Paleontologist Dr Dave Hone answered questions ranging from the best way to ride a T rex to whether or not crocodiles are really dinosaurs
3.08pm BST
Thanks for all of the questions and apologies for some brief answers and not being able to hit quite everything. More questions can be directed to my Ask A Biologist site where I and some friends and colleagues can try to help, and of course there the Lost Worlds here on the Guardian.
Finally if you do have 5 minutes, I’d greatly appreciate people filling in my survey on Jurassic World and science in the cinema. It will greatly help my research! Thanks again and hope you enjoyed it.
3.07pm BST
Do you have any tips for finding fossils on seashores?
Practice goes a long way. Try and find out what to look for and what the local fossils look like (shape, colour and texture) so you have some mental patterns to search for, that helps enormously.
2.56pm BST
When you talk about feathers being 'preserved' on certain specimens how 'preserved' are we actually talking here. Are we talking actual feathers or just the imprint of feathers in a piece of rock?
Important point that! It does vary - in the famous specimens of Archaeopteryx for example mostly of what is preserved in an impression (the feathers have rotted away and its essentially a ‘footprint’ of a feather). However in many of the Chinese specimens the feathers themselves have lithified (just as the bones have) and we are looking at fossilised feathers. Generally with feathers if they are a different colour to the surrounding rock they have preserved and if the same colour its an impression.
2.53pm BST
I don’t know whether you’ve tried this, but it’s definitely worth heading over to the teaching resources section of the Guardian Teacher Network - there might be some suggestions or adaptable activities there.
Is there a fun engagement/ classroom practical activity you would recommend for teaching school children about dinosaurs and paleontology?
I'd love to get my classes excited and interested in the field more and I'm interested in any examples/resources you can recommend?
Umm, not of the top of my head, sorry. I do do various school visits but generally bring things to show and handle and talk dinosaurs but that’s not really the same. I’m a little stumped but I’ll keep this in mind and hopefully someone will point to something.
2.51pm BST
Can a baby triceratop really is strong enough to be ridden by kids in Jurassic World? And if we were to have dinosaur as pet, which would you recommend?
Given the sizes shown on screen, probably. Small kids can just about ride a big sheep so why not?
As a pet I’d avoid anything with a lot of teeth or that was big. Something like Psittacosaurus might do well in a large garden.
2.50pm BST
Just one other thing that I've always wondered. Was the make-up of the atmosphere life-alteringly different back then? Would we be able to breathe the Jurassic atmosphere? Or would a dinosaur be able to breathe our own with no difficulty?
Not my area at all, but I think there may have been a little more oxygen and that’s about it. I think they’d have been fine being here now: most animals are fairly adaptable to things like this (going up or down mountains for example) with a bit of time.
2.48pm BST
SO Dr Dave if a T Rex was a biscuit what would it be - and if a triceratops was a Spice Girl which one would it be?
I can help with the first one thanks to this a friend of mine made years ago. Not sure quite what he was thinking.... :)
2.43pm BST
If the KT event hadn't happened and dinosaurs - in some form - had survived, what do you think would have been early man's chances? We outcompeted several species which went extinct, like the mammoth and so forth, but would we (or our evolutionary ancestors) have been quite so formidable competition for dinosaurs?
Well Conan-Doyle gave a good chance to both ‘ape men’ and to indigenous humans in The Lost World, and certainly a good brain goes a very long way against brawn. Still, there’s enough evidence of humans coming off very much second-best to plenty of things like ancient cats, bears, crocs, eagles and the like and well, some of these dinosaurs were a wee bit bigger and better equipped to take out soft, squidgy humans. It could have been a very close run thing.
2.41pm BST
Jurassic Park or Jurassic World? :)
I genuinely enjoyed the new film and had fun (despite, inevitably, being irritated by plenty of dinosaur issues). This is probably quite sacrilegious but I don’t like the original JP that much as a film, and actually really quite like large chunks of everyone’s least favourite: Jurassic Park III.
2.39pm BST
Do we know if the t-res was likely to be feathered? If so, were their tiny arms hidden among their plumage?
Tyrannosaurus most likely did have feathers though quite how large they were and how much covering these was is hard to say. Certainly those arms could have been hidden in plumage (just like a kiwi bird).
