Endogenous retroviruses have been positively identified in all major vertebrate groups with the exception of the Agnatha (jawless fish). So far, however, endogenous retroviruses in lower vertebrates have received comparatively little attention.

It is quite likely that other animal groups harbor viruses that closely resemble retroviruses in terms of their replication strategy (although they may have a distinct evolutionary origin), and these may also occur as both endogenous elements and infectious viruses in their host species.

Article The Evolution, Distribution and Diversity of Endogenous Retroviruses

Endogenised retroviruses (ERVs), at least initially, have an env gene. This distinguishes them from other retro-elements which are very common and widespread.

Endogenous retroviruses (ERVs) have been studies in many vertebrate species. Though slightly different from the ERVs, retro elements are abundant in many species outside of the vertebrata that includes Plants. In fact, the roles of retro elements in Drosophila and Yeast are well documented. What started as Ac/Ds mobile elements in corn, thanks to the genius of Barbara McClintock, has now spread its wing beyond the world of mobile DNA elements to a larger world of retro elements.

Every kind of organism in the three domains has a virus that infected it, and for that reason is almost a certainty that every kind of organism have TE. Why? Because the evolutionary arm race between the celular organisms and the capsid encode organisms (the viruses) have started since the last universal common ancestor (LUCA).This could be the most exciting fact in the biological science

I would not call it an evolutionary arm race between multicellular organisms and some kind of parasites.

What if transposable elements (and retroviruses) are causing nonrandom genetic reconstructions, which result in "directed" phenotypic changes (=speciation). Couldn't this be the biological framework for orthogenetic evolutionary change?

yes that's right but an arm race doesn't means that the cooperation cannot result or that the arm from one side (a novel DNA sequence) can lose it into the another site (the host genome), even in the war history of the humans has happened.

The arms race has been a phenomenon tremendously creative, but its creative in a accidentally way. The virus from jawed vertebrate has been the authors of the jawed vertebrate arms against themselves, see this http://www.mdpi.com/1999-4915/3/10/1933

See the paper of which I am  joint author: Transposable elements and viruses as factors in adaptation and evolution: an expansion and strengthening of the TE-Thrust hypothesis. Oliver and Greene 2012. Ecology and Evolution  (it is open access)