Our study confirms the transient presence of several atavistic muscles – present in our ancestors but normally absent from the adult human – during normal embry

Our study confirms the transient presence of several atavistic muscles – present in our ancestors but normally absent from the adult human – during normal embryonic human development, and reveals the existence of others not previously described in human embryos. (linked article) Strikingly, some of these muscles, such as the dorsometacarpales shown in the picture, disappeared from our adult ancestors more than 250 million years ago, during the transition from synapsid reptiles to mammals. (https://phys.org/news/2019-10-million-year-old-evolutionary-remnants-muscles-human.html https://phys.org/news/2019-10-million-year-old-evolutionary-...)