2.37pm BST
Presumably the middle of Pangaea would have been hot and dry as the rain couldn't get to it. If such an environment had existed, what sort of dinos would have survived there?
Yes certainly the position of the continents would have had a major effect and things were a lot drier in the Triassic as a result (there’s just been a big paper about it this week). Dinosaurs were not too diverse then, mostly small bipeds and a lot of carnivores or small omnivores.
2.27pm BST
A question.
How did dinosaurs look after thier young?
This is something we know a a fair bit about, though the data comes from various bits of the dinosaur tree. Most dinosaurs probably looked after their eggs and hatchlings (exactly as modern bird and modern crocs do) and we have evidence of parents brooding on nests and preserved groups of babies preserved alongside what are presumed to be their parents. We also have nests containing babies that are far larger than known eggs for those animals so must have hatched some time and if they are still in the nest, their parents must have been bringing them food to eat.
Parental care might have extended beyond this (conceivably for months or even years) but there was certainly some care in the first few weeks of life and this was probably near-universal for dinosaurs.
2.22pm BST
What was life like for Mammals in the Jurassic and Cretaceous eras? How quickly did they develop and rise up the food chain? Were they always just furry rodents hiding form predators in trees, or was there more to them then that?
Mostly as you describe, they were very much at the lower end of things. Actually pretty common (like rats, possums and shrews today), but available as a meal for many animals (birds, crocs, big lizards, pterosaurs and yes, dinosaurs). They certainly were persistent and continued to evolve and diversify (marsupials and eutherians date back to the Jurassic) and it’s been suggested that the first primates actually date back to the Cretaceous and lived alongside the dinosaurs. The one exception we do know of is Repenomammaus - a badger-sized mammal in the Early Cretaceous of China. One specimen was preserved with the remains of chomped baby dinosaurs inside it, so they at least occasionally got to reverse the normal order of things!
2.21pm BST
The dinosaurs lived throughout three periods of the Mesozoic era: Triassic, Jurassic and Cretaceous. Different species of dinosaur lived in different periods. eg. Stegosaurus and Diplodocus are Jurassic, whilst Triceratops and Tyrannosaurus are Cretaceous. We all know there was a mass extinction event at the end of the Cretaceous period, but were there also two other mass extinction events that ended the Triassic and Jurassic periods? If not, how did the Triassic and Jurassic species die out?
Great point! There was indeed an extinction at the end of the Triassic (a pretty bad one actually) and this seems to be what allowed the dinosaur to go from one of many diverse reptile groups on land to pretty much *the* group on land. The end of the Jurassic is far less certain - for sure a lot of things went and some new lineages got going (so the sauropods suffered badly and things like the ceratopsians diversified and spread) but it’s not clear if there was a discernible large extinction.
2.18pm BST
Hi Dave, question from my girlfriend Kathy Wise, who's computer isn't playing nice - 'for you, what’s been the most exciting development in paleontology since you started working in this field’
Not one that I’ve been able to play with really, but it’s basically getting the technology involved. CT-scanning fossils, digitising specimens to make compute models that can then ‘repair’ damage and use them to test things like bite strength or loading on limbs is a truly colossal step forwards, and is giving us incredible new information that we could not have realistically done even 10 years ago. Their use is also accelerating and becoming better and better, we really are entering the digital age.
2.15pm BST
Hi! Do we know whether dinosaurs were cold blooded like modern reptiles, or is that impossible to know?
This is probably the biggest remaining question. I could write pages on this but very, very short and horribly over simplified version - there was almost certainly a mix of strategies (as there are for modern animals, there is no hard and fast ‘warm vs cold’ split but shades between then). Some, indeed, most certainly had a very high metabolic rate (elevated activity levels, fast growth) like most modern mammals and birds, but this might have been linked to sheer size rather than burning tons of calories to stay warm like we do. It’s very complex and picking out individual strategies and patterns is hard.
2.14pm BST
Why did the aquatic reptiles (mosasaurs, plesiosaurs etc.) and flying reptiles (pterosaurs) go extinct? Was it from the KT extinction that wiped out the dinosaurs? How did fish and birds survive this when they lived in the same habitat.
