thank you very much for coming it is always a pleasure to be here at the royal institution
and tonight i'm going to be talking about giant fishing dinosaurs uncovering the behavior of
spinosaurus and allies it's not just spinosaurus we're talking about today it's some other things
too despite that wonderful introduction it's worth talking about myself at least briefly
so hello i'm dave hohn i'm a paleontologist at queen mary university of london i work on
dinosaur behavior in particular predation feeding ecology and that sort of thing
a lot of stuff on sexual selection and communication among dinosaurs
i also work on pterosaurs the flying reptiles that lived with dinosaurs but i'm very importantly
not dinosaurs and i do some various other bits including um working out who's related to who and
growth and some other things like that you can't be a paleontologist and do a public talk without
showing photos of you digging things up so here are some photos of me digging things up in
canada and china these are actually dinosaur eggs up in the roof of a tunnel in china and
top left i always have to talk about this uh it's freezing cold so there's no heating in the museum
the sign on the back wall says that that is the most magical bone in china
and i don't think very many people can claim to have stood next to the most magical bone in china
i'm also responsible for naming a whole bunch of dinosaurs in collaboration with a whole
load of colleagues and some pterosaurs and some other fossil reptiles as well so of course i
want to mention that but you're all here to hear about spinosaurus um the fragmentary enigma i've
called it because um if we go back to 1915 when spinosaurus was first named by german
paleontologist called ernst stromer working on material dug up around north africa particularly
from egypt this is what he had um so there's a there's a jaw down uh in the bottom right
hand corner with some teeth above it and then a whole bunch of vertebrae bit to the backbone with
these very obviously and greatly enlarged spines which is what gives it its name but this and a few
other bits was really all he had uh and 1915 was a time where we didn't know that much about big
predatory dinosaurs what we'd now call theropods tyrannosaurus rex was brand new and we didn't have
a complete skeleton um we allosaurus was perhaps the best dinosaur that we had back then and that
was only known from isolated bits and on top of this stroma had lots of different bits of what
he thought was spinosaurus from various different fossil sites around north africa and he proposed
several different species for these different bits and frankly for the last 200 and what are we now
2022 the last 110 years we've been arguing over exactly how many species that we've got
so this is the reconstruction that stroma put together it was pretty typical of the time
you know if you've seen old documentaries and things of dinosaurs or old mountain museums
they had this really upright almost like kangaroo pose of the tail along the ground
this looks almost like a t-rex he doesn't have the really long snout that we're now
familiar with as being normal for spinosaurus and it's basically standing up and going um
the other thing to note about it is it's got fairly short legs um which is something that
we'll come back to later but stromer had spotted that early on but he basically had this bulky
and upright posture but as i say based on a few bits you can see here they're all colored in grey
and unfortunately come 1945 an allied bombing raid blew up the munich museum where the specimen
was held and destroyed it so this photo that i showed you a second ago is by far
and away our best record um stroma did publish several papers on this there are drawings and
illustrations and photos but this is arguably the single best photo we have of that material
so we don't actually have the specimen anymore and so spinosaurus really were a fragmentary enigma
there was all this stuff that was dug up 100 years ago got blown up that's not a huge amount to go on
and so enter baryonyx um baryonyx is a british dinosaur uh in 1986. this claw unfortunately
this is actually a copy but this claw was found in the uk and an expedition went out from the
natural history museum to dig up uh what turned out to be really in the grand scheme of things
a relatively complete spinosaur and baryonyx this is a modern reconstruction of it we don't
have quite all of those bones but baryonyx um really was kind of the first animal that we now
had okay we've got an idea of what these things look like now we've got most of the skull we've
got bits of the neck we've got bits at the back we've got bits of the arms we've got the hips
and legs we've got chunks of the tail that's pretty much a whole skeleton we've got an idea
and of course that's a much more modern interpretation of a theropod you know much
down low the tail counterbalancing the body and we're extremely lucky that a couple of people
have come over from the natural history museum today or indeed this evening just to bring us
some of that original baryonyx material and so while that is um as i say a copy of the claw
we have here i need to be super careful because this is genuinely very delicate we have here
part of the original snout so you can see the individual teeth sockets along here hopefully
and these lovely preserved teeth and this part of the nose starting to come off um there's quite a
lot more of the skull we only brought a couple of pieces uh what's even more intact and particularly
