U. S. GEOGRAPHICAL AND GEOLOGICAL SURVEY OP THE ROCKY MOL\T\L\ REGION.
J. W. FOWELL, IN CHARGKE.
PALEONTOLOGY OF THE BLACK HILLS,
K. P. WHITFIELD,
CONTAINING DESCRIPTIONS OF NEW SPECIES OF FOSSILS FROM THE
POTSDAM, JURASSIC, AND CRETACEOUS FORMATIONS |
OF THE BLACK HILLS OF DAKOTA.
GOVERNMENT PRINTING OFFICE.
S. GEOGRAPHICAL AND GEOLOGICAL SURVEY OF THE ROC1Y MOUNTAIN REGION.
J. W. FO^VELL, IN CHARGJ-H5.
PALEONTOLOGY OF THE BLACK HILLS,
CONTAINING DESCRIPTIONS OF NEW SPECIES OF FOSSILS FROM THE
POTSDAM, JURASSIC, AND CRETACEOUS FORMATIONS
OF THE BLACK HILLS OF DAKOTA.
GOVERNMENT PRINTING OFFICE.
The new species of fossils described in this preliminary report, by
Professor E. P. Whitfield, from the Potsdam, Jurassic, and Cretaceous
formations, are such forms as are new to science in the collections made
by W. P. Jenney and H. Newton during the exploration of the Black
Hlls of Dakota in the summer of 1875.
These forms, with many others from the same formations, are em-
bodied in the final report on the paleontology of this region, which,
with sixteen lithographic plates, will accompany the publication of the
final results of the exploration in the Black Hills.
The species described in the followiDg pages were collected in and
around the Black Hills during the expedition, and represent the differ-
ent formations recognized, except the Carboniferous, from which the
fossils obtained were few and of little interest.
The horizon of the Potsdam formation of the Black Hills appears to
be, so far as the fossils will serve to determine, about the same as that
of Wisconsin and the neighboring States ; and of some of the layers
the lithological features are so nearly the same that it would be difficult
to distinguish between specimens from the two localities. The purplish-
green quartzitic rock from the head of Red Caiion Creek, containing
Lingulepis pinniformis Owen sp. and several other Brachiopodous shells,
appears to hold nearly the same relation to the rest of the group as
does that at the Falls of the St. Croix, from which the species was orig-
inally described, namely, near the base ; the Eed Caiion Creek beds
resting immediately on the slates of older date (probably Huronian)
while the Trilobitic beds and the soft friable layers occur at a horizon
of about 100 feet below the Carboniferous. The entire fauna of the
Black Hills beds closely resembles that from Wisconsin ; although the
species are nearly all distinct, the generic facies is the same through-
out. Among the fossils from the higher parts of the formation there
are quantities of Plant remains belonging to the genus Palceophycus
which, I am informed, cover the surface of the rocks over large areas
where exposed, being densely matted together. These beds also hold a
position similar to the Plant beds of other localities.
The Jurassic formations seem also to be well represented in this region,
'and many of the beds are highly fossil if ero us. The species are not
numerous, but the individuals are extremely abundant, many of the
slaty calcareous layers being so largely composed of organic remains,
mostly Lamellibrauchiates, as to be quite friable and easily broken in
the hand, and some of the sandy layers have their surfaces densely cov-
ered with the separated shells of one or two species. The absence of
Gasteropoda is a noticeable feature at all localities from which specimens
have been brought, no example of this class of molluscs being present
in the entire collections from this formation. The few species of Fresh-
water Gasteropoda described, as probably from this horizon, in the
Smithsonian Contributions, (Pal. Up. Missouri,) being still doubtfully
referred. This same absence of Gasteropoda is also noticed in all the
collections of Jurassic age we have seen from the western countries.
not more than three or four species having been obtained beyond those
above referred to.