Yes, both groups went in the KT event (though icthosaurs had been gone a while at this point. Very short version is that fish and birds are / were typically much smaller and so had less resource requirements and faster generation times and larger populations, that goes a long way. Plus they did badly too, they just did survive, it’s not like birds were immune, they also had a lot of species lost.
2.10pm BST
Seeing as how 101% of all kids just love dinısaurs, how come there are so few people in your field? One would think you'd have thousands of applicants for every place available! What switches these young minds off this branch of science?
Actually I know one group of kids who are not into dinosaurs - the child of every dinosaur palaeontologist I know have no interest in them at all, I assume because to them it’s very mundane.
Still yes, it is odd why they are so popular and why that interest wanes. I wish I knew how to harness it better. At the academic level at least there are way more people than jobs so that does help keep it a very minority field (sadly).
2.08pm BST
What distinguishes dinosaurs from other reptiles? Is it just how closely they are grouped temporally, or are there major physical differences between the crocodiles and an average dinosaur?
Basically groups like this these days are essentially defined by their evolutionary relationships, so one definition of dinosaurs is essentially everything that’s effectively bounded on a family tree by pigeons AND Triceratops is a dinosaur. However, this group can be identified by certain key traits - one easy one to spot is that all of these animals have a large flange of bone on the upper front part of the humerus (upper arm bone) called the deltopectoral crest (so you can guess what muscles attach to it, anatomists can be quite literal). In other reptiles this is generally quite short but in dinosaurs it’s at least 30% of the total length of the bone.
There’s pretty major differences between modern crocs (and indeed most extinct ones) and the dinosaurs, though naturally go back the best part of 250 million years and they’d be a lot harder to tell apart and the respective evolutionary branches were only just starting to separate.
2.04pm BST
If you could bring one dinosaur back from extinction, which would it be?
Personally I have a real soft spot for the bizarre little sauropod Amargasaurus, but to be honest it’d have to be one of the superlative giants: either Argentinosaurus or, yes, Tyrannosaurus. Size is such a big deal and we’d learn so much for a truly gargantuan animal as well as the obvious wow factor.
2.01pm BST
You're at a dig. What is the most exciting thing you can find? I am guessing that new dinosaurs are relatively common, so is there something else that would instantly make the front page of Dinosaur Expert Monthly and allow you to lord it over your peers for a good while.
Generally either something that is certainly new, or something that is very complete (i.e. most of a skeleton). A huge number of species remain to be found and even the best known dinosaurs have little material going (and most species are known from only a few bones) so a good skeleton, especially if it’s a rare, unusual, or new animal is a special find.
I’ve been lucky enough to find a few goodies -a dinosaur nest, a whole foot (from a group then with little known about their feet) and most of a tyrannosaur.
1.59pm BST
Hello Dave, this is my question:
What is the largest dinosaur you think you could have killed with your bare hands?
Lateral thinking time! :) Well a fair bit of that depends on the nature of them - there are some pretty big animals that are pretty placid and small ones that are vicious, so it’s hard to know. I think I might have a shot at strangling one of the larger ornithomimids (nice long, thin, necks) if they were a bit dumb, but I wouldn’t want to try it. There were some very small and basically defenceless ones out there that wouldn’t put up too much of a fight but I wouldn’t like my chances with most species I can think of.
1.57pm BST
Ten years or so ago in some remote partbof Russia, they sawed a T-Rex bone in half and found the remains of organic material and an internal structure much like a modern bird's bones.
In America, they've found colour pigments on the flanks of dinosaurs.
I think you’re conflating a few things here. Some bones in the US have been found with apparently organic remains preserved (though this is still contentious). I’m not aware of anything like that from Russia for dinosaurs, thought loads of dinosaurs have very bird-like hollow bones. Feathers have turned up in Canada, but with no colours. Pigments don’t preserve (except occasionally the white of ‘no pigment’) but colour-containing organelles do that give an indication of colour – so far all of these are from China though, and some feathers from Germany and China give indications of the chemical composition of colours.
DNA, however, seems to be beyond us, but then even 10 years ago we thought colour and proteins were too. We will always find new fossils and unique sites with unique preservation conditions but predicting what will turn up is incredibly hard.
1.56pm BST
Spinosaurus aside, which out Giganatosaurus, Mapusaurus or T-Rex do you believe was the most terrifying predator?
