Description
It’s hard to escape the increasing realisation that my friends and I are
twenty-somethings. When you’re, say, 22-23, you can dump yourself in the ‘early-twenties’ category and be content that youth and vigour are still happily with you, albeit without the angsty energy of adolescence. Then you hit the 24-26 category, where you’re around the cusp of your third decade on the planet and it slowly dawns on you that time is getting on. A quarter of a century has passed since you were born and doubts start creeping in. You spend a bit of every day wondering if you’re on the right career path; whether you should have your own place by now; thinking a bit more seriously about having some little versions of yourself running around and when, Jesus
when will you loose that gawky physique you gained when you were 16 and turn your naked self into something resembling a man rather than a baby chimp.
However, if one thing comes with age, it’s a taste for good beer. As an underage teenager trying to be served in my local pub – complete with a soft teenage-moustache and enormous goggle-glasses - I was an avid lager drinker. You know: the likes of
Kronenberg,
Stella and, as a special treat, big bottles of
Budweiser. Nowadays, though, I’m really not a lager fan at all. Nope, I’ve moved away to the considerably more interesting and mature world of ales and bitters. Ignoring the weak, crappy taste of
Boddingtons and the like, ales are the way to go. Each has its own unique flavour and strength: some are very watery, some pack strong tastes that linger in your mouth for minutes, and others taste so flowery that I suspect brewers have been liquidising and bottling their local florists. Compared to lager, they’re incredibly flavoursome and rich and, once you’ve matured to Ale Age, there’s no going back. Still, as I watch my younger chums sucking up their lagers, I don’t judge or try to change them: nope, I quietly know that in a few years they’ll be watching other young men through the same, ale-distilled eyes. It’s all right, lager drinkers of the world: we were all there once, we understand, and we’re just waiting for you to join us.
Now, believe it or not, the professional interests of palaeontologists go through a similar maturation. 90 per cent of fresh-faced, first-year palaeontology students are only interested in one thing: dinosaurs. It’s dinosaurs this, dinosaurs that: they tolerate the molluscs and echinoderms put in front of them for description, they begrudgingly look at sediments and will consider basic geological principles like Walther’s Law of Superposition and continental drift but, given any freedom of choice over their topic of study, and they want dinosaurs. Some palaeontologists never grow out of this and, for them, they’re only interested in a fossil animal if their remains are big enough that you can wield them like guitars and pose on the front cover of scientific rock magazine equivalents,
National Geographic and
New Scientist. Thing is, though, this blinkered view obscures some of the true marvels of the fossil record. Some of the most fantastic, amazing things require more patience and contemplation to appreciate. The mysterious Ediacaran fauna. Small but intricately-spiralled graptolites or spiny trilobites. 30 million year-old molluscs and beetles with
bona fidecolour patterns. It’s frustratingly incomplete, but, for the mature palaeontologist, the fossil record is
freaking awesome even without its A-listers like dinosaurs and enormous marine reptiles. Sometimes it’s the richness of a particular fossil deposit that is fantastic, and not necessarily the likes of the Chinese Jehol Group or German Solnhofen Limestones which, with their fantastically preserved early-birds and whatnot, are predictable headline fodder. No, given enough time and patience, even the most unassuming fossil-deposits can be veritable goldmines, assuming you know what you’re looking for and where to find it.
