Name: Genyodectes serus
Name Meaning: Late jaw bite
First Described: 1901
Described By: Woodward
Classification: Dinosauria, Saurischia, Theropoda, Neotheropoda, Ceratosauria, Ceratosauridae
Genyodectes was an early Cretaceous ceratosaurian from the Aptian age, around 112 million years ago. It was found in the Cañadón Grande, Departamento Paso de Indios in the Chubut Province of Argentina. It’s not known from many remains - mainly just the front of the jaw and upper mandible and many teeth. However, given the arrangement of the teeth, it seems to resemble Ceratosaurus more than other theropods. Given that, it was only recently that it was classified as such, and has been named everything from a megalosaurid to a tyrannosaurid. However, recent removal from its display matrix has allowed it to be classified as a ceratosaur. It was also one of the earliest dinosaurs found in South America.
Shout out goes to: kevin-lost-his-voice!
Hi there, I’m glad you like my work! This seems to be a fairly common question when seeing larger dromaeosaurs depicted with large, voluminous “wings”. There are a few things to address about this idea, so let’s first take a look at the fighting dinosaurs specimen:
(Wikimedia commons, by user “Cobalt”)
The Velociraptor here is definitely grappling the Protoceratops with its left hand and being grasped by its beak with its right hand, but it’s not clear whether the animal actually intended to use either hand in the attack. More recent theories on the origin of the flapping motion in birds suggest that the predatory precursors to birds may have stood on top of their prey with their feet, using outspread clawed hands to help with balancing rather than active predation. This behavior could have persisted in dromaeosaur lineages, and a greater surface area of feathers on the arms would have provided better balance.
(Deinonychus atop its prey, using its winged arms for balance. Art by me.)
It’s unclear whether dromaeosaurs were using their hands for predation very often at all. It may well be the case that the clawed hands of dromaeosaurs were employed in a similar way to the hind claws of cats: cats don’t typically use their hind claws to capture prey, but anyone who’s ever been grabbed and “kicked” by a cat knows that it can certainly use them to inflict pain, when it wants to. The fighting Velociraptor specimen may have been grasping the Protoceratops's frill as it was struggling to get away after the tide turned against it. It's hard to say.
Either way, it’s also probably the case that long primaries would have impeded the grasping abilities of dromaeosaurs less than you might think. A 2006 study by Phil Senter and colleagues addressed the question of whether primary feathers on the hands of deinonychosaurs would significantly impede the ability to grasp.
(Diagram from Senter 2006 illustrating grasp ability of deinonychosaur with long hand-feathers. (A) dromaeosaur reaching forward with wrists flexed. The wings do not obstruct each other in this position. (B) obligate supination when reaching forward with right wrist extended. (C) one-handed grasping of an item to the chest; can only be done with one hand at a time.)
Senter showed that a deinonychosaur could hold and grasp objects in several different positions of the hand and arm without obstruction of wing feathers, even if very long. Incidentally, a later study by Senter showed that Bambiraptor, at least, may have had a partially-opposable first digit (thumb) that it could use to grasp a small item against its third digit.
(Senter illustration showing possible dromaeosaur grasping ability of first and third digits.)
In this sort of grasping of the hand, note that the second digit remains stationary. As any present remige feathers would be attached to this digit alone, a stationary position would not cause the “wing” to impede the grasping motion.
It is always possible with the fighting dinosaur specimen, at least, the Velociraptor may have fared better without the long primaries. But the advantages of having voluminous remiges probably outweighed any possible drawback, especially if the animal did not usually use its hands for this purpose in predation. This particular Velociraptor, clearly, fared poorly.