Well none of that four were really very different in size and the only one we know much about was rexy. It certainly had weight and bite power on its side, but really anything in the 12 m range is a simply astonishing animal, let alone a carnivorous biped.
1.55pm BST
What would be the best way to ride a T-Rex? How did they sleep? Would it be possible to construct a saddle of sorts whilst it was sleeping? If so, what would that be like? These questions have been the subject of many debates during boring lessons. Evenually we decided it might be best to construct some sort of cradle with its little forearms. Would it be able to reach us with its head if we were in that cradle? We would be delighted to know what your thougts are on these questions :) Rose
If I was going to, I’d ride it something like a horse but up at the base of the neck. It would of course be madly dangerous however you did it (short of fitting a muzzle) but that should give you a fairly stable riding position and allow you to see and steer. I wouldn’t try it to be honest.
1.54pm BST
Were velocipedes just a bit bigger than chickens and nothing like Spielberg/Crichton would have us believe?
Well velocipedes were old bicycles and I assume you mean Velociraptor. :) This was a fair bit bigger than a chicken, about 2 m long (about half of that was tail) and maybe 1 m high. At least part of the problem with the name is that Crichton seems to have followed a taxonomic revision that put the genus Deinonychus into Velociraptor. They would still be big even then, but the on screen animals are much closer in size to Deinonychus so it’s not quite as bad as is often made out. They do still have odd arms and no feathers though.
1.51pm BST
So is Jurassic Park cloning from mosquito amber idea real? If so, why no dinosaurs been cloned yet? Is it possible in the future?
Sadly not. People have tried it with very recent amber and extracted DNA.... of mosquitoes. I doubt it could ever happen, we have not even found any DNA that old yet, let alone the kind of near complete chromosomes needed and then there are plenty more issues after that you’d need to address to make a dinosaur. Don’t hold your breath.
1.50pm BST
If you were creating Jurassic World, what mix of species would you put in, and would you include meat eaters?
I assume you mean if I was recreating something like the film in which case I’d put in whatever I could get! I certainly wouldn’t be worried about the dinosaurs getting out (including the carnivores), the escapes were down to poor enclosure design. I’ve worked in a few zoos and the JP series have no idea how to keep animals in!
1.48pm BST
Did dinosaurs walk around in circles before lying down?
Not that we know of. As I recall this is supposed to be something animals do to flatten down what they’re about to lie on and most dinosaurs would flatten anything they lay on!
We do actually have several small dinosaurs preserved in resting postures or brooding on nests (they say very much like birds do - arms folded up, head tucked to one side) and one set of tracks with a hand and pelvis imprint showing where it crouched down on all fours.
1.47pm BST
I have two questions:
1. what was the first bird? I know you can say archaeopteryx but it was a dinosaur,not a bird!
Well as birds ARE dinosaurs, Archaeopteryx is perfectly capable of being both. It would not have been the first: birds evolved a good few millions years before it appeared, but certainly it’s the closest thing we have to what the first bird would be.
As for the the stegosaurus, the very short version is probably some kind of socio-sexual dominance signal, i.e. communicating social rank and / or suitability as a mate.
1.46pm BST
When I look at some animals, I think they are living dinosaurs for example the whale, crocodile and even the hippopotamus. What do you consider to be living dinosaurs?
Well evolutionarily birds and crocs, but yes, some other animals can give me a real feel of what they might have been like. Rhinos have a real sense of just power and size (especially when you get close to them!) and then the big crocs are scary and impressive with their jaws, while cassowary and the big ground hornbills are much much like some of the small dinosaurs in my eyes.
1.46pm BST
Did dinosaurs really communicate with each other and could they really learn to open a kitchen door?
Almost certainly – all those crests and frills and so on must have been used to signal something (vocal and visual) and at some level almost all vertebrates communicate in some way, shape or form. At least some dinosaurs were pretty gregarious, or even social, and communication would have been going on. As for opening doors, plenty of animals are surprisingly dexterous with hands or noses (not just elephants, but also things like pigs) and I don’t think a typical door handle would have been much hindrance to many dinosaurs – enough dogs and cats work out how to do it.
1.43pm BST
I have a 12 year old who has always loved dinosaurs. He wants to be a palaeontologist. He's able all round- Maths, English, Science- but what should he steer towards at secondary school apart from biology? What was your career route?
