Quadrupedal Launching In Bats And Pterosaurs

I can't recall when I first heard about 'quad-launching' as a serious suggestion for pterosaurs getting airborne, (I was under a rock, palaeontologically-speaking, between '06 and '12) though Mark Witton's excellent 'Pterosaurs - Natural History, Evolution, Anatomy' was the first time I remember anyone going to any effort to depict it pictorially. Indeed, all of his book's pterosaurs are shown mid-launch for their profile images, as if Mark is making a concerted effort to familiarise readers with the concept. Most of the other books on my shelves tend to hedge their bets, offering up a selection of methods, including (but not limited to) dropping from elevated perches, facing into the wind and spreading their wings, and taking a run up whilst flapping.

My biggest problem with quad-launching was that I found it hard to visualise. I've never seen anything get airborne like that. Given that birds are obligate bipeds and their legs are not connected to their wings by a continuous flight surface, they are free to either jump into the air, as with pigeons, or propel the animal along the ground with an energetic run-up, like swans and geese. Many palaeontologists agree that pterosaurs were obligate quadrupeds and that their fore-limbs and hind-limbs were, in life, connected by the wing membrane. Birds are, therefore, a poor analogue for launching pterosaurs, and it is for these, and other anatomical reasons, that palaeontologists believe that pterosaurs' primary launch method probably involved a highly-energetic 'push up'.

A recent post at Pterosaur Heresies again demonstrates its author's frustrations with the problems he sees with the forelimb launch mechanism. The article points out that vampire bats achieve a considerable height from an initial leap before they perform a single flap, and that pterosaurs would be unlikely to achieve such a feat. In a bid to attempt to understand bats taking off from the ground (only a few species can do this) I looked at video footage of a fringed myotis taking off. Adams et al, in their 2012 paper, looked at how bats use their uropatagium to facilitate launch, and made available the following video:

There are four video links in the online paper, showing launches from various angles. In order to get a better idea of what's going on, I rendered the bat as a very-basic stick figure, traced from screenshots of the first online video. The wings' tracings show the stroke, and the head shows the positions of the animal relative to the ground.

Sequence showing a bat (Myotis thysanodes) taking off from the ground, mapped from screen-shots of film footage. This section of the sequence totals around two-and-a-half seconds. (Sequence drawn by author, traced from footage available with Admas, Snode & Shaw 2012.)

In the next image, the seven stages are overlaid in order to get a slightly clearer view - though I think both diagrams are useful when taken in together. The bat accelerates quickly, with its wings in contact with the ground in stage 1-3 (in 1 and 2, they are still flush to the floor). In stage 4 it begins the upstroke, is preparing for its first proper downstroke at 5, and has achieved that downstroke by stage 7. It's already flying and is only a few inches off the ground. My understanding, at least for M. thysanodes, is that when it jumps its inertia carries it a little higher than it would appear when standing with its arms stretched out beneath it, but it's enough to get the first flap in, and by then it's already airborne.

The same bat's take-off sequence, overlaid in order to better show the small area required for a successful launch. Black numbers denote head positions during launch; red numbers denote left wingtip positions. (Sequence drawn by author, traced from footage available with Admas, Snode & Shaw 2012.)

About a year ago I began work on a graphic novel showing the birth, life and death of Nyctosaurus. I may have underestimated how long this would take to put together, so it's still filed under 'ongoing'. But in order to understand quad-launching, I put together a couple of graphics showing an adult Nyctosaurus getting airborne, both of which inspired the bat graphics:

Overlaid launch sequence for a male Nyctosaurus gracilis. (Copyright © 2014 Gareth Monger)

And the looong version:

Launch sequence for Nyctosaurus. Nicked from my deviantART profile, hence the whole lo-res thing. Copyright © 2014 Gareth Monger)

So there you go. Now that I've done the bat thing, I might refine the Nyctosaurus graphics. I might even put together a cel animation at some point. There's nothing overly scientific in all that, however it might prove useful for those of you out there who are into your leather-flappers and pterosaurs.


References:

Adams RA, Snode ER, Shaw JB (2012) Flapping Tail Membrane in Bats Produces Potentially Important Thrust during Horizontal Takeoffs and Very Slow Flight. PLoS ONE 7(2): e32074. doi:10.1371/journal.pone.0032074

Elgin, R.A., Hone, D.W.E., and Frey, E. 2011. The extent of the pterosaur flight membrane. Acta Palaeontologica Polonica 56 (1): 99–111.

Standing Tall: Stegosaurus

This blog was never conceived with the intention of filling it with speculative palaeoart, but it's as good a place as any to put it. Stegosaurus has had a fair bit of coverage in recent months, with the NHM's mount being used to estimate the animal's mass, and Saitta 2015 looking at apparent differences in individuals' plates to determine the animals' genders. Padian and Carpenter disagreed, and Theropoda looked at the health implications of stegosaurs dragging their tails (such as constipation).