Among the Cretaceous fossils there are many forms of great interest,
especially among the Inocerami and Cephalopoda. Among the former
the forms described under the new generic name of Endocostce are in-
teresting as affording light on a group of shells that, although long
known, have not been fully understood, probably owing to the want of
more and better material which this collection has afforded, the feature
there described having been seen on isolated specimens, poorly pre-
Among the Cephalopods of the Cretaceous there are some fine exam-
ples of the aberrant forms of the Ammonite group, which show very
conclusively that a rich field awaits the future collector in this region. In
some of the localities of this formation, from which collections have
been brought, there appears to be a difficulty in recognizing the divis-
ions of the group, proposed by Messrs. Meek and Hayden, as the fossils
of two of the divisions are found intermingling at the same place and
in the same layers. The specimens brought from the locality, on Old
Woman's Fork of the Cheyenne, are of this character, and there seems
to be the same trouble among those from certain parts of Beaver Creek.
The collection affords no specimens belonging strictly to the Divisions
No. 1 and No. 3, though the beds were observed but not collected from.
FOSSILS FROM THE PRIMORDIAL ROCKS.
PALJEOCHORDA PRIMA, n. sp.
Plate 1, fig. 2.
Plants, the remains of which, as preserved on the surface of the rock,
consist of narrow, linear, grass-like stipes, coiled or twisted without
any regular order, leaving by their removal or decomposition flattened
depressions of from one line to two lines in width and of an indefinite
length, with rounded or obtusely- pointed extremities.
The examples in the collection before us are coiled, forming irregular
curves, usually enrolled, but sometimes sigmoidal. The surfaces are
smooth and structureless, presenting no marking whatever, although
the substance is usually of a somewhat lighter color than the surround-
ing rock. The terminations are usually sharply rounded, and the whole
appearance is more that of the impression of an Annelid than of a plant,
though it is difficult to conceive of the preservation of anything other
than a plant to leave such markings. We have referred them to the
above genus, presuming them to be congeneric with those figured by
Professor McCoy in his Synopsis British Palaeozoic Fossils, plate 1 A,
fig. 3, although they are not elevated or rounded bodies, but flattened
Formation and locality. In the plant beds of the Potsdam formation
(probably Upper Potsdam or Calciferous), Head of Red Water Valley,
Black Hills, Dakota.
GENUS PALJ]OPHYCUS, Hall
PAL^EOPHYCUS OCCIDENTALS, n. sp.
Plate 1, fig. 3.
Remains consisting of strong, subcylindrical, flexuous stems or roots,
covering the surface of the sandstone. The steins are more or less
rounded, although frequently quite flattened, and varying in diameter
from one-fourth of an inch to one inch, frequently bifurcating and some-
times dividing into threes. They are commonly interlaced with each
other, but do not appear to coalesce, but are simply overlapped 5 the
surfaces, although sometimes quite smooth, are generally marked by
indistinct longitudinal pits and ridges of greater or less extent, fre-
quently occurring of an inch in length, while many are merely short,
roughened depressions, which give a corrugated surface to the sterns.
Judging from the specimens in the collection, we should suppose they
often attain considerable length, as on a specimen measuring nearly ten
inches the variation in diameter is scarcely perceptible, but occasion-
ally one will be found to terminate in an obtuse point.
This species bears some resemblance to Fucoides duplex Hall, (Post. &
Whit., Lake Sup., p. 226, pi. A., 23, fig. 1,) but does not present the
longitudinal depression along the middle as in that one, except near a
bifurcation. It is very similar to P. tubularis Hall,. from the Calciferous
Sandstone of Ke\y York ; but is less ridged and has a somewhat differ-
ent mode of bifurcation from any of the specimens of that species which
we have seen. If a larger number of the New York species were ex-
amined, however, it is possible that the resemblance might be much
greater than at present supposed.
Formation and locality. In the plant beds of the Potsdam formation
(probably Upper Potsdam or Calciferous). Head of Bed Water Valley,
Black Hills, Dakota.
LlNGULEPIS CUNEOL.US, n. sp.
Plate 2, figs. 5 and 6.
Shells small, rather below the medium size, triangularly ovate in out"
line, or sometimes subcuneate ; ventral valve triangularly ovate, with
a sharp somewhat pointed beak, the width and length about as three
and four, and the point of greatest length near the lower third of the
length of the valve; cardinal slopes abrupt, scarcely convex; basal line
rounded at the sides but nearly straight in the middle ; surface of the
valve strongly convex, becoming almost subangular in the upper part
dorsal valve much shorter, proportionally, than the ventral, the length
but little exceeding the width ; sides and base more rounded and the
beak truncate ; surface distinctly convex.
