I used to receive random unsolicited emails from an individual who strongly promoted the idea that birds could not not not not be dinosaurs, that the entire dinosaur family tree was screwed up beyond belief, that ‘dinosaurs’ had evolved from random assorted diverse archosaurs, that cladistics was rubbish, and that all mainstream palaeontologists were idiots.
For some reason, the study of dinosaurs attracts people with strong ‘fringe’ beliefs: this must be a by-product of popularity, as you don’t get this with temnospondyls, fossil ostriches, Eocene primates, corals or sea jellies (at least, as far as I know).
Anyway, said individual claimed that the ‘fighting’ specimen of Velociraptor [shown below] provided compelling evidence for his assertion that feathers were indisputably absent in non-avian maniraptorans. I’ve just been doing some writing on the ‘fighting dinosaurs’ (a Velociraptor and Protoceratops preserved locked in combat), so this specimen is on my mind. The Velociraptor is lying on its side, its left hindfoot jammed up against the Protoceratops‘s neck (you know, like a climbing crampon… ), its left hand is gripping the Protoceratops‘s frill, and its right arm is clamped shut in the Protoceratops‘s beak. Anyway, the fact that the Velociraptor in question is on its side, apparently grappling with this formidable opponent, was taken by said individual to show that feathers must have been absent. After all, said individual argued, feathers would get damaged and broken if their owner grappled in this fashion, and hence feathers are utterly incongruous with this sort of predation.
Needless to say this is all fringe whackaloon nonsense. Like it or not, Velociraptor and kin really did have feathers: as if the presence of indisputable feathers in other dromaeosaur and maniraptoran specimens is not proof enough (e.g., Ji et al. 1998, 2001, Zhou et al. 2000a, b, Hwang et al. 2002, Norell et al. 2002, Norell & Xu 2005), the presence of quill nodes in Velociraptor (Turner et al. 2007) demonstrates once and for all that this animal was feathered.
As it happens, the idea that feathered dinosaurs could not/cannot and did not/do not wrestle or grapple with prey is also nonsense. There aren’t loads of cases, but I’m aware of several instances where birds have been recorded rolling and squirming around on the ground (sometimes for protracted periods) when subduing prey or fighting. A series of photographs taken by Shelly Grossman, and appearing in various of Roger Tory Peterson’s books (e.g., Peterson 1968), show a Great horned owl Bubo virginianus fighting with, and killing, a snake. The owl is literally lying on its side, grappling with the snake on the ground and grabbing it in both its bill and feet. Perhaps even more impressive are those cases when birds – particularly passerines – get into territorial scraps and, similarly, roll around on the ground and wrestle with their feet. I’ve seen male Blackbirds Turdus merula do this but have never been quick enough to photograph it (the two individuals concerned are shown below. Despite heroic efforts, I failed to get a shot of them actually fighting).
Due, it seems, to intense competition over nesting boxes, feral starlings Sturnus vulgaris in New Zealand have been observed and photographed engaging in long, protracted wrestling bouts. The two combatants grasp each others heads in their feet and then try to dig their claws into the opponent’s eyes (Flux & Flux 1993). Even when picked up by people, the birds continued to fight, and some individuals had died this way. Bell (2002) reported a case in which two fighting New Zealand starlings fell off the edge of a roof while locked in wrestling combat, landed on another roof, and eventually fell off this too, then landing on the ground four metres below. They fought all the while, this going on for an incredible 45 minutes. There are other reports of this protracted terrestrial wrestling in the starling literature, but it isn’t unique to starlings as Taylor (1969) reported two male Bellbirds Anthornis melanura that were also found locked in combat, and I’m sure there are other examples of this sort of thing in the literature. Wrestling Great tits Parus major are shown at the top of the article.
So, birds can and do wrestle, sometimes engaging in protracted terrestrial bouts of foot-gripping that literally involves the birds tumbling and rolling around on the ground. Ergo, the fact that non-avian theropods like Velociraptor apparently engaged in this behaviour is perfectly concordant with the fact that they were feathered too.
Refs – –
Bell, B. D. 2004. Prolonged aggressive encounter between two starlings below a prospective nest site. Notornis 51, 53-55.
Flux, J. E. C. & Flux, M. M. 1993. Nature red in claw: how and why starlings kill each other. Notornis 39, 293-300.
Hwang, S. H., Norell, M. A., Ji, Q. & Gao, K. 2002. New specimens of Microraptor zhaoianus (Theropoda: Dromaeosauridae) from northeastern China. American Museum Novitates 3381, 1-44.
Ji, Q., Currie, P. J., Norell, M. A. & Ji, S. 1998. Two feathered dinosaurs from northeastern China. Nature 393, 753-761.
– ., Norell, M. A., Gao, K.-Q., Ji, S.-A. & Ren, D. 2001. The distribution of integumentary structures in a feathered dinosaur. Nature 410, 1084-1088.
Norell, M. A., Ji, Q., Gao, K., Yuan, C., Zhao, Y. & Wang, L. 2002. ‘Modern’ feathers on a non-avian dinosaur. Nature 416, 36-37.
– . & Xu, X. 2005. Feathered dinosaurs. Annual Review of Earth and Planetary Sciences 33, 277-299.
Peterson, R. T. 1968. The Birds. Time-Life International (Nederland).
Taylor, R. H. 1969. Male Bellbirds locked in combat. Notornis 15, 63.
Turner, A. H., Makovicky, P. J. & Norell, M. A. 2007. Feather quill knobs in the dinosaur Velociraptor. Science 317, 1721.
Zhou, Z.-H. & Wang, X.-L. 2000a. A new species of Caudipteryx from the Yixian Formation of Liaoning, northeast China. Vertebrata PalAsiatica 38, 111-127.
– ., Wang, X.-L., Zhang, F.-C. & Xu, X. 2000b. Important features of Caudipteryx – evidence from two nearly complete new specimens. Vertebrata PalAsiatica 38, 241-254.