Big Maniraptors

From shortest to longest: Aepyornis maximus, Utahraptor ostrommaysorum, Gigantoraptor erlianensis, and Therizinosaurus cheloniformis

This is a size chart between the largest members of each major maniraptor group: Aepyornis maxmimus (the largest bird at over four hundred kilos), Utahraptor ostrommaysorum (the largest deinonychosaur at over five hundred kilos), Gigantoraptor erlianensis (the largest oviraptorosaur at over a ton), and Therizinosaurus cheloniformis (the largest therizinosaur at nearly six tons). Some dinophiles may question, "What about alvarezsaurids? They're most likely maniraptors and you name yourself after one; why haven't you drawn one here?" The thing is, so far we don't know of any giant alvarezsaurids. The biggest are the turkey-sized. One possible exception is Rapator ornitholestoides, a grizzly-bear-sized theropod once considered an alvarezsaurid. However, the latest studies suggest it was probably a megaraptoran carnosaur (large thumb-clawed meat-eating dinosaur).

Maniraptors are well known for having feathers and similar integument. Oviraptorosaurs, deinonychosaurs, and birds have feathers and therizinosaurs had protofeathers, as well as these weird bristle things that somewhat resemble the quills of porcupines. (The bristle things are called EBFFs AKA Elongated Broad Filamentous Feathers, or something along the lines of that.) Would even the biggest maniraptors have had been fluffy? Most likely yes. To date, all scientific papers on the subject agree that it's unlikely large maniraptors (completely) lost their feathers, as feathers are helpful in both retaining body heat as well as cooling things down. At the very least, large maniraptors would have kept their wing feathers, which were more likely for visual display and had little to do with insulation. Even in the event that they lost their feathers, they probably didn't swap them for scales. We don't know if feathers can revert to scales, but to stay on the cautious side for now, I suggest not. In modern birds that partially lose their feathers (th legs of Struthio camelus and the faces of some arinins, just to name a few), they simply leave the skin bald rather than re-evolve scales.