been suggested, that these fossil rain-drops may have been | |
made by particles of hail; but I think the variety of size and | |
depth of depression would have been more considerable if thus | |
made. | |
Although we have necessarily treated the subject of fossil | |
footmarks in a very brief way, sufficient has been said to show | |
that this new branch of Paleontology may lead to interesting | |
results. The fact that they are, in some manner, peculiar to this | |
region, seems to call upon our Society to obtain a sufficient | |
number of specimens to exhibit to scientific men a fair | |
representation of the condition of Ichnology in this quarter of | |
our country; and we have therefore great reason to congratulate | |
ourselves, that, through the vigilance and spirit of our members, | |
the Society has the expectation of obtaining a rich collection | |
of ichnological specimens. | |
FOSSIL IMPRESSIONS.--II. | |
Since writing the preceding article, I have been able to obtain, | |
through the kindness of President Hitchcock, a number of additional | |
specimens of fossil impressions. By the aid of these, I may hope to | |
give an idea of the system of impressions, so far as it has been | |
discovered, without, however, attempting to enter into minute details. | |
For these, I would refer to the account of the "Geology of | |
Massachusetts," by President Hitchcock; to his valuable article | |
published in the "Memoirs of the American Academy;" and to his | |
geological works generally. | |
The numerous tracks which have been assembled together in the | |
neighborhood of Connecticut River have afforded an opportunity of | |
prosecuting these studies to an extent unusual in the primitive rocky | |
soil of New England. These appearances are not, indeed, wholly new. | |
Such traces had been previously met with in other countries; but, in | |
their number and variety, the valley of the Connecticut abounds above | |
all places hitherto investigated. | |
Twenty years have elapsed since the study of Ichnology has been | |
prosecuted in this country; and, in this period of time, about | |
forty-nine species of animal tracks have been distinguished in the | |
locality mentioned, according to President Hitchcock; which have been | |
regularly arranged by him in groups, genera, and species. | |
I propose now to lay the specimens, recently obtained, before the | |
Society, as a slight preparation for the more numerous and more | |
valuable articles which they are soon to receive. | |
The traces found on ancient rocks, as has been shown in the previous | |
article, are those of animals, vegetables, and unorganized substances. | |
The traces of animals are produced by quadrupeds, birds, lizards, | |
turtles, frogs, mollusca, worms, crustacea, and zoophytes. These | |
impressions are of various forms: some of them simple excavations; | |
some lines, either straight or curved, and others complicated into | |
various figures. | |
President Hitchcock has based his distinctions of fossil animal | |
impressions on the following characters, viz.:-- | |
1. Toes thick, pachydactylous; or thin, leptodactylous. | |
2. Feet winged. | |
3. Number of toes from two to five, inclusive. | |
4. Absolute and relative length of the toes. | |
5. Divarication of the lateral toes. | |
6. Angle made by the inner and middle, outer and middle toes. | |
7. Projection of the middle beyond the lateral toes. | |
8. Distance between tips of lateral toes. | |
9. Distance between tips of middle and inner and outer toes. | |
10. Position and direction of hind toe. | |
11. Character of claw. | |
12. Width of toes. | |
13. Number and length of phalangeal expansions. | |
14. Character of the heel. | |
15. Irregularities of under side of foot. | |
16. Versed sine of curvature of toes. | |
17. Angle of axis of foot with line of direction. | |
18. Distance of posterior part of the foot from line of direction. | |
19. Length of step. | |
20. Size of foot. | |
21. Character of the integuments of the foot. | |
22. Coprolites. | |
23. Means of distinguishing bipedal from quadrupedal tracks. | |
By these characters, President Hitchcock has distinguished | |
physiological tracks, or those made by animated beings, into ten | |
groups provisionally. To these may be added, "organic impressions," | |
made by organized bodies; and the impressions made by inanimate | |
bodies, called "physical impressions." | |
The specimens under our hands enable us to give some notion of the | |
distinctions which characterize the greater part of these groups. | |
* * * * * | |
GROUP FIRST--STRUTHIONES. | |
The ostrich-tracks present a numerous natural and most remarkable | |
group; remarkable from the great size of some species,--all of them | |
tridactylous and pachydactylous. The ostrich of the Old World has only | |
two toes, but this family exists in South America at the present time | |
under the name of Rhea Americana; and tracks of an animal, probably of | |
the same family, are found in the numerous impressions near | |