nice is this most of the lower jaw so we have here again this is the original specimen dug up in 1986
and there's the what we call the holotype this is the name bearing specimens this
this is the one specimen in the entire world that baryonyx is based on and again
i'll flip it over slightly see some of the two sockets in there we will return to those later
but baryonyx therefore was really kind of critical because it gave us an impression of what a full
spinosaur looks like with this really quite nice long and thin um crocodile like it's got rather
different to what we've seen previously and we now have enough discoveries that we recognize
that spinosaurs as a whole we actually split into two groups we have what we call the
baryonychines obviously named for baryonyx and we have the spinosaurines named for spinosaurus
so the spinosaurins here are the particularly big ones at the back the green and grey one
and also this kind of teal one at the front and the core difference kind of between them
is that spinosaurines obviously have this much much bigger sail than does the baryonychines
and they tend to be rather bigger and just how much bigger uh is hopefully made clear by a
few of these pieces so baryonyx as we've seen you know it's a pretty large animal that's a
meter long scale bar so it's an animal eight nine meters long that's a very sizable carnivore indeed
you can see that from the size of this snout this is such a minuses snout super mimas is from niger
in africa and you can see the size comparison when i put them side by side obviously this
socket is much larger the teeth are much larger okay we've got a bigger bit of the skull obviously
but it's much much much more sizable and as you can see the skull would probably finish about here
so it is a much much larger animal and then we have a piece of spinosaurus so here we have
just the very tip of a jaw of spinosaurus so the equivalent of this piece here is just this
and hopefully again the camera is going to pick up the size of those tooth sockets
i think they're big enough that even anyone right at the back of the room
can see just how huge they are the front teeth of a large spinosaurus and they get bigger than
this one is an extremely sizable animal indeed so we've got baryonyx we've got spinosaurus we've got
two separate groups and indeed those fines have continued um so they've stopped being a group kind
of loan from north africa and europe and they're actually something which we now regard as being
not quite a global distribution but we've got a number of specimens down in uh brazil i should
say the baryonykines are here in purple and the spinosaurines in blue so spinosaurus all across
north north africa uh super mymus just below in niger we've got things like uh ichthya venata uh
out in laos and that kind of region we've got a whole load of stuff in spain portugal and france
and there's a bunch of question marks over there there's various different pieces which have been
argued to be spinosaurus baryonychines or spinosaurines but we're not entirely sure
a very common feature is the fact that these things are still fragmentary we don't have
any really good like complete spell it's getting skeletons that you could point to in a way that
you could for something like t-rex or allosaurus or velociraptor we've got multiple complete
skeletons but we do have enough bits where we can have a pretty good idea of their overall anatomy
and they share a bunch of key features together so first of all they have this
really really very long snout that we've just seen and it also has this notch at the front you
can see that notch quite clearly here you can see it in baryonyx but i won't hold that up again you
can definitely see it here at the bottom at the front of spinosaurus so that's really rather nice
it also comes in conjunction with what we call the rosette so it's kind of slightly nice and rounded
at the tip of the jaw so you've got a notch on the side and a rounded end
at the front that's basically unique we pretty much don't see that in any other dinosaur at all
they have these greatly elongated neural spines so again those giant spines that we have in the
middle of the back spinosaurus they're very very straight but you can see this one actually expands
massively so there's some variation in them as well they have a very short and robust humorous
the upper arm bone and again we've got it here for such a minus um extremely fat for its length and
with a real quite massive expansion on both sides and indeed at the lower end as well more so that
we see in kind of any comparable dinosaur normally so this is really greatly expanded and suggests
they had very very strong arms and actually going along with those very strong arms is a really
big set of claws so such a minus is a very large animal and it would have three claws on each hand
this is the smallest this is the medium size and this is the big one they're quite terrifying
remember this is just the bone they would then have the sheath on top which would make them
probably 50 bigger these are extremely large indeed and really quite a formidable series of
weapons and it's characteristic of them that they have these very strong arms with very big claws
on top of that they also have really quite um fat teeth for one of the better fries they're wide in
cross section to put it at a technical level if we switch over to the camera which hopefully is
on and working we did test it earlier lovely um so here we have um in this hand we have a tooth
of dilophosaurus and on this hand we have baryonyx oh the shadows getting in the way
