Raymond Jones 
The Alien (Serapis Classics) [EPUB ebook] 

Just speculate for a moment on the enormous challenge to archeology when interplanetary flight is possible … and relics are found of a race extinct for half a million years! A race, incidentally, that was scientifically so far in advance of ours that they held the secret of the restoration of life!
One member of that race can be brought back after 500, 000 years of death….
That’s the story told by this ORIGINAL book-length novel, which has never before been published! You can expect a muscle-tightening, sweat-producing, mind-prodding adventure in the future when you read it!