New sauropodoramas: Stormy brachiosaurs! Apatosaurine brontosmash!

Realising that Recreating an Age of Reptiles was a bit light on sauropod art, I've been beavering away on two additional sauropodoramas* to pad things out a bit. I thought I'd share them here.

*Sauropods are such special animals that they deserve their own nomenclature for most things, including artwork. See, for another example, 'shards of excellence'.

The first is a reworking of a 2013 image of the Wealden (probable) brachiosaur Pelorosaurus conybeari in hammering wind and rain. We know that Wealden climates were subject to storms and intense downpours on occasion (lightning and floods being, of course, key elements in the production of fossil-rich plant debris horizons in certain Wealden deposits) and it stands to reason that any sauropods around when those rains arrived would have got quite wet indeed. I don't say that just casually: the prospects of being a wild animal the size of a house mean that you're actually pretty exposed to just about everything weather can throw at you. When unexpected meteorological fit hits the shan, your options as a giant are pretty limited. Running away is out, because your legs are pillar-like structures adapted for supporting immense weight, not nimble escape. Seeking shelter is not an option either, because you're bigger than everything else around you. You're just too darned huge to do anything but stand there and take it. The life of a sauropod must've been spent baking in the sun, being battered by wind, and drenched in rain. I find that idea quite romantic and evocative as an artist. When painting sauropods, I often wonder how cracked, weathered and worn their skin must've been through a lifetime of battles with changing weather.

Like masts in a storm, three Pelorosaurus conybeari brave typically English weather, c. 135 million years ago. They're doing their best to look tough next to a couple of rainbows.

Second is an image inspired by a recent SVPCA talk by sauropod expert Mike Taylor and his colleagues Matt Wedel, Darren Naish and Brian Engh. Regular readers of the palaeoblogosphere will probably already know where this is going, given that Mike's talk (and the upcoming Wedel et al. paper) has been given some hefty coverage at SV:POW!. Those familiar with sauropods will know that apatosaurines (Apatosaurus, Brontosaurus and a few other taxa) have atypically proportioned, large and robust neck vertebrae, with their cervical ribs being especially elongated and reinforced. These structures possess peculiar buttresses on their underside which, it seems, are not products of muscle or ligament attachment (if they are, they have no modern analogue). Instead, they might relate to an epidermal feature like a boss or horn, as such structures sometimes leave peculiar swellings on underlying bones. Exactly what these anatomies indicate has long been puzzling, and all the more so because all apatosaurines show neck vertebrae with these features. Some (like Brontosaurus) were more extreme than others in development of these features, but even modest apatosaurines were doing crazy, mysterious stuff with their neck anatomy. Question is, what?

Matt, Mike and others have recently been outlining a first principles approach to this conundrum. They note that the reinforced construction of apatosaurine necks, the additional muscle attachment afforded by vertebral expansion, and those strange vertebral buttresses might render their necks effective clubs or wrestling appendages, particularly well suited to rapid, powerful downward motions. Summarised a little more succinctly: there is reason to think Brontosaurus and kin might've smashed the crap out of each other, or other animals...

...with their necks.

Yowsers. But outlandish as the Brontosmash hypothesis seems, it really isn't just idle speculation: a paper is in the works, the Taylor et al. SVPCA talk abstract is a preprint at PeerJ, and you can see the case explained in Mike's talk slides here. I find it pretty convincing myself: I mean, there had to be some reason apatosaurines had those crazy necks. Evolution is a sloppy craftsman at times, but the energy put into growing and maintaining such massive neck anatomy must've been substantial, and that almost certainly reflects a certain adaptive purpose. Combat might well have been that driving force. We also know from living animals - camels, giraffes and some seals - that necks are used for fighting, and that neck-based combat can promote reinforcement and restructuring of neck anatomy. It certainly sounds provisionally convincing to me, and I'm sure we'll hear a lot more about it in the future as the hypothesis is developed.

We're also sure to see this concept frequently in future palaeoart. Mike has been collecting some of the early artwork of this idea over at SV:POW!, including a wealth of coloured sketches and concepts by Brontosmash coauthor and palaeoartist Brian Engh, palaeoartist Bob Nicholls, #MikeTaylorAwesomeDinoArt (the revolution palaeoart deserves, if not the one it needs) and an alternative interpretation of apatosaurine neck data provided by myself (we secretly know I'm on the money with that one). I also decided to attempt a full on painting:

Multiple tonnes of Brontosaurus excelsus in disagreement.

There're two nods to classic palaeoartists here. There's a Knightian influence to the style (not the first time he's infected my work), as well as, via the very upright postures of the wrestling animals, a hat-tip to Robert Bakker's famous 'boxing Brontosaurus' image. The latter had a big impact on me when I first saw it as a teenager, and it's been on my mind for obvious reasons with all this talk of fighting apatosaurines. I thought it also made for a bit of a contrast to Brian's 'official' depictions as well, these showing the animals in quadrupedal or near-quadrupedal poses (I assume at least some of the postures in those artworks mimic neck combat in elephant seals, a favoured modern behavioural analogue of Team Brontosmash). The setting is meant to be in the wetter, northern parts of the Morrison Formation palaeoenvironment, alongside swollen river margins. Initial plans were to record the progression of the wrestling match in muddy footprints, but adding splashes and visual noise to proceedings was too much fun, especially with those tails whirling around everywhere. Sloshing water provided a means showing specific actions, too, the splashes from colliding brontosaur hide signifying each powerful, multi-tonne impact. This was definitely a fun image to put together, and it's certainly a favourite of my recent work. Brontosmash!

That's all for now. Coming soon (probably): The Triassic! And a boring old pterosaur that we just can't leave alone!

These sauropodoramas were brought to you by Patreon

Regular readers will know that this blog and artwork is sponsored by patrons who pledge support at my Patreon page. For as little as $1 a month you can help keep this blog going and, as a reward, you get to see a bunch of exclusive content, and I'm really grateful to everyone who contributes. I'm especially thankful at the moment because, around a week ago, my art PC almost flatlined. My patrons have taken the sting out of repair costs, as well as given an incentive for futureproofing my hardware. Thanks chaps - you're awesome (if, sorry, not quite as awesome as neck smashing brontosaurs. But what is?).

New takes on the Wealden Supergroup palaeobiota, part 2: Baryonyx, freshwater plesiosaurs, ornithomimosaurs and others

Last week we took a look at some new art of animals from the Wealden Supergroup, the intensively studied, historically important Lower Cretaceous rocks of Southern Britain. We all know the Wealden for celebrity dinosaurs like Iguanodon and Baryonyx, but there's a heap of other interesting animals in there which get relatively little publicity. It's mostly these we're focusing on here, in the second (and final) part of these 'picture of the day'-style posts. 

As before, if you like anything here, remember that you can buy prints of them all from my shop (the Wealden section might be relevant) and its new Facebook outlet. Indeed, if you like my work and are on Facebook, why not 'like' the new Mark Witton Palaeoart page? It's the best place to see when new prints and finished pictures are available.

Baryonyx walkeri: king of the fishers, redux

Baryonyx walkeri, off for a stroll among the crocodyliforms and pterosaurs.

Let's break this post in with a familiar animal: spinosaurid Baryonyx. It's hard to appreciate now how weird this animal seemed back in the 1980s and 1990s. At this point, other spinosaur material was only very poorly known, and laymen and scientists alike found this weird, superficially-crocodile like animal fascinating. Ironically, it's recently turned out that we first collected Wealden spinosaur material centuries ago, but struggled to recognise its significance until more complete remains were unearthed in the 1980s. We now know that Baryonyx can be found throughout a good chunk of upper Wealden stratigraphy and teeth referable to it - or another spinosaurid - are fairly common, at least as Wealden dinosaur fossils go. Baryonyx provided the basic template we'd recognise for all spinosaurid anatomy until last year when, famously, some spinosaurs were proposed to be rather different. It's clear that, whatever is going on with Spinosaurus, Baryonyx retains more conventional hindlimb and pelvic proportions, and may not have been so aquatically adapted as true spinosaurines. In this updated image, B. walkeri is splashing into a body of water while goniopholidid crocodyliforms and gnathosaurine pterosaurs go about their business around it. Note how much larger Baryonyx is compared to the crocs: Baryonyx is the largest theropod in the Wealden Supergroup, by a good margin.

