Easter egger and americaunas are the same thing, mixed breed birds that lay pastel eggs.
Ameracauna, notice the middle A instead of an I, are a real pure breed that lay blue eggs.
AMERAUCANA is a purebred bird. Spelled any other way, it is a mixed breed, "mutt," commonly called an Easter Egger. Very popular, much less expensive than a true Ameraucana, but lays a colored egg, usually blueish, greenish, but also possibly pink or brown. So .. Americana, Ameracana, etc., any other spelling, buyer beware. Not purebred, won't breed "true."