Well first I’d be honest and cautious and say just how few jobs there are and how bad it is right now for palaeo. Certainly focus on the sciences and especially maths if possible (my lack of maths has been a big handicap for me). At uni in the UK you can go the biology or geology route and they give rather different options and skills, depending on quite what he is keen on and wants to push (and how much he might want the degree to be a back-up for other jobs later) he can go either way. I went through the biology route and didn’t switch to palaeo till my PhD, but most people in the UK come through geology.
1.42pm BST
When have you been most scared working with dinosaurs?
When I used to work at Bristol Zoo and a large vulture had a go at me. Also, avoid being bitten by penguins: not scary but they have phenomenal serrations on their beaks and give very nasty nips that really rip and bleed badly.
1.39pm BST
What was wrong with the name 'brontosaurus'?
Also: dip-luh-DOH-cus or dip-LOD-uh-cus?
Basically when named it was apparent that the thing called Brontosaurus was really not very different from the already named Apatosaurus and basically not worthy of a new name and so it was synonymised. More recently new finds and new analyses shows that actually it was quite different and hence the name returned.
Both pronunciations are acceptable, the former is more common in the UK the latter in the US. These days a lot of new names of species come with pronunciation guides to help unify things like this to aid communication (and it is a problem for non-native English speakers talking).
1.39pm BST
I'm always so irritated by the growling and roaring of dinosaurs in movies. I've never really heard a reptile make a noise so I always imagined them to be pretty quiet. Do we know anything about the noises they would have made?
A few reptiles do make noises, enough snakes hiss and so too do a few lizards. Crocodilians in particular have quite a range of calls (including a roar) and there’s no reason to think dinosaurs didn’t have at least a few calls at their disposal, though probably not the range that many birds show, as these have rather specialised windpipes that dinosaurs probably lacked. Some, like some of the big hadrosaurs, seem to have been built to make loud sounds with their crests acting as resonating chambers (check out Parasaurolophus in particular).
1.36pm BST
If there were dinosaurs living in Antarctica where it was dark (and presumably very cold) for several months a year how did they survive if there was no sun to heat their bodies up? Hibernation?
Well it was much warmer than now for a great deal of that period but yes, there were dinosaurs in the high arctic and Antarctic in the (occasional) dark and cold. A combination of not staying there all year, large size (for insulation), feathers in many (also insulating) and differing conditions was probably sufficient.
1.36pm BST
Is it possible that some dinosaur species survived the K-T event but died out soon afterwards say within a million years?
I’m sure they did, it could even have been several millions of years. It’s easy to imagine some small population in a valley or on an island keeping going but they’d always be vulnerable to some nasty event or just inbreeding and finally keel over. The problem of course is finding them and assuming a few some holdouts did happen, the odds of them every being found are basically nil. Quite a number of times bones have been found suggesting dinosaurs persisted but these always turn out to be ones that have been ‘turned over’ from older sediments.
1.36pm BST
Just as a general note, I’ve tried to be pretty systematic till now and hit every question but that’s obviously increasingly impossible with the flood. I’m also starting to see duplicates or near duplicate questions, so I’ll be a bit more varied now and try to hit questions I think are really interesting and / or different and dot around a bit as I go. Thanks for all the interesting comments and questions, much appreciated.
1.34pm BST
Which part of the world do you believe has the most potential for dinosaur finds?
Hard to say. Even very productive areas like China, the US, South Africa and Germany still have a lot to offer. Argentina and Australia are currently the places that are doing very well (lots more time invested and lots of good stuff coming) and places like Ecuador and the Arabian peninsular are starting to produce material when it was utterly unknown just a few years ago. My best bet would be Brazil, but we’ll have to wait and see.
1.33pm BST
Is there anything to disprove that T-Rex moved like a kangaroo? BOING! BOING! BOING!
I think Conan-Doyle in The Lost World described Megalosaurus as moving like a great kangaroo. To my knowledge none of them did (though some might have done, we’ve yet to find any examples). In the case of the big tyrannosaurs we have tracks showing them walking like any other biped and of course it would probably be tricky to say the least for 6 ton animals to bounce unless they liked having shattered leg bones.
1.31pm BST
From my 7 year old. "Did the Postosukus walk on 4 legs?"