Surface of the shell apparently smooth, but usually exfoliated, in
which condition a few fine radiating lines are visible.
The shell differs from L. pinnaformis Ovven, in size and in the more
distinctly cuneate form of the ventral valve. At first sight, it might be
taken for the young of that species, but a little critical examination
soon reveals marked distinctions in the truncation of the front margin,
and especially in the form of the cardinal slopes, which are rounded
and never concave, as in almost all ventral valves of that species. In con-
sequence of this latter feature, the beak does not appear so attenuated
as in that one, although proportionally quite as long. In the general
surface characters and form of the valves it corresponds with the genus
Linyulcpis, although we have not been able to distinguish the muscular
Were it not for the difference in the size of the shells, we should be in-
clined to think this might be the species figured by Messrs. Meek and
Haydeu, (Pal. Upp. Missouri, p. 3, PI. 1, fig. 1 a and &,) as. Dakotensis;
but as their figures appear to be of the natural size, we should suppose
it to be very distinct, as all the specimens of our shell noticed have
been small, none exceeding one-fourth of an inch in length.
Formation andloeality. In soft, friable sandstone of the Potsdam group,
at Red Canon Creek, in the Southwest Black Hills, Dakota.
LTNGULEPIS PERATTENUATUS, n. si).
Plate 2, figs. 7-9.
Shell spatulate or elongate-ovate, becoming acutely pointed toward
the beak; sides below the middle of the length of the ventral valve,
rounded ; front margin very regularly curved ; cardinal slopes straight,
or sometimes slightly convex, greatest width a little more than half the
length of the ventral valve and sometimes nearly two-thirds as great.
Surface of the ventral valve depressed convex, very slightly subangular
along the middle above the lower third of the length, and a little more
distinctly so in the upper part. Apex scarcely truncate. Dorsal valve
considerably shorter than the ventral, broadly truncated at the upper
end, the line of truncation being distinctly arched. Surface evenly con -
vex. Structure of the surface of the shell polished, with fine, somewhat
lamellose, lines of growth.
The shell in many points closely resembles L. pinnaformis Owen, but
is a proportionally longer shell and not exceeding one-half the size of
the adult specimens of that species. When compared in shape, it is
more elongate in front, the lower end of the shell forming a section of
an ellipse rather than of a circle as in that one; the cardinal slopes are
convex and the valves proportionally longer, the apex being more elon-
gated in proportion to the size of the body of the shell, but not so nar-
row. The two species are associated in the same blocks, and the dis-
similarity between examples of the same size is so perceptible that there
will not be the slightest difficulty in recognizing them as distinct.
Formation and locality. In greenish-purple sandstone of the Potsdam
formation, at the Headwaters of Red Cafion Creek, southwest Black
GENUS CREPICEPHALUS, Owen (?LOGANELLUS, D
CREPICEPHALUS (LOGANELLUS) CENTRALIS, n. s}).
Plate 2, figs. 21-24.
Species recognized only by the glabella and fixed cheeks, with a few
imperfect fragments of the movable cheeks. The former parts, when
united, are somewhat quadrangular in outline, broadest at the base and
gently narrowing in front ; glabella rounded-conical, higher than wide,
the anterior end somewhat sharply rounded ; surface highly convex and
marked by three pairs of distinct lateral furrows, which are strongly
bent backward in their direction from the margin, and on the larger
specimens the posterior pair almost unite in the middle. Occipital fur-
row distinct, extending entirely across the base of the head ; occipital
ring strong, rounded, and in the older individuals supporting a short
spine; dorsal furrows well pronounced, extending with equal clearness
in front of the glabella. Fixed cheeks broad, more than equaling one-
half the width of the glabella; palpebral lobes small and slightly angu-
lar, situated opposite the middle of the glabella; ocular ridges distinct,
directed anteriorly in passing from the eye to the dorsal furrow. Frontal
limb short, not more than one-third as long as the glabella, one-half of
its length formed by the strong, rounded marginal rim and furrow.