Connecticut River,--all of them having three toes in front, and the | |
rudiment of a fourth behind. | |
This group contains a number of genera. The FIRST GENUS, denominated | |
_Brontozoum_, presents the tracks of a most extraordinary bird. These | |
tracks appear less questionable since the discovery in Madagascar of | |
the eggs of the Epyornis. | |
The tracks of the largest species, the BRONTOZOUM GIGANTEUM, are | |
four times the magnitude of those made by the existing ostrich of | |
Africa. They are very numerous, and congregated together. The foot of | |
the Brontozoum Giganteum, including the inferior extremity of the | |
tarso-metatarsal bone, which makes a part of the foot, measures in our | |
specimen twenty inches; in the Mastodon Giganteus, the foot measures | |
twenty-seven inches; the width also is less, being ten inches across | |
the metacarpals, while that of the Mastodon is twenty-two: but the one | |
is a bird, the other a quadruped. The toes are three in number, and | |
present the same divisions with existing birds; the inner toe having | |
three, the middle four, the outer five phalanges. Some of the | |
articulations of the toes of this noble specimen are remarkable for | |
the manner in which they illustrate the mode of formation of the | |
tracks. These phalanges have become separated from the solid rock in | |
which they were encased, so as to be removable at pleasure; and they | |
thus show that the whole foot is not a simple impression in the rock | |
which contains it, but a depression filled by foreign materials, i.e. | |
by sand, clay, and other relics of pre-existing rocks. These materials | |
had been gradually deposited in the mould formed by the bird's foot, | |
and are therefore independent of this rock, in the same way as the | |
plaster-of-Paris cast of a tooth, or any other body, is independent of | |
the mould to which it owes its form. The impressions are in gray | |
sandstone. | |
On the reversed surface of the slab is seen a small piece of broken | |
quartz, about half an inch square. This piece forms a beautiful | |
illustration of a part of the process by which the sandstone rocks are | |
formed. | |
The second species of the same genus is the BRONTOZOUM SILLIMANIUM. | |
Of this we have three specimens; the tracks have the same general | |
character with the preceding, but are smaller. | |
The third species of this genus is styled the BRONTOZOUM LOXONYX, | |
from _loxos_, a _bow_, and _onyx_, a _nail_,--a curved nail. It is | |
smaller than the Sillimanium, and has the nail set to one side. | |
The fourth species, still smaller, is the Brontozoum Gracillimum. On | |
this slab the impressions are in relief; viz.: 1st, of Brontozoum | |
Gracillimum; 2d, of Brontozoum Parallelum; 3d, of the track of a | |
tortoise, fourteen inches long, and two wide. Other extensive | |
eminences and depressions, with rain-drops, may be observed on the | |
same surface. | |
The fifth species is called BRONTOZOUM PARALLELUM, from the tracks | |
being on a line with each other. Of this there are two specimens, one | |
of them, however, being a single track. On the surface of the other | |
slab there are at least five distinct tracks, one of them being a | |
small new and undescribed species,--thus making the whole number of | |
species of Brontozoum which we possess to be at least six. | |
The SECOND GENUS of Struthiones is called _AEthyopus_, from | |
_aithuia_, a _gull_, and _pous_, a _foot_,--gull-footed. This genus | |
is smaller than the Brontozoum Giganteum; and we have two species, | |
viz. the AETHYOPUS LYELLIANUS, which is the larger, and two specimens | |
of AETHYOPUS MINOR. All of these are distinguished from the preceding | |
genus by the winged foot, and in the Lyellianus by the shallowness of | |
the impression. The AEthyopus Minor is not always distinguished by the | |
superficiality of its impression. This is sometimes deep. Therefore | |
this character may not be considered a distinctive one, or the | |
AEthyopus Minor might be referred to another genus. Of the two | |
specimens of this latter species, the first is in depression, | |
tridactylous. The depressions are deep with rain-drops, marks of | |
quadrupeds and zoophytes over the whole surface. The ornithichnic | |
impressions are two in number; one superficial, the other very deep. | |
The reversed surface of this slab contains one tridactylous impression | |
in relief. The second specimen has three depressions; two of which are | |
superficial, and the third is quite deep, displaying, by a depressed | |
surface, the webbed character of the foot. | |
* * * * * | |
GROUP SECOND. | |
We shall take, to characterize this group, the _Argozoum_, from | |
_arges_, _swift_, _winged_. | |
Of this genus there are two species, the larger of which is the | |
ARGOZOUM DISPARIDIGITATUM. It is leptodactylous, and remarkable for | |
the length of the middle toe. We have another species, which is | |
smaller than the last named, and in which the toes are nearly of equal | |
