Olenellidae

The Olenellidae are a family of trilobites, a group of extinct marine arthropods. They lived during the late Lower Cambrian (Botomian/Toyonian) in the so-called Olenellus-zone in the former paleocontinent of Laurentia plus parts of what became the Famatinian orogen in what is now Argentina. This family can be distinguished from most other Olenellina by the partial merger of the frontal (L3) and middle pair (L2) of lateral lobes of the central area of the cephalon, that is called glabella, creating two isolated slits.