Electrocteniza is an extinct monotypic

Monotypic

In biology, a monotypic taxon is a taxonomic group with only one biological type. The term's usage differs slightly between botany and zoology. The term monotypic has a separate use in conservation biology, monotypic habitat, regarding species habitat conversion eliminating biodiversity and...

 genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of Trapdoor spider

Trapdoor spider

Trapdoor spiders are medium-sized mygalomorph spiders that construct burrows with a cork-like trapdoor made of soil, vegetation and silk. Some similar species are also called trapdoor spiders, such as the Liphistiidae, Barychelidae, Cyrtaucheniidae and some Idiopidae and Nemesiidae...

 in the Ctenizidae subfamily Ctenizinae and at present, it contains the single species Electrocteniza sadilenkoi. The genus is solely known from the Early Eocene Baltic amber

Baltic amber

The Baltic region is home to the largest known deposit of amber, called Baltic amber or succinite, with about 80% of the world's known amber found there. It dates from 44 million years ago...

 deposits in the Baltic Sea

Baltic Sea

The Baltic Sea is a brackish mediterranean sea located in Northern Europe, from 53°N to 66°N latitude and from 20°E to 26°E longitude. It is bounded by the Scandinavian Peninsula, the mainland of Europe, and the Danish islands. It drains into the Kattegat by way of the Øresund, the Great Belt and...

 region of Europe.

History and classification

Electrocteniza sadilenkoi is known only from one fossil, the holotype, number "PIN, no. 363/88". It is a single male individual preserved in a clear amber specimen with several unidentified insects associated. The amber specimen was first identified as significant while residing in a private collection housed in Moscow, Russia. The specimen was then donated to the Paleontological Institute of the Russian Academy of Science in Moscow. E. sadilenkoi was first studied by Kirill Eskov and Sergei Zonstein, with their 2000 type description being published in the Russian Paleontological Journal

Paleontological Journal

Paleontological Journal is a monthly peer-reviewed Russian journal of paleontology established in 1967. It focuses on the paleontology and the fossil records of Eastern Europe and Asia. Articles are published simultaneously in Russian and English.The journal is edited by Alexei Yu...

. The generic

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 name was coined by K. Eskov and S. Zonstein as a combination of the Ancient Greek

Ancient Greek

Ancient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being predated in the 2nd millennium BC by Mycenaean Greek...

 word electron, meaning "amber", and Cteniza

Cteniza

Cteniza is a small genus of Old World mygalomorph spiders in the family Ctenizidae.-Species:* Cteniza brevidens * Cteniza ferghanensis Kroneberg, 1875...

, the modern trapdoor spider genus for which the family was named. This is in reference preservation of the type specimen and the genus that Electrocteniza is possibly related. The specific epithet "sadilenkoi" was designated by K. Eskov and S. Zonstein in honor of the collector of the specimen, K. M. Sadilenko.

Description

Electrocteniza sadilenkoi is 5.88 millimetre (0.231496062992126 in) in length when the chelicerae

Chelicerae

The chelicerae are mouthparts of the Chelicerata, an arthropod subphylum that includes arachnids, Merostomata , and Pycnogonida . Chelicerae are pointed appendages which are used to grasp food, and are found in place of the chewing mandibles most other arthropods have...

 are included in the measurement. Of that length the carapace

Carapace

A carapace is a dorsal section of the exoskeleton or shell in a number of animal groups, including arthropods such as crustaceans and arachnids, as well as vertebrates such as turtles and tortoises. In turtles and tortoises, the underside is called the plastron.-Crustaceans:In crustaceans, the...

 is 2.63 millimetre (0.103543307086614 in) and the abdomen

Abdomen

In vertebrates such as mammals the abdomen constitutes the part of the body between the thorax and pelvis. The region enclosed by the abdomen is termed the abdominal cavity...

 is 2.5 millimetre (0.0984251968503937 in). The shape and general structure of the carapace indicates a close relationship to the modern genera Latouchia from Asia and Sterrochrotus from South Africa. There are several notable differences between the genera. Electrocteniza, in general, has a more notably raised eye tubercle

Tubercle

A tubercle is generally a wart-like projection, but it has slightly different meaning depending on which family of plants or animals it is used to refer to....

then Latouchia and Sterrochrotus. Unlike the modern genera of Ctenizidae, Electrocteniza has completely spineless tibiae, metatarsi and tarsi on legs I and II and chelicera which lack a rastellum.