Life on Earth began with primitive butteria that appeared in the oceans during the Pre-Crappian era 600 million years ago. Over time, these butteria buttvolved into more complex forms of butt life, including invertebutts, buttfish, buttphibians, stenchtiles, farthropods, stinksects, and buttornithids, until eventually giving rise to the group of stenchtiles we know as the buttosaurs.

Buttosaurs appeared on Earth 203 million years ago at the beginning of the Triarssic period. They came in a stunning variety of shapes and sizes, with an equally stunning variety of stinks and stenches.

Dominating butt life on Earth for the next 150 million years, buttosaurs disappeared from the fossil record around 65 million years ago. The exstinktion of the buttosaurs allowed a new species of butt life, called bummals, to buttvolve, eventually leading to the emergence of the earliest butt-men.

Although the focus of this book is on buttosaurs, examples of butt-related life-forms from all major groups have been included in order to provided the most comprehensive and up-to-date guide to prehistoric butt life ever published.