Avian type I interferons have been characterized and preliminarily assigned to subtypes (IFN I, IFN II, and IFN III), but their classification into subtypes should await a more extensive characterization of avian genomes.
Functional lizard Type I IFNs can be found in lizard genome databases.
Turtle type I interferons have been purified (references from 1970s needed). They resemble mammalian homologs.
The existence of amphibian Type I IFNs have been inferred by the discovery of the genes encoding their receptor chains. They have not yet been purified, or their genes cloned.
Piscine (bony fish) Type I IFN has been cloned in several teleost species. With few exceptions, and in stark contrast to avian and especially mammalian IFNs, they are present as single genes (multiple genes are however seen in polyploid fish genomes, possibly arising from whole-genome duplication). Unlike amniote IFN genes, piscine Type I IFN genes contain introns, in similar positions as do their orthologs, certain interleukins.