Simon, they do drill holes in pottery sometimes to repair it. Also, sometimes they would drill holes on opposing sides of the rim, to suspend them by (like in seed jars). However, in this case...I believe it's a case of Hopewellian pottery (rarer than hen's teeth) that had the nodes broken off at the top, making the "holes". I have several pieces of pottery like it and let me tell you, it's some of the most rare and hard to acquire pottery there is. I have hundreds of pottery vessels (yes, hundreds)...and not a single totally complete Hopewellian pot. They are more rare than any clovis, Eden, Complete Calf Creek, Folsom, or even a Mimbres Figural. I have found alot of Cooper Zone Stamped vessel shards..but none close to complete, it's a goal of mine. If I can remember some time, I'll take pics of some Hopewellian pottery just like that shard to show.