Matthews 1979

Matthews JV Jr. 1979. Late Tertiary carabid fossils from Alaska and the Canadian archipelago. In: Carabid Beetles: Their Evolution, Natural History, and Classification (Erwin TL, Ball GE, Whitehead DR, Halpern AL eds.). Dr. W Junk bv Publishers, The Hague, Netherlands.

For this special symposium, this author summarizes recently discovered and analysed beetle fossils dating from the late Tertiary, and compares them with similar fossils from the Pleistocene. Most Tertiary fossils of insects are either casts or impressions, and beetle fossils tend to be crushed and scattered too severely for good identification and analysis. However, fossils dating from the late Miocene and early Pliocene (roughly 5 million years ago) were discovered at several sites across the western islands of the Canadian Archipelago and a site in western Alaska that resemble Pleistocene fossils in their quality of preservation. The western Alaska site is particularly valuable because the fossil-bearing layer is overlain by a layer of basalt flow, possibly from a volcanic eruption, that can be dated without recourse to biological materials. There was apparently a narrow connection between Alaska and Siberia at the time these fossils were produced.

In general, smaller-bodied beetles are better preserved than large, but many specimens of numerous genera were discovered. Matthews (1977) includes a complete list of all fossil Coleoptera found, including the carabids described here. Several examples of species-diagnostic features were found, including highly detailed elytra and parts of male genitalia.

The first part of the discussion of this paper is a critique of the strictly-Hennigian methods of Phylogenetic Systematics, which disallows phyletic evolution, i.e. changes in species phenotypes through time without associated lineage splitting. Later parts of the discussion describe the probable Taiga ecosystem present at very high latitudes in the late Miocene. The author ends the paper with optimism that similar high-quality Tertiary fossils may soon be found in other high latitude areas around the world.