The record-union., 1898-05-04
FOSSIL BIRD TRACKS.
RECENT FINDS NEAR THE root
@ OF MOUNT TOM
Some Account of President Hitch
cocks Investigations of
Half Century Ago.

The recent discovery of fossil bird
tracks in a sandstone ledge at the foot
of Mount Tom recalls the great sensa-
tion in scientific circles a half CEN
tury ago, when the late President
Hitchcock of Amhurst College publish
ed the results of his labors in Frank
lin and Hampshire Counties.
The red sandstone strata border the
Connecticut River on both sides
through the whole of Massachusetts
and as far south as Middletown. where
the river turns eastward, and the sand
stone area passes straight on to the
Sound. These strata dip eastward at
an angle Of twenty to thirty degrees
and are cut by frequent fissures and
faults. Wherever large sheets of
sandstone denuded, as at Dibble's
Crossing, in the southern part of Holy
oke,. it will be noticed that they pre-
serve approximately the same angle.
which would indicate that the thick
ness of the strata is between 5000
and 10000 feet. The whole series of
sandstone is very distinctly stratified
and in many parts beautifully tissile
The earlier and lower formations, such
as are met with in the sandstone quar-
rles at East LongmeadoW, are not so
finely laminated, but the later strata.
such as are encountered on the bank
of the Agawam River, near the bridge
at Mittineague, and at Delaney's quar-
ry, at Holyoke, are almost as fissile as
slate. If these later deposits are broken
open along their marks of Iamination.
all kinds of shore marks are found in
the greatest perfection, namely, rip
pie marks, rain prints and sun cracks:
at Dibbles' Crossing a large area of
sandstone gives a magnificent example
Of this shoal water deposit. 1t is In
such strata that we may hope to find
bird tracks
We may easily imagine the circum-
stances under which these tracks were
formed During the Jura-Trias period
there We're in this region a shallow
inland sea, connected by a narrow out
let with the ocean. The ebb and flow
OF the tide left extensive flats of mud.
shower pitted the soft mud. already
ribbed with ripple marks, and the sun
dried and cracked it, This occurred
constantly for many ages, when we
find huge birdlike reptiles sauntering
along the shore in search of food. The
returning tide gently covered the
tracks, preserving them forever; that
race or reptiles passed away and the
SLOW deposits of mud buried all trace
of them beneath hundreds of feet of
deposit
About sixty years ago a number OF
reptilian tracks We're unearthed at
Turner's Falls and, in the vicinity of
Greenfield. Later, foot tracks were
found south of Amhurst. and also an
M1ddletown,. Conn. Edward Hitchcock
examined more than fifty species. and
his magnificent collections are now in
the possession Of oAmhurst College.
These tracks vary n1sze from a half
men long to twenty inches, Some have
lVe toes, some four and some onlv
three toes on the hind feet. Some had
lore and hind feet, of nearly equal size
and walked in quadrupedaI fashion.
others, whose fore feet were much
smaller than, their hind feet. walked
almost entirely with the hind feet
putting down therefore feet occasional
ly. have in mindoa slab in the Ichno-
losical museum, at fAmhurst, showing
the ordinary bipedal track. the i'm
pfesslon maze as the animal rested on
It's launches, and the small prints LEFT
49, - NA C-'POb 1lSf AioIt IRfsI before If.
Another. slab bears small bipedal tracks
win sthe raalt of a dragging tail; as
the reptile sWervedfin it's course the
tdll served as rudder to balance it
pu' these last are so rare and doubt
Iul that 1t is generally supposed that
Tue animals were long legged and short
tailed 5-,.
But to return to the newly discovered
tracks north of Holyeke John D Col
ton, to Whom the credit of the discovery
Is due, and / made a hasty survey of
the ledge some weeks, ago, and secured
a few slabs bearing three-toed impress
sions about six inches in length We
turned over slabs about thirty inches
square containing,sin some cases. eight
or ten three-toed tracks ranging from
three inches to eight inches in length.
1t was impossible Z to determine the
stride of the reptiles, as we had no
means of stripping off large areas of
the ledge and determining the record of
any one set of tracks In several in
stances we noted what appeared to be
the impressions of a dragging tail but
the tracing was too faint to warrant
much credence. BY far the largest
tracks are on the surface but owing
to the peculiar erosion it will be i'm
possible to find a complete record until
tons of. sandstone are removed. Or
ganic remains are scarce in sandstone;
but in this ledge we noticed fine traces
of coal in the same strata that bear the
tracks. This coal appears in thin
like segregations Of about four
inches in length Altogether. we await
with +interest expert investigation of
this ledge.
tracks be those of birds or reptiles. This
is not so strange as it may at first
appear. Doubtless were we to see the
birds themselves, we should be puzzled
to decide whether to call them reptil-
ian birds or bird-like reptiles. These
two classes were probably not yet fully
separated from each other In these
newly discovered tracks there is reg
ular progression in the number of
Joints to the toes, rs in birds and the
track of a bird exactly resembles these
tridactyl tracks But it has been dis
covered by Marsh and Cope that many
reptiles of the Jura-Trias period had
but three functional toes on the hind
foot and the same number of joints as
birds possess On the other hand, Dana
has shown that a bird whose stride is
four feet and the length of whose
tracks is eighteen inches must have
been wingless as its size is far beyond
the limit within which flight is possible.
But the doubts in regard to these rep
tiles have been cleared up by the dis
covery by Marsh of nearly perfect
skeleton. This skeleton resembles that
of a kangaroo as closely as that of any
animal of the present day; it walked,
however on its hind feet. instead of