Button-toothed crocs, redux

Bernissartid Koumpiodontosuchus aprosdokiti foraging for molluscs. It's eating a mud snail, Viviparus cariniferus, while tiny (6 mm long) physid gastropods Prophysa crawl over pond scum in the lower left of the image. Dragonflies provide scale, and unnamed tetanurans prowl around the background.

Last year I was lucky enough to provide the first restoration of Kompiodontosuchus aprosdokiti, a small neosuchian crocodyliform common to the Wessex Formation, and perhaps other parts of the Wealden sequence. Koumpiodontosuchus is a bernissartid, a group of small-bodied crocodyliforms with robust, shell-cracking teeth at the back of their jaws. As you'll know if you read my write up last year, these were likely employed in smashing molluscs and insects. The tetanuran theropods in this image are unnamed, but are not thought to be referable to any existing Wealden taxa. We probably need more material of them to consider them nameable, however: recognising that they are different from other Wealden theropods is only half the battle. Modern students of Wealden fossils famously do their best to preserve historic names based on fragmentary bones, but there seems to be an effort to 'future proof' Wealden taxonomy against confusion by only naming well-represented, characteristic animals. I guess I could have chosen one of the better known theropods to play the 'This was the Age of Dinosaurs' card for this PR image, but I think it's good to show that not all large theropods in the Wessex palaeobiota were Neovenator, Baryonyx or Eotyrannus. 

Welcoming the new Wealden ornithomimosaurs

A flock of Wessex Formation ornithomimosaurs forage in a marshland, while istiodactylid pterosaurs skulk about behind them.

Those keeping their ears to the ground will know that the newest arrivals to the Wealden dinosaur palaeobiota are ornithomimosaurs, commonly known as ostrich dinosaurs. Two specimens show that these animals were present in both the Weald and Wessex basins of the broader Wealden succession, and one of these fossils represents a historic taxon named in 1889: Valdoraptor oweni. Key to identifying ostrich dinosaurs in the Wealden was the discovery of abundant ornithomimosaur remains in France, many of which are so reminiscent of Valdoraptor and other Wealden theropod material that they may represent the same taxon. If you want to know more about these and their relationship to the complex story of Wealden theropods, check out Darren Naish's post on this at Tetrapod Zoology.

The above new painting shows a group of (nameless) Wessex Formation ornithomimosaurs in a well-vegetated marshland, in the rainy season, while istiodactylid pterosaurs mosey about in the background. The abundance of ostrich dinosaurs and juveniles in the middle-right are nods to the frequent recovery of abundant specimens of different levels of maturity at many ostrich dinosaur sites, including the new, French 'Angeac ornithomimosaur'. Note that the wings of the running foreround animal are somewhat swept back: I don't think the more common way of reconstructing ornithomimosaurs with 'dangly arms' looks right. They look like they should be holding shopping bags or something.

Valdosaurus in the forest, redux

Two Wealden dryosaurids Valdosaurus canaliculatus, and a stubborn avialan.

Ornithomimosaurs weren't the only fast runners in Wealden landscapes. Dryosaurids, like Valdosaurus canaliculatus were also fleet-footed animals with powerful, well-muscled hindlimbs, and tiny bodies attached to the front. In this reworked image, two of these 3-4 m long animals are taking it slow through a Wealden woodland. Although Wealden climates were quite warm and arid, leaving much of the landscape looking quite chaparral-like, some relatively upland parts seem to have been more vegetated: it's here that this picture is set. In my mind, these animals always walked with the stooping posture of the foreground animal - as noted last time, I like the idea that prehistoric animals had characteristic postures varying slightly from those we consistently restore in skeletal restorations. Note the avialan on the left of the image, which is a nod to the recovery of bird teeth from Wealden deposits. Anyone who's ever been forced to walk around a stubborn reclined mallard will recognise the situation now facing the Valdosaurus.

Barilium dawsomi in leathers, redux

Barilium dawsoni, a large and very robust iguanodont from Sussex. A flock of 'Ashdown maniraptorans' add scale.

Last time we featured Iguanodon bernissartensis: now it's the turn of the 'other' big Wealden iguanodont, the stratigraphically older, and osteologically chunkier Barilium dawsoni. In this redone painting, I've tried to make the Barilium skin more interesting than just plain old scales, covering the back in small, horny ossicles and creasing the flanks as if the skin is particularly thick, leathery and folded. I think we should be rendering more interesting skin regularly in scaly dinosaur palaeoart, as it seems most extensive dinosaur skin remains show unexpected features - strangle scales, wattles, folds and that sort of thing - which small skin patches mostly cannot record adequately. It's interesting to contrast these skin impressions with homogeneous restorations of scaly dinosaur appearance presented by some, where every species is covered in smooth hide following perfect contours of the underlying tissues: I'm not sure that's what fossils are telling us. As before, the 'Ashdown maniraptoran' provides scale to the bulk of Barilium. For the uninitiated, the Ashdown maniraptoran is seriously small for a Mesozoic dinosaur - maybe about 30-50 cm long. If you find big iguanodonts exciting, be sure to check out this previous post.

Polacanthus redux, again

A Wealden tree vies for attention with Polacanthus foxii, and some tiny birds.

OK, I'm cheating a bit with this one. This redone version of a much older painting has been posted fairly recently, but it seemed a bit remiss to skip this ankylosaur in this run down of recently produced Wealden palaeoart. Polacanthus foxii is, of course, the Wealden's sacral-shield-bearing nodosaurid, shown here strolling around a Cretaceous hillock with some birds for company. Having scratched the completist itch, let's move on, because we've seen this all before.

Accidentally sinister Leptocleidus, redux 

Mother and calf Leptocleidus superstes, a freshwater leptocleidid plesiosaur, explore a river inlet in Lower Cretaceous Sussex. 

Our final stop is in Wealden rivers and estuaries, where Leptocleidus superstes and other species of freshwater leptocleidid plesiosaurs roamed. The new version of this image has added a lot of detail on top of the original, which has inadvertently made the mother and calf Leptocleidus look more sinister than intended - hey, it's not my fault their teeth stick out like that. Back in the original post on these animals I mentioned that pliosaurs may also have been present in Wealden lakes and rivers, but note that this is no longer certain: the Hastanectes valdensis remains once provisionally considered pliosauroid have been placed in Leptocleididae in more recent analyses. That does make for a neater story - it means that leptocleidids retain their dominant role as 'near-shore-or-freshwater' animals, but perhaps a slightly less interesting one.

And that's all for now - I hope you've enjoyed this jaunt back to the ancient Wealden and these revised artworks. I'm sure we'll visit the Wealden again in time. Coming next, probably: walking with non-pterodactyloid pterosaurs.

New takes on the Wealden Supergroup palaeobiota, part 1: Iguanodon, Neovenator, Eotyrannus and others

Regular readers will know that I'm prone to dabbling in palaeoart depicting the environments and animals of the Wealden Supergroup, the 18 million year stretch of Early Cretaceous time represented by mud-and sandstone deposits across the southern UK. Recently, I've been updating some existing Wealden work as well as producing some new stuff of other Wealden species. With no time to produce a new post of substance, here's a bumper 'picture of the day'-type post. Initially, I was going to chuck something like ten images on here, but time has run short and I'll have to split it in two.

If you like anything here, remember that you can buy prints of them all from my shop (there's now a Wealden section, too), which is now also browsable from the comfort of Facebook. OK, enough preamble: into the Wealden once again...

Iguanodon bernissartensis: thumb wars

Two Iguanodon bernissartensis, the quintessential Wealden iguanodont, decide to settle their differences, while members of their herd watch on.

Poor old Iguanodon doesn't get the attention it used to, and a lot palaeoart we do see of it tends to focus on tried and tested behaviours: lots of standing about and eating, but not much else. In this new painting, I've attempted to show two big Iguanodon individuals settling an intra-specific dispute via use of thumb spikes. Long-term readers may recall that we've covered iguanodont thumb spikes before, and that I. bernissartensis has especially big ones. Here, they've been swinging their thumbs at each other's soft bits, causing deep, bloody wounds. This might seem extreme, but there are plenty of modern animals which take intraspecific fights to similarly gory levels - elephant seals were a key inspiration here. I imagine battling Iguanodon would look like an armed sumo-wrestling match, albeit with longer tails and less rice. Note that you can see the breath of several animals here: Wealden winters are not meant to be especially warm.

Rebbachisaurids vs. Neovenator salerii redux

Carcharodontosaurian Neovenator salerii stalks a pair of rebbachisaurid sauropods, using darkness as cover.

