Last months challenge was apparently very easy. WarK was able to guess the correct answer within a matter of hours. However, later in the day Aught3 gave an even more correct answer.

Some kind of terror bird but not a moa 

Diatryma?

Edit:
Dammit WarK!
How about Gastornis giganteus then? Just to try and be even more correct.

Aught3 is correct that this is Gastornis giganteus, formally known as Diatryma giganteus, however, Aught3 is incorrect in thinking that this is a terror bird (also, moas were not terror birds).

(Taken at the New Mexico Museum of Natural History and Science)

Gastornis ranged across much of North America, Europe, and Asia during the late Paleocene and early Eocene 56-45 million years ago. It is largely believed that Gastornis was the apex predator of its day, like the “terror birds” that inhabited mostly South America. However, Gastornis and its relatives lack the curved beak and sharp-clawed feet found in their distant cousins, the “terror birds”. The lack of those features leads some paleontologist to believe that Gastornis may have been a vegetarian, using its large beak to crack nuts and branches.

Gastornis’s skull and large size (~2 meters) often lead it to be confused with “terror birds”. Gastornis is sometimes called a “terror crane” because it is allied with the wading birds (such as cranes). Often you will see the junior synonym Diatryma used in books or museum displays. The reason this happens, I believe, is because Edward Drinker Cope, a very famous U.S. paleontologist, gave it that name after discovering a large specimen near Cuba New Mexico. This critter is also the first dinosaur to appear in the “Know Your Bones” series.

Moving on to the new challenge:

(Taken at the New Mexico Museum of Natural History and Science)

Thought I would give a challenging one this month. Good luck to everyone.