Eeek! We’re leaving dinosaurs for some of the other big Triassic reptiles that I don’t know much about. :) IIt certainly did move on four legs, but it might have been capable of bipedal locomotion too based on those arms but this is a bit out of my field.
1.30pm BST
What was the first dinosaur? What creature did they come from?
Well, we’re probably never going to find a true ‘first’ of a lineage (and even if we did we’d probably not know). Obviously as things get closer and closer to their origins it’s harder and harder to tell them apart, so for example we have Nyasasaurus which may or may not be a dinosaur but is about as close a thing as we have to that first one.
1.29pm BST
I have loved dinosaurs since I was 4 and watched the first Jurassic Park film. I proclaimed I would become a palaeontologist and then realised I had to be good at biology. What would be the best way to fuel my want of knowledge about dinosaurs and the latest scientific discoveries when peer reviewed papers are beyond my scientific knowledge.
See the books recommended below and also the suggest link already given for the MOOC Dino101, it’s genuinely excellent.
1.27pm BST
Given that oceans rise and fall over time (lots of time on the geological scale), what fossil deposits remain tantalisingly out of reach under the waves and how might future palaeontologists go about excavating them?
Cool question. Sadly I’ve no idea of the answer as I’m not on the geology side of palaeo. I know a few dinosaur bones have been dredged up or found in cores of samples from the sea bed so they are down there, but I’m not familiar enough to say much about them.
I can’t imagine they’ll be dug up for decades if not centuries - there’s too much on land and that’s already hard to get to given the funding limitations.
1.25pm BST
Are there any realistic calculations on how big the dino population was?
Very short answer: no. Slightly longer answer: no because there are so many confounding variables that currently we have no hope of sorting out. There’s tons of massive biases in the fossil record and seeing how they work out is a bit beyond us right now.
1.23pm BST
Can you recommend a good book that gives an over-view of the topic, without being too sciencey? I'm a 35-year old, who loved dinosaurs when I was little, but then fell out of touch, what with school pretty much ignoring them. Would love to read a good book on all the developments and discoveries over the last 20-odd years...
I’d always recommend the book “Dinosaurs: the most complete and and up-to-date encyclopedia for dinosaur lovers of all ages” by Tom Holtz and illustrated by Luis Rey. It really does cover everything for the beginner whether they are 8 or 80. A bit heftier and more in depth is “The Complete Dinosaur” (new second edition) edited by Brett-Surman, Holtz and Farlow, and then to go beyond that, Steve Brusatte’s “Dinosaur Palaeobiology” should get you up to the point you could dive into the scientific literature. Enjoy!
1.23pm BST
why CAN'T we bring dinosaurs back from extinction?
Quite simply we don’t have the genetic material that would permit us to recreate them (and if we did, how on earth it would be formed into chromosomes and then got to a viable embryo are arguably even bigger hurdles). It’s been suggested we could poke around with bird genetics to produce something like a small theropod dinosaur, but they’ve been separate from the dinosaurs for 150 million years so it’s not likely to be that informative (and for the record I think it’s a bad idea) and would tell us nothing about things like the horned dinosaurs that are so very far from birds.
1.20pm BST
What would the world look like today if dinosaurs hadn't been hit with the extinction event?
Probably very different, but I’d hate to speculate. The one really interesting thing is that South America had a very different fauna to most of the rest of the world in the Cretaceous, and it would be cool to see how that developed and then intermingled when South America rejoined with the north.
1.20pm BST
Does anything explain the physical similarity between mythical dragons and real dinosaurs? Is it possible these myths started when people discovered dinosaur fossils centuries before William Buckland found Megalosaurus bones in 1824?
It’s been suggested a fair few times, but mostly I don’t buy it. The good places for dinosaurs (deserts, badlands) are not places where humans spent a lot of time (poor for crops and animals) and fossils don’t just lie out on the surface as complete skeletons, you tend to just get bits as they slowly come out and erode away, so I doubt many people came across anything that we’d recognise as a dinosaur, and tended to come across the odd skull or arm which is not really the same thing.
1.18pm BST
Depictions of dinosaurs often show a place teeming with them - what in fact was there distribution? If a time traveller went back in time, would dinosaurs be easy to find or, despite the massive size of some, would you have to search them out in a relatively empty landscape?
