Our world is full of unique animals that have squat fatty bodies, with all kinds of soft tissue features that are unlikely to have survived in fossils, such as pouches, wattles, or skin flaps. "[...] "The biggest thing is teeth and facial fat. Readers have to be aware that all dinosaurs they see in all media, and especially in popular culture, seem to have their heads flensed. They've always got these weird grins with only the teeth visible." As he points out, most animals have lips and gums and lumps of facial fat that change the profile of the head, and cover the teeth.
These are swans. Note the distinctive murder-spikes! 
This is a baboon. 
This is a hippo. 
Honorable mention. Previously, previously, previously, previously, previously, previously, previously, previously, previously, previously, previously, previously, previously, previously.
As a cyclist, I'm glad I sat out the part of evolution that featured mantis-geese.
ObFuckGeese.
Psst. Dude. I have bad news for you.
Alex, I'll take "Middle aged married women" for $200.
Wow these are fantastic.
Why didn't swans develop agriculture with those scythe arms?
Ahem.
The author is a cryptozoologist, not a scientist. "Paleoartists" take a double degree with a heavy concentration in comparative anatomy, so his fictionalized art is immensely ignorant of real, careful scientific work based on study of vascular systems – no blood, no fat. From the thousands upon thousands of dinosaur fossils, there's no evidence of dermal-facial muscles in dinosaurs, as in modern birds and reptiles. Even so, the whimsical rendering of a swan isn't so far removed from an actual de-feathered swan. NdGT wittering on about dragons is vastly more scientific than this guy, but hey, thanks for the laugh!