refers to the distinct setigerous puncture at base of each abbreviated scutellar stria (= parascutellar stria) near base of elytra. A. littoralis must have such a pair, otherwise consider rekeying this specimen. Incidentally, Fritz Hieke (2000) revised the Amara impuncticollis species group which yielded five sibling species in my area of WI: A. impuncticollis (uncommon), A. littoralis (common), A. otiosa (rare), A. turbata (rare), A. ovata (rare, introduced). They are difficult to separate externally and most require genitalic confirmation. The previous keys by Lindroth and Downie & Arnett are obsolete and misleading for this species group.

This is a tough group. There are no ocellate punctures or setae that I can see in my seven specimens that appear at least superficially to be the same species. I've seen such punctures in Pterosti*chus. As such, I'm clueless on this one.

and presence of other features you noted would redirect branch of identification key toward species like Amara convexa or A. aenea. These two have all your features including the three punctures on apical elytra. So far I favor A. convexa based on image possibly showing oblique depressions near pronotal hind angles - but under scope these depressions should appear quite distinct. If the only distinct pair of pronotal depressions are near midline and parallel to midline, then consider A. aenea. There are of course more differences than these.