The Pnei Yehoshua (DH Sham Lo Ani) proves that "Bnei Adam" is an earlier time. The proof goes as follows:

1) First, the Pnei Yehoshua asks why does the Gemara not ask at this stage which Shi'ur is the earlier one, in the same way that the Gemara asks (8 lines from the end of the Daf) which Shi'ur -- the pauper and the Kohen -- is earlier? The Pnei Yehoshua answers

that this is because it is obvious that the Kohen eats later than Bnei Adam. The proof for this is the fact that there is a dispute between the Chachamim and Rebbi Meir in the Beraisa, where the Chachamim maintain the Shi'ur of Kohen while Rebbi Meir maintains

the Shi'ur of Bnei Adam. The Chachamim cite a proof from "Mishmar" that the day continues until the stars come out. This implies that the Chachamim are trying to disprove the opinion of Rebbi Meir, who must hold that once the sun goes down, it is already night (as the Gemara states, 29 lines from the end of the Daf, "v'Chi Teima mi'Chi Arva Shimsha Lailah Hu," which suggests that Rebbi Meir himself holds that "Arva Shimsha" is indeed night).

2) We now know that Rebbi Meir holds "Arva Shimsha," which therefore is the Shi'ur of Bnei Adam. This proves that the time of Kohen must be later than the time of Bnei Adam.

3) Therefore, since the Gemara at this stage (21 lines from the end of the Daf) maintains that Ani and Kohen are the same time, it follows that since Kohen is later than Bnei Adam, Ani must also be later then Bnei Adam.

Kol Tuv,

Dovid Bloom