Bigjaw Bumblebeast

A giant gravedigger of the hothouse world redevelop a form proven successful for tens of millions of years... with a new twist. 

The bigjaw bumblebeast is the biggest gravedigger of the new era, and a far cry from its shrinking relatives such as the kittyhawks. Widespread and formidable, these animals have adapted quickly to hunt big prey in the relative absence of former competitors, including their own close relatives like the bumblebears, none of which survived the great thaw.  In many ways, they have simply come to resemble them: now, the bigjaw reaches a weight of 500 pounds. Bigjaw bumblebeasts now stand eye-to-eye with a man on all fours. But unlike the bumblebears, the bumblebeast doesn't have to stay on all fours.

These gravediggers have begun to run on their hind legs. They are not well-balanced, and yet as long as they keep moving at a quick pace, they can stay upright for significant periods of time as they ambush thorngrazer prey. Sickle-like arm claws are used to grab and pull down big game, but in doing so, they have become too long to walk in the conventional way. Now when the bumblebeast does drop to all fours, it folds them up and bears weight on the sides of its knuckles like a ground sloth. The bigjaw bumblebeast's feathers have become sparse as it has grown in size and no longer needed to retain body heat; the belly, limbs, and head are now almost bald, and these areas now radiate heat, as well as stay cleaner in the wet, muddy environment that now dominates Serinarcta, where thick feathers can trap debris and moisture, and provide shelter for parasites. As in vultures, the featherless head also comes in handy to keep clean when feeding inside large animal carcasses, and can be easily rinsed.

The bigjaw bumblebeast is a large prey specialist; it is extremely strong and can kill nearly all thorngrazer species, including the brontocorn, and so has taken a role as an apex predator in the newly-stabilizing sogland ecosystem, seeming to rule over the smaller but much more social sawjaws which in turn favor the faster-running and less robust thorngrazer species. Only the adult thorny monstrocorn is beyond the reach of this hunter's deadly jaws, though it sometimes kills its calves. Still aggressive toward their own kind and solitary, a lack of cooperative behavior means that they are unable to bring down anything beyond the means of a single individual, while sawjaws - by working together - can accomplish far greater kills relative to their body size. And as some sawjaws, too, are now growing bigger, they become better at competing with this giant for food and for territory. Despite some new adaptations, and current success, this creature is a relic of a bygone age. Its continued dominion in the hothouse - a world of extremely rapid evolutionary changes - is not guaranteed.