length; hence called ARGOZOUM PARIDIGITATUM. | |
The other genus of this group is the PLATYPTERNA, and our specimen | |
is named _Deaniana_. This genus is remarkable for the width of the | |
heel; hence the name, from _platys_, _broad_, and _pterna_, _a heel_. | |
It has three toes like the other genera of this group. | |
* * * * * | |
GROUP THIRD. | |
This and the succeeding group are tetradactylous; having one toe | |
behind, three forwards. | |
The third group is leptodactylous; foot usually small, but sometimes | |
of medium size. Of it we have two specimens, viz.: ORNITHOPUS | |
GALLINACEUS, and ORNITHOPUS GRACILIS. The former is so called from the | |
resemblance to the domestic fowl: for convenience sake, in this and | |
other instances, we use the whole for a part. It is about three inches | |
in length, and the Ornithopus Gracilis about two. | |
This latter specimen is particularly interesting. It consists of two | |
parts, which open like the covers of a book. These covers present four | |
impressions: first, the superficial, which is distinct, slender, and | |
beautiful--the heel is broad; second, corresponding with this | |
depression and on the inside, is a figure in relief as distinct as the | |
depression; third, on the inside of the second cover is a depression | |
corresponding with the relief last mentioned; fourth, on the outer | |
side is a second relief corresponding with the second depression, but | |
less distinct than either of the other three, still, however, | |
exhibiting three toes pointing anteriorly, but the hind toe is | |
wanting. The whole of this double slab forms a series of cameos and | |
intaglios, measuring four inches by three, and in thickness an inch | |
and a quarter. | |
* * * * * | |
GROUP FOURTH. | |
Of the fourth group we have five specimens. The _Triaenopus_, so called | |
from its resemblance to a trident, has besides three leptodactylous | |
toes pointing forwards, a fourth extending backwards in a remarkable | |
way, like the handle of a trident; the impression, however, being | |
expanded so as to show an extensive displacement of the mud. All the | |
specimens of Triaenopus are in a beautiful red shale, very thin and | |
fragile, but presenting well-defined impressions, generally about | |
three inches long. | |
There are two species to this genus. Of the TRIAENOPUS EMMONSIANUS we | |
notice three impressions in relief. In another specimen there is the | |
appearance of a part of the toes of the Anomoepus Scambus, and on the | |
upper side are seen two excavations corresponding with the three | |
impressions. In the last slab, the track of the TRIAENOPUS BAILEYANUS | |
appears to have been made by two feet placed successively in the same | |
spot, which led President Hitchcock to suspect it might have been made | |
by a quadruped. One of the specimens has the Triaenopus tracks | |
intermixed in a peculiar way with other impressions. | |
The specimen representing the genus HARPEDACTYLUS is larger than the | |
preceding; and, though leptodactylous, the toes are much broader and | |
also more curved, whence the name Harpedactylus, _sickle-finger_, from | |
_harpe_ and _daktylos_. | |
* * * * * | |
GROUP FIFTH. | |
The fifth group differs much from the four previous ones. In this and | |
the following groups we pass from the vestiges of birds to those of | |
other animals, some of which are bipeds, some quadrupeds. Many | |
impressions are without any distinct character, belonging probably to | |
the lower animals, to vegetables, and unorganized bodies. | |
The fifth group comprehends the tracks of an extraordinary animal, the | |
OTOZOUM.[C] The name which has been given to it is taken from that | |
of an ancient giant, Otus, who with his brother Ephialtes, according | |
to heathen mythology, made war with the gods. These fabled giants | |
were, at nine years of age, nine cubits in width and nine fathoms in | |
height. | |
[Footnote C: The specific name of Moodii has been attached to the | |
Otozoum, from its having been discovered by Mr. Moody.] | |
The foot is divided into four toes; the two outer of which seem to be | |
connected by a common basis. The inner toe has three phalanges; the | |
second toe, also three; the third and fourth toes, four each. The | |
first is the shortest, the second longer, the third longest, the | |
fourth shorter than the third. It will appear, then, that this track | |
differs from that of birds in the number of toes pointing forwards; | |
these being four, while in birds the forward toes are only three. | |
There is a difference also in the number and arrangement of the | |
articulations. | |
The track in our possession is twenty inches long by thirteen and a | |
half inches broad. The rock in which it is imbedded is a dark-colored | |
sandstone. President Hitchcock has a slab showing a regular series of | |
tracks of this animal; the distance between the steps being about | |
three feet, and the tracks equidistant and alternate, which would not | |
