LI B R.AFIY
OF THE
U N 1VER.SITY
or ILLINOIS
GEOLOGICAL SERIES
OF
FIELD MUSEUM OF NATURAL HISTORY
Volume VI Chicago, April 29, 1938 No. 20
POST-GLACIAL FOSSIL VERTEBRATES FROM
EAST-CENTRAL ILLINOIS
By Edwin C. Galbreath
Records of fossil vertebrates in Illinois are relatively few, and
still fewer of these records are accompanied by reliable evidence as
to their age. Considerable interest is therefore attached to recent
discoveries of vertebrates, together with mollusks and wood, of un-
doubted post-glacial age, in Coles County, Illinois. The specimens
were found in the Polecat Creek gravel pits, one mile south of
Ashmore in the north half of sec. 6, T. 12 N., R. 11 E., Coles County.
The fossils collected from these pits are sufficiently varied to give
a reliable picture of conditions prevailing in the region subsequent
to the withdrawal of the last ice sheet. The majority of the verte-
brates have been presented to Field Museum of Natural History,
Chicago. The specimens of mollusks are in the Museum of Natural
History, University of Illinois.
I am indebted to several persons for aid received during this
investigation. Mr. Russell Cutler, operator of the gravel pits, has
cooperated in saving specimens for more than ten years. Dr. George
E. Ekblaw, of the Illinois State Geological Survey, very kindly visited
the locality and explained several physiographic and geologic ques-
tions. In the determination of the vertebrates I have been mate-
rially aided by Mr. Bryan Patterson and other members of Field
Museum staff, and by Mr. A. S. Coggeshall, formerly Director of the
Illinois State Museum, now Director of the Santa Barbara Museum.
Dr. Frank C. Baker, of the Museum of Natural History, University
of Illinois, identified the mollusks. The specimens of wood were
examined by Professor E. L. Stover, of the Eastern Illinois State
Teachers College, Charleston. To all these gentlemen I wish to
express my most sincere thanks.
GEOLOGY OF THE PITS
The faces of the worked pits present four strata (see fig. 81).
The uppermost level is black earth averaging two feet in depth.
No. 411 ^ 303
Nnturn] History Svtmf
Librarv
304 Field Museum of Natural History— Geology, Vol. VI
Beneath this occurs a layer, two or three feet in thickness, of gravel
impregnated with iron oxide. Lenses of black muck containing many
mollusks and fragments of wood are frequently encountered in this
stratum. The mollusks and wood fragments are also found in the
gravel itself, but not in comparable quantities with those found in
the lenses. Below this gravel is a layer of blue clay from four to ten
inches thick, often containing wood. The lowest stratum is a com-
mercially important grayish-colored gravel from thirty to forty-five
feet thick. Worked pits fill with water to the top of this stratum.
The gravel constituting this bed is an outwash of Wisconsin age,
apparently associated with the Shelby ville glacial lobe.' The de-
posits above it, i.e., the blue clay, gravel with lenses, and black
earth, are alluvial and represent a fairly continuous deposit of post-
Shelbyville age, the black earth indicating a minor change in stream
drainage.^ Vertebrates occur in all three post-glacial strata. With
the exception of two small undetermined bone fragments, no fossils
were collected in the basal gravel.
WOOD
Pieces of wood ranging from portions of boughs to small splinters
are very numerous in the alluvial gravel. Professor Stover has
identified tamarack (Larix sp.), elm {TJlmus sp.), and hickory
(Hicoria sp.). Larix is typical of the Canadian zone and is a strag-
gler to the southward. Ulmus and Hicoria are typically austral forms.
No attempt to obtain pollen samples has been made. The pos-
sibility that pollen might be found in the muck lenses in the alluvial
gravel should be kept in mind by anyone who is planning work in
the locality,
INVERTEBRATES
The mollusks found in the iron-impregnated gravel show con-
clusively, according to Dr. Baker's determinations, that the alluvial
strata are of post-glacial age. Ten species are represented, and all
but one are members of the recent fauna of Illinois. The species
present are as follows:
Sphaerium sulcatum (Lam.) Stagnicola reflexa (Say)
Pisidium sp. indet. Fossaria obrussa (Say)
Goniobasis livescens (Menke) Physa gyrina Say
Helisoma anceps (Menke) Physa Integra Haldeman
Gyraulus altissimus (Baker) Ferrissia fusca (C. B. Adams)
Gyraulus altissimus, while not represented in the recent fauna of
Illinois, is present in Post- Wisconsin deposits all over the northern
and central part of the state. .
