302 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1914. 
In Middle Cretacic times the oceans began again to spread over the 
continents and this transgression of the seas was one of the greatest 
of the geologic past. It is interesting to note that even though there 
was great opportunity for expansive evolution, but few new marine 
stocks appeared here, and it was rather a time of death to many 
characteristic stocks. This well-known fact is clearly brought out 
by Waither in his interesting book, “Geschichte der Erde und des 
Lebens”’ (1908), in chapter 26, entitled ‘Cretaceous time and its great 
mortality.’’ Entire stocks of specialized forms vanished, just as did 
other stocks at the close of the Paleozoic. In late Cretacic time it 
was the ammonites, belemnites, the rudistids that begaa to develop 
in great numbers in the Lower Cretacic, and the other thick-shelled 
large bivalves (Inoceramus) that perished. In addition, there was 
a great reduction among the reef corals, the replacing of the dominant 
ganoids by the teleosts or bony fishes, and, finally, the complete dying 
out of the various stocks of marine saurians. 
On the land, with the further rise of the Angiosperm floras, we see 
the vanishing of the reptilian dragons known as pterodactyls, and, 
at the very close of the Cretacic, the last of the large and small 
dinosaurs and the birds with teeth. ‘‘We thus see the reptiles 
displaced from the seas by the fishes; on the land they are restricted 
by the rise of the mammals, in the air after a short struggle by the 
more finely organized birds—in short, the reptilan dominance 
is destroyed with the end of the Mesozoic era, m which entire time 
they were the characteristic feature.” (Koken, 1893.) 
The Upper Cretacic was therefore a time of great mortality among 
animals, ‘‘here sooner, there later; although numerous relict faunas 
are preserved for a time and last into the Cenozoic, still there never 
was so great a mortality as that taking place toward the close of the 
Cretacic.””’ (Walther, 1908.) 
During the Upper Cretacic, but more especially toward the close 
of the period, mountain making on a vast scale went on, along with 
exceptional outpourings of lavas and ashes. These movements, 
though of less intensity, were repeated in early Tertiary times, 
and while they were equaled only by those of the closing period of the 
Paleozic, they were exceeded by the crustal deformation of late 
Tertiary time; they form the Laramide revolution of Dana, embracing 
the mountains of western North and South America from Cape Horn 
to Alaska and the reelevation of the Appalachian and Antillean 
Mountains. Throughout the Eocene in the Rocky Mountains there 
were many volcanoes throwing out immense quantities of ashes 
in which is entombed a remarkable vertebrate fauna. Then in late 
Cretacic time in peninsular India occurred the Deccan lava flows, 
the most stupendous eruptions known to geologists, covering an area 
of 200,000 square miles, in thickness anywhere up to a mile or more. 
