Repeated evolution: Striated muscles in cnidarians and bilaterians evolved independently

what is left of common ancestry ?

Striated muscles are present in bilaterian animals (e.g. vertebrates, insects, annelids) and some non-bilaterian eumetazoans (i.e. cnidarians and ctenophores).

The striking ultrastructural similarity of striated muscles between these animal groups is thought to reflect a common evolutionary origin

Here we show that a muscle protein core set, including a Myosin type II Heavy Chain motor protein characteristic of striated muscles in vertebrates (MyHC-st), was already present in unicellular organisms before the origin of multicellular animals.