' Dr. George E. Ekblaw, personal communication.
PL
V. G
3.0
Post-Glacial Fossil Vertebrates
305
VERTEBRATES
The specimens from the black earth and from the alluvial gravel
are presumably of slightly different ages and are accordingly listed
separately. The one specimen found in the blue clay layer is in-
c^
.■< \i
yjCti'^
BLACK
EARTH
WATER
LEVEL
o'. •-.■
« o^'.*-« ^^«-?. .»•--<
. '^oJ'o'ioao.Ool
- - "• O'.O ,;■.■
C5-. • • • .. .-.
To • o. o o o - o-tf w
ALLUVIAL
GRAVEL
blue clav
Glacial
GRAVEL
Fig. 81. Section at the Polecat Creek gravel pits, Coles County, Illinois.
eluded in the gravel list. Due to the method of working the pits, it
is unfortunately necessary to add a third "uncertain" list. The
operators first strip off the black earth with a steam shovel and then
start an excavation in the gravel face, the gravel from both sides
slumping into the excavation. Many finds were made in such exca-
306 Field Museum of Natural History — Geology, Vol. VI
vations. While it is highly probable that these specimens came from
the alluvial gravel, the faint possibility remains that they might
have come down from a patch of black earth that escaped the shovel,
or might have dropped to the ground from a shovelful of black
earth. The excavations continue well down into the lower glacial
gravel, but I do not consider it at all likely that any of the fossils in
question came from this stratum. The two fragments collected
from its face are very different in appearance from the other remains
obtained, being heavily abraded, whitish in color as opposed to
brown, and much harder. In the following lists the extinct forms
are marked by a dagger.
SPECIMENS FROM THE ALLUVIAL GRAVEL
Blarina brevicauda (Say). Short-tailed Shrew.
Posterior part of right mandible with much worn M^. The first
fossil record for the central states (Ohio, Indiana, Illinois, Michigan,
Wisconsin, Minnesota, Iowa, and Missouri). F.M. No. P15191.
Sylvilagus floridanus (Allen). Cottontail.
Calcaneum. The only other fossil record for Illinois is from the
lead region about Galena (Hay, 1923, p. 337). F.M. No. P15193.
fCastoroides ohioensis Forster. Giant Beaver.
A large tibia-fibula (F.M. No. P15272) exceeding in size that of
the splendid skeleton in the Field Museum collections from Fair-
mount, Grant County, Indiana.
MEASUREMENTS
MM
Tibia, maximum length 237
Tibia, tr. diameter of proximal end 64
Tibia, a.-p. diameter at center of shaft 31
Tibia, tr. diameter of distal articular surface 28
Tr. diameter of distal end of tibia-fibula 49
t(?)Megalonyx sp. Ground Sloth.
Incomplete neural arch of an anterior dorsal vertebra. F. M. No.
PI 5770. Three finds of Megalonyx jeffersoni in Illinois have been
reported. One of these is from the crevices in the Galena region,
another from undoubted post-glacial deposits near Urbana (Hay,
1923, p. 33). The third is from the "post-mid-Pleistocene" (Leigh ton,
1921) of the Alton region.
Canis latrans Say. Coyote.
Left femur. E.C.G. Coll. No. 2929. A specimen from the Galena
crevices provides the only previous fossil record in Illinois.
Post-Glacial Fossil Vertebrates 307
Canis familiaris Linnaeus. Indian Dog (fig. 82).
Left mandible, slightly imperfect in the incisor region, P^, P^,
M^, preserved. F.M. No. P15192.
This specimen did not agree with any of the wild North American
canids preserved in the Field Museum collections, and I suspected
that it might be from a domestic form. The specimen was sent to the
United States National Museum for comparison and examined by
Major E. A. Goldman, who reported as follows: ^ "I have compared
Fig. 82. Canis familiaris. Lateral view of left mandible. F.M. No. P15192.