see if they can make that a little better and hopefully you can see that the baryonyx teeth
oh yeah that wonderful thank you uh the baryonyx tooth is getting on for kind of twice as wide as
the comparable dilophosaurus tooth and if we move over to a full-sized spinosaurus teeth
and here with a aradontosaurus so an animal of similar size to it we can see that the spinosaurus
tooth much much rounder and doesn't have that really kind of nice sharks thin curvature that you
see on normal dinosaur or more normal carnivorous dinosaur teeth they also have these nice flutes
so these little ridges and furrows of enamel up the side that's very very common in these
and that's actually very similar to what you see in a lot of crocodiles including a bunch of fossil
crocodiles that lived alongside them um if you know your spinosaurus you know that spinosaurus
teeth or at least what are named as spinosaurus teeth are very very commonly sold on the internet
a good chunk of them i think are giant crocodile teeth because they're really quite hard to
tell them apart so that's a slight issue but it actually gives us a hint about what these animals
are doing and it's long been recognized that spinosaurs as a whole have some kind of
aquatic affinity and in particular we're probably eating fish this is a famous illustration from a
major paper describing baryonyx or kind of doing extended study of baryonyx in 1998 and you see
here baryonic standing ankle deep in water and grabbing at fish so this is not a new idea at all
and anyone looking at their teeth and looking at their skulls with that notch
might immediately think of something like a crocodile with very spiky teeth and a kind
of notch and a kind of rounded expansion at the end so this wasn't a new idea at all so
there was a long-standing idea that spinosaurs of various types were probably eating fish
and we actually have some really direct evidence of that and we're lucky to have some of that here
and hopefully this shows up we did struggle to get this
shooting earlier this may not look particularly exciting um this is a single fish scale
that was found inside the chest cavity of the baryonyx skeleton and indeed show some damage to
it which was interpreted as acid etching from the stomach so this is literally a fish scale found
inside the body from a fish that it had eaten so that's quite a strong indication that it's eating
fish it's got this very kind of crocodilian-like jaw we literally found fish inside it but it
wasn't the only thing what is often overlooked is the fact that there were bones of a baby iguanodon
found in slash alongside baryonyx as well suggest that it's also eating dinosaurs
and indeed we also see evidence of other spinosaurs eating other things so here we
have a chain of three neck vertebrae from a large pterosaur flying reptile
found i think this one's in north africa and as you can see there's a little arrow that says
tooth and you can hopefully see something fairly circular there and on the close-up underneath
you can see that tooth just jammed through the vertebra and having snapped off
and then this lovely illustration by mark whitten showing what probably happened
so even though we've got fish in the diet we've also got evidence of them eating dinosaurs
and we've also got them eating pterosaurs so it looks like they probably had a fairly varied diet
and that takes us up to about the early 2010s so 10 years ago give or take when suddenly
to the amazement of enormous number of people a new spinosaurus interpretation was published
spinosaurus bits had been coming out of north africa from
morocco algeria and egypt to various times bits like this for example which had been published
but now we had part of a new skeleton which allowed us to have a new interpretation
and you can see that here all those wonderful kind of harlequin colors goes into emphasize that point
i made about just how incomplete so many of these skeletons are and therefore actually those various
different colors represent different specimens and even different species that dark yellow that makes
up uh most of the shoulder and both arms is super mimos so a baryonic kind not even a spinosaurine
we don't even have a good set of spinosaurian arms yet but all that dark red stuff and orange
stuff including the pelvis the legs and some more vertebrae was part of the new discovery
and as you can see really short legs even shorter than stroma had suggested and looking like a very
kind of front heavy animal and suggesting that it was um there were suggestions that
it was quadrupedal though no one ever really quite said that they sort of hinted at it
um and then that was then quickly not exactly overturned but revised yet again by the same
team when they found um even more material in the same hillside and pulled out a fairly complete
tail as you can see illustrated here with these super long thin rod like expansions on the tail
um and they said this is a big fin and that this animal is probably swimming with them
and they suggested it was an aquatic pursuit predator that's actively chasing after fish
and other things in the water um but i have to say there were some problems with this some of which
kind of already existed so if you look back at work done um the french paleontologist roman amio
who'd be looking at isotopes so elemental signatures in bones and teeth of various
specimens he'd already been looking at spinosaurus from north africa and you don't need to know too
much detail to read this chart but the spinosaurs as you can see have the little black triangles and
