''Dlusskyidris'' is an
extinct
Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...
genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
of
ant
Ants are Eusociality, eusocial insects of the Family (biology), family Formicidae and, along with the related wasps and bees, belong to the Taxonomy (biology), order Hymenoptera. Ants evolved from Vespoidea, vespoid wasp ancestors in the Cre ...
in the
Formicidae subfamily
Sphecomyrminae
Sphecomyrminae is an extinct subfamily of ants in family Formicidae known from a series of Cretaceous fossils found in North America, Europe, and Asia. Sphecomyrminae contains eight genera, divided into two tribes Sphecomyrmini and Zigrasimeciin ...
, and is one of the five genera placed in the tribe
Sphecomyrmini. The genus contains a single described species, ''Dlusskyidris zherichini'', and is known from three
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the more recent 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 ''cre ...
fossils which have been found in
northern Russia.
History and classification
The three males of ''Dlusskyidris'' have been identified from adults that are preserved as inclusions in
Taymyr amber.
The ambers of the peninsula occur in the upper levels of the
Kheta Formation, which is exposed in a number of locations in the Taimyr region. Age estimates of the Kheta Formation are between the
Coniacian and
Santonian
The Santonian is an age in the geologic timescale or a chronostratigraphic stage. It is a subdivision of the Late Cretaceous Epoch or Upper Cretaceous Series. It spans the time between 86.3 ± 0.7 mya ( million years ago) and 83.6 ± 0.7 m ...
, and the ambers are found consistently in the uppermost units, giving a Santonian age range for the inclusions.
The ''Dlusskyidris'' adults were collected from the Yantardakh locality,
which is approximately upstream from the confluence of the
Maimecha River with the
Kheta River, on the bank of the Maimecha.
Based on the flora and fauna of the
Ledyanaya and
Mutino formations which surround the Kheta Formation, the paleoforest likely has a humid and warm temperate climate with the trees growing along river banks. While the resin producing trees have not been identified, the resins were likely dropped into the river systems and buried quickly in
deltaic sediments.
The three males were first studied by Russian paleoentomologist
Gennady Dlussky, who published the genus and species description in a 1975 paper. In that paper Dlussky named the genus "''Palaeomyrmex''" and the species "''Palaeomyrmex zherichini''". However the genus name ''Palaeomyrmex'' had already been used over a hundred years earlier by
Oswald Heer for ''
Palaeomyrmex prodromus''. Due to the name being
preoccupied, the species was moved to the new genus name ''Dlusskyidris'' in 1994 by
Barry Bolton.
Russian paleoentomologist K. S. Perfilieva re-examined the holotype and paratype fossils 2011. Perfilieva noted that the visibility of the wings and the refractive index of the amber had been altered due to years of storage in
castor oil.
The oil had seeped into the amber, filling in air bubbles and making the wings nearly invisible under light microscope examination.
Description
The ''Dlusskyidris'' males are distinguished from other Sphecomyrminae males based on several features. There are spurs present on the tibias of the hind and mid legs.
The
tergite of the end abdominal segment is triangular in shape, as is the subgenital plate. There are well developed cerci on the abdomen, the
parameres are narrow with slight curving in the middle and pointed tips.
In Dlussky's original description, he considered the wing venation primitive and similar to that of
Armaniidae genera with complete cells 1r+2r, 3r and 2rm. Perfilieva noted however that two different versions of the venation were presented by Dlussky.
References
{{Taxonbar, from=Q18102432
Sphecomyrminae
Cretaceous insects
Monotypic fossil ant genera
Fossil taxa described in 1975
Fossil taxa described in 1994
Cretaceous insects of Asia
Taimyr amber