Facial suture directed gently inward from, the front of the eye lobe to
the anterior margin, with but little curvature; behind the eye it is
directed backward and outward at an angle of from thirty-five to forty
degrees with the occipital line of the head, with a slightly sigmoidal
curvature, giving an elongate triangular form to the postero-lateral
There is considerable variation in the form and proportions of the
glabella among the different individuals in the collection, the larger
specimens being proportionally broader and the lateral furrows much
more distinctly marked. On the smaller one figured the furrows are
not distinct enough to indicate without exaggeration. The presence or
absence of an occipital spine is also noticed, dependent apparently on
the same cause. It is possible that the two individuals may belong to
different species, but from their great similarity in other respects we
feel confident that this is not the case.
This species resembles in some of its characters C. (Batkyurus ?) an-
gulatus, H. & W., from the same formation on the west side of Pogonip
Mountain, White Pine, Nev., described in Mr. Clarence King's report,
but lacks the angular frontal limb of that species, and the facial sutures
converge in front of the eye, while in that one they are slightly diverg-
ent. We know of no other species with which it is closely related,
unless it should prove to be more nearly related to Agraulus Oiceni,
Meek & Hayden, Pal. Upp. Missouri, p. 9, figs. A, B, C, than we are
inclined to believe. There are several particulars in which it differs
very materially from their figures, and also from the description given,
that would at once mark it as distinct, if it were not that the imperfect
material in both cases tends to lead to error. The difference in the
width of the occipital lobe is a very marked one, and also the length of
the frontal limb, while the form of the glabella varies much in being
more distinctly conical than in that species.
Formation and locality. In coarse sandstones of the Potsdam forma-
tion, at Castle Creek, West Black Hills, Dakota.
CREPICEPHALUS (LOGANELLUS) PLAXUS, n. sp.
Plate 2, fig. 20.
Glabella and fixed cheeks, when united, subquadrangular in outline,
narrowest across the eyes and slightly expanding in front, and more
abruptly so posteriorly. Glabella very depressed convex, slightly
conical and somewhat squarely truncate in front, the width across the
base being equal to about three-fourths of the height above the occipital
furrow, and that of the anterior end to about half the height j lateral
furrows very faintly marked, oblique, and extending about one-third of
the width from the margin. Occipital furrows not strongly marked,
extending entirely across the base of the head ; ring narrow, and with-
out spine. Dorsal furrows distinct, but not deep, extending around
the front of the glabella. Fixed cheeks wide, more than half as wide,
opposite the eyes, as the middle of the glabella. Frontal limb of moder-
ate length, at least as long as the width of the anterior end of the gla-
bella, but its entire extent and anterior margin have not been fully ascer-
tained. Facial suture cutting the anterior border at right angles to the
margin of the head and directed slightly inward to the eyes, behind which
it is directed obliquely backward, at an angle of about 60 with the base
of the head, to the occipital furrow, behind which it runs more directly
outward. Ocular ridges distinct. Palpebral lobes small and situated
behind the middle of the head.
The species is only known by the glabella and fixed cheeks, and is
remarkable only for its general flatness and want of prominent charac-
ters. There is no known species from the same formation either in the
Wisconsin locality or from the more western regions that is so closely
related to it as to be readily mistaken. <?. (L.) quadra-vis, H. & W.,
of Clarence King's report, from the slates above Call's Fort, North
Wahsatach Mountains, is perhaps as closely related as any, but differs
in having the glabella more rounded in front and proportionally broader.
Formation and locality. Associated in the same beds and locality
with the preceding species.
FOSSILS FROM THE JURASSIC ROCKS.
GENUS ASTERIAS, Linneus.
ASTERIAS ?DUBHJ3I, n. Sp.
Plate 3, fig. 3.
Several impressions of a species of star-fish, apparently of the genus
Asterias, are present in the collection from a bed of light-red sandstone,
which occurs at a horizon of from 80 to 100 feet above the Triassic red
The specimens are not in a condition to afford a full description of
their specific characters. They are of small size, the rays being from
three-fourths of an inch to one and one-fourth inches long, measuring
from the center of the body. The rays are slender and flexuous, most
of them being more or less curved in their direction and elevated along
the middle, as shown on a gutta-percha cast taken in a natural mold of
a group of three individuals. The upper surface is subangular, and in
structure they are apparently composed of small nodiform plates, placed
in longitudinal rows. The center of the body or disk is marked by an
obscurely pentangular depression on the upper surface. None of the
specimens show the under side of the body or rays, so that the charac-
ters of these parts are entirely unknown.