A while back I posted about dinosaur predation, noting that modern animal predator acts are often far less gladiatorial and epic than we might imagine. It's this slow, considered approach to predation which I'm attempting to show here, as the carcharodontosaur Neovenator stalks two rebbachisaurid sauropods in the dead of night. The idea is that the Neovenator has much better eyesight than the sauropods, who know they're in trouble, but can't really respond adequately. Note the rain: some recent models of Wealden palaeoclimates suggest it was wetter than previously modelled (albeit with very high evaporation rates for much of the year).

Anteophthalmosuchus hooleyi vs. Hypsilophodon foxii, redux

Large goniopholidid Anteophthalmosuchus hooleyi takes advantage of a flooding river to hunt two stranded Hypsilophodon foxii.

Speaking of rain, we know that some parts of the Wealden were prone to flooding following particularly intense downpours. That's good news for animals adapted for powerful swimming, but less welcome to species which prefer dry land. Here, in this reworked painting, the large Wealden goniopholidid Anteophthalmosuchus hooleyi has found a stranded pair of adult and juvenile Hypsilophodon foxii, and is taking full advantage of the situation. Goniopholodids are a group of almost-crocodiles characterised by long forelimbs, interlocking scutes and overbitten jaws - you can read more about them here.

Eotyrannus lengi: firestarter, redux 

Early tyrannosauroid Eotyrannus lengi stalks the edge of such a wildfire. 

What else does rain bring? Sometimes, lightning. When introduced to a parched Wealden landscape, lightning strikes caused short-lived canopy fires which, ultimately, created conditions ideal for fossil preservation. In this reworked painting, a fully-feathered tyrannosauroid Eotyrannus lengi is prowling the periphery of a Wealden canopy fire to grab any animals flushed out by the flames.

The tiny wars of Wesserpeton evansae, redux 

Two Wesserpeton evansae get in each other's faces, because some animals are just jerks.

OK, enough about Wealden weather. Here's a reworked version of two of the Wealden's tiniest tetrapods - indeed, some of the smallest fossil tetrapods of all - facing off in leaf litter. Recently named Wesserpeton evansae, these are albanerpetontids, very small amphibians which only died out a few million years ago. The 35 mm snout-vent length of these animals did nothing to temper their ferocity, and numerous jaws of Wesserpeton have healed fractures and breaks from intraspecific tussles. The animals in this picture are speaking the aggressive body language of modern salamanders as a prelude to their conflict. Two sauropods hang around in the background because, hey, it's called the Age of Dinosaurs for a reason. Some people have suggested this image borders on the trippy and surreal. Stay off the shrooms, kids. 

Rebbachisaurids and chums

Lower Cretaceous rebbachisaurids and giant sauropod 'Angloposeidon' look for water in this desiccating Wealden lake.

I do like rebbachisaurids, that group of sauropods who didn't get the memo about long necks. They're only represented by scrappy remains in the Wealden (a scapula) which is enough to tell us they were there, but not substantial enough to carry a name. Here, a few individuals are digging around a rapidly drying lake-bed to find a substantial source of water: digging elephants were the inspiration for this scene. In the background, probable brachiosaurid 'Angloposeidon' struts its stuff. It's meant to be walking particularly tall - I like the idea that fossil animals would carry themselves in different, characteristic ways, just as modern animals do. A pink gnathosaurine pterosaur has snuck into the foreground, just because. 

A lesser-seen Wealden scene: the Hastings Beds palaeobiota

Finally for now, here's one more new painting. This is a reconstruction of a swollen river representing part of the Hastings Beds, the oldest deposits of the Wealden, complete with local reptile fauna. The animals shown here are really poorly known: titanosaur 'Pelorosaurus' becklesii (bits of forelimb), possible carcharodontosaurian Becklespinax altispinax (three dorsal vertebrae), eucryptodiran turtle Hylaeochelys belli (a shell), and the possible azhdarchoid previously known as 'Palaeornis cliftii' (humerus). So yes, take the 'restorations' of these animals with an evaporite mine of salt: they're really just better known, fairly 'generic' representatives of groups represented by these Wealden taxa, air-dropped into a Wealden setting. Becklespinax is obviously modelled closely on Concavenator, as they seem to be pretty closely related and have a similar taste in dorsal ornamentation. I gave Becklespinax a more vertical anterior sail margin however, as indicated by the fossil. There's an article waiting to be written on palaeoart like this - should we even bother 'reconstructing' poorly known scenes and species? I clearly think we should, but we'll have to discuss the reasons why another time. 

I'm just now realising that there's a lot of confrontation in these images. Come back soon for a more placid, relaxed set of pictures in part 2...

Palaeoartworks, the case studies, part 2: Feathered dinosaurs and tiny Crocodyliformes

It's time for part 2 of our 'Palaeoart Case Studies' series, this time featuring two subjects: the tiny Cretaceous crocodyliform Koumpiodontosuchus and the probable Lower Cretaceous troodontid Yaverlandia bitholus. Unlike our last subject in this series, giant pterosaurs, neither of these animals is huge. Koumpiodontosuchus is particularly diminutive with an estimated adult length of 600 mm long. Presenting the scale of an animal accurate is important for good palaeoart, as it's not only an important factor in the animal's biology and ecology, but also an integral part of it's character. Small animals present palaeoartists with a particular challenge because many folks hold the preconception that all extinct animals were large. For diagrammatic images, simply adding a person, modern animal or familiar object next to our creature shows its size, but this cannot work when rendering scenes that took place millions before familiar entities appeared. How do palaeoartists get around this? Read on to find out.

Yaverlandia represents the result of a recent palaeoart success story. After many years of trying, it seems palaeoartists have finally got the hang of recreating convincing-looking feathered dinosaurs. How did they do this? In short, by abandoning the need to show all dinosaurs as scaly reptiles and embracing the birdiness inherent to many species (or, to flip this around, realising that many traits unique to modern birds were common to many of their dinosaur ancestors). But what does this mean for the way we reconstruct troodontids and other feathered dinosaurs? Again, the answers are below.

This series of case studies is in aid of my art gallery in Lyme Regis, running until May 4th, at the Town Mill. Full details here.

Koumpiodontosuchus: a tiny, button-toothed crocodyliform

Reconstruction of the tiny Wealden bernissartid Koumpiodontosuchus aprosdokitii. Hopefully, you can see that it's not a large animal without having to think about it too much, but why is that? Prints of this image are available here.

The size of extinct animals a favourite topic of palaeontology aficionados, and presenting it accurately is an important goal for palaoartists. Although we often think of extinct species as very large animals, most were not giants. The skull of the tiny Cretaceous crocodyliform Koumpiodontosuchus show below, for instance, belonged to an adult individual that, in life, was about 600 mm long. But how can palaeoartists express a sense of animal size - big or small - without the use of modern objects, animals or people for reference?

Some general trends of animal appearance can be useful in conveying size in extinct species. These probably aren’t features that most of us think about when observing animals, but they provide palaoartistists with some tricks to give a sense of scale to their subject matter without using other objects or animals for scale. Generally speaking, facial features - particularly the eyes - of larger creatures are relatively smaller than those of more diminutive animals. The limb bones of larger animals are more robust and, as they approach the extremities, are proportionally shorter. Smaller animals often have less conspicuous muscle contours than larger animals, particularly if they have a fluffy covering and, in being lighter, smaller creatures are frequently more sprightly and ‘weightless’ than larger ones.

Animal proportions only give a very general sense of scale, however. To give a more precise measure, palaeoartists often juxtapose relatively familiar species alongside their subjects. The use of ‘background’ animals, or different varieties of plants, are useful in this respect. Even if the audience is not very familiar with these background entities, their proportions in relation to the subject gives an impression of scale. This can work in inverse, too: bigger animals or plants, shown in low contrast at a distance, can help reinforce the size of smaller subjects. Crafty consideration of point of view can also help: does the subject need a very low, tight point of view to be seen, or does a wider frame capture it more adequately? Again, these are not necessarily factors that we consider when viewing animals or artwork of them, but they are essential considerations for palaeoartists attempting to reconstruct not only the anatomy and lifestyle of their subject, but also their size and physical presence.

Yaverlandia: Britain's most bird-like dinosaur

Two Yaverlandia investigate a termite-riddent tree stump in Lower Cretaceous Britain. As with many other dinosaurs, their depiction here as very bird-like creatures is the result of palaeoartists having to completely overhaul the way feathered dinosaurs are rendered. 

