The hunchback of Cuenca

 

Reconstruction of the possible aspect of C. corcovatus, by Raul Martin. Alternative recreations here and here, thanks to Alain Bénéteau.

Unearthed from Las Hoyas deposit (Cuenca, Spain), the fossil of this theropod surprised its discoverers at first due to the bone prolongation of the front vertebrae of its pelvis, responsible for its notorious hump. This feature led this new species to be baptized as Concavenator corcovatus ("hunchback hunter of Cuenca").

However, the importance of this fossil, nicknamed "Pepito" by the paleontologist that brought it to light, goes beyond the peculiarity described lines above. In fact, its arms have small bumps that are very similar to those present in the Coelurosaurids and their living descendants, the Birds, that hold the large wing feathers used by the latter for powered flight.

The fascinating (and exciting) thing about this feature is that "Pepito" belongs to a group of dinosaurs (the

Allosaurids) which representatives, until now, did not presented any evidence of having feathers or similar structures. The discovery of this Spanish reptile may indicate that feathers would have appeared far before of what was considered this far, i.e., in the more primitive dinosaurs that were common ancesters for Coelurosaurids as well as for the group that contains C. corcovatus.

Underlined in red in the graphic bellow (based on a cladogram proposed by Weishampel et al. in 2004) are the dinosaur groups whit at least one feathered representative:

As can be seen, the Alosaurids may ben counted from now on within the feathered dinosaurs thanks to the discovery of the Concavenator.

The find of "Pepito" seems to underpin the idea that feathers were a feature common to all dinosaur groups, along with evidence from species with no relation with theropods such as the Psittacosaurus and the Tianyulong, which may have had (at least) proto-feathers.

Yes, I know: and what about the hump? Well, about it, two hypothesis have been formulated so far:

1. That it may have been (as usual) an exhibitional structure to attract females.
2. That it may worked as a thermal regulator element, likewise the Spinosaurus sail, animal main character of the latest movie of the Jurassic Park saga.

Some final data on C. corcovatus:

• The Cuenca fossil is the most complete dinosaur scheleton discovered in Spain so far. Even fossilized skin was discovered.
• It lived between 130 and 125 million years ago approximately, during the Early Cretaceous.
• It was about four meters long.

More information on "Pepito" can be found here.