''Cephalopone'' 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 of ants in the formicid subfamily

Ponerinae Ponerinae is a subfamily of ants in the Poneromorph subfamilies group, with about 1,600 species in 47 extant genera, including '' Dinoponera gigantea'' - one of the world's largest species of ant. Mated workers have replaced the queen as the ...

described from fossils found in

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

. There are two described species placed into the genus, ''Cephalopone grandis'' and ''Cephalopone potens''. ''Cephalopone'' is one several Lutetian Ponerinae genera.

History and classification

When described, ''Cephalopone'' was known from three fossil insects which are compression-impression fossils preserved in layers of soft

sedimentary Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name for processes that cause these particles ...

rock. Along with other well preserved insect fossils, the ''Cephalopone'' specimens were collected from layers of the

Lutetian The Lutetian is, in the geologic timescale, a stage or age in the Eocene. It spans the time between . The Lutetian is preceded by the Ypresian and is followed by the Bartonian. Together with the Bartonian it is sometimes referred to as the ...

Messel pit The Messel pit (german: Grube Messel) is a disused quarry near the village of Messel (Landkreis Darmstadt-Dieburg, Hesse) about southeast of Frankfurt am Main, Germany. Bituminous shale was mined there. Because of its abundance of well-preserved ...

World Heritage Site A World Heritage Site is a landmark or area with legal protection by an international convention administered by the United Nations Educational, Scientific and Cultural Organization (UNESCO). World Heritage Sites are designated by UNESCO for ...

. The formation is composed of brown coals, oil shales, and

bituminous shale Oil shale is an organic-rich fine-grained sedimentary rock containing kerogen (a solid mixture of organic chemical compounds) from which liquid hydrocarbons can be produced. In addition to kerogen, general composition of oil shales constitut ...

, which preserved numerous insects, fish, birds, reptiles, and terrestrial mammals as a notable lagerstätten. The area is a preserved

maar lake A maar is a broad, low- relief volcanic crater caused by a phreatomagmatic eruption (an explosion which occurs when groundwater comes into contact with hot lava or magma). A maar characteristically fills with water to form a relatively shallo ...

which initially formed approximately 47 million years ago as the result of volcanic explosions. At the time of description, 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 seve ...

and

paratype In zoology and botany, a paratype is a specimen of an organism that helps define what the scientific name of a species and other taxon actually represents, but it is not the holotype (and in botany is also neither an isotype nor a syntype). O ...

specimens were preserved in the Senckenberg Research Station Messel fossil collections. The fossils were described by Gennady Dlussky and Sonja Wedmann in a 2012 paper on the poneromorph ants of Messel, with the genus and both species named in it. The genus name is a combination of the ant genus ''

Ponera ''Ponera'' is a genus of ponerine ants. The name is the Latinized form (') of the Ancient Greek ' (, 'wicked, wretched'). Description Workers are very small to small in size (1–4 mm); queen are similar to workers but winged. This genus ...

'' and the

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

word ''cephale'', meaning head. 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, bo ...

"grandis" is derived from the

Latin Latin (, or , ) is a classical language belonging to the Italic languages, 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 ...

meaning "strong," while the name "potens" is based on the Latin meaning "strong" or "powerful". ''Cephalopone'' is one of five extinct genera from three subfamilies which have species described from Messel Formation fossils by Dlussky and Wedmann in 2012. Three of the other genera ''

Cyrtopone ''Cyrtopone'' is an extinct genus of ants in the formicid subfamily Ponerinae described from fossils found in Europe. There are four described species placed into the genus, ''Cyrtopone curiosa'', ''Cyrtopone elongata'', ''Cyrtopone microcepha ...

'', ''

Messelepone ''Messelepone'' is an extinct genus of ants in the formicid subfamily Ponerinae described from fossils found in Europe. ''M. leptogenoides'' is the only species assigned to the genus, which is one of several Lutetian Ponerinae genera. Histor ...

'', and ''

Protopone ''Protopone'' is an extinct genus of ants in the formicid subfamily Ponerinae described from fossils found in Europe and Asia. There are seven described species placed into the genus, ''Protopone? dubia'', ''Protopone germanica'', ''Protopone ...

'' are also placed in Ponerinae. The genus '' Casaleia'' is placed in Amblyoponinae, while the last genus ''

Pseudectatomma ''Pseudectatomma'' is an extinct genus of ants in the formicid subfamily Ectatomminae described by from fossils found in Europe. The genus contains two species dating from the Eocene, ''Pseudectatomma eocenica'' and ''Pseudectatomma striatula'' ...

'' is in

Ectatomminae Ectatomminae is a subfamily 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 t ...

Description

The ''Cephalopone''

queens Queens is a borough of New York City, coextensive with Queens County, in the U.S. state of New York. Located on Long Island, it is the largest New York City borough by area. It is bordered by the borough of Brooklyn at the western tip of Long ...

from Messel are described as large, having approximate body lengths ranging over . Species have heads that are up to, but no longer than 1.5 times the length of the

mesosoma The mesosoma is the middle part of the body, or tagma, of arthropods whose body is composed of three parts, the other two being the prosoma and the metasoma. It bears the legs, and, in the case of winged insects, the wings. In hymenopterans of t ...

. The subtriangular mandibles are large, being over 80% of the length of the head, and have nine to ten teeth on the chewing faces. Like ''Protopone'' species, the antennae sockets are widely placed on the head, in contrast to those seen in ''

Pachycondyla ''Pachycondyla'' is a ponerine genus of ants found in the Neotropics. Distribution ''Pachycondyla'' is currently distributed from southern United States to northern Argentina, but some fossil species (e.g. '' P. eocenica'' and '' P. lutzi'') ar ...

'' which are close together. On both the hind and middle tibiae there are a pair of spurs, one simple and one pectinate. The petiole is rounded with a helcium that projects of the front face of the gasteral segment.

''C. grandis''

''C. grandis'' is known from a single fossil, consisting of a winged gyne preserved with the top of the body showing in the fossil. The body has an approximate length of with a squared off head that has slightly bulged back margin with rounded corners on each side. The clypeus has a slight downward cure along its front edge and bears a pair of protrusions on the lateral edges. The antennae have segments that range from 1.2 to 2 times as long as they are wide, with a scape is slightly extending past the back edge of the head. The large mandibles are about 87% of the head length and each one has ten teeth. The two teeth at the ends of the mandibles are both large, while the remaining teeth alternate between large and small.

''C. potens''

Two specimens were used to describe ''C. potens'', both of mostly complete winged queens preserved as dorsal impressions. The body length of the queens is between with a square shaped petiole and a

that is 1.5-1.6 times longer than the head. The small eyes are placed just to the front of the heads midpoint. The clypeus is rounded on it front edge and the antennae have a scape which reaches the back edge of the head. The

mandible In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower teeth in place. The mandible sits beneath the maxilla. It is the only movable bone ...

s are approximately the length of the head, subtriangular in shape, and have nine teeth alternating between large and small.

References

External links

* * {{Taxonbar, from=Q21344590 †Cephalopone Fossil taxa described in 2012 Hymenoptera of Europe Fossil ant genera Prehistoric life of Europe Eocene insects