Known only from skull caps, Yaverlandia bitholus is one of Britain’s lesser known dinosaurs. Found in Lower Cretaceous Wessex Formation cliffs close to its namesake, the Isle of Wight coastal village of Yaverland, it was thought for a long time to represent a member of the bone-headed dinosaur group Pachycephalosauridae. Recently, it has been reinterpreted as Britain’s first troodontid, an omnivorous theropod dinosaur closely related to birds and familiar carnivores like Troodon, Velociraptor and Deinonychus. Troodontids were big brained, nimble animals and most were rather small. Yaverlandia was no exception, with a tentative length estimate of about 2 m. 

Any restoration of Yaverlandia and its kin has to incorporate data on dinosaur feathering, details of which have only been available in earnest for the last 20 years or so. The uptake of feathered dinosaurs among palaeoartists has been variable. Some restrict them to specific regions of the body, while others provide smatterings of feathers across primarily scaly skin. Increasing numbers of artists restore these animals as very bird-like however, with feathers across their entire bodies including their heads, tails and legs. Fossil evidence is clearly in line with this latter approach. Bird-like dinosaurs, including troodontids, have been discovered with extensive feathering that covers their not only their torsos necks, heads and tails, but even sometimes their legs and toes. 

These discoveries have given palaeoartists a lot to think about when restoring the appearance of bird-like dinosaur species. Feathers are complex, three-dimensional structures which alter the body profile of their owners. They plump the appearance of the body and smooth contours of the animal’s profile. Thus, if a dinosaur has complex feathers, we can no longer simply restore their musculoskeletal system and wrap skin over it, as often done in the past. What’s more, palaeoartists have to think carefully about the way feathered dinosaur arms and hands are rendered, because their feather configuration is similarly complex modern bird wings: feathers erupt from the tip of the second finger to the elbow, with feathers of the shoulders covering the ‘gap’ between forelimb and body feathering. 

These ‘new look’ dinosaurs are more bird-like than ever, and evidence is mounting that feathers appeared much earlier in dinosaur evolution than classically realised. It is even quite probable that Tyrannosaurus was feathered. This is disheartening to some who ‘prefer’ the appearance of scaly dinosaurs, and many still erroneously render troodontids and their kin with scaly hides. Wholly feathered restorations of such dinosaurs are without doubt factually accurate renditions however, and entirely uncontroversial among scientists. 

Can palaeoart prevent the over-commercialisation of fossils?

If money was no object, would you buy a sauropod skeleton, or artwork of one? A question to ponder while these Lower Cretaceous rebbachisaurids and 'Angloposeidon' look for water in this desiccating Wealden lake. Prints of this image are available here.

The greatest threat to 21st century palaeontology is the inflating commercialisation of fossils. At least, this the view put forward in a recent article by Kenshu Shimada and colleagues (2014), and I don't disagree with them. While the commercialisation of fossils is not inherently wrong, the explosion in auctioning spectacular fossil specimens, often at prices which are well beyond the reach of the scientific institutions, presents many concerns for palaeontological science. This is more than just jealousy from poor palaeontological institutions: it causes illegal plundering of fossil specimens, locality vandalism and loss of specimen provenance, robbing fossils of almost all scientific worth. Some legitimate scientists are involved in this game, either selling, lending their interpretation to auction lots, or publishing details of privately-owned fossils in peer reviewed literature. The latter, even when done with the best intentions (e.g. Sereno et al. 2009; Tischlinger and Frey 2013) panders to the private fossil market, sending a signal that scientists will accept and make-do with this new status quo. Even museums are getting in on the act, toying with the idea of selling off historically-valuable specimens for funding. At auction, commercial dealers often mislead buyers with scientific over-advertisement to increase lot appeal, making claims which have not been substantiated by genuine scientific investigation. The result has been years of debate over the legalities, economy and ethics of fossil commercialisation, with little evidence of a balance between those wanting to profit from and privatise fossils, and those who want them publicly preserved, studied and shared.

Desperate times call for desperate measures, and maybe a radical approach is needed to help settle these debates. Such an idea was pushed forward by Shimada et al. (2014), who proposed that commercialising palaeoart may be a viable alternative to selling spectacular fossils. This is not quite the first time this idea has been mentioned, although I think it's the first time it's been mentioned in print. Shimada et al. do not dwell on the point too long, merely stating that:

"...suggestions have also been made that, similar to the annual meetings of the SVP, our paleontological community can perhaps promote the sales of fossil replicas and 'paleo arts' (e.g., paintings and 3-D models of extinct organisms) as acceptable alternatives [to real fossil specimens]." Shimada et al. 2014, p. 3

Intuitively, this seems like a good idea. Combining the lucrative art market with palaeontology should allow collectors to own fossil-related wares without loss of scientifically-important specimens. Palaeoartists would make money, more specimens would end up in academic institutions, and collectors would obtain rare and valuable items - everyone seems to win in this arrangement. As someone with some experience of working within the palaeoart industry however, I'm not convinced that this plan could be executed in the foreseeable future, nor that it provides a solution to the problems of over-commercialising fossils. There seem to be three problems here: 1) original palaeoart and fossil specimens are not as readily interchanged as some may think; 2) our art is not seen as particularly interesting or varied to wider audiences, and 3) the palaeoart community is simply not in shape to offer the high-value, desirable art required for this bid, and will not be until it receives a lot more support from the scientific community at large.

A Tarbosaurus specimen made famous - or more rightly infamous - when put up for auction in 2012. It was ultimately repatriated to Mongolia after palaeontologists pointed out the illegal nature of its exportation from its native country. Image from (shudder) the Daily Mail.

1. Palaeoart cannot compete with genuine fossils for aesthetic appeal or as a status symbol

As with any material item, the ownership of fossils is pursued because of academic interest, the collector mindset of owning unique objects, admiration of the natural beauty and the attainment of status. Fossil specimens, particularly large and spectacular ones, not only meet these criteria but exceed them. They're extremely rare. They cost lots of money to buy and maintain. And they're amazing. Looking at a fossil reminds us of unfathomable depths of time and evolution, and the very limits of our human experience. You don't have to know anything about fossils or palaeontology to be awed by them: their mystery, impressiveness, rarity and worth is obvious to anyone. It's little wonder that fossils can be sold at auction for large sums of money: they're immensely charismatic objects, and make major statements about the taste and wealth of their buyers.

If we intend on replacing fossils with palaeoartworks at auction, the latter needs to replace this appeal. Unfortunately, even the best-executed, most accurate, or most famous palaeoartworks can't inspire the same interest and awe as fossils themselves. That's not because palaeoartists are bad at their jobs, but because fossils and palaeoart are completely different entities. Fossils are natural objects obtained by chance and perseverance, and palaeoart is a human-derived statement about palaeontological science. It seems naive to expect rich buyers to turn from fossils to fossil-related artwork when the two have such different cultural statuses, and I think we are misunderstanding the people buying fossils if we think we can simply swap one for the other. We should probably abandon any hope of palaeoart being fossil substitutes, and realise that we need to sell palaeoart on its own merits.

Like any art, selling palaeoart is dependent on it being a fashionable commodity, culturally significant enough that it seems worth spending money on. Working against palaeoart in this regard is its real lack of status outside of the (largely online) palaeontology community. Palaeoart processes and credibility are poorly understood among the public and its most revered practitioners are entirely unheard of. It seems mostly considered a branch of dry scientific illustration, anonymous visual manifestations of what palaeontologists are imagining at a given time. Other times, palaeoart is seen as art for children, or pseudo-fantasy work with a similar target demographic to science fiction and fantasy media. In short, palaeoart is neither considered fashionable or culturally significant, and is not likely to appeal to the rich companies and celebrities who buy spectacular fossils at auction. The fact that master palaeoartists frequently find it difficult to auction their work at worthwhile prices lends credence to this idea. Sales of high-value palaeoart will not happen until we can demonstrate its cultural significance to people outside of palaeontology, and that's going to be an uphill struggle.

