New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1881-07-17
SCIENCE FOR THE PEOPLE.



Professor j. S. Newbcrry has a long letter in
the last number Of Nature, in reply to Mr.. j.
Starl>le Gardner, who had stated that the fossil
plants III our CretaceOus rocks represented Il
llOra really Tertiary, and that no American or
European sO-callcd Cretaceous land flora could
he found to be as old the English white
chalk. In commenting upon these statements
Professor NcWhcrry cites the following facts ::
In our Triassic series we have in some places
beds OF coal and the remains of Il vegetation
decidedly McS0zOic in character, consisting of
CycadS, Conltcrs and Ferns, but, as far as we
yet know, without Il single AngiOsperm. In the
JuraSslc age the eastern half Of the North
American Continent formed land-surface for
the sediments of the Jurassic are confined
10 somewhat irregular area in and west of the
Rocky Mountain belt. OF the ,Jurassic fora of
North America we as yet know little or nothing ;
but the continent that bordered the Julasslc
sea ultimately became covered with Il new,
varied and highly organized flora, OF which the
origin Is yet unknown.
In the CrctaceOuS age all the continent lying
east of the Wasatch Mountains was affected by
n subsistence which brought the sea in from the
Gulf of Mexico with front 900 miles wide,
and the great inland sea thus formed gradually
extended northward till it reached nearly, if
not quite to the present shore of the Arctic
Ocean. The waves of the Cretaccous sea in
their advance swept before them shore that
was covered with luxuriant forest of at least
one hundred species of AngiOspcrmOus trees !;
and the remains of trunks and twigS, leaves and
fruit, were buried up in the sheet of beach
material which accumulated all along the adj
vancng shore line, and which now forms the
Sandsoncs of the Dakota group. Up to the
present time very few mollusks have been
fotnd III this group, and they are not sufficient
to fix with cXactncSS its relation to the Crcta-
ccous series of other countries. The plants,
too, are distinct from any found in Europe,
though they include, with many extinct forms,
genera which are common in the living forests
of America such IA QucrclS saliX, Magnolia,
Fagus, Liquidamhar, Lirodcndron, etc When
the subsistence which produced the Dakota
group was at its maximum the sea stood sew
cral thousand feet deep over the central portion
of the trough between the AllcghanicS and the
WaSatCh Mountains, and here now find at
least two thousand feet of marine, calcareous,
organic sediment, which have furnished hun
drcdS of species characteristic OF the trctaccOuS
age and large number that are identical with
those contained i'll the Upper Grccnsand and
Chalk of Europe.
1t is true that up to the present time no Neo-
cOmian fossils have been found in the interior
of the Continent, but with that exception the
entire CretaccOuS series of the Old World is
represented there. Hence il Is not true that our
Crctaccous "contains nothing 50 old as the
Chalk Nor Is II true, rs intlmatcd by Mr.
Gardner, that our "sU-cacd Crctaccous rocks y
contain Tertiary flora and fauna, as no Ter
uary species OF either has yet been found there.
The 1ora OF the Dakota group Is more modern
IN It's aspect than thar of thc Lower and Middle
CrctaceouS of Europe, hut It's plants are specific
ally different from amy found in Europe in cur
Middle CrctaccCus Colorado group), Upper
Crctace0uS Laramie group, or Tertiary beds
COT Green River, Fort Union and Oregon. The
facts apparently indicate that the earliest de
NclOpmcnt of AnglOSpcrmOuS Ilant-litc took
place here, and this in Il temperate flora of
which the descendants long att"rWard-in Ter
tiary timcs-Occupicd Greenland, Spitzbcrgcn
etc, and spread by land connections into
Europe and Asia.