38454
The continuity of glaciers , inferred from oriented glacial striations and deposits called tillites , suggested the existence of the supercontinent of Gondwana , which became a central element of the concept of continental drift .
 Gondwana
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Gondwana