The evening tribune. (Pawtucket, R.I.) 189?-190?, 1897-05-01
'SLOTH AND SCIENCE.
BONES or THIS ANIMAL AID IN AN
i IMPORTANT DISCOVERY.


Existed In North America and Then
= Emigrsted to South Americs- Ancient
Isthmus OF Panama.
one OF the greatest mysteries Of science,
perplexity that has harassed the minds
Oh the foremost scientists, stands explained
by discovery recently made by Dr. s. l..
workman OF the department of paleontol-
+, ogy In the American Museum of Natural
History. BY it geographers must change
theories that have prevailed as unchange-
able and alter their reckonings in one in
stance by 10000 years. In another do
main OF science, that which deals with the
monster animals Of prehistoric times and
their life, some interesting conjectures, ac-
cepted almost as fixed belief, must be
dismissed when confronted by the clear
facts set forth with indisputable evidence
by DIR. Workman.
1t proves, so DIR. Workman reasons, that
there was an isthmus OF Panama half a
million years ago-not the neck of tho
present day, but predecessor, which in
the lapse of time came and disappeared.
Geogaphers have contended that the thin
strip of land which connects North and
South America is about 500 years old,
and that before that time there flowed IA
sheet Of water 20 miles wide between the
two continents.
1t shows that those huge sluggards, the
gigantic sloths, as large as an elephant,
came from what are now the southwestern
portions Of the United States, and not
from South America But all traces of
these animals were confined almost ex-
clusively to South America. Now and
then q skeleton has been found elsewhere
"a few remains in this country and some
fragments Of sloth teeth at Egerkingen,
Prussia.
How those great beasts were bred has
been unknown. That lack of knowledge
was a serious defect in the chain of evil
dence proving the doctrine Of evolution.
AS geologists resolutely held that during
the whole of the eocene period, which end
ed several hundred thousand years ago,
there was absolutely no land connection
between North and South America, how
could animals emigrate from one continent
to the other? Some geologists have enter
tained the belief that they originated in
North America, which then was tropical,
and marched to Alaska, then over the an
cient land bridge which connected that
country with Asia, then strodc into Eu-
rope, later visiting Africa, and finally
marched across a sunken antarctic conti
nent to South America.
The true solution of this profound prob
lem was discovered in the San Juan basin,
In the northwestern part of New Mexico,
by DIR. Workman. He gave brief technical
account in a memoir, and it has excited
much interest among scientists all over the
world, upsetting, as it does, many theories
and throwing strong fiashlight upon the
origin of things. In another memoir, en-
titled "The Ganodonta and Their Rela
tionsbip to the Edentata," DR.. Workman
describes his find more fully.
In q canyon ,000 feet high in the San
Juan basin, which is part Of the Bad
Lands of New Mexico, he hit upon skulls
and fragmentary remains which in an in
slant, as IL were, revealed the tale of the
sloth and armadillo tribe, how they grad
ually eyoluted from smallness TO mon
strous proportions and how they emigrat-
ed. This discovery clears the long obscured
point of the origin and descent Of the en-
tire sloth group and brings 1t back into
the closest relationship with other orders
of mammals.
Deep down in that canyon he disinterred
one skull and q foot, lying in the lowest
eocene stratum in North America. Now, as
this particular layer of sediment, which
later turned into stone, was deposited not
less than 500, 900 years ago, DIR. Workman
recSons the original sloth to whom that
skull belonged lived that many years In
the past All the region thereabout was
covered by great lake. which gradually,
through the lapse of countless ages, be-
came filed by mud, stone and other matter
washed into il. The lowest eocene stratum
is mile and q half below the present
surface of the earth.
This skull is not that of the gigantic
sloth, but of his most primitive, clearly
defined ancestor, whose girth was about
that of bulldog-certainly not larger.
Here, then, was the cloths original home,
and here it first 1ourished. When this
moderate sized fellow died, its corpse be-
came imbedded In the muddy bottom OF
the lake. Tens of thousands of years after
this another sloth passed away, and its
body tumbled into the lake and sank. This
one was larger than the other, and, as the
lake kept rising all tho time, its bones are
found hundreds of feet higher up in the
canyon. But thero came q time when the
lake had risen 80 high that IL overfowed
and disappeared. The mud that had ac-
cumulated in its bottom gradually turned
into sandstone In this water through an
almost endless procession of years cut its
way, and so formed the canyon in the
depths of which DIR. Workman was enabled
to grasp tho evidence scientists 50 long
have sought.
Thus tho first known ancestor of the
sloth has been placed and indisputably had
his origin here and nowhere else. Through
the whole Of the vast eocene period, which
ended 500, 900 years a go, the sloth flourished
and evoluted until 1t became, as other re-
mains found by DR.. Workman in higher
eocene deposits show, as large as yearling
steer
Then came-a sudden and most startling
change At the close of the eoccne period
deposits all traces of the sloth in North
America disappear abruptly and reappear
in South America. This fact Is full OF the
deepest significance.
1t means, says DR.. Workman. that, not
withstanding the theories of geographers,
shere was IN isthmus Between North and
South America SOC, 900 years ago. Vol
ranic disturbances all of a sudden closed
the watery gap between the continents, and
over this land bridge the animals from the
limited Sfatpa and Maxico rnadp gradually