A 21-year-old man from Thanedistrict in Maharashtra has been allegedly killed by his cousin over some petty dispute, police said on Monday.The incident occurred around 9 pm on Sunday in Usrovali village in Bhiwandi taluka, around 15 kms from here, when the accused Kishore Waghe (26) allegedly smashed the head of Balu Waghe with a stone, a police officer said.The accused is yet to be arrested.A case of murder has been registered by local police, the officer said.