-Now THAT is a giant alligator gar (Atractosteus spatula) skull (upper-jaw)! We were able to skim through several gar specimens on a recent trip to The Field Museum and check out some very impressive fishes! As you can see here, this fish would have been on the very large end of the spectrum for modern-day alligator gars (easily over 8 feet long). Unfortunately there was not a lot of data tagged with this fish (as can be the case with very old specimens), but given the appearance of the skull we can assume it was many decades old.
The genus Atractosteus is often diagnosed from the genus Lepisosteus (the two genera make up Lepisosteidae) by the presence of a prominent second row of teeth in the upper jaw (Lepisosteus has only a minor secondary row in the upper jaw). I have inspected many gars, but this secondary row was GIANT compared to anything else I have seen. Could it be that these teeth grew much larger in these very old, giant specimens? We plan to inspect more preserved specimens and pay close attention to living ones as our gar research continues! More to come from this visit and others!–