DINOSAURS
Chapter 10:
GEOGRAPHICAL DISTRIBUTION
OF DINOSAURS.
Remains of
Dinosaurs have been found in all the continents, but chiefly in Europe and North
America. Explorations in other parts of the world have not as yet been
sufficient to show whether or not each continent developed especial kinds
peculiar to it, nor to afford any reliable evidence as to whether the relations
of the continents were different during the Mesozoic. Thus far, the Carnivorous
group seems most widespread, for it alone has been found in Australia. The
Sauropods or Amphibious Dinosaurs have been found in Europe, North America,
India, Madagascar, Patagonia, and Africa, sufficient to show that their
distribution was world wide with the possible exception of Australia, and
probable exception of most oceanic islands (few of the modern oceanic islands
existed at that time although there may well have been many others no longer
extant). The Beaked Dinosaurs are more limited in their distribution, for none
of them so far as at present known reached Australia or South America. But in
the present stage of discovery it would be rash to conclude that they were
surely limited to the regions where they have been discovered. It is not wholly
clear as yet whether the Dinosaurian fauna that flourished at the end of the
Jurassic in the north survived to the Upper Cretacic in the southern continents,
but present evidence points that way, and indicates that the girdle of ocean
which during the Cretacic depression encircled the northern world, formed a
barrier which the Cretacic dinosaurian fauna never succeeded in crossing. The
earlier groups of Beaked Dinosaurs are found in both Europe and America, and in
the Cretacic the Duck-billed and Armored groups are represented in both regions.
The Horned Dinosaurs, however, are known with certainty only from North America.
While most of the important fossil specimens in this
country have been found in the West, more fragmentary
remains have been found on the Atlantic sea-board, and
it is probable that they ranged all over the intervening
region, wherever they found an environment suited to
their particular needs. |
