Seat bolts: need helping identifying head type

[sh0rtlife]

sorry to say...but...thats EXACTLY what i expected to happen

now...grab a chissel and try and bite the edge of the base of the bolt and hit it in a direction of loosening it, it may or may not budge but keep doing it all the way around and youll either chew enough material off to get the seat off the bolt or youll loosen it up and it will slowly walk out

if you chew the ridge off the head so the rail can come off you can easily get a set of vise grips on the head and slwoly work it back n forth