Step in, then, my University of Portsmouth colleague, Dr. Steve Sweetman. Clearly not interested in discovering fossils that you can pose alongside while being circled by expensive photographers, Steve’s spent the last several years working on the microfossils of the Lower Cretaceous Wessex Formation of the Isle of Wight. To find them, he dried samples of silty clay taken from lignite-infested plant debris horizons found within the Wessex, washing the clay away and painstaking sifting through the remaining plant material to find the animal fossils. This required literally hundreds of hours of work to retrieve the fossils alone, let alone figure out what they were. As you might expect, such a project is worthy of a several-hundred page book, and, indeed, it’s results formed the subject of Steve’s Ph.D. thesis. However, the God-knows how many hours spent identifying his fossils have, thus far, only allowed him to review the Wessex tetrapods – vertebrates with/that once had four limbs – without even approaching the fish discoveries. Thing is, this alone has, by Jingo, totally changed what we know of the Wessex palaeofauna. Essentially doubling the number of known tetrapods from the Wessex Formation, Steve found a whopping
48 new types of critter from the Wessex, including dirty-big dinosaurs, tiny amphibians and mammals, and more middling-sized lizards, birds and mammals. His work allows for a much more complete picture of the 115 million year-old ecosystem record in these deposits, and, luckily and very honourably for me, Steve asked yours truly to paint a picture of the ecosystem that he is now more acquainted with than anyone else in the world. The result is above: it’s the biggest picture I’ve ever painted digitally and took 7 days to get from rough paper to your screens. There’re lots of things I would change if I had a few more days to work on it: some details of the water need work, there’s not nearly enough shading, everything looks too clean, some areas have been really, really, roughly coloured… Thing is, with a tight deadline to meet, I had to draw the line somewhere: eventually, you have to concede that you’re out of time and a project will have to be presented as it is. I guess it’s all right, but I reckon it could be better. Ho hum.
Anyway, enough moaning about my lack of artistic finesse: what’s going on in that crowded scene? Well, the picture can be divided into two parts. The top-half of the image is pure, Classic Wessex, full of big dinosaurs, big trees and big crocodiles. It also presents the Wessex palaeoenvironment, showing the kilometre-wide river that was responsible for depositing the clays of the Wessex Formation. This river meandered its way eastwards across a vast, seasonal floodplain through a landscape covered with ponds, conifer trees and ferns, with the biggest trees localised on the low hills found to the west of the floodplain. To the right of the image, the vegetation on these hills is being set alight by lightning storms that seasonally ravaged the floodplains, burning off the canopy and creating the floods that filled ponds, river channels and what-have-you with the sediment and plant muck that would eventually form the plant debris beds. En route, these floods would pick up animal carcasses and other remains – shed teeth, loose bones - and deposit them in the same plant debris horizons. As such, these storms played a vital role in recording the story of the Wessex fauna. Hooray for ancient storms, then.
The back- and midground of this scene holds some familiar characters - in fact, these well-known critters have already featured on this corner of the Interweb (check out this set
here for some old sketches of vanilla Wessex forms). In the far distance, there’re a couple of titanosauriform sauropods: big ‘Angloposeidon’-type brachiosaurs and more derived titanosaurs next door. To the right of these strapping chappies is a lone
Caulkicephalus, an ornithocheirid pterosaur surveying the water for fishy morsels (see
this for a discussion of dip-feeding in ornithocheirids). To the right of him, moving into the middle ground, is a small group of
Iguanodon-like ornithopods, though they aren’t necessarily
Iguanodon proper. Why? Well, bucko, the taxonomy of iguanodonts was overhauled recently, suggesting that many of the large ornithopod remains lumped into
Iguanodon actually represent several, highly-distinctive forms. Hence, the slender forms shown in the picture here aren’t
Iguanodon, but the smaller, recently-christened
Dollodon.
Just in front of the wading
Dollodon is another group of ornithopods, the 2 m long
Hypsilopohodon, some of which are being harassed by the large crocodilian
Goniopholis (oh, and look closely and you can see some baby
Hypsilopohodon amongst the adults, too). Just right of the central midground and around the
Goniopholis are basking and swimming
Bernissartia, crocodilians that specialised in grubbing-out and eating molluscs. Left of these, in the mouth of the tributary feeding the main river, is the back of
Lepidotes, a metre-long armoured fish being eyed by the biggest predatory dinosaur yet known from the Wessex,
Baryonyx. The fish-eating habits of
Baryonyx are well-documented, being based on gut content (including digested remains of
Lepidotes, dontchaknow), tooth morphology, skull biomechanics and other observations of spinosaur functional morphology, so it’s interest in the
Lepidotes here is well-founded.