I think on the whole they would not be too hard to find. Just like today some places would be rammed and others a bit sparse (and don’t forget how much humans have disrupted things; even 500 years ago a lot of wildlife would have been much more plentiful). Size would have helped: it’s occasionally easy to miss giraffe and elephant in the wild, herds of animals each of which were 20 tons would probably be easier to find generally. :)
1.16pm BST
Why and how did dinosaurs grow to such immense size?
What were the benefits of this growth?
Now this is a complex one. Very briefly, many species often get big as there are competitive advantages to large size, but what often stops them are physiological / anatomical limits and the fact that larger species are more vulnerable to extinction. Dinosaurs at least partly facilitated giant sizes by being efficient locomotors and also probably having very efficient digestive systems (a big of a self-fulfilling prophesy once you get really big as you have a longer digestive time).
1.15pm BST
Hi, I am a year 4 student. I am interested in T -Rexes and Velociraptors.
I want to know how fast T-Rex and Velociraptors could run in mph?
Well, working out absolute speeds of extinct animals is all but impossible, anything will have to be a ballpark figure and even relative speeds can be hard to assess. Best guess (based on half-remembered research papers and intuition) is around 15 mph for Tyrannosaurus and maybe 25 for Velociraptor but don’t quote me on them.
1.13pm BST
Do you think that we've discovered all of the major types of dinosaur now or may there still be some surprises out there? for instance is there an ecological niche that the dinosaurs didn't fill which you would have expected them to?
Oh what a question! I could write a treatise on this! I suspect we have not found all the major groups, but we may have found all the major groups we will find. A lot of things would have had very narrow geographic or temporal distributions and so would be very unlikely to be fossilised or found, so not only are we missing tons of species but there could be some groups hidden in there.
One great example is the alvarezsaurs: they only really turned up in the 1990s and were this amazing new group, but then once we had a few good fossils it turned out this specimen from Europe from the late 1800s was an alvarezsaur (it had been confused with a bird). We could only ID it correctly once we had a better idea of what it looked like, so it’s possible we do have some bits of super-odd ‘new’ animals but don’t yet realise, as a leg on its own won’t reveal that the arms and head were strange.
1.12pm BST
As shown in the movie, is it really possible to train a predator, such as dinosaur or lion, to follow human commands in open space, not just in a cage? I thought it is the instinct of any predator to hunt, not to get domesticated.
Well it’s hard to know, but plenty of ‘untameable’ species have been domesticated (at least partly) at various times including things like lions and bears. I certainly don’t think it would be any harder or more difficult than many other carnivores. Difficult and dangerous for sure, but not unrealistic.
1.11pm BST
Which dinosaurs had the biggest social group/large brain combination? Could they have gone on to evolve into creatures similar to primates in terms of sophistication?
Very hard to say based on the available data, though the troodontids are the best candidates. Who knows? Very hard to predict the future of our species, let alone multiple lineages that died out tens of millions of years ago. That said, based on what some parrots and crows are capable of, I’d go with ‘possibly’.
1.09pm BST
Imagine youve arrived at a pristine dig site. What fossil would you most like to find? Would it be a new never before discovered one or a particular dinosaur?
Well it depends massively on what lived and died there, how things were preserved, the rock types etc. etc. Assuming it was a place that did have a lot of dinosaurs the thing you generally find are teeth - each animal had huge numbers of them, scavengers won’t eat them (unlike some other bones) and the enamel makes them very tough and unlikely to erode or decay so they preserve well. We have huge numbers of dinosaur teeth and some species are known only from their teeth.
1.08pm BST
I've always been stumped by the apparent uselessness of T-Rex type forearms. The body form appears to have developed separately many times in different lines. Could they actually be useful? I've heard the argument that the limbs are simply evolutionary relics that have not completely gone away. If that is the case, is there any fossil evidence to confirm the intervening stages? What would the evolutionary benefit be to remove the forelimbs (vs re purpose, ie ostrich)? I've also read that the T-Rex was a carrion eater and did not need speed to hunt. If true, how would smaller forearms improve it's chances of survival.