X Vi- Drawn by Carl F. Gronemann.
the jaw rather carefully with a number of coyotes in our large col-
lection, and with modern dogs and Indian remains. I think the
jaw is that of an Indian dog. I have not been able to match it
exactly, but both Indian dogs associated with kitchen middens and
modern dogs vary tremendously, and this conclusion is based on
general resemblances and the probabilities in the case. It really
most closely approaches the jaw of a modern dog than any other.
Mr. Gerrit S. Miller, Jr., to whom I showed the jaw, concurs in this
conclusion."
This find is of importance since it indicates that man was con-
temporaneous in Illinois with large mammals that are now extinct,
but which survived the Wisconsin glacial advance.
1 Letter to Mr. Bryan Patterson, December 21, 1936.
308 Field Museum of Natural History — Geology, Vol. VI
MEASUREMENTS
MM
Length, condyle to It* 113.0
Length, Pt-M^j (alveolar measurements) 64.0
Length, Pt-? (alveolar measurements) 33.0
Pjj, a.-p 8.0
Pj, tr 3.5
P5, a.-p 10.0
P5, tr 4.5
M^, a.-p 7.5
M^, tr _ 5.5
Depth, coronoid process to angle .* 42.5
Depth of ramus beneath P^ 16.0
Depth of ramus beneath Mx 17.0
* The jaw being slightly imperfect anteriorly, this measurement is to a small extent estimated.
tMammut americanutn (Kerr). American Mastodon.
Incomplete left mandible with My-^, M^ not yet erupted, F.M.
No. P15201. Portion of symphysis, E.C.G. Coll. No. 2880.
Odocoileus virginianus (Boddaert). White-tailed Deer.
Two antler fragments, one from the blue clay, incomplete tibia.
F.M. Nos. P15195, P15196.
Ovibovinae, gen. et sp. indet. Undetermined Musk-ox.
Anterior dorsal vertebra. F.M. No. P15273. From the com-
parative material available, it is not possible for me to decide whether
the specimen is referable to Ovihos or to one of the extinct forms.
MEASUREMENTS
MM
Width across transverse processes 97
a.-p. diameter of centrum at center 53
Tr. diameter of anterior face of centrum 61
Tr. diameter of posterior face of centrum 62
Anterior diameter of neural canal 21
Posterior diameter of neural canal 24
Bison bison (Linnaeus). American Bison.
Incomplete cervical vertebrae and distal end of humerus, F.M.
No. P15194. Cervical vertebra, E.C.G. Coll. No. 2931.
specimens probably, but not certainly, from alluvial gravel
Homo sapiens Linnaeus. Amerind.
Complete right parietal, slightly waterworn in one spot, with
fragments of the occipital attached. It is highly regrettable that
this specimen was not collected in situ. In common with the others
encountered in the excavations it very probably came from the
alluvial gravel, but the possibility of intrusion from the overlying
black earth cannot be eliminated entirely. However, the finding of
Post-Glacial Fossil Vertebrates 309
the domestic dog jaw in situ in the alluvial gravel re-enforces the
probability that the specimen came from this level. F.M. No. P15211.
Ondatra zibethica (Linnaeus). Muskrat.
Incomplete tibiae-fibulae of three individuals, one of them young.
A skull found in post-glacial deposits of the Sag low-water stage of
Lake Chicago near Lemont, Illinois (Baker, 1920, p. 89), represents
the only previous fossil record of the species in the central states.
F.M. No. P15200.
Canis lupus Linnaeus. Wolf.
Left squamosal and otic region. F.M. No. P15197. Pocock
(1935) has recently reduced most of the groups of wolves formerly
regarded as distinct species to the rank of subspecies of C. lupus, an
arrangement that has been followed by Goldman (1937). This
simplifies treatment of fragmentary Pleistocene material. Earlier
authors have referred fragments to nuhilus or to occidentalis despite
the fact that it is apparently difficult to separate these forms even
when series of skins and skulls are available. The earlier alterna-
tive of listing such material as Canis sp. required explanatory text
if readers were not to be left in doubt as to what type of canid was
represented.
Procyon lotor (Linnaeus). Raccoon.
Incomplete left mandible with molar alveoli preserved. The
first fossil record of the species from the central states. ^ F.M. No.
P15198.
Ursus sp. cf. U. horribilis Ord. Grizzly.