be the case if the animal had been quadrupedal. In a quadruped, the | |
horse for example, the hind feet are set down near the fore feet, and | |
sometimes even strike them. Hence it must be inferred that the track | |
in question was that of a biped, or of a quadruped which did not use | |
its fore feet in progression, like a kangaroo. We naturally ask, What | |
kind of biped could this have been? Evidently not a man, the size of | |
the foot being too large to admit such a supposition; nor could it | |
have been a bird, the number of toes and their direction not admitting | |
this hypothesis. | |
Tetradactylous birds, or those which have four toes, have only three | |
of them directed forwards, and the fourth backwards, generally. There | |
are, however, exceptions; some birds have four toes directed forwards: | |
this is the fact with the Hirundo Cypselus and the Pelicanus Aquilus | |
of Linnaeus, or Man-of-war Bird. But the articulations are different in | |
the two animals, birds having regularly two, three, four, and five | |
phalanges, and the spur, where it exists, supported by a single | |
osseous phalanx; whereas the Otozoum has three phalanges in the inner | |
and second toe, four in the third and fourth toes. In this last | |
arrangement, the Otozoum is decidedly different from all known birds. | |
It is not likely to have been a tortoise or a lizard. The kangaroo has | |
four feet, and uses only two in progression, moving forward by leaps; | |
also, like the Otozoum, it has four toes; but the size of the toes | |
does not accord with that of the Otozoum, nor is the structure of the | |
foot the same, so far as we know. It has been suggested by Professor | |
Agassiz, that this animal might have been a two-footed frog. Nature | |
had, in those days, animal forms different from those we are | |
acquainted with; and this might have been the fact with the Otozoum. | |
* * * * * | |
GROUP SIXTH. | |
We have in this group a specimen of the track of a four-footed animal, | |
which may have been a frog, though different from ours. The feet are | |
unequal in size, and present a different number of toes. In existing | |
frogs there are four toes in the fore feet, and five in the hind; but, | |
in the specimen before us, the front toes are five in number, and the | |
back toes three. It is called, therefore, ANOMOEPUS, _unequal-footed_. | |
These impressions are in the red shale of Hadley, and very distinct. | |
In some of them the lower leg is indicated, forming an impression six | |
or seven inches long. The feet being smaller than the legs, the | |
impression made by the latter is more expanded, superficial, and | |
broader, yet still very definite. The opinion of President Hitchcock | |
and Dr. Deane is, that the different impressions of five and three | |
toes are those of the anterior and posterior extremities of one animal, | |
which, from the size of the limbs, might be a frog three feet high. | |
On the same schist with these footmarks, are other curious | |
impressions. The back of the slab is almost covered with the imprints | |
of rain-drops. In the midst of these is a tridactylous impression, | |
probably of a quadruped, crossed at its root by a single depression, | |
nearly an inch broad, and two and a half long: this seems to form part | |
of another broad superficial impression of about seven by four inches, | |
which is probably also quadrupedal. Other parts present the | |
impressions of nails and worm-tracks. At the opposite end is a deep, | |
smooth, regular excavation, which might have been made by a Medusa. | |
* * * * * | |
GROUP SEVENTH. | |
The seventh group contains the impressions of the feet of Saurians or | |
lizards. We have a specimen of quadrupedal marks, with five toes to | |
each foot, about an inch long, which may have been made by these | |
animals. The impressions are small, but very distinct. There are | |
lizards of the present day with five toes, about the size of these | |
impressions; and these may, therefore, be set down as belonging to | |
this order of reptiles. Like a number of the last-named specimens, | |
they are in red shale. | |
* * * * * | |
GROUP EIGHTH. | |
The eighth group is assigned by President Hitchcock to the Chelonian | |
or turtle tribe. The slab bearing impressions of Brontozoum | |
Gracillimum has a mark about fourteen inches long and two wide, which | |
may be attributed to the plastron or breast-plate of the tortoise. On | |
the slab from Turner's Falls there is a longitudinal furrow, which | |
might have been made by the tail of a turtle; and in various of our | |
slabs are impressions which we think belong to this tribe. We shall | |
have occasion to notice hereafter remarkable tracks of these animals | |
in the old red of Morayshire, in Scotland. | |
The most distinct of the traces of chelonians are on the large slab | |
lately obtained for me by President Hitchcock from Greenfield. (_Vide_ | |
Plate.) This interesting slab contains the traces of quadrupeds, | |
various birds, and two trails of chelonians: the largest of these is | |
