8886
" M. brentbaatar " was described by Robert T. Bakker in 1998 , who originally placed it in the genus " Ctenacodon " .
 Robert T. Bakker
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Robert T. Bakker