You are bidding on Megalodon's Lunch a Large Bone Valley Dugong Rib Bone Section ( Metaxytherium Floridanum) precursor to today's Manatee.Rib section was found in the Phosphate pits in Bone Valley in 2007 and is Miocene age 14.2 million to 6.7 million.Rib sections are Black and Dark Brown  .Measurements, Length largest piece 4.246 " , 2nd 4.233 " 3rd 4.009 " 4th 2.931 " and last piece 2.084 "weight 2.lbs . Good Luck from Kingfossils !!!!