Complex sentence: In South America, "C. dirus" specimens that have been dated to the Late Pleistocene were found along the north and west coasts, but none have been found in Argentina that was inhabited by "Canis gezi" and "Canis nehringi".
Split into simpler sentences: In South America, Late Pleistocene "dirus" remains have been found along the north and west coasts but nowhere else. Its remains have not been found in Argentina that was inhabited by "Canis gezi" and "Canis nehringi".