transition.
Enter prehistoric Proboscidea, ancestors of the elephants, some of whom did not vanish until as recently as c. 400 AD. Prior to the most recent ice age, the order abounded, and included mammoths and mastodons. Paleontologists know of about 170 fossil species they now classify as belonging to the Proboscidea group, the earliest known being Phosphatherium dating from paleocene deposits of Morocco. A number of creatures described below, such as the genera Stegotetralophodon, are placed by some authorities within the Gomphotheres; others consider these beasts to be true Elephantidae. Yet uncertainty lingers, juggling elephants being harder than it looks.
Spoiler alert. Some entries in the Table make veiled reference to entries elsewhere. Because some of you tell us you’ve enjoyed discovering these associations on your own, may we suggest holding off reading the rubric items until you’ve spent some time with the Table as a whole? Which, if you can’t spring for the print, you’re welcome to find here.