Any other fans of the Phasmatodea out there? For years, we kept a collection of stick insects — they are extremely easy to raise, and although they aren’t exactly dynamos of activity, they’re weird enough to be entertaining — and so I perk up when I notice a paper on them. The latest news is the discovery of a fossil leaf insect (also a member of the Phasmatodea, but a smaller subgroup specialized to resemble leaves rather than twigs) from 47 million years ago that resembles modern forms very closely. The cryptic camouflage of this group is ancient, and probably coevolved with the emergence of angiosperms.
Here’s the specimen.
In case you were wondering about relationships, here’s a very nice cladogram. One other detail is that there are about 3000 species of phasmids with the stick form, but only 37 that are leaflike, and all are confined to Southeast Asia; this fossil was found in Europe, where no such species are native.
Now I’m pining for our old insect pets — we had to leave them behind in one of our many moves. Anyone want to mail me some phasmid eggs?
Wedmann S, Bradler S, Rust J (2007) The first fossil leaf insect: 47 million years of specialized cryptic morphology and behavior. Proc Nat Acad Sci USA 104(2):565-569.