When i got my fluid changed there was a piece in the oil pan, what is it?

i have a 2006 dodge 5.9l diesel bighorn edition. my truck was shifting funny so i took it in for a fluid change, the mechanic brought me out a piece and said he didnt know what it was, the part looks like the end of a crowbar. my truck still moves, overdrive and towing still works, i just dont know what this thing was and neither did the mechanic.