Via bizarre and unexpected circumstances I recently* found myself secretly and furtively attending a lecture by Brian J. Ford. Ford is a British author and researcher who dabbles widely in matters of science and science communication. As readers interested in dinosaurs will know, Ford made something of a name for himself in the world of vertebrate palaeontology back in 2012 by announcing that palaeontologists have gotten dinosaurs completely wrong. Non-bird Mesozoic dinosaurs were, so says Ford, perpetually aquatic animals that actually sloshed around, shoulder-deep, in the water and were completely unsuited for life on land: the mainstream palaeontological view that these animals were strongly adapted for terrestrial life is, so he says, misguided and woefully wrong.
* "Recently" = during the latter part of 2014.
Ford published an article announcing his infallible hypothesis in science newszine Laboratory News (Ford 2012). Aided and abetted by an inciteful media, his idea received gargantuan coverage in the global press. Instinct told me to ignore the whole circus – in any case, colleagues were already doing a good job of saying what nonsense it was. Alas, I was specifically invited to produce a response and eventually decided, as a damage-limitation exercise, to do so (Naish 2012).
But – surprise surprise – Ford is having none of it, as I learnt from the aforementioned lecture. So, what did he say?
Unsurprisingly, the lecture covered the exact same stuff we heard last time around (Ford 2012). Non-bird dinosaurs, so Ford reasons, were just so big and heavy – and with tails soooo massive – that they only “make biomechanical sense” if we imagine them immersed in water. He referred to problems they must have faced as goes supporting their mass and pertaining to yaw as solvable only if we imagine them as aquatic. A video of a grotesquely overweight captive Komodo dragon that was only able to move along at a slow shuffle was said to provide proof of the ineffectual terrestrial abilities of land-living dinosaurs. He further pointed to the duck-like snouts of duckbilled dinosaurs and to the presence of dorsal sails in some species as evidence for aquatic habits. Finally, he noted that the presence of dinosaur tracks on tidal muds, lakeside sediments and so on surely show how these animals had actually been walking on submerged substrates, not emergent ones.
Needless to say, all of these claims are erroneous and easy to contradict based on the data we have. I’d like to hope that this was all obvious to the people in the audience, but sadly it’s human nature to assume that a person who speaks with authority on an unfamiliar topic is reliable and likely correct, so don’t get your hopes up.
Ford claims that dinosaurs like sauropods and big theropods “make infinitely more sense” if only we imagine them standing shoulder-high in water. This makes me wonder if he’s ever tried wading through deep water himself, since it’s very easy to demonstrate that pushing through water would be significantly difficult for an animal built like a sauropod or theropod. Animals that routinely swim or wade have spreading (typically webbed) hands or feet, rotund bodies, tails built for propulsion and so on. Think of newts, otters, swimming rodents, crocodiles, or ducks.
Sauropods, no matter what Ford may like to tell us, are built like long-tailed, long-necked elephants. They mostly have deep bodies, slender limbs and proportionally small, compact hands and feet – precisely the opposite of what we’d see if they were built for routine life in the water. Those of you who know the dinosaur literature will be aware of the fact that the precise same arguments were used long ago to dispel the erroneous 20th century view that sauropods were perpetual swamp-dwellers (Bakker 1971, Coombs 1975): those arguments have been widely accepted by palaeontologists because they appear to be valid, not because (contra Ford) palaeontologists are dogmatically adhering to a status quo because they’re worried about losing research funding or whatever.
Then there’s the extensive skeletal and soft-tissue pneumatisation we know that sauropods had. Ford ignores this, doesn’t mention it and might even (for all I know) be wholly unaware of it, but it’s been shown that sauropods were so air-filled (the bones of some species being up to 89% air) that – if and when they did swim – they must have floated high in the water and been prone to tipping (Henderson 2003). Again, their anatomy shows that they were not suited for a life in water, contra Ford. The extensive tooth wear we see in sauropods is also indicative of a terrestrial life that involved the stripping and biting of foliage belonging to ferns, conifers and so on.
As for the ‘duck-like’ snouts of duckbilled hadrosaurs, it generally helps when formulating a hypothesis to look at as much evidence as possible, not at just one of the many bits of data on offer. Yes, I suppose the snouts of some hadrosaurs recall those of dabbling ducks or platypuses when seen from above. But... what about the batteries of hundreds of teeth, the compact, tiny hands and short-toed feet, the stomach contents that reveal diets involving ferns, conifers and terrestrial flowering plants, the fact that the fossils of some species come from semi-deserts and parklands, and so on? I'm sure a hypothetical aquatic hadrosaur could nibble on bank-side vegetation, no doubt, but: if these animals were aquatic to that degree, why does every bit of anatomical, palaeoenvironmental and palaeobehavioural evidence indicate otherwise? [Image below by Ballista.]
