Presence and absence of dUTPase and env is variable between lineages within ERV3. Maximum likelihood phylogenies were created from the RT domain of Crocodilian ERV3 and ERV3 sequences deposited in Repbase. The ERV3 lineage encoding dUTPase is shaded in grey. Elements encoding a recognisable env are indicated by boxes. Symbols represent the taxa from which the sequences were derived. The numbers of CrocERV groups are shown outside of corresponding consensus sequences. Major retroviral groups are indicated brackets. Numbers within the phylogeny indicate aLRT values greater than 90%. The scale bar indicates branch length.