2. Palaeoart is probably too stylistically and compositionally homogenous to appeal to wider audiences

Because some art is sold on the strength of its style or composition, palaeoart may make some headway in the high-stakes open market so long as it offers a range of styles and subjects, with varied compositions and themes. Currently, palaeoart offers quite the opposite however, as it's compositionally and stylistically rather homogenous. Only rarely do palaeoartists deviate from realistic-ish portraits of animals, or animals in landscapes, to more stylistic or abstract waters. To my knowledge, this has never been done for significant financial gain. And yes, while palaeoartists do differ stylistically, it's a marginal difference compared to the spectrum in other branches of art. It's little surprise that palaeoart has entered a deconstructionist phase in recent years because its practitioners have noticed how repetitive and trope-filled a lot of palaeoart is (Conway et al. 2013). From a marketing point of view, this is dangerous territory. It's easy to imagine that many will take the attitude that 'once you've seen one piece of palaeoart, you've seen it all', and if its general style or compositions are not to taste, there's little chance of it being bought. We must remember that our objective here is to make palaeoart appeal as widely as possible, and not only to palaeontologists and dinosaur fans.

Those of us who know palaeoart may argue that it is continually changing and developing, and subject to fashions and trends as much as other artworks. These are mostly related to the methods of reconstruction and changes in science however, which are subtle to the point of near-undetectability for lay audiences. Palaeoartists and palaeoart fans may consider the publication of All Yesterdays (Conway et al. 2013) a recent landmark in palaeoart methodology, but for the uninitiated, it's just an excuse to draw extinct animals in different postures or with slightly tweaked anatomy. In short, unless potential buyers are up on palaeontological and palaeoart history - and most aren't - this significance of palaeoartworks will be missed. Our current lack of artistic diversity may be a real problem for those wanting to make palaeoart a valuable commodity.

Misty the Diplodocus, auctioned last year in the UK for £400,000. Image by Luke MacGregor/Reuters, from here.

3. Palaeoart needs support to develop the culture required for commercialisation

The points made above highlight palaeoart's biggest problem: it basically lacks context and culture outside of a tiny community. There's no way we can take this little industry to auction and expect it to compete with awesome fossils. There may be ways we can alter this, but it might require a significant overhaul of the way palaeoartists work with scientists, educators and the media. To be honest, palaeoartists are presently treated quite awfully with little public promotion, a resulting lack of public identity and an infamously poor and unreliable economy. This condition describes the 'major players' or 'masters' of palaeoart as well as its lesser-known or new, fledgling artists. We need to change this if we want palaeoart to step into the world of high-value auctions.

How might we go about this? Firstly, it is time that artists were obviously and publicly credited for their work. In other industries, artist names are essentially brands. Artwork is frequently valued because of who produced it rather than the art itself. In most off-line activities, palaeoartist accreditations are difficult to spot or, worse, allocated to faceless institutions or companies. This is even so in richly illustrated palaeontology books, where artists are treated as secondary importance to authors. This may be why palaeoart is often only seen as an extension of science: funny as it sounds, we rarely acknowledge palaeoartist roles in producing palaeoart. As long as we largely deny exposure and name-recognition to palaeoartists, no-one will pay top dollar for their work. Perhaps we should start prominently naming artists who make significant contributions to palaeontological projects - galleries, articles and books - to start building their reputations. With time, artist association may pay off commercially, lending 'brand recognition', credence or quality to the projects they work on. People could start to follow palaeoartist careers in the way we can musicians and actors and, when their original work comes up for sale, potential buyers will have some concept of its significance to the artist as well as wider scientific culture.

We also need to stamp out the idea that all palaeoart, and palaeoartists, are interchangeable. Not only is it highly detimental to palaeoartworks, but it cripples the industry as a whole. Book publishers, outreach coordinators and even major museums regularly have in-house artists directly copy palaeoartworks rather than using original work. Sometimes, the shamelessness of these acts is unbelievable. The reasons for this are normally to do with money and desire for 'in house' styling. This is a disaster for multiple reasons. From an outreach perspective, plagiarising artists often misunderstand their subjects and make mistakes: we fail in our goal of conveying palaeontology accurately. More broadly, these acts are questionable ethically and legally, they dilute the importance and impact of original work, are insulting to the original artists, and ultimately reduce the market value of palaeoartworks. I can't think of another artistic medium which allows this. Radio stations didn't play cover versions of Beatles songs because they don't want to pay royalties. Book publishers do not force artists to re-draw the Mona Lisa so it matches their house styles. They herald the art for what it is, its significance, and the hard work of the people behind it. By allowing palaeoart to be copied so liberally, we send the message that the artists are unimportant, which means their work is also worthless and undesirable.

The sort of crap palaeoartists have to put up with all the time. One is an original image considered shocking and thought provoking when first published, the other is a direct knock-off, produced for profit by a renowned palaeoart plagiarist. The institution hiring the latter has since taken the offending image, and others of similar derivation, out of circulation. 

This has to change if palaeoart is to develop any real sense of culture. After all, if the palaeontological community does not respect its artists, how can we expect wider audiences to? We need to stop employing individuals who repeatedly rip off other people's work and, if asked, palaeoartists themselves should refuse outright to rip-off the art of their colleagues. Authors, exhibition developers, publishers, and educators should employ genuine palaeoartists rather than knock-off illustrators, and obtain the education to know when 'historically important' images are more appropriate than new ones. We cannot have culture without a sense of history, after all. Some folks within the palaeontological community already strive to do this, often against the tide of publisher might. Palaeoartists do also sometimes get treated well by publishers, even being featured in well publicised, high quality books celebrating their art (e.g. White 2012). Unfortunately, these are exceptional instances in the palaeontological community, when they should be normal. I don't doubt this proposal will require more money to obtain original artwork for projects rather than second-rate copies, but the investment might pay off: better treatment and more business for palaeoartists; higher quality work for the products concerned; and more marketability for both. This would be a major step towards offering palaeoart as a replacement for fossil specimens.

Longer term, granting palaeoartists more fame, income and success can only have a positive outcome. Financially comfortable artists have more time to make art, which gives us more art to sell instead of fossils. Moreover, it allows time for experimentation. Palaeoart really needs this if we want it to float economically outside of the immediate palaeontological community. We need more stylised and abstract art in addition to more conventional scientific illustrations, or service to dinosaur fanboys. We can look to the popularity of modern animal artwork as a guide here: it's very popular, but also mostly stylised. Palaeoartists have little to offer in this area at the moment, and, if palaeoart is to really help push against over-commercialisation of fossils, we need fossil-based art which is as interesting and striking as the fossils themselves.

But will any of this ever happen?

The palaeoart industry has always been a bit of a slum to work in. Even Charles Knight, arguably the most famous palaeoartist ever, spent much of his career on sporadic contracts which made relatively little money (Milner 2012). There's no obvious sign that this is going to change either, or - from a strictly functional perspective - that it even has to. Palaeoart will probably always be around, its practitioners making the best they can from the opportunities that come their way. But this is not to say that perseverance alone makes it fit for high profile auctions as an antidote to over-commercialisation of fossils. There's very little palaeoart can do to develop itself, let alone take the brunt for another cause, until it is properly supported and respected by scientific and media communities, and we stop treating it as a near-worthless addendum to palaeontological science.

References

• Conway, J., Kosemen, C. M. & Naish, D. (2012). All Yesterdays: Unique and Speculative Views of Dinosaurs and Other Prehistoric Animals. Irregular Books.
• Milner, R. (2012). Charles R. Knight: The Artist who Saw Through Time. Abrams.
• Sereno, P. C., Tan, L., Brusatte, S. L., Kriegstein, H. J., Zhao, X., & Cloward, K. (2009). Tyrannosaurid skeletal design first evolved at small body size. Science, 326(5951), 418-422.
• Shimada, K; Currie, P. J., Scott, E., & Sumida, S. S. (2014). The greatest challenge to 21st century paleontology: When commercialization of fossils threatens the science. Palaeontologia Electronica Vol. 17, Issue 1; 1E: 4 p;
• Tischlinger, H. & Frey, E. (2014). A new pterosaur with mosaic characters of basal and pterodactyloid pterosauria from the Upper Kimmeridgian of Painten (Upper Palatinate, Germany). Archaeopteryx, 31: 1-13.
• White, S. (2012). Dinosaur Art: the World’s Greatest Paleoart. Titan Books, London.

Episode 3: Bernissartids, the button-toothed Crocodyliformes

3/3 - this, ladies and gentlemen, is the end. At least, until the inevitable prequels where I'll ignore the canon of the expanded universe and do my best to tarnish everything you liked about the original trilogy.

