298 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1914. 
and pinched” condition, as has often been said. “In North Carolina, 
Virginia, and Arizona there are trunks of trees preserved some of 
which are 8 feet in diameter and at least 120 feet long, while hun- 
dreds are from 2 to 4 feet in diameter. Many of the ferns (some 
are tree ferns) are of large size, indicating luxuriant growth, while 
Equisetum stems 4 to 5 inches in diameter are only approached by 
a single living South American species. * * * The complete or 
nearly complete absence of rings in the tree trunks indicates that 
there were no, or but slight, seasonal changes due to alternations of 
hot and cold or wet and dry periods.’ On the whole, the climate 
was ‘‘warm, probably at least subtropical” (1910). 
Of insects, too few species (27) are known to be of value for 
climatic deductions. On the other hand, the reptilian life of the 
Triassic in America, Africa, and Europe was highly varied, and with 
the dinosaurs dominant and often of large size again gives evidence 
that appears to be indicative of uniform and mild climate. 
The marine Triassic deposits consisted largely of thick limestones, 
and such are well developed in arctic America and arctic Siberia. 
One of the oldest faunas, known as the Meekoceras fauna, has a very 
ereat distribution from Spitzbergen to India and Madagascar, and 
from Siberia at Vladivostok to California and Idaho. In general, 
however, the Triassic assemblages were more provincial, and it was 
not until middle and late Triassic time that the faunas again had 
wide distribution. Limestones with thick coral reefs, of the same 
age, appear in the Alps (up to 1,000 meters thick), India, California, 
Nevada, Oregon, and arctic Alaska. Smith, from whom most of 
these facts were taken, states that this shows there was during the 
Triassic ‘“‘nearly uniform distribution of warm water over a great 
part of the globe” (1912). 
We may therefore conclude that the rigid climate of the Permic 
had vanished even before the earliest of Triassic times, and that the 
climate of the latter period until near its close was again mild and 
fairly uniform though semiarid or even arid the world over. 
Late Triassic-Lias.—Throughout much of late Triassic time there 
was renewed crustal instability, for we have the evidence of volean- 
ism on a great scale all along the Pacific from central California into 
far Alaska, in eastern North America from Nova Scotia to Virginia, 
in Mexico, South America (in southern Brazil 600 meters thick), and 
New Zealand. The volcanoes of western North America were prob- 
ably insular in position, for their lavas and ash beds are found inter- 
bedded with marine sediments. Just how important this movement 
was and what effect it had upon the climate is not yet clear, but 
there is important organic evidence leading to the belief that the 
temperature was considerably reduced during latest Triassic and 
earliest Jurassic time. 
