My Home, The Sauropod - Part I: Getting Filthy

The idea of an organism playing host to a multitude of other organisms is well known, and is something which most of us are familiar with - even if it's only through catching headlice at school or pushing a worming tablet down a cat's throat. On a smaller scale, there are gut bacteria, some of which perform an important role in keeping the digestive tract healthy. Others are less helpful, as those who frequent dodgy kebab shops will testify - if they're still alive. And it's not all restricted to Animalia, with trees being well-studied examples of a complex ecosystem centred around an individual.

It's not just about parasitism. Sharks, large fish, turtles and whales are often seen with a posse of remora, unusual fish with a sucker-like organ on top of the head, allowing them to hitch a ride. They take advantage of a steady food supply, in the form of particles of food dropped by the host animal, sloughed skin and faeces, but they also help keep the host healthy by consuming parasites which may attempt to adhere to its surface. In return, the host doesn't (always) eat them. On land, large mammals may be parasitised by blood-sucking invertebrates, but these, in turn, may be preyed upon by birds, which the larger mammals are big enough to bear the weight of - and the additional irritation. So, there's a constant battle being enacted on and in many animals, by other organisms, and often this affects the way these animals look and behave. A consideration of how parasites, symbiotes and associated organisms interacted in ancient settings may steer palaeoart in the direction of increased accuracy. It may also result in depictions which look rather different to what we're used to. After all, nature isn't always a tidy place.

Now, portraying these kinds of interactions probably drops this type of speculative palaeoart somewhere in the All Yesterdays camp. Of course, it's only 'speculative' with regard to how one might decide to show those interactions; they undoubtedly happened, but fossilised remains of those interactions are exceedingly rare. And not all of those interactions will be targeted encounters between a parasite or symbiote, and host, and this is what I have attempted to show in the following sketches.

Sauropods represent an interesting branch of Dinosauria, and include the largest terrestrial animals ever to walk the earth. The idea of these keystone species forming some sort of walking ecosystem is an attractive one, as they no doubt carried a contingent of parasites which may have attracted animals which predate those parasites. In addition, they may have provided a perch for flying reptiles and insects, and a surface for non-parasitic organisms to grow on. It's probably also not unreasonable to imagine some sauropods accumulating leaf litter and a twigs, especially if one restores certain species with a row of spines and other ornamentation, as some palaeontologists and artists do. It's hard to imagine sauropods successfully ridding themselves of all the material which rains down on them from the forest canopies under which they must have spent some time. That's not to say an apatosaur would never have dislodged accumulated forest junk from its back, but it would probably have found cleaning itself with any kind of precision difficult.

An apatosaurine sauropod, sketched up quickly and based on Scott Hartman's 'Apatosaurus' excelsus skeletal illustration. The dorsal spines form a trap for falling leaf and branch material, whilst the mosaic of scales and osteoderms provides a surface on which lichen fragments and diaspores adhere.  (Copyright © 2015 Gareth Monger)

That probably looks like a lot of twigs and branches, but these are long-lived animals which may have spent a long time in wooded environments. A smooth-backed sauropod probably won't accumulate twigs in any appreciable quantity, but you might expect to see a bit of lichen growth, especially on those surfaces which see little abrasion from rubbing against trees and other surfaces, or areas of skin which experience minimal flexing. A sauropod might look rather colourful - and different - if adorned with a collection of brightly-coloured lichens, dried on leaves, and small branches. And different populations of a single species might look different, depending on the differences in the vegetation of their respective home-ranges.

An apatosaurine sauropod, as viewed from above, wandering through a pine forest. Dead twigs and branches constantly rain down onto the forest floor, with some inevitably landing on passing sauropods. Reference photo: SV-POW! (Copyright © 2015 Gareth Monger)

For the fans of wild speculation, it might be fun to imagine that certain sauropods used a pile of vegetation in sexual displays, with those male sauropods carrying the largest pile of woody compost most likely to attract a female. Behaviour is one aspect of palaeoart which is wide open to ideas. You've only to look at extant animals' courtship displays to realise that from the future skeletal remains of, say, the bird of paradise, you'd never come close to guessing how they go about impressing a potential mate. There's every reason to think that some non-avian dinosaurs could have been at least as weird. And for palaeoartists, that's where a little imagination can prove useful.

Next up: some more thoughts on Yi qi...   ...and maybe something quick on Stegosaurus.

Posterboy For Open Access: Aquilops

After tweaking the papercraft Aquilops americanus skull, made available at SV-POW!, I figured I'd throw together a desktop 'ornament'. A. americanus is fast becoming the unwitting poster boy for open access palaeontology, so it's an apt choice of dinosaur. In keeping with the intentions of the paper's authors, it's freely available. Download the image from here or, if you want the PDF of the Ai file so that you can edit it, email me at microraptor_at_hotmail.com.

Quadrupedal pose perhaps overstated. Don't like it? Change it!

This model is designed to work without glue BUT! glue will make it look better, giving closer, neater joins. It's up to you. Make it better!

Papercraft Aquilops americanus (by Gareth Monger)

It works best printed at the intended size of A3 (420x297mm) but A4 (297x210mm) will work at a push. Print onto thicker stock if possible, say, 250gsm. If you carefully trim the barbed tabs, they should 'click' into the receiver tabs without the need for glue. Score folds for a neater finish. A good craft-knife (or, better still, a scalpel) and a steel rule/straightedge give best results.

Edit it, share it, distribute it. Keep it fun and keep it free.

See SV-POW! for more Aquilops stuff.

New Year Blues Fix: Skulls, Papercraft and Aquilops

Woohoo! Those wonderful chaps at Sauropod Vertebra Picture Of The Week have made available a papercraft skull pattern for Aquilops. Sure, it's (intentionally) simple and it's only really meant to be taped together, but I wondered how far I could push it without extensively reworking it. Having printed it on 250gsm paper stock, I cut out all the fenestrae and orbits and then trimmed the main outline, having estimated where to leave tabs for adhesive. There was a couple of repeated elements, such as the upper margins of the orbits, owing to their being visible in the lateral and dorsal elevations from which the pattern was formed. I merged these where possible.

Partially trimmed skull pattern. (© Matt Wedel)

I used regular PVA as I didn't want any visible adhesives (i.e., tape) and it's pretty strong and easy to handle. All-in-all, it took about 90 minutes to complete. Two files are available at SV-POW! - a pair of smaller skulls and a larger one. I used the larger one, but printed it up twice on an A3 sheet. This was because I cut out some additional elements and attached them to the complete skull in order to give the cheeks and mandible that flared look.

Completed skull, showing additional cheek and mandible elements, cut from a second, identical pattern.

You'll see from the photos that I added various incisions in order to open up the skull so that it better resembled the real thing. Also, a small amount of black paper was inserted to get rid of that 'lit from within' look and keep the nares and orbits nice and shadowy. The result is a fairly pleasing paper skull, which compares fairly well with Garrett Stowe's digital sculpt, in the same article. What a great way to get hold of good, 3-D reference material! With luck, we might see more of these paper templates in the future.

Aquilops americanus papercraft skull, modified from original pattern.

Anyway, there you go. Just a quick one to see in the new year. Big thanks to Matt Wedel whom, along with co-blogger Mike Taylor, I was fortunate enough to meet at SVPCA, last September. Very nice guys. And go here to read the paper on Aquilops americanus.

Farke AA, Maxwell WD, Cifelli RL, Wedel MJ (2014) A Ceratopsian Dinosaur from the Lower Cretaceous of Western North America, and the Biogeography of Neoceratopsia. PLoS ONE 9(12): e112055. doi:10.1371/journal.pone.0112055