Thank you for your thoughts :-)
We are a bit stumped as to tyrannosaur forelimbs (something I’m vaguely working on with some colleagues). My best guess is that actually they didn’t do very much and if left a few more million years might have been lost. The big tyrannosaurs were scavengers yes, but were also very much active carnivores , though the arms were pretty much an irrelevance to this.
1.07pm BST
Reconstructing a dinosaur from a partial skeleton - how accurate can we be?
Great question! Actually quite often very accurate depending on the species and quite how small the fragments are. I wrote a piece on this here which explains a bit more.
1.06pm BST
Are crocodiles dinosaurs or was my GCSE biology teacher lying to me all those years ago?
The crocodilian lineage (crocs, gators, gharials, caiman) are the closest living relatives to the dinosaurs (birds being less ‘relatives’ and more ‘descendants’) and so do provide us with a lot of useful info and have many similarities, but are not dinosaurs.
1.06pm BST
Is the new thinking that many dinosaurs were feathered? If so,why is there not more evidence of fossil feathers? Would the Moa of New Zealand have been a good depiction of this sort of thing?
Well many theropods for sure had feathers (the bipedal, primarily carnivorous lineage). We get this from both preserved feathers, and indicators on bones of feathers being present. While not that many specimens have been found with them we can use this to infer wider patterns in close relatives - we don’t need hair on fossil humans to infer they had hair given how all modern primates do, for example.
In other dinosaurs it gets complicated quickly with there being various feather-like structures in some ornithschian dinosaurs. None of this rules out scales though: many dinosaurs certainly did have scales, the tricky thing is that of course many may have had both. At the moment I would not say ‘most’ dinosaurs had feathers but certainly lots did and it’s far from impossible the many more had feathers or something like them,
1.02pm BST
What is the relationship between dinosaurs & birds? Did birds co-exist with dinosaurs, or did they evolve from them?
Well, birds are literally dinosaurs. Birds evolved from dinosaurs but they also lived alongside them - a new species or new lineage appearing doesn’t mean the instant extinction of the ancestral stock or other near relatives. So birds actually appeared around 150 million years ago and lived alongside the other dinosaurs until the big extinction 65 million years ago - birds were a major part of many dinosaurian faunas.
1.02pm BST
.
1: If it is true that the dinosaur fossil record shows a great fall in numbers in the millions of years running up to their extinction, which many people blame on the effects of the huge volcanic eruptions of the deccan Traps, why do people believe the meteorite/asteroid theory for the extinction ?
1. It’s probably not true there’s a big fall-off (based on the latest studies that I’m aware of) and even if there were, the asteroid was a pretty big ‘finishing off’ event. The evidence for the asteroid (Iridium, shocked quartz, crater) is pretty overwhelming.
2. It’s a big question as to why some others didn’t make it, though most birds went extinct too. It’s not like birds all survived easily and only the dinosaurs got hammered.
3. It’s not that inconsistent if you look at the overall patterns going on. Big things tended to suffer, small things and those that lived in water did relatively well. I cover a lot of this here.
12.58pm BST
Hello! Just as a general introduction I thought I’d say that obviously there’s a lot of questions here, and even though I’ve prepared some answers up front there’s no way I’m going to get through everything in the next couple of hours so forgive me if I don’t address everything, though I’ll try to cover a range of questions here. It also means I’m dashing off answers with no time to look things up so I may well make some errors or omissions and expect the traditional typos.
Also obviously a lot of these address complex issues, so the answers may have to be a bit brief and lack nuance, and in places I’ll probably link across to existing blogposts of mine that can answer these things more fully. Finally, yes birds are literally living dinosaurs and so throughout here, when I talk about ‘dinosaurs’ I do really mean the non-avian dinosaurs that would fit with most people’s definitions. OK, here goes:
7.52pm BST
Last weekend Jurassic World enjoyed the highest-grossing worldwide opening of any film in history. The weekend before, National Geographic’s T. rex Autopsy drew audiences keen to see the dissection of an anatomically realistic T. rex. With dino-excitement reaching fever-pitch, paleontologist Dr Dave Hone will be here from 1pm BST on Friday 19th June to answer your questions about all dinosaurs great and small.
In the meantime, citizen science ahoy! If you have already seen Jurassic World, Dr Hone is conducting a survey on science in cinema and would greatly appreciate a few minutes of your time here.
Continue reading...