As I recall, In MoR, the Marauder's Map is an ancient artifact that's starting to break down a bit, so "Messers Moony, Padfoot, Wormtail, and Prongs" are not Lupin, Sirius, Peter, and James Potter under animagus-based nicknames. Unless Fred and George are wrong about the Map's origins, though being the master pranksters of the MoRniverse (and canon, for that matter) it seems likely that their judgment would be sound in this case. So, evidence that MoR!Pettigrew, et. al. are not necessarily animagi.
I interpreted it that the Messrs put their names on the front of this ancient artefact. From Chapter 25:
And the Weasley twins weren't about to turn the Map over to Dumbledore. It would have been an unforgivable insult to the Marauders - the four unknowns who'd managed to steal part of the Hogwarts security system, something probably forged by Salazar Slytherin himself, and twist it into a tool for student pranking.
By the way, this reminds me that the Twins seem to have found a couple of errors on the map:
..."Intermittent one fixed itself again. Ot
ETA: There is now a third thread, so send new comments there.
Since the first thread has exceeded 500 comments, it seems time for a new one, with Eliezer's just-posted Chapter 33 & 34 to kick things off.
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