Just to clarify, Lithuanian is not a direct descendant (in language terms) of Sanskrit. It is an Indo-European (IE) language, so part of the same family that includes Sanskrit and also Russian and English, among many others. Lithuanian is famously conservative and therefore the cognates between it and the ancient IE languages are quite obvious, however, that should be confused with Lithuanian being directly descended from Sanskrit. Lithuanian is a Baltic language, from the Balto-Slavic branch of Indo-European (Russian is in the Slavic half of that branch). Sanskrit is from the Indo-Aryan subgroup of the Indo-European languages, so they might be understood as linguistic cousins.