6334
The blastoids , which included the Pentreinitidae and Codasteridae and superficially resembled crinoids in the possession of long stalks attached to the seabed , attain their maximum development at this time .
 Pentreinitidae, Codasteridae
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Pentreinitidae, Codasteridae