1720
It is thought that the common ancestor of all spiders was orthognath and that in the Opisthothelae , comprising Mygalomorphae ( mostly tarantulas ) and Araneomorphae ( all other spiders ) , only the Araneomorphae changed their alignment of chelicerae , while the mygalomorphs retained this symplesiomorphic feature .
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Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
Answer:
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