Here we are then, the last instalment of the Wealden Crocodyliformes Trilogy. Following the posts on atoposaurids and goniopholidids, today we're going out with a bang by covering a newly described Wealden crocodyliform unleashed on the world this morning. The study was written up by my University of Portsmouth chums and colleagues Steve Sweetman, Ulysse Pedreira-Segade and Steven Vidovic (Sweetman et al. 2014), and Steve V. has covered some aspects of his involvement at his blog. The paper is open-access so, for the full skinny on the discovery, you should head here.

This most recently identified Wealden crocodyliform is among the most sophisticated and unusual of all Wealden crocs. Named Koumpiodontosuchus aprosdokitii, it is known from a well-preserved skull which was recovered in circumstances owing much to chance and good fortune (Sweetman et al. 2014). This animal is currently only known for certain from the Wessex Formation of the Isle of Wight, specifically from fossil-rich cliffs next to the seaside village of Yaverland, and the only known skull of it is broken in half. The posterior half was discovered in March 2011 by holidaying fossil hunters, who took it to the local dinosaur museum (Dinosaur Isle, of Sandown) to have it identified. Another family, on a fossil-hunting holiday three months later, then found the front half of the skull. They took this to the same museum where, by chance, the same museum staff who’d handled the first piece were on hand. It was realised that each piece belonged to the same specimen, and the first half was rapidly brought back to the museum to check the degree of articulation. Remarkably, the join between the broken pieces was near perfect – clearly neither chunk had been exposed to weathering effects very long before being discovered – and the entire skull could be seen. Each piece was then donated to the museum to allow its study. Given the chain of events and people involved in the discovery of Koumpiodontosuchus, it’s easy to imagine how only single halves of the skull might be known to science, or even neither. This is clearly yet another story which stresses the importance of amateur fossil hunters to Wealden fossil discoveries, and the benefits of responsible collecting.

Holotype skull and mandible of the button-toothed crocodyliform, Koumpiodontosuchus aprosdokitii. From Sweetman et al. 2014.

Button-toothed crocodiles in context

Koumpiodontosuchus is a member of Bernissartidae, a group named by Sweetman et al. (2014) which only contains two species: Koumpiodontosuchus and Bernissartia fagesii. The latter is a famous, small Jurassic and Cretaceous crocodyliform known from France, Denmark, Spain, Portugal and particularly Belgium, where a spectacular complete skeleton has been unearthed. Indeterminate species of Bernissartia also seem to occur in the Ashdown Formation of Hastings (Salisbury and Naish 2011), but this identification may eventually warrant reappraisal now that Koumpiodontosuchus has been discovered. Bernissartid remains are not new, some of the first material of these animals being documented in the 1850s and Bernissartia itself being named from Belgian fossils in the 1880s. Isolated teeth, likely referable to Koumpiodontosuchus, have been found in Wealden deposits since at least the 1970s (Buffetaut and Ford 1979), so were clearly present across the entire geographic and stratigraphic range of the Wealden Supergroup.

Bernissartia has long been a bit of an oddball among Crocodyliformes, possessing some unusual anatomy and being of uncertain placement in crocodyliform systematics. The discovery of Koumpiodontosuchus provided a bit of light on this front, suggesting that Bernissartia was part of a group containing at least one other similar species, and that they occupy an evolutionary place between atoposaurids and the goniopholidid + Eusuchia radiation. This position isn’t too surprising, as there are a number of features in bernissartids which link them to Eusuchia – see below. Bernissartidae is primarily defined by dental characteristics, with the most obvious one also being the namesake of Koumpiodontosuchus: “button-toothed crocodile” (if anyone wants a common name for these Crocodyliformes, this is the one to use). The posterior teeth of bernissartids are rather globose – wide, short and blunt – and distinctive compared to the dentitions of most other Crocodyliformes. It’s these teeth which, even in isolation, betrayed the presence of bernissartids in the Wealden well before the more substantial Koumpiodontosuchus fossil was discovered. Their other teeth are quite different to this, however. The mid-region dentition is rather conical in shape; ‘pseudocanines’ erupt about 25 % of the jaw length from the jaw tip, and conical teeth emerge procumbently from the jaw tips themselves. Koumpiodontosuchus has two large pseudocanines on its lower jaw, which erupt so close to each other that they share a single, enlarged tooth socket. Bernissartia, by contrast, only possesses one.

The new Wealden bernissartid Koumpiodontosuchus aprosdokitii foraging for molluscs. It's eating a mud snail, Viviparus cariniferus, while tiny (6 mm long) physid gastropods Prophysa crawl over pond scum in the lower left of the image. Dragonflies provide scale, while unnamed tetanurans (based on findings of Benson et al. 2009) prowl around the background. An earlier version of this reconstruction was featured in Sweetman et al. (2014). Prints of this image are available here.

Bernissartids packed this sophisticated dentition into relatively tiny jaws: these were not big crocodyliforms. Indeed, with body lengths of approximately 600 mm, bernissartids were probably the smallest crocodyliform species in the entire Wealden succession. Like goniopholidids, bernissartids bore osteoderm shields on their backs and bellies, but the dorsal series was rather more complex than those of other Wealden crocodyliforms. Rather than possessing two rows of interlocking osteoderms as we saw in goniopholidids and atoposaurids, bernissartids possess four rows of osteoderms along their backs. These comprise two sets of rectangular, double-keeled scutes along the midline, and laterally bordering square osteoderms with single keels (Salisbury and Frey 2001). None of these interlocked, and – based on what we’ve discussed for other Wealden Crocodyliformes – it’s worth considering what impact this had on bernissartid locomotion. Rather than supporting their trunks with scutes, it seems that bernissartids developed procoelus trunk vertebrae (that is, vertebrae with centra extending into the corpus of the vertebra behind) to support their bodies when walking (Salisbury and Frey 2001). This feature, along with their relatively complex osteoderms, is shared with eusuchians and are some of the reasons why these animals have classically been allied to these Crocodyliformes. Of further interest here is the biconvex nature of the first bernissartid tail vertebra – this has further implications for their locomotion, which we’ll get to below.

The bit on palaeoecology

Ecologically, it seems that bernissartids had a preference for hard shelled prey. Their blunt posterior dentition has been labelled as ‘tribodont’ – literally meaning ‘crushing teeth’ – and, like slamming a couple of anvils together, are ideally shaped to crunch hard shells. Some confirmation of this idea is seen in the wear facets often seen on tribodont bernissartid teeth. Classically, their prey was largely considered to comprise molluscs such as the freshwater snails and clams populating Wealden streams and lakes (Buffetaut and Ford 1979). Recently, a broader diet has been postulated for bernissartids however, the logic being that hard shells are hardly restricted to molluscs even in freshwater settings (Sweetman et al. 2014). Insects and crayfish probably formed as much of their diet as molluscs, all of which were likely procured or extracted from soft-substrates with the procumbent anterior teeth. We should not forget the savage-looking pseudocanines of these animals however: these would be of little use against hard prey items, but may have allowed for spearing relatively soft-animals. Perhaps bernissartids are best viewed as rather opportunistic feeders, primarily taking hard-shelled prey but not turning their noses to other types of food when the opportunity arose.

If gastropods like this Wealden mud snail, Viviparus cariniferus, had nightmares, they contained bernissartids. 

Where was most of this prey caught? There is evidence that bernissartids were equally at home in water and on land. Their biconvex first tail vertebra suggests their tails were capable of considerable movement for providing burst propulsion through water and, unlike most other Wealden Crocodyliformes, their lack of interlocking osteoderms facilitated lateral trunk motion (Salisbury and Frey 2001). While compromising overall speed, this may have permitted greater amounts of manoeuvrability – ideal for pursing nimble, if relatively slow, aquatic arthropods. We’ve already mentioned that the reinforced trunk vertebrae of bernissartids would provide ample reinforcement for terrestrial locomotion, and their small size is relevant here as well. Like the small-bodied atoposaurids, and unlike the big goniopholidids, bernissartids had relatively small amounts of weight to lug around on land and could likely sustain long periods of terrestrial locomotion without tiring. It’s possible, therefore, that they found much of their prey on land as well as in water, perhaps enjoying the beetles, cockroaches and other tough-shelled terrestrial insects known to occur in Wealden deposits.