nearly five feet long, and four inches in diameter. The trail is | |
composed of a number of parallel elevations, comparatively | |
superficial. | |
* * * * * | |
GROUP NINTH. | |
Of the ninth group, containing the marks of Annelidae, Crustacea, and | |
Zoophytes, we have various specimens. | |
The impressions of insects do not seem as yet to have been | |
distinguished on the ancient rocks. There is reason to believe, | |
however, that many of the marks we discover in the rocky beds might | |
have been made by the feet and bodies of large insects; and small | |
species of the same tribes have been found imbedded in, and actually | |
constituting, immense masses of calcareous and siliceous rocks. | |
The tracks of worms are numerous. No doubt these worms drew together a | |
concourse of birds to the shores on which they rolled. On various | |
slabs we find long cylindrical furrows, about the eighth of an inch in | |
diameter, and of different lengths; one of them, in the slab from Dr. | |
Deane, being eight or nine inches long. To these impressions the name | |
of HERPYSTEZOUM, from _herpystes_, _crawling_, has been given. They | |
vary, however, and some of them are very likely to be the tracks of | |
the common earth-worm, or of some species of worm which existed when | |
these rocks were formed. These impressions vary in length and in | |
diameter; some of them are moderately regular, and others irregularly | |
curved. | |
Very interesting tracks have been found in the ancient Potsdam white | |
sandstone of Beauharnais, on the St. Lawrence, by Mr. Logan, an | |
excellent geologist of Canada, and determined by Professor Owen to | |
belong to Crustacea, crabs. The number of impressions made by each | |
foot is sometimes seven, sometimes eight, and even more. This track, | |
showing the traces of Crustacea, goes to form another link in the | |
chain of fossil footsteps. | |
The Medusae, commonly called jelly-fish, dissolving as they do under | |
the influence of the sun and air, would hardly be expected to leave | |
their traces impressed on ancient rocks. Professor D'Orbigny, however, | |
has watched the dissolution of these animals on the sea-shore, and | |
found that, after wasting, they may leave their impressions on the | |
sand; which, not being disturbed by a high tide for nearly a month, | |
retains the impression of the zoophyte, and serves as a mould to | |
receive materials which take a cast and transmit it to subsequent | |
ages. We find one of these impressions on the slab of the Anomoepus | |
Scambus; and President Hitchcock, having examined it, is of opinion | |
that it retains the traces of a Medusa. The impression is about five | |
inches in diameter, of a darker color and smoother texture than the | |
rest of the rock. Its edges fade away gradually in the surface of the | |
subjacent sandstone. A similar impression is found on the superior | |
surface of the slab containing the Argozoum. | |
* * * * * | |
GROUP TENTH. | |
The tenth group contains the HARPAGOPUS, a name derived from | |
_harpage_, _seizure_, _rapine_. It is represented by President | |
Hitchcock as having the form of a drag. The figure given by him | |
resembles in a degree the foot of the African ostrich; being a long | |
thick toe, with a shorter one, not unlike a thumb, on the side. An | |
impression approximating this, but of small size, may be seen on the | |
slab of the Anomoepus Scambus. | |
* * * * * | |
The formation of bird-tracks is well represented by a clay specimen, | |
about an inch thick, and ten inches long. This is a piece of dried | |
clay, obtained by President Hitchcock from the banks of the | |
Connecticut, and produced by washings from clay on the shore above, | |
covered with foot-impressions of a small tridactylous bird, and dried | |
in the sun. This piece shows, in a way not to be questioned, the | |
manner in which the ancient vestiges were produced. Sir Charles Lyell | |
noticed a similar fact on the banks of the Bay of Fundy. | |
ORGANIC IMPRESSIONS. | |
The _second_ great division of fossil impressions is called ORGANIC, | |
meaning impressions made by organized bodies; the bones of animals, | |
fishes, and vegetables. | |
Near one extremity of the slab of the Ornithopus Gallinaceus is an | |
elevation, about a foot long, and between one and two inches wide, | |
projecting from the surface nearly half an inch. It has the appearance | |
of a round bar of iron imbedded in the rock, which is clayey | |
sandstone. This apparent bar of iron was probably a bone, buried in | |
the stone, now silicified and impregnated with iron; the animal matter | |
having entirely disappeared. In the slab of the Brontozoum Sillimanium | |
is a projection about seven or eight inches long, and half an inch | |
wide; probably the bone of an animal, perhaps a clavicle of the | |
Brontozoum Giganteum. | |
The vestiges of fishes are very numerous in the sandstone rocks of | |
Connecticut River. We have not less than two dozen specimens from this | |
