Pterosaurs # 2, March 2019 (Patreon)

More pterosaurs! Rather than share the whole of the montage, I thought I'd just post the section that includes the new additions. Ornithocheiroid pterosaurs - essentially the same group as that termed Anhangueria by some authors (though it's complicated..) - consist of several lineages, and I aim to depict members of all of them. One of these lineages is Boreopteridae, a group of especially slender-jawed pterosaurs with tiny feet and elongate, straight teeth that presumably formed a 'cage' for grabbing small aquatic prey. The striped, dark-faced pterosaur at far left is a representative of this group: Zhenyuanopterus longirostris, from the Chinese Yixian Formation. Also new is Scaphognathus crassirostris, the long-tailed pterosaur at lower right. Scaphognathus is a rhamphorhynchid. Some authors have argued that Scaphognathus  and kin form a distinct clade that's either a group within Rhamphorhynchidae, or placed elsewhere... though other studies dispute this result, and find 'scaphognathines' to be in different places within Rhamphorhynchidae. Either way, I wanted a scaphognathine, so here we are.

Reconstructing a boreopterid

Zhenyuanopterus  was reconstructed after taking measurements from the skeletal reconstruction provided by Witton (2013). It took a bit of work to get things to work if I wanted the animal to be in a normal standing pose. Based on work published on forelimb posture in ornithocheiroids generally, I agree with those who think that these pterosaurs stood with an erect pose (not one where the forelimbs were sprawled out to the sides), the wings tucked in close to the body. The whole animal needed to look fairly big, since its wingspan is 3.5 m.

As usual, the soft tissue outline was mostly added by applying what seemed like an appropriate amount of musculature, skin and pelage. It should be obvious that my pterosaurs feature extensive filamentous pelts or coats consistent with recently described fossils. The colour scheme/pattern of this animal is wholly speculative. I imagined this as an animal that would want camouflage in waterside vegetation, but might also have features recalling those of spoonbills and other open-water feeders, so things here are inspired by tiger herons and bitterns as well as spoonbills. The dark face made sense as an anti-glare adaptation for an animal that often has its face close to the water surface. The rectangular crest looks, as usual, like a display structure so has been given the suggestion of a pattern where there might be brightly coloured patches.

 Reconstructing a scaphognathine

I've discovered that I really dislike drawing pterosaurs in flight, even though it seems more traditional and standard for most species... so I think I'll mostly be drawing them in standing pose. The Scaphognathus here was drawn following Witton's 2013 skeletal and measurements of the original (which I saw in person in Munich a few years ago). As per usual, the process involved producing a correctly proportioned skeletal wireframe before applying soft tissue matching our understanding of musculature and other soft tissue details...

A few decisions are worthy of note. Scaphognathus has very long teeth, so long that at least some were likely visible even when the jaws were closed. I opted to show the upper teeth only, and assume that the lower jaw teeth were concealed in life -- but this could be wrong and I might change it. Matt Martyniuk's reconstruction - where all the teeth are visible - looks plausible to me, so it can be done. I'm assuming for these pterosaurs that much of the snout and sides of the face and lower jaw was naked and covered with a combination of rhamphotheca and leathery skin. The serrated tail structure is based on that of Sordes - it may be that structures like this were widespread in long-tailed pterosaurs, and that the vane-like structure present in Rhamphorhynchus was not widespread, contra our traditional thoughts. I remain confused by the orientation of the 5th toe but assume that it projected posterodorsally and acted as the trailing edge for the uropatagium. But did the uropatagium attach to the side of the tail (as depicted here), or was it continuous ventral to the tail and fused with the membrane on the other side? It may be that the uropatagium was mostly folded up beneath the tail during standing and hence way less obvious than what's shown here.. we really don't know.

Finally, the colour scheme of the animal is, as usual, totally speculative. Scaphognathus and similar pterosaurs were likely generalist predators of riverside habitats and woodland and scrub close to lagoons, lakes and big rivers. As such they might have been predators of big arthropods, fish and small tetrapods like lizards. With all of this in mind, I went for a colour scheme/pattern that's a combination of gull-like and corvid-like (jay-like). The banding on the tail is consistent with a display role for the tail, the countershading could be consistent with life in wooded habitats as well as near water. I think the final result is pretty good.

That's all for now -- more pterosaurs coming soon.

Probably next: I need to update the crocodylomorph montage since a colleague would like to use it in the promotion of some new research. So I'll aim to get that done before next week.

Thanks as always for your support :)