Disney+ Reward Open Immediately
http://flatbellytonicz.co/PgKsImF3e31yB4YnfH7D4A5nPdVv8jPXEjYQNEpIJ_lwS8927Q
http://flatbellytonicz.co/1FPokes0mU2ugvklfipx8Hb3aDg8kv-g_htUCLa5TMa5r2tTWA
eculated as far back as 1985 that the Opisthobranchia were paraphyletic, based on morphological evidence, and had given rise to the Pulmonata, a group also of subclass rank.
Because the Pulmonata are a sibling group to an opisthobranch taxon, some authors argued that the Opisthobranchia are therefore not a monophyletic group and can no longer be accepted as a valid taxon. The opisthobranchs are now included within the subclass Heterobranchia, although many manuals and websites still use the old classification.
A phylogenetic study published in November 2004, gave new definitions of the seven main lineages of the Opisthobranchia.
However, in 2005, a study of rRNA gene sequences could not resolve monophyly versus paraphyly of the Opisthobranchia Subsequent taxonomic classification in 2005 overturned the Opisthobranchia as a valid clade, reclassifying it as an informal group within the Heterobranchia. Accordingly, articles no longer use the term Opisthobranchia, replacing it with Heterobranchia to emphasise a different concept.
By 2011, the "Opisthobranchia" were declared artificial and obsolete and were replaced by new phylogenetic hypotheses. The concept was abandoned. It now includes including "Lower Heterobranchia", Acteonimo