Cockroach genera with synanthropic species (Blattella, Ectobius, Supella, Periplaneta, Diploptera and ?Blatta), as well as other insects such as honeybees, although natively limited to certain continents nowadays, had circumtropic distribution in the past. The ease of their reintroduction into their former range suggests a post-Early Miocene environmental stress which led to the extinction of cosmopolitan Tertiary entomofauna in the Americas, whilst in Eurasia, Africa and Australia this fauna survived. This phenomenon is demonstrated here on a low diversity (10 spp.) living cockroach genus Supella, which is peculiar for the circumtropical synanthropic brownbanded cockroach S. longipalpa and also for its exclusively free-living cavicolous species restricted to Africa. S. (Nemosupella) miocenica sp. nov. from the Miocene amber of Chiapas in Mexico is a sister species to the living S. mirabilis from the Lower Guinea forests and adjacent savannas. The difference is restricted to the shape of the central macula on the pronotum, and size, which may indicate the around-Miocene origin of the living, extremely polymorphic Supella species and possibly also the isochronic invasion into the Americas. The species also has a number of characteristics of the Asian (and possibly also Australian) uniform genus Allacta (falling within the generic variability of Supella) suggesting Supella is a direct ancestor of the former. The present species is the first significant evidence for incomplete hiati between well defined cockroach genera -a result of the extensive fossil record of the group. The reported specimen is covered by a mycelium of a parasitic fungus Cordyceps or Entomophthora.
Ectobius kohlsi sp. n. and three undetermined species of the common Eurasian cockroach genus EctobiusStephens, 1835 are reported from the lower middle Eocene of North America. This species indicates a cosmopolitan distribution of the genus during the mid Paleogene, and supports its current relict distribution in modern north-temperate and African ecosystems. When compared with the living species, E. kohlsi was either neutral or plesiomorphic in all characters, but exhibited a close relationship to the extant Ectobius kraussianusRamme, 1923 Species Group in the identical structure of the pronotum. E. kohlsi also was similar to extant Ectobius ticinusBohn, 2004, in the character of its wing venation (see Bohn 2004), in particular the forewing vein M, and to extant Ectobius vittiventris (Costa 1847) in details of forewing coloration. These latter two species are members of the Ectobius sylvestris Species Group (Bohn 1989). Ectobius balticusGermar et Berendt, 1856 —a conspicuously dominant cockroach from mid-Eocene Baltic amber—also appears plesiomorphic in all characters despite being a few million years younger than E. kohlsi. One reason for the complete disappearance of this dominant genus from North America is the peculiar consequence that, after 49 million years, a cool-adapted Ectobius lapponicus (L.) was capable of being reintroduced to a significantly cooler North America than that its antecedents which inhabited North America during a warmer European Eocene. Modern E. lapponicus is synanthropic in North America, even though no synanthropism is recorded for this species in its native habitat throughout Europe.
Cariblattoides labandeirai sp.n. from the Eocene sediments of Green River in Colorado, USA bear only two plesiomorphies, but also several significant autapomorphies within the advanced and highly derived living cockroach genus. Thus, Cariblattoides with extant occurrence in the Caribbean and South America was historically common in the Nearctic, and represents important evidence for the occurrence of derived living genera of cockroaches ∼50 Ma ago. Generally, the vast majority of living genera were absent during the Palaeocene, thus the diversification of most living cockroach lineages near the Palaeocene/Eocene boundary must have been extremely rapid. Females of living C. suave, the type species, have identical (sophisticated) coloration of pronotum, but the most related living taxa are C. piraiensis and C. fontesi from Brazil (supported by phylogenetical analysis).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.