Wednesday 27 May 2015

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...

9 comments:

  1. I'm pretty heavily entrenched in the "don't bother" mindset when it comes to restoring animals from fragmentary remains. I don't feel the resulting pictures are particularly informative and are begging to be falsified by future discovery. Meanwhile, those old pictures are still out in the ether, not so much testaments to what we thought we knew but as how wrong we were. Especially in the Age of the Internet, it's very easy to look back at initial illustrations and furrow one's brow at early attempts to illustrate a given fragmentary taxon. I'll give an example:

    Remember when Siats meerekorum was announced? It came to us with a big bright beautiful illustration--a life restoration of a theropod known from some dorsal vertebrae and a piece of the ilium (not even the whole ilium). People are not going to look at that picture and think "well this is what its relatives looked like," people are going to think "how did they know it looked like this when barely any of the skeleton was found?" And those people are absolutely right. When that image came out, I found it irresponsible and misleading. Of course people should question whether Siats actually looked like that. And sure, maybe it looked just like its relative Neovenator--but maybe it didn't. There is great disparity among closely-related dinosaurs. Look at everybody in the Abelisauridae. Look at ceratopsids. Look at Nigersaurus.

    It would be one thing if these illustrations made it clear that what you're actually seeing is Neovenator, and then a nice big red disclaimer saying something like "THIS IS WHAT NEOVENATOR LOOKS LIKE BUT TO RESTORE SIATS IN THIS WAY WOULD BE DOWNRIGHT IRRESPONSIBLE." This example sticks in my craw because shortly after Siats' announcement, I was giving a lecture about the scientific method for one of my wife's classes, using dinosaurs as examples, and this very thing came up. Somebody asked me if the illustration of Siats was a hypothesis.

    I've given that a lot of thought, and I believe it is. Further testing will reveal how correct that hypothesis is. But you can also simply not make the hypothesis--wait for more data to come down the pipe first. And public perception is very much on the line, here, because these images are released to the public. Members of the community may know better, but the public oftentimes does not. I thought the Siats illustration was irresponsible. I understand why it was commissioned, but that doesn't change how I feel about it.

    I've always felt--even before Siats--that the primary role of paleoart is to educate. We educate people about how these animals looked and lived. It is far better to illustrate one of these fantastic, beautiful animals than to merely describe them. Paleoart has such great power to educate both the community and the public at large, but I believe that power comes with great responsibility (damn you, Uncle Ben). This is not a brush that can be wielded willy-nilly, but with great forethought.

    I should (and probably will) write a lengthy blog post about this in the future. I feel strongly about the topic, as you can probably see, and my feelings may be entirely my own, but there it is.

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    1. Thanks for the comment, Zach. I have to admit to disagreeing with a lot of it, though. For one, _everything_ we do in palaeoart shows hypotheses. Really, everything. Our knowledge of even well-known animals is continually revised and edited, and the art we make of them can only reflect a snapshot of current thinking. If we're always waiting for substantial remains of animals, and robust phylogenetic placements, we won't have many species to draw! Sure, some ideas are more robust and popular than others, but that doesn't make them immune to change. It can be very difficult to tell what ideas will stand up, and what won't, so I don't think we need to wait to see which ideas are best. Sure, there may be some ideas we find ourselves revising very quickly, but I don't see that as a problem.

      Moreover, I don't see how drawing a fragmentary animal based on a current phylogenetic hypothesis is wrong. If the describers of Siats thought it was a carcharodontosaurian, why not depict it as one in art? They're not being dishonest, only showing an illustration based on their preferred phylogenetic interpretation, and how that slots into what we know of the Cedar Mountain ecosystem. If that's wrong, so what? Palaeontology is a great science for demonstrating how new data revises older ideas, and palaeoart is a powerful agent for showing that change. I agree that footnotes along with such artworks are ideal - "we don't have much of this new animal, but it might have looked a bit like this" - and often lost in PR activities, but at least getting a picture out there helps to engage people with new science, even if only a brief glimpse of it.

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  2. Awesome pictures! I love the lighting in the Eotyrannus one, and those amphibians are awfully uglycute.

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  3. These are wonderful pictures. Paleoart at its purest stage: natural and spontaneous.

    Although I agree with zachary, I must say that the last picture is also my favourite - that composition is simply gorgeous.

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  4. They're only represented by scrappy remains in the Wealden (a scapula).

    Sure that would be "only represented by scappy remains"?

    I'll get my coat.

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  5. Is that azdarchoid restored specifically as a tapejarid? Looks so to me. If so, any reason, instead of something more generic like Vectodraco?

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    1. It's a fairly non-committal reconstruction. Not a tapejarid (sensu the most restricted usage of the term), but something quite middle-of-the-road. So yes, a bit like what I did for Vectidraco. I guess this is a strategy for minimising the wrongness!

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  6. Wouldn't it depend on what the reconstruction was for? To me, the art is one thing and the science another. I don't want a situation in which the more we learn (generally) the less we choose to speculate. It just seems counter intuitive to me. I've noticed a kind of a disenfranchisement between those who are connected to the science somehow and those who find themselves on a site like Deviantart, posting their enthusiastic but crude 'reconstructions'. There is some crossover but I wouldn't want paleoart to fully succumb to the embargo mentality that seems to be sweeping the science.

    Paul W.

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  7. Andrew McDonald3 June 2015 at 18:28

    Stunning work, Mark. I like that you have chosen some obscure animals and interesting circumstances for your art.

    The Iguanodon image is especially striking. Among European iguanodonts, Hypselospinus also has a large thumb spike, while that of Mantellisaurus is comparatively small and slender, and that of Barilium is robust but rather short and blunt. Similar variation is present in the North African iguanodonts Lurdusaurus, which has a massive thumb spike, and Ouranosaurus, which has a much more slender spike. Intriguing.

    Your restoration of "Pelorosaurus" (now Haestasaurus) becklesii is very timely: http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0125819

    Among the dinosaurs of the Hastings Beds, the iguanodonts, Barilium and Hypselospinus, are the most completely known (Norman 2011, 2014).

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