various theropods have some black circles and we see that actually in various places on that graph
the theropods and spinosaurs overlap each other in other words there are some spinosaurs that appear
to have identical diets to fully terrestrial carnivorous theropods ones that are eating
other dinosaurs and are not eating fish so at least some spinosaur individuals are just eating
terrestrial prey and aren't eating fish at all which doesn't really match with the idea
of a specialist swimmer and don henderson a paleontologist in canada published a paper
looking at the buoyancy of these animals and how they would float in water and what position they
would take and suggest that spinosaurus not only kind of floats like any other carnivorous dinosaur
suggesting it's not particularly well adapted to being in water but actually that big sail
would kind of make it top heavy and unstable you can see from this reconstruction it was
done before the tail paper came out but of course the tail would actually cause the same
problem if you extend the tail up you're just putting more weight above the surface so there
were some early criticisms of this and similarly myself and my colleague tom holtz looked at this
and we said well look you know there's there's quite a collection of issues here another one
again um andrew cuff emily rayfield had published a paper a few years ago looking at the skull shape
and we see here spinosaurus above baryonyx below they're a little different the spinosaurus skull
is generally a bit stockier it's got these bigger teeth but fundamentally they're very similar
indeed in overall structure and what they showed is their mechanical performance how they respond
to stresses and load when they're doing things like grabbing stuff and hauling on large items
they actually respond very very similarly indeed so if spinosaurus was truly doing
something unique and different even to the other spinosaurus like baryonyx you'd expect maybe
that its skull was rather more specialized and was capable of doing other things or different
things and in fact it looks just like the one which we don't think swam at all and so
this kind of culminated in myself and tom holtz a colleague of mine in the states putting together a
research paper where we tried to summarize all of the information that we had about spinosaurus
and baryonyx and some of these other animals and how they might be responding they'll be
focused particularly on spinosaurus i won't go through this entire thing nor will i go through
my paper blow by blow that's not what anyone here is going to go through but the short version is
anything on here is a white arrow is something we think actively supports a hypothesis
a gray arrow is neutral you could read it either way it might be context dependent
and a black arrow is something which is actually problematic for that idea
and as you can see the idea of a terrestrial walking spinosaurus hunting its prey has a lot
of white arrows and a handful of grey and the idea of a high-speed swimming one has a lot of black
and we as i say we tried to test that we tried to do a proper scientific analysis
and actually test those hypotheses and this is one of them this is building a basically a
graph of how similar different shapes are to each other and so we looked at a whole bunch of things
like crocodiles which obviously are swimming around in water and hunting fish we got some
spinosaurs of course we got some other theropods and then we got some other aquatic reptiles
and what we find is actually the crocodiles in red and the other aquatic reptiles in orange
and a couple of them in blue really look most most like each other they sit in the same bit
of the graph and they overlap a lot and the spinosaurus in red actually sit with all the
other carnivorous dinosaurs in green spinosaurus and baryonyx have very crocodile sorry have very
dinosaur-like skulls and they don't particularly have very crocodile or marine reptile-like skulls
and we can see some more of that if we actually start looking at these things
in a bit more detail so if we look at a heron skull for example and indeed
i have the exact same heron skull that i used in the figure of my paper right here
we see the nostril position characteristically is really far back on the skull it's actually right
up close to the eyes and it's not actually at the tip of the nose and this means when they're
feeding if the head is down they can push that into the water and still breathe and grab stuff
whereas crocodiles oops let's be careful with that whereas crocodiles and their relatives have both
their eyes let me make sure i'm holding this right have their eyes right at the top of the head and
the nostril right at the top so that they can do exactly again as shown in this photo they can sit
almost with the entire head underwater and still be able to breathe through their nose and still
be able to see with their eyes and as we can see spinosaurus can't really do that its nostril is
quite a long way back on the side of the face so it has or certainly could have a rather heron like
function where it can stick stick the tip of its snout under the water
and still breathe and still grab stuff but as you see in b if it tries to be a crocodile and lie in
the water it's actually got to push most of its head above the surface before it can breathe and
if it's a real deep swimmer and actually spending its time down the bottom and only coming up for
air it's not very kind of whale like or again even crocodile-like it's actually got to stick
most of its head up to get the nostril clearer of the water so it's not a very convincing set of
