c. 1000 B.C. - 400 B.C.
c.
c. 1000 B.C. – 400 B.C.: An established cultural frontier in Puerto Rico separated the Ortoiroid peoples from the Casimiroid groups residing in Hispaniola. This boundary facilitated the interaction and exchange of rare commodities, such as crystals and conical stone pestles, between the two distinct populations.
Source · p. 69
Rouse, The Tainos, 69