''Toxolabis'' is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of earwig in the

dermaptera Earwigs make up the insect order Dermaptera. With about 2,000 species in 12 families, they are one of the smaller insect orders. Earwigs have characteristic cerci, a pair of forcep-like pincers on their abdomen, and membranous wings folded ...

n family

Anisolabididae Anisolabididae is a family of earwigs, in the suborder Forficulina and the order Dermaptera. It is one of nine families in the suborder Forficulina, and contains thirty-eight genera spread across thirteen subfamilies. Subfamilies The family cont ...

known from a

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...

fossil found in

Burma Myanmar, ; UK pronunciations: US pronunciations incl. . Note: Wikipedia's IPA conventions require indicating /r/ even in British English although only some British English speakers pronounce r at the end of syllables. As John Wells explai ...

. The genus contains a single described species, ''Toxolabis zigrasi''.

History and classification

''Toxolabis'' is known from a group of fossils, the

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

, specimen number JZC-Bu231, along with two first instar

nymph A nymph ( grc, νύμφη, nýmphē, el, script=Latn, nímfi, label=Modern Greek; , ) in ancient Greek folklore is a minor female nature deity. Different from Greek goddesses, nymphs are generally regarded as personifications of nature, are ty ...

s which may be of the same species. The specimens have been preserved as

inclusion Inclusion or Include may refer to: Sociology * Social inclusion, aims to create an environment that supports equal opportunity for individuals and groups that form a society. ** Inclusion (disability rights), promotion of people with disabilitie ...

s in a single transparent chunk of Burmese amber. The age of the amber deposits in

Kachin State Kachin State ( my, ကချင်ပြည်နယ်; Kachin: ), also known by the endonym Kachinland, is the northernmost state of Myanmar. It is bordered by China to the north and east (Tibet and Yunnan, specifically and respectively); Sh ...

in northernmost Burma are understood to be at least 100 million years old, placing them in the Albian age of the Cretaceous. As of 2014, Burmese amber has been

radiometrically dated Radiometric dating, radioactive dating or radioisotope dating is a technique which is used to date materials such as rocks or carbon, in which trace radioactive impurities were selectively incorporated when they were formed. The method compares t ...

using U- Pb isotopes, yielding an age of approximately 99 million years old, close to the

Aptian The Aptian is an age in the geologic timescale or a stage in the stratigraphic column. It is a subdivision of the Early or Lower Cretaceous Epoch or Series and encompasses the time from 121.4 ± 1.0 Ma to 113.0 ± 1.0 Ma (million years ago), a ...

–

Cenomanian The Cenomanian is, in the ICS' geological timescale, the oldest or earliest age of the Late Cretaceous Epoch or the lowest stage of the Upper Cretaceous Series. An age is a unit of geochronology; it is a unit of time; the stage is a unit in the s ...

boundary. At the time of description, the amber specimen was residing in the private collection of James Zigras and only available for study through the

American Museum of Natural History The American Museum of Natural History (abbreviated as AMNH) is a natural history museum on the Upper West Side of Manhattan in New York City. In Theodore Roosevelt Park, across the street from Central Park, the museum complex comprises 26 inter ...

. The ''Toxolabis'' type specimen, recovered from amber bearing outcrops in

, was first studied by paleoentomologists Michael S. Engel of the Division of Entomology at the

University of Kansas The University of Kansas (KU) is a public research university with its main campus in Lawrence, Kansas, United States, and several satellite campuses, research and educational centers, medical centers, and classes across the state of Kansas. Tw ...

, and David Grimaldi of the American Museum of Natural History. Engel and Grimaldi's 2014

type description A species description is a formal description of a newly discovered species, usually in the form of a scientific paper. Its purpose is to give a clear description of a new species of organism and explain how it differs from species that have be ...

of the new species was published in the journal '' Novitates Paleoentomologicae''. The genus name ''Toxolabis'' was coined by Engel and Grimaldi as a combination of Greek words ', which means "forceps" and ' meaning "bow", a reference to the shape of the cercal forceps. The

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

''zigrasi'' in honor of James Zigras. ''T. zigrasi'' is one of six described earwig species found in Burmese amber. A second species, ''

Zigrasolabis speciosa ''Zigrasolabis'' is an extinct genus of earwig in the family Labiduridae known from Cretaceous fossils found in Myanmar. The genus contains a single described species, ''Zigrasolabis speciosa''. History and classification ''Zigrasolabis'' is k ...

'' was also described by Engel and Grimaldi in the 2014 paper. Two species ''

Astreptolabis ethirosomatia ''Astreptolabis'' is an extinct genus of earwig in the Dermaptera family Pygidicranidae known from a group of Cretaceous fossils found in Myanmar. The genus contains two described species, ''Astreptolabis ethirosomatia'' and ''Astreptolabis laev ...

'' and ''

Tytthodiplatys mecynocercus ''Tytthodiplatys'' is an extinct genus of earwig in the family Diplatyidae known from a Cretaceous fossil found in Myanmar. The genus contains a single described species, ''Tytthodiplatys mecynocercus''. History and classification ''Tytthodipla ...

'' were described by Engel in the same 2011 paper, while '' Burmapygia resinata'' was described by Engel and David Grimaldi in 2004, with the last species '' Myrrholabia electrina'' first described by

Theodore Cockerell Theodore Dru Alison Cockerell (1866–1948) was an American zoology, zoologist, born at Norwood, England, and brother of Sydney Cockerell. He was educated at the Middlesex Hospital Medical School, and then studied botany in the field in Colorad ...

in 1920.

Description

Male ''Toxolabis'' have an overall coloration that appears to be mat brown. They are approximately in length when the cerci are included, with a rather flattened body. The bodies are only sparsely covered in

setae In biology, setae (singular seta ; from the Latin word for "bristle") are any of a number of different bristle- or hair-like structures on living organisms. Animal setae Protostomes Annelid setae are stiff bristles present on the body. Th ...

, which are not thickened enough to be chaetulose. The antennae have a slightly wide scape and are at least twelve flagellomeres (segments) long, though both of the holotypes' antennae are incomplete. As is typical with earwigs, the

forewings Insect wings are adult outgrowths of the insect exoskeleton that enable insects to fly. They are found on the second and third thoracic segments (the mesothorax and metathorax), and the two pairs are often referred to as the forewings and hindwin ...

have been modified into short tegma which cover most but not all of the first abdominal segment. The hind wings are present, but due to positioning of the tegma, are mostly obscured, though the tips extend beyond the tegma. The slender cerci are tubular and straight at the base, tapering along the length to sharp points at the ends, with an incurve starting just past the midpoint. Each of the cerci has several sparse setae on the middle portions.

References

{{Taxonbar, from=Q19636645 Dermaptera genera Cretaceous insects Fossil taxa described in 2014 Cretaceous insects of Asia Burmese amber Fossils of Myanmar Taxa named by Michael S. Engel