arguments that this is really sitting in water it's got a skull which is fundamentally more
like a heron in terms of its eye and nostril than it is a crocodile or a swimming animal
spinosaurus also doesn't look like a very good swimmer this is rather an old paper and i love
the actual kind of cartoon drawings but it makes the it makes um a really good illustration of
this there are loads and loads and loads of marine reptiles something like 15 different
lineages went back into the water and expanded and radiated during the time of the dinosaurs
you've probably heard of things like plesiosaurs with their long necks you've probably heard of
ichthyosaurs these dolphin-like mimics that we see in the top left and pliosaurs and mosasaurs
and stuff like this and big marine turtles and marine crocodiles but there's even more than that
and you can roughly divide these up into some groups based on how they swim
and bowel plan one as it's come here a bowel plant is a german word kind of meaning
overall shape uh bowel plan one are the fast swimmers the ichthyosaurs these dolphin-like
very streamlined fast swimming animals bowel plant ii are actually the really quite slow swimmers and
you see crocodiles and various marine relatives of crocodiles down in that group if spinosaurus
is supposed to be a fast swimmer it should really be shaped like an ichthyosaur but it's not it's
shaped like these relatively slow swimmers they are still predators of fish um they actively chase
them but what crocodiles tend to do is have a little burst of speed just one or two body lengths
very rapid to grab something they don't chase it the way that dolphins do or ichthyosaurs did and
similarly spinosaurus doesn't seem to have a lot of the kind of adaptations we see of animals which
really are specialized for a life in water again this is from a review paper of marine and aquatic
reptiles and you can see they very often have paddles for their limbs or they've really reduced
the limbs to the point that they don't exist like the little rear fin here we see on the ichthyosaur
for example if they do have some kind of tail fluke like you might see in a dolphin it's right
at the tip of the tail it's not the whole length of the tail they don't tend to go in for really
big paddles in the way that things like eels do for example and again eels are slow swimmers so if
spinosaurus was really chasing after stuff we'd expect it to be really hydrodynamic this
really smooth tuna dolphin shark shape and it's got that dirty great sail on its back
and actually that's a real problem moving in water is difficult anyone who's tried to swim
or wade through water knows just how difficult it is to make real headway in the stuff
and in particular we have a thing called drag and drag is basically the friction between the fluid
and you trying to move through the fluid and that is really what slows you up and that's why super
fast things like tuna or even boats that want to go fast are as smooth as possible and have
as few things sticking out as possible to cut down their drag it's also true that bigger things have
proportionately more drag than you'd expect from smaller things and spinosaurus is very very big
indeed some of the upper estimates are over 15 meters that is an extraordinarily large animal
so you'd really want to minimize drag for fast swimming and you've got this
sail on your back and the big arms and quite a chunky head and worse than that
there is a thing called surface drag when you're close to the surface you actually pick up more
drag than if you're deep under water you actually get some interference with the surface if you've
ever seen things like whales or dolphins what they actually tend to do is come up to
the surface breathe and then dive deep and then swim along once they're deep underwater because
they're getting away from that surface drag and it makes them swim more efficiently
and that's really a question of how deep you can get having something two meters tall so about
this on your back means you're automatically close to the surface even when you're deep under water
so that means that spinosaurus isn't going to be an efficient swimmer until it's dive to the bottom
which is not great if you want to be swimming fast after fish but what about that tail fin
surely that's a big swimming trait it's just like you see in a whole bunch of swimming animals
well is it the top row here a is spinosaurus's tail you can see that lovely long thin expansion
that we talked about and a a through f are some animals which i'll show you in a minute which are
i think similar in structure with these very long thin rods uh g h i j and k however are actually
animals that are specialized swimmers and yeah they have some expansions to that tail
but they're kind of big flat plates rather than long thin rods we can look at a few of them here
so we've got a mosasaur at the top it does have a bit of a tail fluke but again just at the end
um it's got paddles it's got a pretty streamlined body um and it has yeah these pretty flattened
plate-like expansions um we have uh that's an eater sore in the middle a extinct crocodile-like
animal with the lifestyle very similar to modern crocodiles and again similar tale
and again this uh lovely weird thing hoversaurus from madagascar down the bottom again some
expansions but nothing like these long thing rods what we do see with long thin rods are animals
that signal to each other and have some kind of display structure on their tail uh most obvious
