| Strabopidae Temporal range: | |
|---|---|
 | |
| Fossil of Strabops thacheri . | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Clade: | Arachnomorpha |
| Order: | † Strabopida Hou & Bergström, 1997 |
| Family: | † Strabopidae Gerhardt, 1932 |
| Type species | |
| † Strabops thacheri Beecher, 1901 | |
| Genera | |
| |
Strabopidae is the only family of the order Strabopida, an extinct group of arthropods known from the Cambrian period. [1]
The order Strabopida contains three valid genera and one doubtful, Khankaspis , Paleomerus , Parapaleomerus and Strabops , all assigned in the family Strabopidae. [2] Previously, it also contained the genera Caryon , Lemoneites and Neostrabops , but after a study, they were reassigned as a trilobite, a glyptocystitid echinoderm and a cheloniellid arthropod, respectively. [2]
Paleomeridae was also previously included as a family, but after the discovery of a fourth Paleomerus specimen and its study, Paleomeridae was synonymized into Strabopidae. [3] Although often suggested to be closely related to aglaspidids due to their similar morphology, their exact phylogenetic placement is uncertain due to the poor preservation of all known strabopids. A 2013 attempt to place them in a phylogenetic analysis recovered them as part of a polytomy with megacheirans, marrellomorphs, crustaceans and artiopodans. [1] Still, strabopids are often classified as part of the clade Arachnomorpha. [3] In fact, Dunlop & Selden (1998) defined Paleomerus as "perhaps the best model of a primitive arachnomorph". [4]
