What is this? '75 Dart Swinger

Well... I felt something was missing from there...
Im actually sure that is what the bump shook off, because up until this point the car has driven phenomenally, though its use is extremely limited.
To be honest the entire suspension needs an overhaul, bushings are all old, and either crushed, or spaced so far away from where its supposed to rest on one side that its getting crimped on the other... After disc brakes get swapped in the rears Ill be tending to the fronts.

I did check to make sure that the lower control arm is intact, and I got lucky in that it is. It does seem slightly elongated though (tire doesnt sit straight and it was about a month ago).

As for the "bump"... I was visiting a buddy, and on the way to his place a wild pothole appeared out of nowhere. Almost bottomed out the car.
Thank you all for identifying the problem and some areas to tend to, your experience is greatly appreciated.