''Cananeuretus'' 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
ant
Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from vespoid wasp ancestors in the Cretaceous period. More than 13,800 of an estimated total of 22 ...
in the
Formicidae subfamily
Aneuretinae
Aneuretinae is a subfamily of ants consisting of a single extant species, ''Aneuretus simoni'' ( Sri Lankan relict ant), and 9 fossil species. Earlier, the phylogenetic position of ''A. simoni'' was thought to be intermediate between primitive a ...
, and is one of two Cretaceous genera of the subfamily. The genus contains a single described species ''Cananeuretus occidentalis'' and is known from one
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the ...
fossil which has been found in
North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...
.
History and classification
''Cananeuretus'' is known from an adult fossil, 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 "TMP 8.89.7", and an additional partial worker tentatively assigned to the species. At the time of description, both specimens were residing in the paleontology collections housed at the
Royal Tyrell Museum
The Royal Tyrrell Museum of Palaeontology (RTMP, and often referred to as the Royal Tyrrell Museum) is a palaeontology museum and research facility in Drumheller, Alberta, Canada. The museum was named in honour of Joseph Burr Tyrrell, and is situa ...
,
Drumheller, Alberta
Drumheller is a town on the Red Deer River in the badlands of east-central Alberta, Canada. It is northeast of Calgary and south of Stettler. The Drumheller portion of the Red Deer River valley, often referred to as Dinosaur Valley, has ...
.
The holotype specimen is composed of a mostly complete
worker caste
Eusociality (from Greek εὖ ''eu'' "good" and social), the highest level of organization of sociality, is defined by the following characteristics: cooperative brood care (including care of offspring from other individuals), overlapping genera ...
adult female which has been preserved as an
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 disabiliti ...
in a transparent chunk of clear yellow
Canadian amber
Canadians (french: Canadiens) are people identified with the country of Canada. This connection may be residential, legal, historical or cultural. For most Canadians, many (or all) of these connections exist and are collectively the source of ...
. The
amber
Amber is fossilized tree resin that has been appreciated for its color and natural beauty since Neolithic times. Much valued from antiquity to the present as a gemstone, amber is made into a variety of decorative objects."Amber" (2004). In Ma ...
specimen was recovered from deposits of the
Foremost Formation
The Foremost Formation is a formation (stratigraphy), stratigraphic unit of Late Cretaceous (Campanian) age that underlies much of southern Alberta, Canada. It was named for outcrops in Chin Coulee near the town of Foremost, Alberta, ForemostGlas ...
near
Grassy Lake,
Alberta, Canada
Alberta ( ) is one of the thirteen provinces and territories of Canada, provinces and territories of Canada. It is part of Western Canada and is one of the three Canadian Prairies, prairie provinces. Alberta is bordered by British Columbia to t ...
.
Canadian amber has been dated to an age of approximately 79–78 million years old, placing it in the
Campanian
The Campanian is the fifth of six ages of the Late Cretaceous Epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campanian s ...
of the Late Cretaceous. Analysis of the amber composition indicates it originated as
cupressaceous resins which were deposited in lagoons and salt water marshes along the
Western Interior Seaway
The Western Interior Seaway (also called the Cretaceous Seaway, the Niobraran Sea, the North American Inland Sea, and the Western Interior Sea) was a large inland sea that split the continent of North America into two landmasses. The ancient sea, ...
.
The fossil was first studied by paleoentomologists
Michael Engel
Michael S. Engel, FLS, FRES (born September 24, 1971) is an American paleontologist and entomologist, notable for contributions to insect evolutionary biology and classification. In connection with his studies he has undertaken field expedit ...
and
David Grimaldi, both of the American Museum of Natural History.
Engel and Grimaldi's 2005
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 genus and species was published in the journal ''American Museum Novitates''.
The genus name ''Cananeuretus'' was coined as a combination of the genus name "''
Aneuretus
The Sri Lankan relict ant (''Aneuretus simoni'') is a species of ant placed in a tribe of its own within the family Formicidae. The genus is monotypic, with the only species endemic to Sri Lanka, where it is known from just a few locations. It ...
''" which is the type genus of the subfamily Aneuretinae, and Canada, in recognition of the country of origin. 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 ...
''occidentalis'' was based from the
Latin
Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...
word meaning ''from the west'', a reference the genus being the first Mesozoic aneuretine found in the Western Hemisphere.
''Cananeuretus'' is one of six ant species described from the Grassy Lake site, the others being ''
Canapone dentata'', ''
Chronomyrmex medicinehatensis'', ''
Eotapinoma macalpini'', ''
Haidoterminus cippus'', and ''
Sphecomyrma canadensis''.
In the type description, Engel and Grimaldi described ''Cananeuretus'' as a formicomorph genus based the
plesiomorphies
In phylogenetics, a plesiomorphy ("near form") and symplesiomorphy are synonyms for an ancestral character shared by all members of a clade, which does not distinguish the clade from other clades.
Plesiomorphy, symplesiomorphy, apomorphy, and ...
that are suggested to define the subfamily Aneuretinae. They excluded the genus from
Dolichoderinae
Dolichoderinae is a subfamily of ants, which includes species such as the Argentine ant (''Linepithema humile''), the erratic ant, the odorous house ant, and the cone ant. The subfamily presents a great diversity of species throughout the world ...
, which ''Eotapinoma'' belongs to, and separated the two genera based on the well developed sting on ''Cananeuretus'' in combination with an apparent lack of acidopore. ''Cananeuretus'' is the second Mesozoic genus to tentatively be placed into Aneuretinae, after the slightly older ''
Burmomyrma
''Burmomyrma'' is an extinct genus of aculeate hymenopteran, suggested to be an ant. The genus contains a single described species, ''Burmomyrma rossi''. ''Burmomyrma'' is known from a single Middle Cretaceous fossil which was found in Asia.
Hi ...
'' found in
Burmese amber
Burmese amber, also known as Burmite or Kachin amber, is amber from the Hukawng Valley in northern Myanmar. The amber is dated to around 100 million years ago, during the latest Albian to earliest Cenomanian ages of the mid-Cretaceous period. The ...
.
Description
''Cananeuretus'' has "primitive" mandibles, each having four distinct teeth present, the basal most being the largest. The compound eyes are small and well developed, being positioned low on the head making observation on the two described specimens hard, and ocelli are absent from both specimens. The twelve segmented antennae are placed in slightly upward positioned antennae sockets and have an elongated scape. The alitrunk is elongated in nature with a narrowing at the front forming a neck like appearance at the front. There are no lobes or projections on the
propodeum
The propodeum or propodium is the first abdominal segment in Apocrita Hymenoptera (wasps, bees and ants). It is fused with the thorax to form the mesosoma. It is a single large sclerite, not subdivided, and bears a pair of spiracles. It is strongl ...
, rather it is smoothly rounded. The legs are slim with a developed grove on the femurs forming trochantellus. The fore-legs have a calcar, or enlarged and modified seta, present. There are small brushes of grouped setae on the interior surfaces of both the
protibia and
probasitarsus. The
gaster is attached to the petiole with an elongated and enlarged connection on the second metasomal segment, while the petiole has a node in the middle. A number of large setae are scattered on the upper surface of the gaster and a large sting is present and extended from the gaster tip.
References
{{Taxonbar, from=Q21078765
Monotypic fossil ant genera
Cretaceous insects
Fossil taxa described in 2005
†
Aneuretinae
Prehistoric insects of North America
Canadian amber
Taxa named by Michael S. Engel