What version of Premiere Elements? What computer operating system?
Those green circles with black dot give the appearance of Timeline markers, specially Timeline scene markers.
Did you apply Markers to that Timeline at any time?
These markers function in the Movie Menu used to navigate the end disc product at playback.
There should be at least 5 frames between Timeline markers so the spacing between those markers in your screenshot is questionable.
Please consider, and supply more details.
Thanks for the follow up.
Are you OK with the explanation for those green circles each with black dot above your Timeline?
The green scene markers are used in other versions besides 11.
Please let us know if you need supplemental information.