is this beautiful animal in the bottom left here we have the skeleton and the living animal
basilicus also called the basilisk also some of you may have heard us the jesus christ lizard
because they're famous being able to run across the surface of the water and they have just like
spinosaurus a crest on their head a big sail down their back and then a big sail down their tail
that's one one of the other animals i showed you in my illustration was protoceratops so a
desert dwelling horned dinosaur not a swimmer and again these big thin long extensions in its tail
and here we have a triturus in this case a great crested newt so a uk native species and yeah
they have this beautiful big long tall thin expansion on their tail and indeed on their back
but it's sexually dimorphic it's present in males and not in females if this was a really strong
swimming adaptation we'd expect both sexes to have it they both live in water and they both swim
so actually this doesn't particularly look like a swimming tail and it does look quite
a lot like a signaling tail even if it shows up in some aquatic swimming animals like newts
so if we put all of that together we have some problems with the idea of this being
a far swimmer that's chasing fish the head shape is similar both to baryonyx and um super mimos but
also other theropods generally the body shape is closer to that of slow swimmers than fast swimmers
we've got that huge sail on the back which is going to cause a lot of drag it might be unstable
in water if don henderson is right that finn is not particularly efficient for swimming and again
it looks like it has some signaling properties and we have at least some isotype data showing
that some spinosaurs certainly not all but some were feeding exclusively on land
and so this led to our alternate interpretation i wish i'd come up with the idea of hell heron
myself that comes from a colleague of mine andrea cow it was far too good not for me to steal
but this is the idea you know a heron or a stalk like animal you're probably used to
seeing herons standing on the banks of rivers and lakes and ponds and just grabbing at fish
uh but herons eat snakes and rats and frogs and baby birds and eggs and pretty much anything
they can get down they will grab and swallow um and so that's where this comes from these are
not just fishing animals these are chunking down absolutely anything they can get their head around
so yeah this nostril position this nostril far back on the
on the jaw oh so again if you have a look at super mimos um so yeah quite a long way back
from the front nothing like as extreme as the heron i admit but certainly not
at the tip of the snout or at the top like a crocodile and that would allow them to dip in
while they're foraging in water we have that similarity of skull shape of spinosaurus to
other spinosaurs suggesting they're all kind of doing the same thing and we think that sucromise
and baryonyx are hunting on riversides but again also eating dinosaurs also eating pterosaurs
we see that diverse diet again the neck adaptation i haven't talked about this at all but there's a
beautiful spinosaurus specimen from north africa which some people including myself think belongs
to a different animal called single masosaurus some people say it is spinosaurus but either way
it's clearly a very close relative and a wonderful recent study of that by sarah joshua evers
and colleagues shows that the neck is actually really well adapted for striking down rapidly
that makes a lot of sense if you're standing over a body of water or standing over a small
dinosaur and trying to grab at it again it makes much less sense if you're swimming to
the bottom of lakes and then trying to grab fish and again those isotopic signatures
that we've seen produce a suggest at least a varied diet of terrestrial and aquatic animals
so this led to this beautiful reconstruction by my friend bob nichols who did this for us
to accompany our paper and suggest spinosaurus as this kind of yeah ankle or even chest deep wading
animal foraging around with its snout just below the surface and then grabbing away at whatever
comes its way and of course doing this on land as well so we do think spinosaurus is primarily
episcopal it's a fish eater it absolutely has a series of adaptations in the skull and neck to go
after fish and that's probably a very large part of its diet but we think it did this primarily
by standing on the shore or standing you know somewhat in water and then striking down at things
tom and i have also suggested in an earlier paper these animals might actually be good at digging
that sounds like a very odd thing to do but this short fat humerus that we discussed which is very
very powerful indeed is actually really good at this kind of action which is a classic thing that
diggers do particularly into hard substrates and there is one thing that's knocking around in the
environment in particular spinosaurus but also some of the others and that's lungfish lungfish
was very very common these are animals which under the right circumstances such as when there's no
water will bury themselves into mud which can dry up and become very hard indeed and if you
can access lungfish when no one else has any food you can see how that could be a considerable
advantage it's just a hypothesis we haven't been able to test that yet but it's quite an idea we
think they might be digging they would certainly be good scavengers loads of stalks and things like
that are happily to pick away at dead bodies and of course crocodiles are famous for doing that
