Task: Sentence Expansion
Input (English): Neotropical Pygmy Squirrel , " Sciurillus pusillus " , is a very small squirrel species from South America .
Output (English): The Neotropical pygmy squirrel ( " Sciurillus pusillus " ) is a South American species of tree squirrel , being the only living species in the genus Sciurillus and the subfamily Sciurillinae .