I saw this symbol in the schematic of the ADPD2140z eval board. From what Ive seen online, ferrite bead symbols are usually slanted rectangles with right angled corners. This is slightly different, but is this also a symbol for a ferrite bead?
Yes, it is indeed a ferrite bead symbol.
There are standards for component symbols, however as with all standards, people choose not to follow them, and instead make up their own variants (obligatory XKCD Comic).
Yes, its a 50Ohm ferrite. Usually manufacturers post BOM's with their eval boards but with analog deveices it's hit or miss. So its hard to say what the part number is but I'll bet its an 0805 or 1206 (or metric equivalent) size.
Analog really likes to separate out ground planes which is interesting but not necessary to control noise (you can do this with proper layout to control return currents). So I would think this not necessary but it depends on the board layout.