It’s worth pointing out that bernissartids may not be the only Wealden Crocodyliformes adapted for hard-shelled prey. The poorly known, 1.5 m long Wealden eusuchian Hylaeochampsa vectiana also has large posterior teeth ideal for smashing shelled prey (Clark and Norell 1992), although the dentitions of other hylaeochampsids are complex and it’s possible Hylaeochampsa had a very varied diet. As discussed for other Wealden Crocodyliformes, it’s likely that the size difference between the bernissartids and Hylaeochampsa would prevent too much overlap in prey preference: the latter may have been capable of eating large molluscs or even small armoured vertebrates, which were probably unavailable to bernissartids. There's lots more we could say here, but I'd best not - maybe Hylaeochampsa will warrant dedicated discussion at a later date.

The end

And I guess that's where we'll leave the Wealden Crocodyliformes for now. As alluded to above, there are other crocodyliform species and groups we could discuss, but they're generally less well known than the taxa we've covered across these posts and it would be difficult to discuss them in comparative depth. I hope you've enjoyed this series of themed posts and, if artwork of ancient Wealden animals is your thing, come back soon for a big announcement about an event related to just that.

References

• Benson, R. B., Brusatte, S. L., Hutt, S., & Naish, D. (2009). A new large basal tetanuran (Dinosauria: Theropoda) from the Wessex Formation (Barremian) of the Isle of Wight, England. Journal of vertebrate Paleontology, 29(2), 612-615.
• Buffetaut, E., & Ford, R. L. E. (1979). The crocodilian Bernissartia in the Wealden of the Isle of Wight. Palaeontology, 22(4), 905-912.
• Clark, J. M., & Norell, M. (1992). The Early Cretaceous crocodylomorph Hylaeochampsa vectiana from the wealden of the Isle of Wight. American Museum novitates; no. 3032.
• Salisbury, S. W. & Naish, D. (2011). Crocodilians. In Batten, D. J. (ed.) English Wealden Fossils. The Palaeontological Association (London), pp. 305-369.
• Salisbury, S. W. & Frey, E. 2000. A biomechanical transformation model for the evolution of semi-spheroidal articulations between adjoining vertebral bodies in crocodilians. In Grigg, G. C., Seebacher, F. & Franklin, C. E. (eds) Crocodilian Biology and Evolution. Surry Beatty & Sons (Chipping Norton, Aus.), pp. 85-134.
• Sweetman, S.C., Pedreira-Segade, U., & Vidovic, S. (2014) A new bernissartiid crocodyliform from the Lower Cretaceous Wessex Formation (Wealden Group, Barremian) of the Isle of Wight, southern England. Acta Palaeontologica Polonica (in press)

Episode 2: The Wealden River Masters, goniopholidid Crocodyliformes

Insert your own whoops, hollers,cheers, or discharging firearms here. 

Welcome to Episode 2 of the snappily-titled Wealden Crocodyliformes Trilogy!* We'll waste no time with introduction - read this if you haven't already - and dive straight into our second group, the goniopholidids. Much of the information herein is derived from Salisbury and Naish (2011) so, if in doubt, consult this tome for further details.

*Snappily titled? And it's about crocodiles...? Man, I'm so wasted on you guys.

Without question, the Wealden waterways were lorded over by a group of Crocodyliformes known as Goniopholididae. The namesake of this group, Goniopholis, is one of the more familiar Mesozoic crocodyliforms after famous taxa like Sarcosuchus and Deinosuchus, and is well known as a relatively ‘conventional’ crocodyliform compared to some of the other weirdo crocs doing the rounds in the Mesozoic. Goniopholidids are found throughout Jurassic and Cretaceous rocks in the Northern Hemisphere and are part of several famous fossil faunas, including being the best known crocodyliforms of the Wealden fauna. Miscellaneous goniopholidid teeth and scutes occur throughout the Wealden, and their existence has been known for a long time. Teeth ultimately attributed to indeterminate goniopholidids were found in Sussex during the 1820s by Gideon Mantell as part of the same collections of crocodile’ material which was later found to contain unappreciated early records of Wealden baryonychines.

Despite this long history, work on Wealden goniopoholids is still developing (Salisbury and Naish 2011). At one time, most Wealden goniopholid taxa were considered members of Goniopholis proper, the famous Owen-named genus of great historic significance. As with many 'classic' genera, Goniopholis is now appreciated to be a bit of a taxonomic mess and claims of 19 species are being scrutinised (e.g. Salisbury and Naish 2011; Andrade et al. 2012). Recent reviews have suggested that the Wealden goniopholidid assemblage contains a sole Goniopholis species from the Weald Sub-basin and two other genera from the Wessex Sub-basin, all known from good skull material and, in the latter instances, a series of articulated postcranial remains (Salisbury and Naish 2011). These named species include Goniopholis willetti from the Grinstead Clay Formation, Sussex; Anteophthalmosuchus hooleyi (below), from the Wessex and Vectis Formations of the Isle of Wight, and Vectisuchus leptognathus, also of the Wessex Formation (why Vectisuchus when it’s not found in the Vectis Formation? ‘Vectis’ is the Roman word for the Isle of Wight, so ‘Vectis’ frequently pops up in animal names from this part of the world). The latter was almost known from a complete skeleton, but a cliff fall during its collection rendered much of the hindlimb, pelvis and tail inaccessible. In spite of this incident, it’s still fair to say that this group has one of the better records among Wealden reptiles, and it might get even better. Fragmentary goniopholidid jaw fossils hint at further, unnamed species, but they are currently too poorly represented to warrant naming.

The Wealden goniopholidid Anteophthalmosuchus hooleyi takes advantage of a flooding river to hunt two stranded Hypsilophodon foxii. The big one is Using the Ballet to escape. Prints of this image are available here.

Goniopholidids vs. modern crocodilians, round 1: anatomy

What kind of Crocodyliformes were goniopholidids? Because these animals appear to resemble modern crocodiles in size, shape and probably lifestyle moreso than any other well-known Mesozoic Crocodyliformes, they are often reconstructed as ancient copies of large modern species like Nile or saltwater crocodiles (e.g. Karl et al. 2006 - see reconstruction here). This isn’t really the case, however: goniopholidids may look a little similar to modern crocodilians at first glance, but much of their anatomy is unconventional and their possible habits were likely rather different. If we compare these aspects directly, their differences will soon become apparent.

We’ll start with size. Here, it must be said, goniopholids are undoubtedly pretty similar to modern crocodilians. The largest Wealden goniopholidids – Anteophthalmosuchus and G. willetti - were large animals each attaining at least 3.5 m long. This is a pretty comparable size for many modern crocodiles, and may even seem a little on the small side compared to the 5 m+ lengths attained by some extant crocodilians. Don’t be fooled into thinking this makes Wealden goniopholids diminutive creatures, however: a 3.5 m long crocodyliform would somewhere around 200 kg in weight and stretch longer than your 3-seater sofa. These were undoubtedly big, bulky animals. Vectisuchus, by contrast, was a much smaller species, only attaining 1.2 m in length.

In fine anatomy, we start to see obvious differences between the ancient goniopholids and modern crocodilians. Goniopholidid backs were covered with two rows of rectangular osteoderms with interlocking pegs at their distal margins – they are much like the atoposaurids we met last time in this respect (Salisbury and Frey 2000). These are largely devoid of ornamentation with only slight keels along their dorsal surfaces. This configuration is rather different to the more complex and ornate osteoderm arrangements seen in modern crocodyliforms, and goniopholidid osteoderm shields would probably seem rather simple and inelegant by contrast. Also unlike modern crocs, goniopholid osteoderms do not extend far up the neck, perhaps because doing so would impair neck mobility (see below), and further osteoderms were found along their bellies. These were formed of hexagonal plates rather than long, rectangular ones however. Another key distinction between goniopholidids and modern crocodilians is found in their forelimbs. Most goniopholids have arms which are at least as long as their legs and many species - including Anteophthalmosuchus and Vectisuchus – have forelimbs which surpass the length of the hindlimb. This increased length is provided by relatively elongate humeri and wrist bones, and would give goniopholidids taller statures than those of all modern crocs, which are always shorter up front than behind. If we extending this comparison further, we’ll see that goniopholidid forelimb length is almost unique among all Crocdyliformes, being longer than virtually all of their relatives.