as well and they could even have lunged in water you know a powerful forward lunge a thrust with
that big tail would be very useful over a short distance uh i'm sure they did that on occasion
and so we've got these animals that are perhaps moving between what we call a patchy resource
imagine a whole bunch of river channels or lakes or things or ponds or things like this often in
very dry environments i should say spinosaurus is fundamentally egypt back then and north africa was
not a million miles away from where it is now it was a very hot dry arid environment if you weren't
close to water it was not particularly nice place to be so being able to move from body of water
to body of water to find your food might actually be a really useful tactic they do have short legs
they're perhaps not brilliant walkers and runners but they're going to be much better than the
local crocodiles they're going to be able to move from place to place and then when they get there
start eating the fish and the idea is that the crocodiles probably aren't as good at getting from
place to place and the carnivorous dinosaurs are much better but then when they get there they're
not good at catching fish so spinosaurus can perhaps sit in a gap between those two different
animals and therefore make a living even though they're potentially competing with big carnivores
for dinosaurs and competing with big crocodiles for fish they're able to do both and then we think
that both the big spines along the back and that kind of fin along the tail are probably signaling
structures they're advertising to each other in some way shape or form but going back to what i
said right at the start spinosaur fossils are still frustratingly fragmentary the original
baryonyx from 1986 is still the single best spinosaurus skeleton that we have from anywhere in
the world despite all those numerous little arrows and question marks that i dotted around that map
and some really extensive excavations in some of those countries we keep finding claws we keep
finding snouts we keep finding mandibles the lower jaws we find them again and again and again there
is something like 20 or 30 of these spinosaurus snout tips and lower jaws knocking around in
various museums no complete skull no complete arms no complete legs it's incredibly frustrating
that yeah i remember barry onyx being discovered and being on the news and the team from the
natural history museum presenting it then and being extremely excited and here i am 30 odd
years later it's the exact same thing as what we're working on but we do continue to find new
species and they get named and identified we have oxalia from brazil we have ichthyovenator from
laos which i mentioned earlier very recently had camarillosaurus in spain and valley
valley bonavenatrix one is a mouthful also from spain and then just at the end of last year so
less than six months ago uh chris barker as lead author with myself and a whole bunch of colleagues
who i'm afraid i'm not going to name all of you on camera because there's about nine of us
named two new baryonychines from the isle of wight siratasukops and raparov venata and here they are
um so yeah we now have two new ones the uk has three baryonykins from the south
so yeah both names from material collected from the isle of wight uh both are really quite similar
in size to each other and to baryonyx so one thing that has come up in the past is people have
suggested for example actually that baryonyx is a small sucromimus and given enough time it would
grow into that animal um i don't think anyone now is convinced by that idea but it has been put out
there before and so one obvious question is well maybe you've mixed up some adults and juveniles
when they're all exactly the same size it's hard to argue that one is the baby of another and here
actually the fact that we keep finding the same bits of these animals is actually quite useful
because we actually have the snout tips for both of them and baryonyx and we have the back of the
skull for both of them and baryonyx and those are all bits that contain an awful lot of information
that scientists have traditionally used for tell species apart particularly among spinosaurus
because they have such this unusual set of teeth and jaw shapes and so we were able to
do some comparisons between all three of those bits sorry all three of those animals and those
two different bits and we came to the conclusion that yes they are all genuinely different and that
both of these two guys get a new name as you can see they are both pretty incomplete we have these
jaw tips we have these skull parts and then for one of them we have a large chunk of tail which
you can see doesn't have the expanded fin or at least not as exaggerated as it is in spinosaurus
now a big question that comes up is can you really have three very
similar animals feeding on the same stuff in the same time and same place
well the first thing is we don't actually know for sure if they are actually from the exact same
time and place saratasukops and rapara venata were found very close to each other on the beach uh one
was found in the rock and the other had already washed out of the hillside so we don't actually
know exactly where it came from it could be older it could be younger it could be the same age
so they may or may not have been together and baryonyx is around the same time
it's from the south of the uk rather than from the isle of wight proper but again it's of a similar
age but we don't know if it's the exact age so the first answer to that is well we don't even
