Blattoptera
Encyclopedia
Blattoptera , or proto-cockroaches, is a name given to various "roachid" fossil insects related to cockroach
es, mantis
es and termites, and of general cockroach-like appearance and possibly habit. The group is on the rank
of an order
, though being paraphyletic is most often given without formal taxonomic rank. Several alternative names have been suggested for this fossil group, including Blattodea, a name currently used for the group including the modern cockroaches (order Blattaria) as well as their fossil relatives.
. 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 mantis
es and termite
s. 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.
, legs built for running, flattened body and heavily veined wings with the distinct arched CuP-vein so typical of modern cockroach wings. 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. They probably inserted eggs singly into soil or crevices. The egg pods, called ootheca
, 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 mm in body length.
Cockroach
Cockroaches are insects of the order Blattaria or Blattodea, of which about 30 species out of 4,500 total are associated with human habitations...
es, mantis
Mantis
Mantis is the common name of any insect in the order Mantodea, also commonly known as praying mantises. The word itself means "prophet" in Latin and Greek...
es and termites, and of general cockroach-like appearance and possibly habit. The group is on the rank
Taxonomic rank
In biological classification, rank is the level in a taxonomic hierarchy. Examples of taxonomic ranks are species, genus, family, and class. Each rank subsumes under it a number of less general categories...
of an order
Order (biology)
In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
, though being paraphyletic is most often given without formal taxonomic rank. Several alternative names have been suggested for this fossil group, including Blattodea, a name currently used for the group including the modern cockroaches (order Blattaria) as well as their fossil relatives.
Systematic position
Cockroaches are popularly thought to be an ancient order of insects, with their origins in the CarboniferousCarboniferous
The Carboniferous is a geologic period and system that extends from the end of the Devonian Period, about 359.2 ± 2.5 Mya , to the beginning of the Permian Period, about 299.0 ± 0.8 Mya . The name is derived from the Latin word for coal, carbo. Carboniferous means "coal-bearing"...
. 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 mantis
Mantis
Mantis is the common name of any insect in the order Mantodea, also commonly known as praying mantises. The word itself means "prophet" in Latin and Greek...
es and termite
Termite
Termites are a group of eusocial insects that, until recently, were classified at the taxonomic rank of order Isoptera , but are now accepted as the epifamily Termitoidae, of the cockroach order Blattodea...
s. The origin of these groups from a blattopteran stock are now generally thought to be in the early Jurassic
Jurassic
The Jurassic is a geologic period and system that extends from about Mya to Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...
; the earliest modern cockroach found is from the Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
. Thus the “Palaeozoic cockroaches” are not cockroaches per se, but a paraphyletic assemblage of primitive relatives.
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 antennaeAntenna (biology)
Antennae in biology have historically been paired appendages used for sensing in arthropods. More recently, the term has also been applied to cilium structures present in most cell types of eukaryotes....
, legs built for running, flattened body and heavily veined wings with the distinct arched CuP-vein so typical of modern cockroach wings. 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
Ovipositor
The ovipositor is an organ used by some animals for oviposition, i.e., the laying of eggs. It consists of a maximum of three pairs of appendages formed to transmit the egg, to prepare a place for it, and to place it properly...
, a primitive insect trait. They probably inserted eggs singly into soil or crevices. The egg pods, called ootheca
Ootheca
An ootheca is a type of egg mass made by any member of a variety of species .The word is a latinized combination of oo-, meaning "egg", from the Greek word ōon , and theca, meaning a "cover" or "container", from the Greek theke...
, 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
Carboniferous
The Carboniferous is a geologic period and system that extends from the end of the Devonian Period, about 359.2 ± 2.5 Mya , to the beginning of the Permian Period, about 299.0 ± 0.8 Mya . The name is derived from the Latin word for coal, carbo. Carboniferous means "coal-bearing"...
Archimylacris
Archimylacris
Archimylacris is an extinct genus of cockroach-like Blattopterans, a group of insects ancestral to cockroaches, mantids and termites.Archimylacris lived on the warm swampy forest floors of North America and Europe 300 million years ago, in the Late Carboniferous times...
and the Permian
Permian
The PermianThe term "Permian" was introduced into geology in 1841 by Sir Sir R. I. Murchison, president of the Geological Society of London, who identified typical strata in extensive Russian explorations undertaken with Edouard de Verneuil; Murchison asserted in 1841 that he named his "Permian...
Apthoroblattina
Apthoroblattina
Apthoroblattina is an extinct genus of primitive cockroach from the Carboniferous Period. Fossils of the genus have been found in England, Wales, the United States, and Russia. The paratype specimen for the species A...
, the latter who could reach 50 mm in body length.