Like many modern crocodilians, goniopholidids possess the well-built, powerful skulls of formidable predators. There is also overlap in general skull shape with modern crocs too, with G. willetti and Vectisuchus having rather long, slender snouts which are narrower than the posterior regions of their jaws. By contrast, the skull of Anteophthalmosuchus belongs to a real bruiser; its jaws only gently converge from the enormous posterior region to form a chunky, roughly triangular skull with a rounded muzzle. Both skull types are equipped with goodly-sized, slightly recurved conical teeth which would not look out of place on modern crocodilians. Again however, there are differences in detailed anatomy. Of particular interest is the orbits of Anteophthalmosuchus, which only permitted forward vision rather than anterolateral as is usual for Crocodyliformes (its name, roughly meaning ‘forward-eye-crocodile’, reflects this - see Salisbury and Naish 2011). A similar condition is also seen in Vectisuchus, but it is not quite as well developed and seems to have arisen independently. Goniopholid skulls are also rather flatter than those of modern crocs, and have distinctly over-biting upper jaws. An unusual hollow in the cheek region, known as the maxillary depression, was also present, apparently representing an unusually large pressure-sensitive region of the goniopholidid face (Andrade 2009).

A house-proud Goniopholis willetti stands at the entrance to his burrow. Note his long arms, narrow jaws, and lack of a doormat.

Goniopholidids vs. modern crocodilians, round 2: habits

It may be expected that these similarities and differences between modern crocodilians and goniopholididis may translate to overlapping, but also slightly different lifestyles. Happily, because the anatomy of Wealden goniopholidids is well-documented, we can make some informed speculation as to how these animals may have lived and, indeed, this seems to be the case. The size and robust skeletons of G. willetti and Anteophthalmosuchus suggests that the ecological bucks of Wealden waterways stopped with them: occasional visits from spinosaurids aside, they were the largest predators in Wealden lakes and rivers and clearly well suited for tackling large prey items. We might imagine each as the apex predators of their respective waterways, taking small or medium-sized terrestrial animals, large fish and other aquatic reptiles as prey. This gives these animals a role much like those filled by several species of large crocodilians today. Smaller Vectisuchus, by contrast, probably ranked it in the mid-league of ancient Wealden ecosystems, probably capable of holding its own against most aquatic Wealden species but wanting to be wary of its larger cousins. Applying trends of snout shape and prey preference of modern crocodiles to Wealden goniopholidids suggests they likely differed in general prey preference: slender-snouted Vectisuchus and G. willietti probably took relatively smaller prey than the massively-jawed Anteophthalmosuchus. Through overall body size and jaw shape, these animals probably avoided stepping on each other’s ecological toes – at least Anteophthalmosuchus and Vectisuchus were contemporaries which probably practised niche partitioning (Salisbury and Naish 2011).

We might expect goniopholidids to exploit their large size in a similar way to modern crocodilians. Large modern crocodiles often focus their predation efforts to certain times of year when environmental conditions are favourable, such as times when rivers and lakes are in flood, when prey is particularly abundant, or at least the climate is more forgiving. Given how extreme the Wealden climate was - summer temperatures in some parts of the Wealden reached 36–40°C and experienced annual droughts (Sweetman and Insole 2010) – goniopholidids may have used similar strategies. As with big modern crocodilians, their large bodies hold ample reserves to wait out leaner or stressful times, and it’s possible that some goniopholidids waited out the long, hot Wealden summer in cooling pools or burrows (see image, above), while smaller crocs had fewer resources to fall back on and continued to exert themselves throughout hard times.

Beyond these generally favourable comparisons however, many aspects of goniopholidid anatomy hint at different habits to modern crocodilians. For instance, the development of goniopholidid maxillary depressions likely represent enlargements of sensory organs present in modern crocodilians used to detect prey at the water/air interface (Andrade 2009). All else being equal, does this indicate that goniopholids were more routinely grabbing prey at the water surface rather than diving for food or living generalist lifestyles? In other instances, it’s not clear what significance goniopholidid anatomical quirks may have. It’s difficult not to wonder why some Wealden goniopholidids possess entirely forward-facing eyes, for instance, and if this was related to feeding. Ordinarily, increased amounts of forward vision are associated with development of binocular vision and heightened abilities to judge distances. Might that mean predation techniques were unusual in some goniopholidids, involving chases, or carefully judged lunges and strikes at prey?

The preferred habitats and locomotory methods of goniopholidids are also worth pondering. There is some evidence that larger Wealden goniopholidids were mostly confined to a semi-aquatic existence, as their interlocking osteoderms likely strengthened their backs and improved terrestrial competency (as it does for atoposaurids and several other type of ancient crocodyliform), but their sheer weight likely impeded terrestrial locomotion over sustained periods (Salisbury and Frey 2000). The same is true of large modern crocodiles: here, reinforced vertebral joints perform a similar job to osteoderm bracing but still fail to facilitate effective, fast terrestrial locomotion for long periods. Larger crocodilians therefore spend much of their time in water, and certainly find most of their food there. If so, this makes the atypically long forelimbs of goniopholidids all the more interesting. Often, development of relatively equate limb lengths in quadrupeds is considered a sign of good terrestrial proficiency, betraying a well-balanced animal with effective carriage and equal gait efficiency in both limb sets. But how can this apply to large, heavy goniopholidids if they weren’t walking very much? Doubtless, an increased forelimb stride length was useful on occasions when large goniopholidids did leave the water, but why develop these features if much of their lives were spent in deep water? Did these animals ‘walk’ along river beds more than other Crocodyliformes? Was this trait even important for big adults? Perhaps smaller or juvenile goniopholidids took advantage of long forelimbs before they outgrew real terrestrial proficiency, spending more time on land before becoming more thoroughly aquatic at larger sizes. We could speculate all night about the intriguing possibilities here: Crocodyliformes are sophisticated creatures which do a lot more than eat, sleep and wander about: they also dig burrows, construct nests, climb onto trees and rocks, and are very sociable. Could their long forelimbs be related to these behaviours? Vertical size is seemingly more intimidating to modern Crocodyliformes than girth (Farlow and Dodson 1975) - might long arms and a tall stature have incurred social significance for goniopholidids? It’s not inconceivable that the long arms of goniopholidids were influenced by these activities rather than just locomotion, and I suspect an investigation into the evolution and functionality of their forelimbs would yield some very interesting results.

The outcome

In sum, then, it seems that we need to be cautious when thinking of goniopholidids as 'conventional' Crocodyliformes or simply forebears of modern crocodiles. Many aspects of their anatomy are not only different from those of modern crocodiles, but actually downright odd, and likely impacted on their habits and lifestyles significantly. Palaeoartists - bear all this in mind the next time you set out to draw your goniopholidids skulking in the background of your dinosaur artwork.

For the concluding post in the Wealden Crocodyliformes Trilogy, we're going out with a bang and an exciting new discovery - and it's not very far off now. Stay tuned!

References

• Andrade, M. B. (2009). Solving a century-old mystery: the structure and function of the maxillary depressions of Goniopholis (Crocodylomorpha, Neosuchia). In Journal of Vertebrate Paleontology (Vol. 29, pp. 54A-55A). 
• Andrade, M. B. de, Edmonds, R., Benton, M. J., & Schouten, R. (2011). A new Berriasian species of Goniopholis (Mesoeucrocodylia, Neosuchia) from England, and a review of the genus. Zoological Journal of the Linnean Society, 163(s1), S66-S108.
• Farlow, J. O., & Dodson, P. (1975). The behavioral significance of frill and horn morphology in ceratopsian dinosaurs. Evolution, 353-361.
• Karl, H. V., Gröning, E., Brauckmann, C., Schwarz, D, & Knötschke, N. (2006). The Late Jurassic crocodiles of the Langenberg near Oker, Lower Saxony (Germany), and description of related materials (with remarks on the history of quarrying the “Langenberg Limestone” and “Obernkirchen Sandstone”). Clausthaler Geowissenschaften, 5, 59-77.
• Salisbury, S. W. & Frey, E. 2000. A biomechanical transformation model for the evolution of semi-spheroidal articulations between adjoining vertebral bodies in crocodilians. In Grigg, G. C., Seebacher, F. & Franklin, C. E. (eds) Crocodilian Biology and Evolution. Surry Beatty & Sons (Chipping Norton, Aus.), pp. 85-134.
• Salisbury, S. W. & Naish, D. (2011). Crocodilians. In Batten, D. J. (ed.) English Wealden Fossils. The Palaeontological Association (London), pp. 305-369.
• Sweetman, S. C., & Insole, A. N. (2010). The plant debris beds of the Early Cretaceous (Barremian) Wessex Formation of the Isle of Wight, southern England: their genesis and palaeontological significance. Palaeogeography, Palaeoclimatology, Palaeoecology, 292(3), 409-424.