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" Eogastropoda " was a previously used taxonomic category of snails or gastropods , a subclass which was erected by Ponder and Lindberg in 1997 .
 Ponder, Lindberg
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Ponder, Lindberg