Complex sentence: These holdings were consolidated into The Pridemore Oil Company, portions of which were later acquired by Standard Oil, Adkins Oil and the McJunkin-Red Man Corporation, though some are still privately held by Pridemore's descendants.
Split into simpler sentences: These holdings were consolidated into Pridemore Oil Company, portions of which were acquired by Standard Oil. Other oil holdings were eventually merged into Adkins Oil and the McJunkin-Red Man Corporation, though some are still privately held by Pridemore's descendants.