locality; a number equal to all the other specimens in our collection. | |
These impressions of fishes are generally from three to six inches | |
long, and three or four inches wide. They are of the grand division | |
denominated by Professor Agassiz "heterocercal," having their tails | |
unequally bilobed, from the partial prolongation of the dorsal spine; | |
and they are considered to be of lower antiquity than the fishes which | |
are entirely heterocercal. The most remarkable of the fish-specimens | |
in our collection is a CEPHALASPIS (?): this fish is found in the | |
specimen containing tracks of the Brontozoum Gracillimum, and traces | |
of a turtle or tortoise. This fossil was discovered in the upper layer | |
of the old red sandstone of Scotland, and had been mistaken by some | |
for a trilobite: to us it appeared to be a Limulus, but further | |
observation leads us to believe it to be a _Cephalaspis_. It exhibits | |
a convex disc, four inches across, by two inches from above downwards, | |
and a tail at right angles with the disc, the uncovered part of which | |
is three inches long. The animal has been described by Professor | |
Agassiz as being composed of a strong buckler, with a pointed horn at | |
either termination of the crescent, and an angular tail. | |
To the vegetable impressions discovered among the sandstone rocks a | |
peculiar name has not yet been assigned. When, however, we consider | |
the strong probability that many impressions of stalks, leaves, | |
fruits, and other parts of vegetables, may be hereafter discovered in | |
these rocks, it will be found convenient to have a distinctive | |
denomination. Vast numbers of vegetable impressions of a distinct and | |
beautiful appearance, and in great variety, have been found in the | |
coal-formation, which is nearly allied to the sandstone: such are the | |
Sigillaria, Stigmaria, Equisetaceae, Lycopodiaceae, Coniferae, Cycadeae, | |
&c. It is sufficient to say that the number of these has been already | |
swelled to many hundreds: we must also believe, that some of the | |
impressions in sandstone rocks which have been assigned to other | |
substances ought to be attributed to vegetables. We may, therefore, | |
venture to call the vegetable impressions "phytological." | |
A number of our slabs bear impressions of vegetables; either twigs of | |
trees, or spires of plants. In a fragment broken from one of the toes | |
of the Brontozoum Giganteum, we see a cylindrical depression, three | |
inches long, and half an inch in diameter, marked by transverse lines, | |
about the sixth of an inch apart, and presenting an unquestionable | |
appearance of a fragment of a twig of an ancient vegetable, which had | |
been trodden under the foot of the mighty Brontozoum. On the reversed | |
surface of the same slab are found impressions, which were produced by | |
a number of fragments of sticks, five or six inches long, lying at | |
right angles, or nearly so. One of these sticks has been broken, and | |
its pieces are slightly displaced from each other. Various other | |
specimens contain the marks of sticks, or twigs of trees. The striae, | |
so distinctly discernable in a number of these portions, having been | |
compared with twigs of the existing coniferae (?), were found to | |
resemble them. Some of these sticks show the appearance of incipient | |
carbonization; yet the rock is sandstone, presenting, as already | |
mentioned, distinct appearances of quartz, and other substances of | |
which the arenaceous rocks are composed. | |
PHYSICAL IMPRESSIONS. | |
The _third_ great division of impressions in the sandstone rocks is | |
called PHYSICAL, meaning those made by inanimate and unorganized | |
substances; such are rain-drops, ripple-marks, and coprolites. | |
1. Marks of rain-drops, described on page 20, appear to be quite | |
common. We have two or three specimens in relief, and as many in | |
depression. They occur as follows: 1st, on the upper surface of the | |
slab first described; 2d, on that of the Platypterna; 3d, on that of | |
the AEthyopus Lyellianus; 4th, on that of the Brontozoum Gracillimum; | |
5th, on that of the AEthyopus Minor; 6th, on that of the Anomoepus | |
Scambus; 7th, on the recent clay; also in one small hand-specimen, and | |
in a second containing two fishes. They show that, in those ancient | |
periods when the Brontozoum Giganteum and the Otozoum resided in these | |
parts, showers were frequent, and probably abundant for the supply of | |
the wants and the gratification of the appetites of these animals, | |
then common, but which now appear to us so extraordinary. | |
2. Ripple-marks are seen in a number of these pieces; for example, on | |
the slab first described, on the Brontozoum Sillimanium slab, on the | |
Brontozoum Gracillimum slab, on one of the Triaenopus, and on the upper | |
surface of the Greenfield slab. These marks are represented by | |
parallel curves, or straight lines, distant from each other from half | |
