These blocks have been mined on the old mainnet chain, presumably having failed to update the miner software for the Constantinople fork - a waste of money...
block 7280000 miner 0x06b8c5883ec71bc3f4b332081519f23834c8706e extradata .......geth.go1.10.4.linux
block 7280001 miner 0x96338149e9f6c262d4cb7aeec1cf4c652079a11c extradata .......Parity-Ethereum.1.30.1.li
block 7280002 miner 0x28974b4a92e7be907418722b37446f2eb60184cc extradata .......geth.go1.10.linux
block 7280003 miner 0x06b8c5883ec71bc3f4b332081519f23834c8706e extradata .......geth.go1.10.4.linux
block 7280004 miner 0x96338149e9f6c262d4cb7aeec1cf4c652079a11c extradata .......Parity-Ethereum.1.30.1.li
block 7280005 miner 0x8e59176cd996342da6fdf20c85cb02bca095d552 extradata .Grupo+58
block 7280006 miner 0x96338149e9f6c262d4cb7aeec1cf4c652079a11c extradata .......Parity-Ethereum.1.30.1.li
block 7280007 miner 0x06b8c5883ec71bc3f4b332081519f23834c8706e extradata .......geth.go1.10.4.linux
block 7280008 miner 0x96338149e9f6c262d4cb7aeec1cf4c652079a11c extradata .......Parity-Ethereum.1.30.1.li
block 7280009 miner 0xeea5b82b61424df8020f5fedd81767f2d0d25bfb extradata .a/BTC.COM/
block 7280010 miner 0xeea5b82b61424df8020f5fedd81767f2d0d25bfb extradata .a/BTC.COM/
block 7280011 miner 0xeea5b82b61424df8020f5fedd81767f2d0d25bfb extradata .a/BTC.COM/
block 7280012 miner 0xeea5b82b61424df8020f5fedd81767f2d0d25bfb extradata .a/BTC.COM/
block 7280013 miner 0x06b8c5883ec71bc3f4b332081519f23834c8706e extradata .......geth.go1.10.4.linux
block 7280014 miner 0x06b8c5883ec71bc3f4b332081519f23834c8706e extradata .......geth.go1.10.4.linux