Complex sentence: The earliest chariots known are from chariot burials of the Sintashta-Petrovka culture in modern Russia, clustering along the upper Tobol river, southeast of Magnitogorsk, from around 2,000 BC, containing spoke-wheeled chariots drawn by teams of two horses.
Split into simpler sentences: The earliest chariots known are from around 2,000 BC, in burials of the Sintashta-Petrovka culture in modern Russia in a cluster along the upper Tobol river, southeast of Magnitogorsk. They contained spoke-wheeled chariots drawn by teams of two horses.