Abstract
Tristromaviridae is a family of viruses with linear, double-stranded DNA genomes of 16-18 kbp. The flexible, filamentous virions (400±20 nm×30±3 nm) consist of an envelope and an inner core constructed from two structural units: a rod-shaped helical nucleocapsid and a nucleocapsid-encompassing matrix protein layer. Tristromaviruses are lytic and infect hyperthermophilic archaea of the order Thermoproteales. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the Tristromaviridae, which is available at www.ictv.global/report/tristromaviridae.