The tail is not a dead weight, and sails do not evidence aquatic habits
Ford’s primary contention – that sauropods and other dinosaurs were so heavy, especially in the tail, that terrestrial living was maladaptive in evolutionary terms – is arm-waving at its worse, and flatly contradicted by what we know about vertebrate biomechanics. No matter what Ford may like to claim, there is every indication that sauropod bones, ligaments and cartilage capsules were easily capable of supporting their weight on land. There are even calculations specifically devoted to testing this (Taylor 2005).
The tail is not – contra Ford – some impossibly heavy dead weight that would have required the burning of vast quantities of metabolic energy to keep it aloft, but a structure that (like your neck) was held in a perpetually raised position due to interspinous ligaments and non-tiring muscles.
Yes, that’s right: there are muscles in the vertebrate body that are constantly firing, do not tire, and are in continual use in supporting bony structures, and there are ligaments and tendons that function 100% of the time as well.
Ford has also claimed that the dorsal sails we see in some dinosaurs are another ‘clear’ sign of aquatic habits because, so he says, they're unique to sailfish and other sail-backed fishes. He claimed that palaeontologists never talk of the dinosaurs concerned as having ‘sails’ but of having ‘humps’ instead. This is completely false. While the idea that the tall neural spines of these dinosaurs might have supported a hump has indeed been suggested on a few occasions (Bailey 1997, Conway et al. 2013), it's very much a minority opinion. We routinely talk of dinosaurs with tall neural spines as sail-backed dinosaurs, and recent work on one of the key taxa here – Spinosaurus – has come down firmly on the idea that the tall neural spines did indeed form a sail (Ibrahim et al. 2014). As for Ford’s claim that dorsal sails are indicative of a life in water, I’ll just leave these pictures here... [photos below by The Rambling Man, Brendan Gray and Benjamin Klingebiel.]
Applying the specific to the general
In the end, I (and my like-minded colleagues) can only repeat the same thing so many times. When we look at the anatomy of Mesozoic dinosaurs, virtually all species display clear adaptations for dedicated terrestrial life. Sure, they likely swam or wallowed on occasion, but they were not aquatic as Ford wants us to believe.
However, the diversity of animal groups typically makes it impossible to construct generalisations that apply to all members of a group. Were all dinosaurs committed terrestrial animals, ill-suited for aquatic life? No, members of many lineages did indeed adapt to life in water. Most water-adapted dinosaurs belong to the group of theropods we call birds. Ducks, swans, penguins, pelicans, cormorants, loons, grebes and so on are all amphibious dinosaurs, and their bodies betray clear adaptation to lifestyles that involve paddling, swimming, diving and the procurement of aquatic prey.
Within recent years evidence has gradually come together indicating that Spinosaurus – a long-snouted, sail-backed giant theropod from the Upper Cretaceous of northern Africa – was adapted for a life at the water’s edge, and the newest data shows that it has strongly reduced medullary cavities in its long bones, proportionally short hindlimbs, a spreading, functionally four-toed, probably fully webbed foot, and other specialisations for an amphibious or even fully aquatic life (Ibrahim et al. 2014). Ford takes this as support for his primary contention, but he’s cheating.
Firstly, the idea that Spinosaurus might be aquatic isn’t an idea that the community has been contesting, nor was Ford the first to invent it. Au contraire: as more and more data has come in, we’ve seen Spinosaurus make the metaphorical transition from an animal that waded at the water’s edge (Taquet 1984) to one that routinely swam (Amiot et al. 2010) to one that was predominantly aquatic (Ibrahim et al. 2014). We’ve made this transition on the basis of the accruing of evidence – you know, the sort of thing that scientists are supposed to do. Does what we think about Spinosaurus apply to other big theropods, or to other big dinosaurs, as Ford insists? No. The aquatic features of Spinosaurus are (so far as we know at the moment) unique to Spinosaurus, making it wrong for Ford to point to this one taxon and say “I told you so!”.
The community responds, and Myth of the Lone Truther
I’d now like to move away from a discussion of anatomical data and fossil evidence and more towards the philosophical approach we’re seeing here.
