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°Hay, Oliver Perry
Science
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°
Hay, Oliver Perry
Paleontology -- North America; Paleontology -- Pleistocene; Vertebrates, Fossil
2. _Ashland, Cass County._—In the U. S. National Museum (No. 2195) are
some remains of an elephant, referred to _Elephas primigenius_, found at
Ashland in the spring of 1901. The remains consist of pieces of one
tusk, the symphysis of the lower jaw, the right and left upper
hindermost molars, the right lower last molar, a fragment of the rear of
a much-worn upper second molar, and another of a correspondingly worn
lower second molar. They were found in tilling a farm near Ashland by
Mr. J. W. Arnold, of Jacksonville, Illinois.
The upper teeth resemble greatly those figured by the writer in his
report on the Pleistocene Mammalia of Iowa (Iowa Geol. Surv., vol.
XXIII, plate LIX); but the teeth from Ashland are more worn than those
found in Milwaukee. The last molars from Ashland are worn back to about
the eleventh ridge-plate, and the second molar is worn so that only its
rear portion remained. The length of the upper molars is about 275 mm.
The height of the eleventh plate is 185 mm.; the breadth of the
grinding-surface is 90 mm. One or two of the hinder plates are missing,
but evidently there were at least 24. There are 9 or 10 ridge-plates in
a 100–mm. line on the worn surface; farther towards the base 8 plates in
the same space. The ridge-plates are little bent; the enamel is thin and
little sinuous in its way across the worn surface of the tooth.
The lower last molar is 315 mm. long, 152 mm. high, and 85 mm. wide. It
is thus longer than the upper molars, slightly narrower, and not so
high.
A fragment of the hinder end of what appears to be the lower left second
molar shows 7 ridge-plates remaining. These form two series, an inner
and an outer, entirely separate from each other. This condition is
sometimes seen in little-worn teeth.
The geology of this region may be studied on the Tallula-Springfield
Folio, No. 188 of the U. S. Geological Survey. The Tallula Quadrangle
includes a narrow strip of the eastern border of Cass County. Here the
surface forms a nearly level prairie. According to the geologists Shaw
and Savage, the surface in the region next to Cass County and much of
the rest of the quadrangle is covered by a blanket of loess. Its
thickness varies from 4 to 20 feet; under this, sometimes, in wells, is
to be found a dark-colored ill-smelling deposit, of no great thickness,
which is believed to represent the Sangamon stage. Underlying the loess
everywhere is the Illinoian drift.
As regards the geological age of the elephant described above, it is
quite certain that it lived after the Illinoian stage. It is quite
probable, too, that its teeth and bones were found in the loess which
overlies the Sangamon soil in some places in the quadrangle. This loess
may have accumulated during the Iowan glacial stage or during the
succeeding Peorian interglacial. Considering what we know about the
habits of _Elephas primigenius_, it appears most probable that the
animal in question passed its life during some part of the Iowan.
Public-domain text, read in full here on John Shaqi.
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