know if there are were all three together but even if they were that's actually not
anything like as unusual as you might think it's actually very normal in both modern and
ancient ecosystems to have multiple similar closely related species living together this
is just a little map that i've done of various crocodiles crocodiles uh garials so i didn't
mention my gario earlier but i brought it along so it's a shame not to show it off
and uh in south america cayman as well and um each one of those different colors represents
different species so you see here for example this dark green arrow in australia is uh the estuarine
crocodile and we find that in australia the philippines in all the way through
indonesia and in various places with various other different crocodile species we have three
large crocodiles in india together we have both crocodiles and alligators in florida and even four
cayman living in the same place in south america so again you can have very similar size shaped and
evolutionarily close animals living together and it's not just them this is a paper by schnitzeler
and hermann i've really mangled their quote to get it to fit into the limited space but they were
looking at relatively recent the last few hundred thousand years of as you see part of anna taylor
and turkey transcorskia georgia armenia azerbaijan and the caspian islands to western pakistan
that's a fairly big chunk of area but actually rather smaller than for example north africa
and as you see um had an impressive assemblage of carnivores lion tiger cheetah leopard links brown
bear gray wolf jackal and strike hyena that is an awful lot of really quite similar large carnivores
all apparently competing for food in the same time and at the same place even in india today
you have leopards lions and tigers living in the same environment together and they're all members
of the same genus panthera so very close relatives are actually very commonly found together so there
is no particularly big reason to think that serato sukups and riparia venata couldn't have both made
a living even if they were alongside baryonyx so as a final summary uh the spinosaurs are really
really large carnivores again even baryonyx about the smallest adult spinosaur that we have
um would well i'm quite probably a bit too big for it to eat but i certainly wouldn't
wouldn't want to mess with it it is a large carnivorous animal all the way up to these giant
spinosaurs that are perhaps 15 meters long and probably in the realm of seven tons spinosaurus
probably is a better swimmer than the others um but certainly not a high-speed pursuit predator
or a particularly good deep diver or anything like that all of these spinosaurs are probably
eating fish predominantly it's a major part of their diet but they're not fish specialists
and that's where i'd come back to my gariel so you know as we've seen spinosaurs have this
really rather crocodile like shape these rather crocodile-like teeth and these still rather narrow
but fairly robust skulls if we look at real fish specialists yes they have similar teeth but what
they tend to have is really really long skulls where every single tooth is exactly the same size
that's what we see in something like agarial that's what we see in something as different
as this dolphin a very long straight thin jaw with lots of identically shaped teeth
and that's really quite different to what we see in again you can see it even in the spinosaurus
there's huge teeth up front but tiny teeth almost immediately behind it there's a huge variation in
tooth size and we see you know that expansion of the notch and the rosette which we really
don't see in these guys at all so they are fish eaters but they're not specialist fish eaters
and multiple spinosaurs living together seems to be normal
though exactly how they did or didn't compete and quite what they were doing
isn't clear at the moment and then finally just like there is lots more to come you know we
desperately need new spinosaur skeletons if anyone knows many please let me know
uh if anyone wants to be a paleontologist please go and dig some up uh there are rumors of more
stuff coming out of egypt in particular back to the original sites that stroma and his team were
working on over a hundred years ago that would be great we know there's a new description coming of
ichthyo venator from laos that will be great it's got a tail which we haven't been described before
it's got legs which hadn't been described before that's all going to be exciting and relevant and
hopefully there's more stuff coming out of the isle of wight soon i've already heard rumors
of some more jaws that have been discovered there so there is more to come um certainly the
the the arguments the disagreements uh the science the progress there is lots more on
this uh these are still early days but i think we have a decent idea of where things are going
um and i'll just finished with some thanks obviously tom holtz because i've collaborated
with him on multiple papers uh a whole list of colleagues but particularly chris barker
darren nation andrea cow neil gosling who are some of my collaborators and again chris led the paper
on serato c and raparo venata a whole bunch of people who kindly lent me their artworks or photos
or various bits from their papers to illustrate this and i'll leave you with a selection of photos
of my books videos podcasts twitter and other things that you might be interested in if you
want to know more in the future so i'll leave it there thank you very very much for your time
really fantastic stuff