Now, these chaps are undeniably interesting, but they’re nothing new. No, the real interest of this picture is found in the foreground and in the skies. Looking skywards first: Steve’s found that
Istiodactylus, a pterosaur found in the Isle of Wight’s lagoonal Vectis Formation, also occurred in the terrestrial deposits of the Wessex. Next to this critter is a mysterious ‘early bird’, here suggested to be an
Archaeopteryx-type thing but, in actuality, only represented by teeth that, while undeniably avian, could belong to a number of basal birds. Moving to the bottom of the image, you can find a pond in the bottom-left corner that features a bonzanza of new Wessex forms: salamanders and frogs sit on the pond margins and swim beneath the water (and, hey, check this out: I found one of Steve’s best salamander specimens during my dissertation studies); ctenochasmatoid pterosaurs sieve the water for prey; lizards of all shapes and sizes bask on a dead tree and rare turtles watch the river slink by. Alongside our anapsid friends are a pair of hesperornithiformes, two sitting on the riverbank and another swallowing a fish in the river itself. Some derived hesperornithiformes famously lost all ability to fly, becoming specialised diving predators in the process. However, early Cretaceous hesperornithiformes weren’t anywhere near as specialised and, to my shame, I probably should’ve drawn such early forms instead of fully-fledged, aquatic forms – whoops. Another mistake is to be found in the foot morphology of these chaps: rather than goose-like webbed feet as I’ve drawn here, hesperornithiformes are known to have individually lobed toes like grebes and coots. Annoyingly, this thought crossed my mind when drawing them, but I thought I was confusing them with something else and didn’t think to verify it. Grr.
Anatomical and temporal blunders aside, the middle foreground features a small maniraptoran dinosaur - suggested here to be a small troodontid. Dangling from its mouth is a tiny, tiny albanerpetontid; an amphibian that, if it weren’t busy being lunch, would be happy burrowing through damp soil. Beneath these fellas is yet another lizard, while to their right are the flagfliers for Wessex Formation Mammalia: rat-sized multituberculates and a shrew-sized dryolestid. These chaps are climbing over lumpy termite mounds, things that, to my knowledge, are yet to appear on reconstructions of the Wessex palaoenvironment. Now, no termite mounds have been found in the Wessex, but the sheer abundance of termites is clear from the masses of termite droppings that Steve sifted through in the course of his studies. The morphology of these mounds is very speculative: while there are some Late Cretaceous termite nests known, we known next-to-nothing of Mesozoic termite mound structure because their fossilisation potential is pretty poor. It’s entirely possible that the Wessex termites were entirely subterranean, but the Wessex clays weren’t kind to terrestrial trace fossils and any evidence of such termites has probably disappeared entirely. Hence, while we know that termites were swarming all over the Wessex floodplain, the jury’s still very much out on their accommodation of choice: the depiction you see above is merely to demonstrate their presence, not infer their way of living.
And that’s just about it, I suppose. I should re-emphasise that the animals you see here are only representative of the
kinds of animals in the Wessex Formation: they were considerably more speciose than depicted here, but, hey, you can only fit so many types of critter on a sheet of paper before it becomes overcrowded. Still, it’s a far richer scene than anyone would’ve been able to paint years even four years ago, so hats-off to Steve for taking all that time and effort to turn the Wessex from a bland(ish) lager to a deep-tasting palaeontological ale. On that note, it’s time to finish my nice, floral-tasting beer and get myself to bed. Hence, I’ll thank Steve for asking me to help present his findings to the world – I’m genuinely honoured that he holds my work highly enough to ask me to illustrate what I think is a real scientific achievement – and point out that full-size versions of this image can be found on various news websites around the ‘Net, including this one
here. Oh, and Steve and I have produced a visual key to the different forms if you’re having trouble finding them: in fact, one look at
this and you'll realise that you needn't have read the last 2000 words.
Anyway, ‘night all.
