[6][7] They are classified into genera based on their genomic properties and on the diversity of their terminal appendages, which are involved in host cell recognition.

The originally proposed genus Alphalipothrixvirus was renamed Alphatristromavirus and moved to family Tristromaviridae.

In addition, the filamentous particles of rudiviruses and lipothrixviruses are built from structurally similar, homologous major capsid proteins.

Due to these shared properties viruses from the two families are classified into an order Ligamenvirales.

[12] Members of the Ligamenvirales are structurally related to viruses of the family Tristromaviridae which, similar to lipothrixviruses, are enveloped and encode two paralogous major capsid proteins with the same fold as those of ligamenviruses.

[1] Virion assembly and egress have been studied in the case of Sulfolobus islandicus filamentous virus (SIFV).

Binding of the major capsid protein dimers to the linear dsDNA genome lead to the assembly of nucleocapsids, which are subsequently enveloped intracellularly through an unknown mechanism.