The species appears to have been some.what abundant, judging from
the condition in which they are grouped on the sandstone, and although
the specimens are obscure and too imperfect for positive determination
and description, it has been thought best to designate them by name,
as they will undoubtedly prove a characteristic form over a certain
region, and of a limited horizon. The sandstone is marked, on the
layers in which they are found, by ripple or wave marks, having a
width of about 3 inches, and indicates a near proximity to a shore-line
over the area where they were obtained, and that the individuals are
probably stranded specimens. A single very imperfect impression of a
Lamellibranchiate shell is represented on the same fragments of rock,
but too imperfect for determination.
Formation and locality. In red sandstones of Jurassic age, Park
Sands, 70 feet above the red beds, on the east side of Spear-Fish Creek,
near its junction with the Bed Water, northeast of Crow Peak, Black
GENUS PECTEN, Brug.
PECTEN NEWBERRYI, n. sp.
Plate 4, figs. 12-15.
Shell of moderate size, suborbicular in outline, erect and subequilat-
<eral, the height and length nearly equal. Valves depressed-lenticular
in a transverse section when united ; their surfaces depressed- con vex,
except along the sides of the valves near the cardinal slopes, where the
surface is elevated so as to form a broad, rounded, fold-like border on
this part ; with a broad, undefined, shallow depression separating it
from the body of the valve. Hinge line short; that of the left valve
less than half as long as the shell below ; straight or a very little slop-
ing outward from the apex of the valve, which is small, appressed, and
not projecting above the line of the hinge. Anterior side of the hinge
a little longer than the other, the anterior wing being rounded at the
extremity, more than as long again as the height above the body of the
valve at its widest part ; separated from the shell below by a very shal-
low, rounded byssal notch, and along the surface by a scarcely percepti-
ble groove bordering the body of the valve. Posterior wing smaller,
triangular, a little obtuse at the outer upper angle, and proportionally
somewhat higher or longer on the lateral border than the anterior wing.
Surface of the left valve marked, except on the fold and depression
bordering the cardinal slopes, by strong, flattened radii, which are vari-
able in strength, size, and distance, and are separated by flattened
interspaces, usually of greater width than the ribs themselves. The
surface is also marked by closely arranged, distinctly elevated, regular,
lamellose, concentric lines parallel to the outer margin, and coincident
with the lines of growth, and are slightly arched backward in crossing
the radii. These latter markings also cover the surface of the folds of
the cardinal borders and the cardinal auriculations.
A single right valve of small size associated with a number of left
valves, on the same block, has the same general form and the same
fold-like feature of the cardinal slopes, but appears to be entirely desti-
tute of the radii on the body of the valve ; and the concentric markings
are also much less distinct and regular than on the opposite valve. The
anterior wing is also very small and obtusely triangular, but may have
been somewhat mutilated. There can be little if any doubt, however,
that this right valve belongs to the same species.
This species may be readily distinguished by the peculiar fold like
feature of the cardinal slopes and the character of the concentric mark-
ings, being entirely different in these respects from any other of the
genus described from rocks of this age.
Formation and locality. In reddish and buff colored argillaceous
limestones of Jurassic age, at T Spring, west of the Black Hills
PSEUDOMONOTIS (EUMICROTIS) ORBICULATA, 11. sp.
Plate 3, figs. 17-19.
Shell of moderate size, orbicular in outline, nearly equilateral and
subdiscoid. Left valve depressed-convex, most rotund just below and
anterior to the beak ; beak small, full, slightly incurved, and projecting
somewhat above the cardinal border. Anterior wing very short, almost
obsolete, the anterior end regularly rounded from its extremity to and
along the basal margin ; posterior wing of moderate size and com.
pressed, shorter than the shell below, the posterior margin rounding
backward from its extremity to near the middle of the length of the
valve, thence somewhat regularly rounded to the base. Surface of the
valve marked by numerous unequal, slender, and slightly elevated radii,
which are separated by wider flattened interspaces ; also by irregular
concentric stride of growth, which often give a knotty or roughened sur-
face to the radii where crossing them, especially toward the posterior
border and near the outer margin. Eight valve less convex than the
opposite one, with a smaller inconspicuous beak, which does not project
beyond the cardinal line. Anterior side of the hinge line characterized
by a small and very obscure wing, which is reduced to a mere point,