Large upper canine, comparable in size to canines of large
grizzlys and to those of the U. gyas group. F.M. No. P15199. The
large size of the specimen, 18.5 mm. in transverse by 27.5 mm. in
antero-posterior diameter at the alveolar level, immediately excludes
it from U. (Euarctos) americanus. The bears of the U. gyas group
are confined to the extreme northwest and are very probably recent
immigrants from Asia. It is almost certain therefore that the
canine indicates the presence of a bear of the U. horribilis group,
thus constituting the fifth record of fossil grizzlys in North America,
and the second in the central states. The other finds have been
made in Oklahoma (Stovall and Johnston, 1935; Stovall, 1936) and
in Ohio. The Ohio specimen, Ursus procerus, is a member of the
grizzly group, according to Stovall and Johnston.
^ The extinct P. priscus Leidy comes from the Galena region.
310 Field Museum of Natural History — Geology, Vol, VI
Gervus canadensis Erxleben. Wapiti.
Incomplete antler. F.M. No. P15207.
fGervalces roosevelti Hay. Roosevelt's Deer-moose.
An incomplete antler of this species adds one more record to the
increasing number of Cervalces finds. The major character sepa-
rating C. roosevelti from C. scotti is the much greater length of the
beam in the holotype of the former (Hay, 1913, p. 5). The antler at
hand and those recently recorded by Riggs (1936, p. 664), although
not as long in the beam as Hay's type, are closer to roosevelti than to
scotti. The beam lengths of these specimens from the burr to the
base of the ascending branch are as follows: Ashmore, Coles County,
Illinois, 281 mm.; Beecher, Will County, IlHnois, 286mm.; Minooka,
Kendall County, Illinois, 204 mm. (young) ; White River, near Hazel-
ton, Gibson County, Indiana, 268 mm. The Indiana specimen is
the most complete specimen of the species so far found and includes
a large part of the ascending branch extending well beyond the point
of divergence of the anterior and posterior portions. The maximum
width of the base of the posterior portion is considerably less (58
mm.) than that of the Princeton specimen of C scotti (131 mm. on
the right side, 119 mm. on the left).^ More and better specimens
may show other differences. On the other hand it seems entirely
possible that more material would show that the recorded differences
are merely individual variations, or perhaps of subspecific value only.
The holotype of C. roosevelti, from Iowa, and a specimen recently
recorded from Nebraska (Schultz, 1934, table A and p. 388), are
stated to have come from interglacial or glacial deposits. The Illinois
specimens from Beecher and Minooka (White Willow) (Hay, 1923,
pp. 107-108, 337), as well as that from Ashmore, are from post-
glacial deposits. The age of the Indiana antler is unknown.
Odocoileus virginianus (Boddaert). White-tailed Deer.
Four incomplete antlers, incomplete atlas, cervical vertebra,
incomplete scapula, three pelvic fragments, two incomplete adult
humeri, one young humerus, incomplete tibia, astragalus. F.M.
Nos. P15202-6.
Bison bison (Linnaeus). American Bison.
Incomplete periotic, incomplete dorsal and lumbar vertebrae,
rib fragment, incomplete tibia, two incomplete metacarpals from
young individuals. F.M. Nos. P15209, P15210.
^ I am indebted to Dr. Glenn L. Jepsen for these measurements.
Post-Glacul Fossil Vertebrates 311
Meleagris gallopavo Linnaeus. Wild Turkey.
Distal half of ulna-radius. The first fossil record of the species
in the central states. I am indebted to Dr. Alexander Wetmore for
the determination. F.M. No. P15212.
Terrapene ornata (Agassiz). Box Turtle.
Incomplete carapace. The first fossil record of the species.
F.M. No. P15213.
Pseudemys sp.
Two plastral fragments. The first fossil record of the genus in
the central states. F.M. No. P15214.
(?)Chrysetnys sp.
Plastral fragment. If the tentative identification is correct,
this specimen represents the first fossil record of the genus in the
central states. F.M. No. P15215.
specimens from the black earth deposit
Can is lupus Linnaeus. Wolf.
A canine with two holes bored in the root, evidently by Indians.
F.M. No. P15216.
Lynx sp. Bobcat.
Distal end of humerus of young individual with entepicondylar
foramen injured. The first fossil record of the genus in the central
states. F.M. No. P15218.
Odocoileus virginianus (Boddaert). White-tailed Deer.
Two antler fragments, incomplete tibia, astragalus, and a very
small scapula which compares well in character with adult scapulae.
