| Pachycondyla succinea Temporal range: | |
|---|---|
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| P. succinea male | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Insecta |
| Order: | Hymenoptera |
| Family: | Formicidae |
| Genus: | Pachycondyla |
| Species: | †P. succinea |
| Binomial name | |
| †Pachycondyla succinea (Mayr, 1868) | |
| Synonyms | |
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Pachycondyla succinea is an extinct species of ant in the formicid subfamily Ponerinae described from fossils found in Europe. P. petrosa is one of three middle Eocene Pachycondyla species found in Baltic amber.
When described Pachycondyla succinea was known only from three queen fossils which were fossilized as inclusions in transparent chunks of Baltic amber [1] [2] which are now presumed lost. [3] Additional queens have since been found in Baltic, Rovno, and Scandinavian amber. [1] Males were later identified from Baltic and Bitterfeld ambers. [3] [4]
Baltic amber is approximately forty six million years old, having been deposited during Lutetian stage of the Middle Eocene. There is debate on what plant family the amber was produced by, with macrofossil and microfossil evidence suggesting a Pinus relative, while chemical and spectroscopic evidence suggests Agathis or Sciadopitys . [5] [6] The paleoenvironment of the Eocene Baltic forests where the P. eocenicum lived was that of humid temperate to subtropical islands. The forests were composed of mostly Quercus and Pinus species, while the lower sections of the forests had paratropical plant elements, such as palms. [5] Rovno amber, recovered from deposits in the Rivne region of Ukraine, is slightly younger in age, being dated to the Bartonian to Priabonian of the Late Eocene. [7] Bitterfeld amber is recovered from coal deposits in the Saxony area of Germany and the dating of the deposits is uncertain. Bitterfeld represents a section of the Eocene Paratethys Sea, and the amber that is recovered from the region is thought to be redeposited from older sediments. The fossil record of Bitterfeld and Baltic amber insects is very similar with a number of shared species, and that similarity is noted in the suggestions of a single source for the paleoforest that produced the amber. [8] The amber deposits on the Danish coast, often referred to as Scandinavian amber, is of similar age to the other three European ambers, however a study of the ant fauna published in 2009 indicates Scandinavian amber has a fairly distinct ant assemblage. [1]
The species was first described in 1868 by Austrian entomologist Gustav Mayr based on three queens. He named the species and placed it into the genus Ponera as Ponera succinea. [9] [1] The species was redescribed in 1915 by William Morton Wheeler based on a group of 21 queens, including one of Mayrs three original syntypes. Based on the queens examined, Wheeler moved the species to the genus Euponera as Euponera (Trachymesopus) succinea. The placement was unchanged until 1995 when Euponera was synonymized with Pachycondyla by Barry Bolton. [1] [3] Pachycondyla was split into a number of genera in 2014 with most of the extant species being placed into other genera, but a series of fossil species including P. succinea were not moved. Schmidt and Shattuck in the revision of the genus noted that many of the fossil species were not moved due to specimens not being examined by them, and that the placement of the species was "undoubtedly incorrect". [10] Males of the species were first formally described in 2009, based on specimens preserved in Baltic and Bitterfeld ambers. [3]
P. succinea is one of three Pachycondyla species described from Baltic amber, the other two being P. baltica and P. gracillicornis . In addition to these species, one species is known from Rovno amber, P. conservata , and one species is known from Bitterfeld amber, P. tristis . [3]
The queens have a body length of 4–6 mm (0.16–0.24 in), with dense pitting along all of the body excluding the gaster, which is smooth. There are hairs spread evenly over the body with a mix of decumbent, erect, and partially erect hairs. The flat laying and partially erect hairs of the gaster are longer than the space between adjacent hairs. The head is rectangular in outline with distinctly developed rear corners, a concave rear margin, and small distinct ocelli. The compound eyes, slightly bulged out with oval outlines, are placed far forward on the head, shortening the gena to shorter than the eye diameter. The antennae are composed of 12 segments, with the basal and tip segments longer than wide, while the rest are shorter than wide. The bottom most segment, the scape, is longer than the other antenna segments, but does not reach the rear edge of the head. There are six teeth on the chewing face of the mandibles, and no external tooth on the outer margin. [3]
The males are smaller than the queens, with a total body length between 3.5–4.5 mm (0.14–0.18 in) and an overall shiny exoskeleton. There are longitudinal ridges on the propodeum sides, while the petiole is smooth. There is dense pitting on the head and sparser pitting is present on the gaster and mesosoma. Many upright hairs are found on the gaster, petiole scale, upper surface of the mesosoma, and on the head. Decumbent hairs are present over the whole exoskeleton, showing most distinctly on the gaster, where the hairs are "several times" longer than that of the spacing between each hair. [3] The head is rounded in outline, with a convex rear edge and no distinct rear corners, but instead has a slight expansion of the anterior section and no frontal ridges are present. The eyes are kidney shaped, slightly bulging, and large, placed far forward on the head. The ocelli are also large, but smaller than the distance between each of the three. [3]
The Baltic region is home to the largest known deposit of amber, called Baltic amber or succinite. It dates from 44 million years ago. It has been estimated that these forests created more than 100,000 tons of amber. Today, more than 90% of the world's amber comes from Kaliningrad Oblast of Russia. It is a major source of income for the region; the local Kaliningrad Amber Combine extracted 250 tonnes of it in 2014, 400 tonnes in 2015.
