THE ARCHOSTEMATA (COLEOPTERA) OF NORTH AMERICA: WHERE ARE THE FOSSILS?

Five North American species represent about one-sixth of the global diversity of modern Archostemata, the Coleopteran suborder most often considered the sister group to the rest of the modern Coleoptera. Fossil Archostemata and Archostematan-like beetles are known from the Early Permian onwards; however, the majority of described fossils have been come from Europe and Asia where extant Archostemata are rare. Fossil Archostemata are also known from Australia, Africa, South America, and Antarctica, but until recently, there were few records of fossil Archostemata from North America. The lack of Permian beetles from North America has been especially perplexing since the Wellington formation of Kansas and Oklahoma is one of the most diverse deposits of Permian insects.

Recent discoveries reveal that North America has a much richer and more diverse record of Archostematan beetles than previously considered. The fossil record of beetles in North America now extends to the lower Permian and includes the second occurrence of Coleoptera worldwide, providing evidence that beetles were globally distributed early in their history. The on-going re-examination of LateTriassic material from the East Coast of the United States suggests a once diverse beetle fauna including several Archostematan-like morphologies. And, the Cretaceous of New Jersey has now yielded the first record of the extant South American genus Paracupes. These recent finds contribute to understanding the origin, evolution and geographic distribution of Coleoptera, and support the conclusion that there is an abundance of beetle fossils still to be uncovered.