This is the first printing of the original omnibus edition of Mark's Xenozoic Tales. This sports Mark's original cover illustration which was replaced for the 2013 reprint. This edition is 8.5 x 11, the current edition is an inch shorter.
From the publisher:
After the ecological cataclysm, the last men and women fight to survive a prehistoric nightmare! Xenozoic combines lush and richly realized ink-and-brush artwork with a pulp-fueled narrative to create an action-packed fantasy -- an unrelenting adventure that also serves as a subtle cautionary fable concerning the unforeseen consequences that shortsighted present decisions might have upon future generations.
Introduction by Craig Elliott.