According to a new paper coming from the Chinese Academy of Sciences, a particular type of small feathered dromaeosaurid might have been armed with a venomous bite. The study, led by Enpu Gong, centers on an unusual 12mm-long anterior maxillary tooth from a Sinornithosaurus, a predatory raptor and distant bird-relative first discovered in 1999 in China’s Yixian Formation. Not only does this tooth seem oddly long and fang-like, but it has a thin, distinct groove running right through it from root to tip, a feature which Gong suggests functioned as a channel for venom to pass from the animal’s skull into the flesh of its prey. Gong goes on to describe the hollow pocket in the side of the face as a possible venom gland, and the pitted canal running between it and the base of the teeth as a venom collecting duct.
Comparing the Sinornithosaurus with other anterior-fanged animals such as vine snakes, Gong suggests that it would mainly hunt small birds and mammals, using its long fangs to “grab and hold” its prey and penetrate the layer of feathers or fur to deliver a 6mm-deep poisonous bite. Describing the nature of the venom he hypothesises, “The poison of Sinornithosaurus may have been similar in properties to rear-fanged snakes and helodermid lizards in that it did not kill the envenomated animal quickly but rather placed it into a rapid state of shock.”
But Gong’s claim is not without its critics. No archosaur has been definitively proven to have been venomous as yet, so to state that the Sinornithosaurus was requires some pretty powerful evidence, and not everyone is convinced these grooved fangs provide that. Tom Holtz, a palaeontologist specialising in carnivorous dinosaurs at the University of Maryland notes, “They give a number of different physical features that they interpret as signs of poison or poison delivery systems but which, in my opinion, are more easily interpreted in other types of biological contexts.”
Interpreting the unusual length of the “fangs” as possibly caused by the teeth slipping out of their sockets, Holtz suggests that the grooves could simply be the depressions found in most theropod teeth, only more pronounced in this particular specimen due to wear and tear. The longer-held belief regarding the function of these depressions relates the teeth to bayonet blades, the groove helping to relieve surface tension post-penetration, ensuring a less painful extraction. Further, Holtz states that many dinosaurs have a small cavity in their jawbone, but these have typically been interpreted as air sacs required for cooling, not venom glands. And that the area of the venom collecting canal is damaged in a couple of Sinornithosaurus fossil specimens really doesn’t help to strengthen Gong’s and co-author, David A. Burnham’s case. No one’s denying the possibility of venomous theropods, but more evidence is needed before their claim can be proven definitively.
Arguments aside, Sinornithosaurus, say you did actually have this venomous bite afterall. I’d imagine it’d be the kind of thing you could easily get carried away with, but much to your own peril, I’d wager. Like, you’ll be playing Battleships at Chirostenotes‘ house because your housemate and his girlfriend are fighting about Mario Kart (again, Sinornithosaurus) all like, “Oh my god, did I not tell you last time I wasn’t going to play with you if you’re going to do those shortcuts? No I don’t want to learn how to do them. Fuck,” when Chirostenotes will be like, “I’m going to make a sandwich. If you cheat when I’m gone I’ll totally know.”
“But it’s like almost midnight…”
“Just because you can’t have carbs before bedtime…”
So you’ll sneak a look a his side anyway, because he pretty much just called you fat but you can’t say anything because you’re a guy and you don’t want to look like an idiot. But instead of, you know, playing it smart and littering your fake guesses with a few decoys so it’s not completely obvious that you’re a massive cheat, you go straight for Chirostenotes’ aircraft carrier the moment he gets back, and he’ll be like, “Oh my god, you totally cheated,” his mouth full of bread and some kind of tiny lizard meat.
“No I didn’t.”
“Yeah right. Hey what are you– hey! Heeey!”
“Oh. Sorry, I thought that was your sandwich.”
“Umm no, that was my leg. Jesus! Wait, you’re leaving?”
And before he can point out that if you bring a bottle of wine to someone’s house, you’re not really supposed to take the leftovers home with you, he’ll go into shock, and you’ll have a clean getaway.
But the only lesson you’ll learn from this whole experience, Sinornithosaurus, is how easy it is to get out of a shitty situation by, you know, poisoning your friends. Like, you’ll be at your girlfriend’s house and she’ll try on this hideous new dress she just bought and she’ll be like, “Does this make me look fat?” and it will, Sinornithosaurus, so you’ll be like, “Hey is that a cheesecake behind you?”
“What?” Ow!”
Your boss will ask you what the hell kind of report was that you just submitted (no kind, Sinornithosaurus) so you’ll bite him and take the rest of the day off. You won’t have any change for the bus and the bus driver will give you this look like, “Whatever, man,” when you try to hand over a fifty so you’ll bite him and then wait for the next bus. But while you might think this is all pretty awesome, remember, Sinornithosaurus, that it is only temporary. You’ll be at some party with your new girlfriend and she’ll be all pissy because you picked her up before she was done getting ready and then your ex-girlfriend will turn up unexpectedly all, “I don’t want to get into a whole thing with you here, but I don’t think you’re supposed to poison your girlfriend and then replace her two days later without so much as a phone call, but whatever.” And then your current girlfriend will get even more pissy because she didn’t even know you had an ex-girlfriend, let alone a fat one, and they’ll end up making friends just to spite you and you’ll end up bitter and alone. Plus your boss will almost definitely fire you when you attempt to turn up on Monday morning and he’s unlikely to respond too kindly to any requests for a reference or free stationery. Hardly seems worth it now does it, Sinornithosaurus?
* Fig. 1 by Emily Willoughby. Buy the print here. Figs. 2 and 3 from original study credited to David A. Burnham.
For more info: Dinosaur Tracking Blog // Not Exactly Rocket Science // Original Paper published by PNAS
- bec
