Define ltr dating
Altogether, the data obtained in several taxa highly suggest that these patterns can be generalised for most metazoans.Finally, we highlight the importance of using database information in complement of genome analyses when analyzing transposable element diversity.We found only three Copia clades, including Gal Ea and Hydra which appear to be widely distributed and highly dominant as they account for 96% of the characterised Copia elements.Among the seven BEL/Pao clades identified, Sparrow and Surcouf are characterised for the first time.
Among the five major orders of retrotransposons , elements with Long Terminal Repeats (LTRs) are flanked by large (usually between 100 and 500 bp long) direct repeated sequences.
Copia and Gypsy elements are widely distributed among genomes of plants, fungi and animals but no BEL/Pao elements have been identified in plants, fungi or mammals so far  In metazoans, the three superfamilies display uneven relative abundances among genomes that greatly depend on both the element type and the host taxon considered.
Previous comparative analyses in insects, nematodes and chordates , crustaceans , fungi  and more specifically Pezizomycotina , revealed that Gypsy and Copia elements display different distribution, representativeness and diversity.
Indeed, Copia elements show a relative scarcity and the prevalence of only a few clades in specific hosts.
Thus, BEL/Pao seems to be the second most abundant superfamily.