Evening star., 1947-08-01
Stars, Men and Atoms Hk3a
New Mexico Marsh Yields
Amphibion Monster Fossils
First of Backboned Creatures Became
Dominant on Earth
By Thomas r. Henry


In New Mexican marsh pool about l5o,-
100000 years ago crowded drought-stricken
survivors Of a dying race of cold-blooded
monsters.
For several million years, since their ances-
tors had come out of the seas to become the
hrst backboned creatures on land they had
been among the dominant creatures on earth.
They were the great amphibians, remote rela-
tlves OF the frogs and salamanders of today.
Skulls and other bones of IS of these animals
all found embedded in rock in small area
just south OF Santa Fe, have been collected
Tor the United States National Museum by
Dr. D. H. Dunkle, Smithsonian Institution
paleontologist. The creatures are known only
by the scientific name Of "stereospondyls" but
they were more closely related to the sala-
manders than to anything else extant
Chained to the Water.
A little of their story can be traced back
ever the millenniums. Although they were
land dwellers they were chained, like all other
amphibians. to the water for egg laying ana
development through the embryonic, or tao
pole. stages. During most Of their period cf
dominance on the earth this had been q low
fiat. torpid world. There were few noun.
tains. The seas splsstlea ever on the lands.
There was little drainage. ass earth was
one great swamp.
With the start Of the Triassit geological
period about l5o0oo,O0O yeN2s ago ca me great
change. There were tite,!" uG!a.es ais OF the
earth. Mountain ranyes hprear-.:. THE Swar:5s
drained into che sea 2'd %nat had been
marshes became ieser,s This %rs "a. end
OF the amEhibians Az over me word grrat
numbers of them were l&'t With 10 lccess 70
water. The pools rn wl,.s tiny depended
became smaller and s:nElle- h1nre and mOre
OF them crowded lcgethsr u IT,. vanisf ng
water aoles. to perish in the slid.
Such apparently is the story OF the New
Mexico site, says DR.. Dunkle In no other
way can the great numbers Of fossils ir such
a narrow area be explained In one slab Of
stone about 40 feet square Dr. Dunk,e found
nine skulls
Reptile Rule for Years.
Even as the amphibians were perishing as
the world dried up, another race of cold
bl0oded creatures, in some way remotely re-
lated to them, was taking over dominance Of
the earth. The new creatures were the
reptiles which were to rule for millions Of
years, reaching their ultimate heights in the
monster dinosaurs. They had the great ad-
vantage of being able to pass their entire
life cycles away from water. They were quicker,
more adaptable and probably cleverer than
the incredibly clumsy, stupid amphibians
Remains of these stereospondys are found
all over the world, although nowhere in quite
as great abundance as in this old New Mexican
marsh. They were remarkable for their
enormous skulls Those collected by Dr. Dunkle
average about two feet in length, although
the entire animal was only about seven feet
long. They apparently were quite inadequate
animals to survive through the cosmic change
to which they were subjected.
Only two branches of the amphibian race
the frogs and salamanders, were able to
weather the period of mountain building.