Possibly this scapula was foetal, and may have been extracted by
Indians from a gravid female. F.M. No. P15219.
Bison bison (Linnaeus). American Bison.
Complete metacarpal, lunar, and scaphoid, all associated; F.M.
No. P15220. Incomplete humerus, E.C.G. Coll. No. 1100. Two in-
complete nasal bones, E.C.G. Coll. Nos. 1174, 1175.
Canis latrans Say. Coyote.
A nearly complete humerus was obtained from a locality about
150 yards west of the gravel pits, probably from the black earth
horizon. F.M. No. P15217.
312 Field Museum of Natural History— Geology, Vol. VI
This collection of 21 forms is the largest from any one Illinois
locality that has so far been reported. It increases the known
number of Illinois Pleistocene vertebrates by about one- third. The
extinct forms have all been reported previously from post-glacial
deposits. Their evident association with man is interesting but not
surprising in view of recent discoveries in the western United States.
This association tends to strengthen the belief that man was largely
responsible for the extinction of many large mammals that survived
into post-glacial time in North America.
ENVIRONMENT
The wood remains, particularly Hicoria, indicate climatic con-
ditions essentially similar to those prevailing in northern Illinois at
the present day. The invertebrates, all but one members of the ex-
isting fauna of the state, are in complete agreement. Dr. Baker
states that they indicate the presence of a shallow but not swampy
body of water with "perhaps a small stream . . . draining the surplus
water. "^
The turtle and muskrat remains agree with the invertebrates in
suggesting the presence of a stream. The remainder of the mammals,
with one possible exception, appear to call for wooded areas in the
country surrounding the body of water, interrupted by stretches of
meadow with brushy thickets.
The possibly discordant note is provided by the vertebra of the
undetermined ovibovine. This specimen does not appear to have
been redeposited, for it is similar in appearance to the other speci-
mens found in the alluvial gravel and is not waterworn. It per-
haps represents a winter straggler from a colder isothermal belt that
was not far away to the northward, or it may belong to an extinct
genus adapted to a milder climate than the living Ovibos. Whatever
the case it can hardly affect the conclusion derived from the rest of
the fossil assemblage that the climatic and ecologic conditions pre-
vailing in the area during the time of deposition of the alluvial gravel
were essentially similar to those that persisted into early historic
time in Coles County.
» Letter to Dr. George E. Ekblaw, September 19, 1936.
REFERENCES
Baker, F. C.
1920. The Life of the Pleistocene or Glacial Period, as Recorded in the Deposits
Laid Down by the Great Ice Sheets. Contr. Mus. Nat. Hist., Univ. Illinois,
No. 7, pp. i-xiv, 1-476, pis. 1-57, text figs. 1-5.
Goldman, E. A.
1937. The Wolves of North America. Jour. Mamm., 18, pp. 37-45.
Hay, O. p.
1913. Descriptions of Two New Species of Ruminants from the Pleistocene of
Iowa. Proc. Biol. Soc. Wash., 26, pp. 5-8, text fig. 1.
1923. The Pleistocene of North America and Its Vertebrated Animals from the
States East of the Mississippi River and from the Canadian Provinces East
of Longitude 95°. Carnegie Inst. Wash., Pub. No. 322, pp. i-viii, 1-499, text
figs. 1-25, maps 1-41.
Leighton, M. M.
1921. The Pleistocene Succession near Alton, Illinois, and the Age of the
Mammalian Fossil Fauna. Journ. Geol., 29, pp. 505-514.
POCOCK, R. I.
1935. The Races of Canis lupus. Proc. Zool. Soc. Lond., pp. 647-686, pis. 1-2.
RiGGS, E. S.
1936. Occurrence of the Extinct Moose, Cervalces, in Indiana and Illinois.
Amer. Midland Nat., 17, p. 664.
SCHULTZ, C. B.
1934. The Pleistocene Mammals of Nebraska. Nebr. State Mus. Bull., 1, pp.
357-393, table A.
Stovall, J. W.
1936. A Recent Grizzly Bear Skull found in Oklahoma. Amer. Midland Nat.,
17, pp. 781-783, figs. 1, 2.
and Johnston, C. S.
1935. Two Fossil Grizzly Bears from the Pleistocene of Oklahoma. Jour.
Geol., 43, pp. 208-213, figs. 1-4.
313