Prionomyrmex is an extinct genus of bulldog ants in the subfamily Myrmeciinae of the family Formicidae. It was first described by Gustav Mayr in 1868, after he collected a holotype worker of P. longiceps in Baltic amber. Three species are currently described, characterised by their long mandibles, slender bodies and large size. These ants are known from the Eocene and Late Oligocene, with fossil specimens only found around Europe. It is suggested that these ants preferred to live in jungles, with one species assumed to be an arboreal nesting species. These ants had a powerful stinger that was used to subdue prey. In 2000, it was suggested by Cesare Baroni Urbani that the living species Nothomyrmecia macrops and a species he described both belonged to Prionomyrmex, but this proposal has not been widely accepted by the entomological community. Instead, scientists still classify the two genera distinctive from each other, making Nothomyrmecia a valid genus.
Ypresiomyrma is an extinct genus of ants in the subfamily Myrmeciinae that was described in 2006. There are four species described; one species is from the Isle of Fur in Denmark, two are from the McAbee Fossil Beds in British Columbia, Canada, and the fourth from the Bol’shaya Svetlovodnaya fossil site in Russia. The queens of this genus are large, the mandibles are elongated and the eyes are well developed; a stinger is also present. The behaviour of these ants would have been similar to that of extant Myrmeciinae ants, such as solitary foraging for arthropod prey and never leaving pheromone trails. The alates were poor flyers due to their size, and birds and animals most likely preyed on these ants. Ypresiomyrma is not assigned to any tribe, and is instead generally regarded as incertae sedis within Myrmeciinae. However, some authors believe Ypresiomyrma should be assigned as incertae sedis within Formicidae.
Pristomyrmex rasnitsyni is an extinct species of ant in the genus Pristomyrmex. The species is known from a single Late Eocene fossil which was found in Europe.
Yantaromyrmex is an extinct genus of ants first described in 2013. Members of this genus are in the subfamily Dolichoderinae of the family Formicidae, known from Middle Eocene to Early Oligocene fossils found in Europe. The genus currently contains five described species, Y. constrictus, Y. geinitzi, Y. intermedius, Y. mayrianum and Y. samlandicus. The first specimens were collected in 1868 and studied by Austrian entomologist Gustav Mayr, who originally placed the fossils in other ant genera until the fossils were reviewed and subsequently placed into their own genus. These ants are small, measuring from 4 to 6 mm in length and can be characterized by their trapezoidal shaped head-capsules and oval compound eyes that are located slightly to the rear of the capsules midpoint, with no known ocelli present.
Zherichinius is an extinct genus of ants in the subfamily Dolichoderinae known from fossils found in amber from the Middle Eocene of Sakhalin island Far eastern Russia and Bitterfeld, Germany. At the time of description the species Zherichinius horribilis and Zherichinius rapax were two of eight ant species known from Sakhalin fossils.
Liometopum imhoffii is an extinct species of ants in the dolichoderine genus Liometopum. The species was described from a number of Early Miocene fossils found in what is now Croatia.
Pachycondyla eocenica is an extinct species of ant in the formicid subfamily Ponerinae described from fossils found in Europe. P. eocenica is one of six Lutetian Pachycondyla species.
Pachycondyla lutzi is an extinct species of ant in the formicid subfamily Ponerinae described by from fossils found in Europe. P. lutzi is one of six Lutetian Pachycondyla species.
Pachycondyla? messeliana is an extinct species of ants in the formicid subfamily Ponerinae described by from a fossil found in Europe. P.? messeliana is one of six Lutetian Pachycondyla species.
Pachycondyla petiolosa is an extinct species of ant in the formicid subfamily Ponerinae described by from a fossil found in Europe. P. parvula is one of six Lutetian Pachycondyla species.
Pachycondyla petrosa is an extinct species of ant in the formicid subfamily Ponerinae described from a fossil found in Europe. P. petrosa is one of six Lutetian Pachycondyla species.
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 magna, Protopone oculata, Protopone primigena, Protopone sepulta, and Protopone vetula. Protopone is one several Lutetian Ponerinae genera.
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.
Aneuretellus is an extinct genus of ant in the formicid subfamily Aneuretinae, and is one of eight genera of the subfamily. The genus contains a single described species Aneuretellus deformis and is known from one Middle Eocene fossil which was found in Sakhalin in the Russian Far East.
Bradoponera is an extinct genus of ant in the Formicidae subfamily Proceratiinae, and is one of four genera of the subfamily. The genus contains four described species Bradoponera electrina, Bradoponera meieri, Bradoponera similis, and Bradoponera wunderlichi. The species are known from several Middle Eocene amber fossils which were found in Europe.
Pachycondyla oligocenica is an extinct species of formicid in the ant subfamily Ponerinae known from a fossil found in eastern Asia.
Proceratium eocenicum is an extinct species of formicid in the ant subfamily Proceratiinae known from fossils found in the Baltic region.
Electromyrmex is an extinct genus of ants in the formicid subfamily Dolichoderinae. The genus contains a single described species, Electromyrmex klebsi and is known from a group of Middle Eocene fossils which were found in Europe.
Nylanderia pygmaea is an extinct species of formicid in the ant subfamily Formicinae known from fossils found in the Baltic region.
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