Ctenizidae is a small family of mygalomorph spiders that construct burrows with a cork-like trapdoor made of soil, vegetation, and silk. They may be called trapdoor spiders, as are other, similar species, such as those of the families Liphistiidae, Barychelidae, and Cyrtaucheniidae, and some species in the Idiopidae and Nemesiidae. The name comes from the distinctive behavior of the spiders to construct trapdoors, and ambush prey from beneath them.
Archaeidae, also known as assassin spiders and pelican spiders, is a spider family with about ninety described species in five genera. It contains small spiders, ranging from 2 to 8 millimetres long, that prey exclusively on other spiders. They are unusual in that they have "necks", ranging from long and slender to short and fat. The name "pelican spider" refers to these elongated jaws and necks used to catch their prey. Living species of Archaeidae occur in South Africa, Madagascar and Australia, with the sister family Mecysmaucheniidae occurring in southern South America and New Zealand.
The Baltic region is home to the largest known deposit of amber, called Baltic amber or succinite. It was produced sometime during the Eocene epoch, but exactly when is controversial. 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.
Eoplectreurys is an extinct monotypic genus of spider from the family Plectreuridae, with a sole species, Eoplectreurys gertschi. The fossils of Eoplectreurys were recovered from the ~164 Ma old Middle Jurassic Daohugou formation tuffs in Inner Mongolia, China.
Aspidopleura is an extinct monotypic genus of parasitic wasp in the Eupelmidae subfamily Neanastatinae and at present, it contains the single species Aspidopleura baltica. The genus is solely known from the Early Eocene Baltic amber deposits in the Baltic Sea region of Europe.
Brevivulva is an extinct genus of parasitic wasp in the Eupelmidae subfamily Neanastatinae and contains the single species Brevivulva electroma. The genus is solely known from the Early Eocene Baltic amber deposits in the Baltic Sea region of Europe.
Metapelma archetypon is an extinct species of parasitic wasp in the Eupelmidae genus Metapelma. The species is solely known from the Early Eocene Baltic amber deposits in the Baltic Sea region of Europe. Of the thirty seven described species in the genus Metapelma, M. archetypon is the only species known from the fossil record.
Baltimartyria is an extinct genus of primitive metallic moths in the family Micropterigidae. The genus is solely known from the Early Eocene Baltic amber deposits in the Baltic Sea region of Europe. The genus currently contains two described species, Baltimartyria proavitella and Baltimartyria rasnitsyni.
Glisachaemus is an extinct monotypic genus of planthopper in the Cixiidae subfamily Cixiinae and at present, it contains the single species Glisachaemus jonasdamzeni. The genus is solely known from the Early Eocene Baltic amber deposits in the Baltic Sea region of Europe.
Baltocteniza is an extinct monotypic genus of spider in the family Ctenizidae. At present, it contains the single species Baltocteniza kulickae. The genus is solely known from the Early Eocene Baltic amber deposits in the Baltic Sea region of Europe.
Emiliana is an extinct genus of planthopper in the Tropiduchidae tribe Emilianini and containing the single species Emiliana alexandri. The species is known only from the Middle Eocene Parachute Member, part of the Green River Formation, in the Piceance Creek Basin, Garfield County, northwestern Colorado, USA.
Deinodryinus areolatus is an extinct species of Deinodryinus in the wasp family Dryinidae. The species is solely known from an Eocene fossil found in the Baltic region.
Arostropsis is an extinct genus of broad-nosed weevil in the beetle family Curculionidae known from an Upper Eocene fossil found in Europe. The genus contains a single described species, Arostropsis groehni.
Eulithomyrmex is an extinct genus of ant in the formicid subfamily Agroecomyrmecinae. The genus contains two described species, Eulithomyrmex rugosus and Eulithomyrmex striatus. Eulithomyrmex is known from a group of Late Eocene fossils which were found in North America.
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.
Metanephrocerus is an extinct genus of big-headed flies in the dipteran subfamily Protonephrocerinae, for which it is one of only two genera. The genus contains four described species, Metanephrocerus belgardeae, M. collini, M. groehni, and M. hoffeinsorum. Metanephrocerus is known from a group of Middle Eocene fossils which were found in Europe and a single early Eocene fossil from North America.
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.
Xylolaemus sakhnovi is an extinct species of cylindrical bark beetle in the family Zopheridae. The species is solely known from the Middle Eocene Baltic amber deposits in the Baltic Sea region of Europe. The genus Xylolaemus contains a total of six extant species distributed from western Europe through the Canary Islands and North Africa to India. The species is the first in the genus to be described from a fossil specimen.