an inch to an inch, and presenting a slight degree of prominence. | |
There is another form of ripple-marks(?), differing from those above | |
described. These are of a circular and mammillary form: they are | |
strewed thickly, like little islets, approximating to each other. They | |
are seen distinctly on one of the slabs of the Brontozoum Sillimanium, | |
on that of the AEthyopus Lyellianus, and some others. Whether they are | |
to be considered as accumulations of sand and clay, formed by the | |
action of the sea, we are uncertain; but there seems to be no other | |
cause to which they can be assigned with so great probability. | |
3. _Coprolites_, the fossilized ejections of animals, are intermixed | |
with other animal vestiges in the sandstone of Connecticut River, and | |
afford additional proof of the former existence of animals about these | |
rocks. | |
* * * * * | |
The latest accounts of fossil footprints we have had occasion to | |
notice are those of the Crustacea, already mentioned, as found in | |
Canada, and of the Chelonian in Scotland. The Canadian impressions, | |
called by Professor Owen Protichnites, were discovered in the year | |
1847, and were laid before the London Geological Society in 1851. The | |
most remarkable circumstance about them was their existence, as | |
already stated, in a white sandstone, near the banks of the River St. | |
Lawrence, at Beauharnais. This sandstone, which has been described by | |
New York geologists under the name of Potsdam, is thought to belong to | |
the Silurian system, and to have a higher antiquity than even the "old | |
red." | |
The Scotch footsteps are situated in the old red sandstone, and are | |
those of a Chelonian. So that we have now two series of tracks, the | |
Crustacea in Canada and the Chelonian in Scotland, of higher antiquity | |
than any which had been previously discovered. | |
* * * * * | |
On a review of the labors of President Hitchcock, we are struck with | |
admiration at the immense details that, in the midst of arduous | |
official and literary duties, he has been able to go through with in | |
the period since the foot-tracks were discovered on Connecticut River. | |
Although his labors should be modified by succeeding observers, | |
Science must be ever grateful to him for laying the foundation, and | |
doing so much for the completion, of a work so great, novel, and | |
interesting. | |
This inquiry seems to us to promise a rich variety; and we hope that | |
President Hitchcock and other observers will continue to explore and | |
cultivate it with undiminished zeal. | |
DESCRIPTION OF THE PLATE. | |
We are indebted to Photography for enabling us to represent the | |
remarkable slab from Greenfield, and its numerous objects, in a small | |
space, yet with perfect accuracy. This slab is four feet seven and | |
one-half inches in one direction, and four feet one inch transversely | |
to this; in thickness it measures about an inch. It is composed of | |
gray sandstone, in which the micaceous element is conspicuous, and | |
contains many interesting impressions on both surfaces. | |
The most interesting surface is the inferior; and the objects are, of | |
course, presented in relief. They are, first, two Chelonian tracks; | |
second, four sets of bird-tracks; third, footsteps of an unknown | |
animal. The _Chelonian tracks_ are two in number: the longest measures | |
four feet ten inches; the shorter, two feet nine inches. Both of these | |
impressions are made apparently by the plastron of the turtle. They | |
are from four to eight inches in width, and composed of elevated | |
striae. These striae are formed by raised lines, pursuing a course | |
generally regular, but accompanied with some inflections: they are, as | |
the plate represents, very distinct. The shorter track appeared to me | |
to be crossed by another; but the photographic impression, though only | |
a few inches long, enabled me to ascertain that this appearance was | |
produced by bird-tracks above and below. | |
The _bird-tracks_ are all tridactylous. The first set lies above and | |
to the right of the shorter turtle-track, and is composed of only two | |
steps, proceeding in the course of the plate downwards. The second set | |
of bird-tracks has five impressions, extending from the right superior | |
pointed angle of the slab across the small turtle-track to the larger, | |
in which it is lost. The third set of bird-tracks begins by an | |
impression larger than any other on the piece at the left extremity of | |
the longer turtle-track; and the remainder, three in number, | |
descending towards the right, are the least distinct of any. The | |
fourth set of bird-tracks begins below the longer turtle-track, and | |
ascends by four impressions, crossing the track till it meets the | |
first. | |
The most curious track, consisting of six digitated impressions, still | |
remains. The first is seen on the left of the longer turtle-track, | |
near the largest bird-track; the second is on the track; the third is | |