Ford’s contention about the alleged aquatic habits of dinosaurs makes a good story. It makes for an entertaining talk, and it's a fun topic of the sort that journalists love to write about. Why? Predominantly because Ford can be portrayed as the lone truther battling against a barbarian swarm of opposition. We love stories like this. And a big part of the Ford lecture that I listened to wasn’t about dinosaurs themselves, or about science, but about the ‘community reaction’ to his idea, about the fact that angry palaeontologists and palaeontological writers reacted with abject hostility to his idea (he referred to Brian Switek’s article on a few occasions).
In fact, Ford specifically said that he was surprised at the venomosity and aggression contained in these responses. They clearly prove, so he said, the existence of a blinkered and biased approach in the mainstream palaeontological community, a vested commitment in the textbook dogma that museum displays, research careers and those ubiquitous and easy-to-obtain financial grants are all so dependent on. Such is the appeal of this lone truther concept that – so Ford told us – a book and even a Hollywood movie (all movies are made in Hollywood, right?) are perhaps going to result. Oh puh-leez, pass the sick bucket.
Now, I can absolutely appreciate the appeal of this story as a story. Hey, I watched The X-Files, Dark Skies, The Lone Gunmen, that awful Zeitgeist movie, I’m familiar with David Icke’s ideas, and I’ve hung out with Jon Ronson on several occasions. But all this stuff about a blinkered, biased, hostile palaeontological community that refuses to see sense... oh, come on. Ford’s idea has failed because it doesn’t match the data and mostly relies on misinterpretation and selective ignorance. In other words, it’s classic Dunning-Kruger effect. And it’s hardly a new idea anyway. There have been several efforts over the last 100 years to make dinosaurs aquatic, and they’ve failed because the evidence from the geological record has overturned them.
Seeing as I published a specific response to Ford’s Laboratory News article in an issue of Laboratory News (Naish 2012), I was looking forward to the part of his talk where he would mention me and refer to what I'd said (recall that he was completely unaware of my presence in the audience). But, nope, not a single mention. I think that tells you something.
For previous articles relevant to some of the material covered here, see...
- The Second International Workshop on the Biology of Sauropod Dinosaurs (part I)
- The Second International Workshop on the Biology of Sauropod Dinosaurs (part II)
- There are giant feathered tyrannosaurs now… right?
- All Yesterdays: Unique and Speculative Views of Dinosaurs and Other Prehistoric Animals – the book and the launch event
- 50 million years of incredible shrinking theropod dinosaurs
- The changing life appearance of dinosaurs
Refs - -
Amiot, R., Buffetaut, E., Lécuyer, C., Wang, X., Boudad, L., Ding, Z., Fourel, F., Hutt, S., Martineau, F., Medeiros, A., Mo, J., Simon, L., Suteethorn, V., Sweetman, S., Tong, H., Zhang, F. & Zhou, Z. 2010. Oxygen isotope evidence for semi-aquatic habits among spinosaurid theropods. Geology 38, 139-142.
Bailey, J. B. 1997. Neural spine elongation in dinosaurs: sailbacks or buffalo-backs? Journal of Paleontology 71, 1124-1146.
Bakker, R. T. 1971. Ecology of the brontosaurs. Nature 229, 172-174.
Coombs, W. P. 1975. Sauropod habits and habitats. Palaeogeography, Palaeoclimatology, Palaeoecology 17, 1-33.
Conway, J., Kosemen, C. M. & Naish, D. 2012. All Yesterdays: Unique and Speculative Views of Dinosaurs and Other Prehistoric Animals. Irregular Books.
Ford, B. J. 2012. A prehistoric revolution. Laboratory News April 2012, 24-26.
Henderson, D. M. 2003. Tipsy punters: sauropod dinosaur pneumaticity, buoyancy and aquatic habits. Proceedings of the Royal Society of London B (Supp.) 271, S180-S183.
Ibrahim, N., Sereno, P. C., Dal Sasso, C., Maganuco, S., Fabri, M., Martill, D. M., Zouhri, S., Myhrvold, N., Lurino, D. A. 2014. Semiaquatic adaptations in a giant predatory dinosaur. Science 345, 1613-1616.
Naish, D. 2012. Palaeontology bites back... Laboratory News May 2012, 31-32.
Taquet, P. 1984. Une curieuse spécialisation du crâne de certains Dinosaures carnivores du Crétacé: le museau long et étroit des Spinosauridés. Comptes-rendu de l’Academie des sciences, Paris, series D 299, 217-222.
Taylor, M. P. 2005. Upper limits on the mass of land animals estimated through the articular area of limb-bone cartilage. In Anon. (ed.) Conference programme and abstracts: Progressive Palaeontology 2005, University of Leicester, 15-16 June, p. 18.