Evening star., 1937-05-15
STARS, MEN AND ATOMS
Notebook of Science Progress in Field.
Laboratory and Study.
BY THOMAS r. HENRY

FIFTY million years into the past
reaches the ancestry of the dog.
Inc long trail through time leads to
nlghtmarish marsh land. now Gov
cred by the White Earth River Basin
OF Nebraska and South Dakota, where
sKulklng creatures with long teeth and
small brains waylaid their prey by
wooded stream sides.
This was during the millions of years
OF the Oligocene geological period. 1t
was a prosperous time for primitive
mammal life. The Great Plains area
was loW-lying country, traversed by
a complicated network Of streams and
low divides. In the flood season, when
all the streams overfloWed their banks,
the whole region was converted into
shallow temporary lake which de-
posted fine mud and silt. This covered
up and preserved for the future the
bones OF contemporary animals.
AS result the White Earth River
region long has been for fossil hunters
veritable menagerie of the grotesque
creatures who lived five hundred
thousand centuries ago. Some of these
ancient animals have just been de-
scribed by Prof William B. Scott and
Glenn L. Jepsen of Princeton Uni
versity in monograph on the OIgocene
fauna issued through the American
Philosophical Society.
Already the mammal race had been
on earth a long time. Large groups of
fantastic warm-b -blooded creatures had
f1ourished and disappeared leaving no
descendants. The White Earth River
creatures were placentals, the group
which jnp11lHaS NJ lo q liz q
species of today but they had not clear
ly differentiated into the dominant
genera of the present.
Notable among these creatures of
$4,000, 900 years ago, as pictured by Prof.
Scott, are two groups-one OF large,
f1esh-eating animals, the daphoeni, and
one of very much smaller individuals,
the pseudocynoidea. Both were dog
like. The typical daphoenus. especially,
had a skull which was unmistakably
canine in general appearance, although
it retained many primitive features from
its more remote ancestry which the
canine race has discarded in its evo-
lutionary progress.
A notable difference is in the brain
case. 1t had much smaller capacity,
in proportion to the stature OF the ami
IIldA, llldil IIle CIdIlluIIl VI IAlc AAo0CiAA
dog. The evolutionary path Of the dog
family, like that of the apes and man,
has been toward bigger brains. better
developed association centers, and more
intelligence. In some respects the an
cient creatures were more catlike than
doglike. Their bodies were constructed
for stalking and not chasing their prey.
The tails, for example, were remark
ably long and thick, like those OF the
tiger and the leopard. An evolutionary
achievement of the dog has been the
gradual reduction of tails, which inter-
fere with running. The daphoenus had
slender, long body and short legs,
like many OF the present-day big cats.
Prof. Scott concludes, however, that
they were out of the direct ancestral
line Of the cats, although themselves
descended from the same heritage as
the primitive feline lines.
The reconstruction Of the brain shows
that these ancient creatures were to
a much greater extent smell animals"
than even the dogs of today. The OIL
factory lobes of the brain, where smell
sensitivity is centered, we're large and
uncovered. The later dogs developed
cerebral hemispheres seats Of higher
mental processes, over the primitive
"Snnel1 brain