above the track; the others cross the slab by fainter impressions. | |
Each of them is composed by two feet, and each foot contains four | |
toes, which are seen more distinctly in some impressions than in | |
others. The largest of these double tracks is about three inches in | |
diameter. Perhaps it would be useless to speculate upon what kind of | |
animal they were made by. There is a similarity between these and the | |
tracks of the Anomoepus Scambus, spoken of in the sixth group. In the | |
latter, however, the toes are five and three. Some experienced persons | |
think they are tracks of the mink, Mustela Lutreola, an animal common | |
at the present day in these parts. This has five toes; but it may be | |
in this as in some other digitigrades, that one of the toes in each | |
foot does not make an impression; or perhaps it is safer to believe, | |
till further investigation is made, that it was an animal of a | |
construction not now existing. | |
The direction of these tracks presents a puzzle we are not able to | |
unravel; it exhibits the impressions of four toes, and we have | |
supposed it might possess five. In either of these cases, we have no | |
right to consider it a bird-track, but probably a reptile or a mammal. | |
Admitting this to be the fact, we are unable to account for the | |
direction of the steps, which is not alternate, as in the quadruped, | |
but in straight lines. In other words, this animal, supposed to have | |
four legs, gives us the impressions of two only, and both of these | |
placed together. | |
When the tridactylous tracks are attentively considered, compared with | |
each other, and with the digitated tracks, they appear to exhibit the | |
character of the impressions of the feet of birds so very decidedly, | |
that it would require something more than a philosophic incredulity to | |
question their ornithic origin. | |
The other side of this slab contains interesting impressions. In the | |
first place, this surface is covered with ripple-marks, each about two | |
inches broad, extending with various degrees of distinctness across | |
the slab, and having an interval of an inch. The width of the ridges | |
is greater than in any of the specimens we have seen. | |
This surface is almost covered by rain-drops. It has also, among other | |
impressions, one which has been drawn by Mr. Silsbee, our | |
photographist, and represented by the figure below of its proper size. | |
This figure, nearly four and a half inches in length, is an exact | |
resemblance in form, but not in size, of the great Otozoum, as | |
depicted by President Hitchcock, and shown by the actual impression, | |
in our hands, of the great foot, twenty inches long, and of | |
proportionate breadth. The form of the heel, or posterior part of the | |
foot, is the same in the two figures; the toes are equal in both, viz. | |
four in number; the two internal toes correspond in their | |
articulations, and the two external are nearly alike, with a little | |
allowance for a different amount of adipose texture. Whether this was | |
the impression of an infant Otozoum, I pretend not to determine: the | |
drawing was taken by a gentleman who knew nothing of the Otozoum. | |
There are similar impressions, smaller than that last described, on | |
the same surface. | |
The stone, though now very hard and intractable, having resisted all | |
the chemical agents we could employ, must have remained in a soft | |
state for some time; for the impressions of the foot shown below | |
penetrate to the opposite surface. | |
[Illustration: Fossil foot impression] | |
In this description we have not attempted to point out all the objects | |
worthy of interest on both sides of this curious slab. Every part | |
of it is full of interest, and presents a field for protracted | |
observations. The surface represented in the plate may, by the aid of | |
a magnifier, be studied without the presence of the stone itself; for | |
the photographic art displays the most minute objects without | |
alteration or omission. | |
* * * * * | |
Transcriber's Notes. | |
With the exception of several presumed typographical error which have | |
been changed as noted below, the text presented is that shown in the | |
original printed version. The original text included Greek characters. | |
For this text version these letters have been replaced with | |
transliterations. Also, the 'AE' and 'ae' ligatures are included (for | |
examples, AEthyopus and striae); but the 'oe' ligatures (for example, | |
Anomoepus) are shown as 'oe' for readability as the ligature character | |
is not present in many fonts. | |
Typographical Errors: | |
"Alleghanies" => "Alleghenies" (Pg. 18) | |
"Mastodon Giganteus." => "Mastodon Giganteus," (Pg. 25) | |
Emphasis Notation: | |
_text_ - italicized | |
End of the Project Gutenberg EBook of Remarks on some fossil impressions in | |
the sandstone rocks of Connecticut River, by John Collins Warren | |
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