Updated: Feb 10
I was laying there, in bed, next to my wonderful other half, looking pensively at the ceiling. My eyes were were ablaze with curiosity, my mind riddled with stimulating thoughts enough to keep me awake for hours. My girlfriend turns over to me, placing a hand delicately on my chest, asking 'something on your mind?' I reply 'yes'.
'Well, is there anything we can do to put your mind at ease?'
'Yes' I repeat, turning to look straight into her big blue eyes.
'Tell me... d'you think dinosaurs could puke?' I ask in a husky tone.
'Goodnight Ryan' she replies before rolling over and resigning herself to the fact that she has an obsessed paleontologist for a boyfriend.
Valid question though, right? We have ichnites of dinosaur coprolites (AKA fossilised poop) as well as a myriad of other feeding traces, surely 30-50kg of stomach contents being regurgitated onto sediment would leave mark, especially when it's falling from so far up? But why haven't we ever seen any evidence in the rock record of a dinosaur spewing chunks? Well, let's take a quick look at this deplorable subject...
Could they physically regurgitate?
Whenever we are musing about what a dinosaur could or couldn't do when we don't have physical evidence of it, we do the same thing every time: look to modern avian dinosaurs. For birds, there is actually a difference between vomiting and regurgitating. While vomiting is a sign of some sort of health problem (differentiated by the behaviour and appearance of the vomit...I never said this wouldn't be a gross post), regurgitating is actually a very common practice for birds, for feeding young, becoming more comfortable after a big meal or even courtship. Try it when you're next trying to get someone's number, you never know, it may work.
So, by this logic, there is no reason to believe that dinosaurs didn't regurgitate for just as diverse number of reasons. Many may have used a similar form of regurgitation to feed their young or, indeed, as part of a mating display...personally I couldn't find it hotter when I see the lasagne a girl had the day before.
Is there actually any evidence?
Well, I'm sure glad I wondered this, because there was actually a find that slipped under my radar that I didn't find until researching this question. There is indeed evidence of dino-hurl, in fact, there's a few sites. They consist of what is known as regurgitate pellets, which is where an animal will purposefully chunder up any indigestible parts of a recent meal, such as bones. Fossilised, this will often show up on the bone as degradation caused by stomach acid, but isn't as advanced and lacks the mineralisation of when it comes out of the other end, known as a 'coprolite'. Regurgitate pellets can also include gastroliths, small stones swallowed for a variety of reasons (for terrestrial animals, it's when herbivores need some help to grind up vegetation).
There have actually been some evidence of potential dinosaurs vomiting. A 'gastric eject' deposit was found last year in Utah by leading scientist John Foster et al. showing a pile of amphibian bones. Now, the question is, what puked it up? Foster went on record saying 'how frustrating it is that we don't know'. To be fair, what exactly can you tell, other than the fact it ate meat? Given that it was from the Jurassic period, dating back around 150 million years, there is a very good chance it is some sort of dinosaur, since most things big enough to eat an amphibian of that size with some bones still somewhat intact were theropods at that time. But, alas, we can't say for sure.
Another find was from back in 1989 in the Upper Triassic of Italy, which was a pile o' hurl containing what was thought to be pterosaur bones. Turns out these bones are closer to a Langobardisaurus, which was a tiny Archosaur. I wanted to bring this one up because it has been perpetuated by various news sites as 'dinosaur vomit'. They never flat out say it was by a dinosaur, but they conveniently leave out the fact that that the deposit was a marine one. In other words, it was thrown up when dinosaurs were around, but most definately not by a dinosaur (there is no such thing as a marine dinosaur). So there, my integrity stays intact for all 6 people that will read this over other sites that know what they're doing...I promise I'm not bitter...
What about sauropods?
Well, here is the question that got me thinking in the first place.
To be clear, there are many other questions about a sauropod's neck that need answering first, such as how the hell did it have a heart powerful enough to pump blood all the way up to its brain? But, what the hell, let's run before we can walk.
The question is, did sauropods even throw up? All animals have evolved some sort of way to regurgitate unwanted material that cannot be digested, but how the hell did sauropods push 50 kg (110 lbs) of stomach contents up 9-12 metres (30-40 feet) of neck? Again, if they did, that amount falling that far would be something other dinosaurs would want to get out of the way of and would certainly leave its mark, with around 7 tonnes of force! Honestly? I really don't know.
Maybe there was some kind of special valve system within a sauropods neck that could work with its neck muscles to push things such as blood or regurgitate all the way up. What will answer that question? Only more fossil finds...we'd better get to work...
Until next time!