Blattoptera

Taxobox
name = Blattoptera
status = fossil
fossil_range = Carboniferous to late Permian
regnum = Animalia
phylum = Arthropoda
classis = Insecta
ordo = Blattoptera

Blattoptera is a name given to various "roachid" fossil insects related to cockroaches, mantises and termites, and of general cockroach-like appearance and possibly habit. [Henning, W. (1981): Insect Phylogeny. Wiley, Chichester, Britain] The group is on the level of an order, though being paraphyletic is most often given without formal taxonomic level. Several alternative names have been suggested for this fossil group, including Blattodea [Henning, W. (1981): Insect Phylogeny. Wiley, Chichester, Britain] , a name currently used for the group including the modern cockroaches (order Blattaria) as well as their fossil relatives.Grimaldi, D (1997): A fossil mantis (Insecta: Mantoidea) in Cretaceous amber of New Jersey, with comments on early history of Dictyoptera. American Museum Novitates 3204: 1-11]

ystematic position

Cockroaches are popularly thought to be an ancient order of insects, their origin laying back in the Carboniferous. [Guthrie, D. M. & A. R. Tindal (1968): The Biology of the Cockroach. St. Martin's Press, New York] However, since the middle of the 20th century it has been known that the primitive cockroach insects found fossilized in Palaeozoic strata are the forerunners not only of modern cockroaches but also of mantises and termites. The origin of these groups from a blattopteran stock are now generally thought to be in the early Jurassic, the earliest modern cockroach found is from the Cretaceous. Thus the “Palaeozoic cockroaches” are not cockroaches per se, but a paraphyletic assemblage of primitive relatives. [Grimaldi, D. & M. S. Engel, Michael (2005): Evolution of the Insects, Cambridge University Press, ISBN 0521821495]

Anatomy and habits

The fossils assigned to the "roachids" are of general cockroach-like build, with a large disc-like pronotum covering most of the head, long antennae, legs built for running, flattened body and heavily veined wings with the distinct arched CuP-vein so typical of modern cockroach wings. [Schneider, J. (1983): Die Blattodea (Insecta) des Paleozoicums, Teil II, Morphogenese des Flügelstrukturen und Phylogenie. "Freiberger Forchnungshefte, Reie C 391. pp 5-34] Like modern cockroaches, the roachids were probably swift litter inhabitants living on a wide range of dead plant and animal matter.

Contrary to modern forms, the female roachids all have a well developed external ovipositor, a primitive insect trait [Grimaldi, D. & M. S. Engel, Michael (2005): Evolution of the Insects, Cambridge University Press, p 227] . They probably inserted eggs singly into soil or crevices. The egg pods seen in modern cockroaches and their relatives is a new shared trait separating them from their primitive ancestors. Some of the roachid species could reach relatively large sizes compared to their modern relatives, like the Carboniferous "Archimylacris" and the Permian "Apthoroblattina", the latter who could reach 50 cm in body length.

References