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.
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.
Electrinocellia is an extinct monotypic genus of snakefly in the family Inocelliidae containing the single species Electrinocellia peculiaris and known from Eocene aged Baltic amber.
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 Metapelmatidae 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.
Electrocteniza is an extinct monotypic genus of spider in the family Ctenizidae. At present, it contains the single species Electrocteniza sadilenkoi. The genus is solely known from the Early Eocene Baltic amber deposits in the Baltic Sea region of Europe.
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.
Pseudogarypus synchrotron is an extinct species of pseudoscorpion in the family Pseudogarypidae known from only two Eocene fossils found in Europe. P. synchrotron is one of four species in the genus Pseudogarypus to have been described from fossils.
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.
Aphaenogaster mersa is an extinct species of ant in the subfamily Myrmicinae known from a pair of Middle Eocene fossils found in Europe. A. mersa is one of three species in the ant genus Aphaenogaster to have been noted from fossils found in Baltic amber by William Morton Wheeler.
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.
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.
Halonoproctidae is a family of mygalomorph spiders, split off from the family Ctenizidae in 2018. Species in the family are widely distributed in North and Central America, Australasia, Asia, southern Europe and North Africa. One species is recorded from Venezuela in South America. They are relatively large, sombrely coloured spiders, that live in burrows with some kind of trapdoor.
