As a followup to her fascinating timelapse of cell division in a frog egg over a 33 hour period, Wildlife and Science filmmaker Francis Chee created a new, equally fascinating timelapse that starts where her previous one left off shows the amazing process in which the divided cells develop into a tadpole with visible blood flow through its newly formed gills.
This is of course another zygote developing shown with a time lapse. The same equipment was used. The video starts where the other one essentially left off. You can see the blastopore forming as well. That is where you end up with countless cells, it is hard to distinguish the individual cells, formation of the neural crest and embryonic eyes and gill and tail development. The last scene is a large magnification of blood flow within the embryonic gills.