Superb illustrations by John Conway and Mark Witton got me thinking about those plates. Palaeontologists have put forward various ideas regarding their purpose, the most popular of which being thermoregulatory aids, display structures and defensive structures. In nature, structures often have multiple functions, with secondary functions being unrelated to their primary function. Feathers, for example, probably developed initially for insulation, but could have been easly modified for use in display, either through behavioral means or by changes in pigmentation. Structural modification of the feather - and other key anatomical features - then endowed the owner with an aerodynamic advantage.

That's a long-winded way of suggesting that Stegosaurus's plates probably did not perform one single function. Some of that's already been touched on in this earlier post, but I'm keen on the idea that part of Stegosaurus's display is concerned with how tall an individual looks, i.e., how much vertical space it occupies, especially in the eyes of potential mates, conspecific rivals and would-be predators. With fuzziness now known to be present in (some) ornithischians, I'm happy to speculate that some stegosaurs may have used stiff fur or 'fuzz' as it's often called, to extend the margins of the dorsal plates. Many palaeoartists, palaeoillustrators and palaeontographers already restore those dorsal plates with a sizable soft-tissue (see comments) keratinous extension. An additional growth of stiff hairs as a light-weight projection could, in theory, increase the size of the plates' appearance. Compared to a bone-and-flesh plate, the hair component would be less demanding on the animal, given that once the hair as at the surface, it's a dead structure, and no longer requires a blood supply in order to maintain it.  Of course, if it's concerned with sexual display, it may be renewed seasonally, and shed after mating. This would get around the problem of it getting trashed through day-to-day activities, and filling up with dirt, mould and parasites - which nobody wants.

Stegosaurus stenops, displaying some serious fuzz. Not unlike a filthy old coconut husk. (Copyright © 2015 Gareth Monger)

Anyway, it's just a thought. And this post is supposed to be short and sweet, like the Holocene.

Next up: Yi qi (again).

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.

The Fossil Record Throws A Curveball: Yi qi

Those crazy, crazy theropods. If there's one thing palaeontology has showed us about dinosaurs, it's that you shouldn't get used to their popular reconstructions because, sooner or later, something will turn up that'll really screw with your mind. And it's not like these events are necessarily rare; Deinocheirus and Spinosaurus got make-overs in the last couple of years, and they're both pretty high-profile.

Less high-profile are the Scansoriopterygidae, small, feathered, theropodan dinosaurs with the long arms you'd expect of an arboreal, aerial-capable dinosaur, but with an immensely-long third digit. A popular notion is that this digit was an adaptation to an arboreal lifestyle, enabling the creature to wrap its arm around tree trunks and branches, like naturalist David Bellamy, just, y' know, sharing the love.

B-b-but - what's this? A new paper by Xu, Zheng, et al, announces the discovery of a new scansoriopterygid, Yi qi, preserving not only the long fingers and feathers, but also a new, hitherto unseen structure. A long bony, or cartilaginous, rod projects backwards from each wrist, and patches of membrane suggest a set-up not totally unlike that of bats or pterosaurs. Or dragons, but I didn't say that. There's still some debate as to how the proximal margins of the wing chord may articulate, i.e., does it merge with the thoraic region or something else. And what is the true arrangement of the manual elements, in particular, the rear-pointing 'prong', referred to in the paper as the styliform element? They offer up a couple of possible arrangements, such as something superficially bat-like, and a set-up where the styliform elements are directed inwards, towards the body, helping to maintain a narrower chord. If this animal did indeed undertake powered flight, it's not too difficult to imagine it 'scooping' the air with its membranous hands, as bats do. Bats' hands' 'palms' form a sort of concave shape as they fly, which looks like a sort of arial butterfly stroke. Their fingers are fully jointed, enabling them to alter the shapes of their manus as required, resulting in a rather effective wing. The paper offers up three potential arrangements for Yi qi's 'wings', the two more plausible (to me) of which are shown here:

Two of three different arrangements proposed in Xu, Zhen, et al (2015), showing a proximally-pointing styliform element running parallel to the forearm (left), and the same feature, free of the forearm, pointing posteriorly and supporting a much-deeper membrane. (Illustrated by Gareth Monger; modified from Xu, Zhen, et al 2015.)

With regards the styliform element, I wonder if, rather than being curved in a horizontal plane (as restored, left) it instead curved ventrally (right), helping to maintain the aerofoil section - and a bat-like scoop. Some time after death, and prior to fossilisation, it has tipped over, rotating approximately 90 degrees, and settling in an unnatural position (left). Compression of the bones and associated remains during preservation could be masking the true shape of this apparently-unique element, but some lateral compression in life would make structural sense in terms of giving it strength during a downstroke. But that's all speculation.

In the paper, the wing reconstructions (shown in dorsal view) show the hind limbs of the animal trailing behind it. Although the main point of the graphic is to demonstrate the possible extent of the membrane, a trailing position for the hind limbs is unlikely; it pushes the centre of gravity back, and increases turbulence. For a volant theropod, it would seem unlikely that it would extend its legs behind it if they're not supporting part of a flight surface, and it also seems unlikely that a volant animal would rely on a narrow wing as suggested in the left-hand diagram. The right-hand diagram shows a deep chord, within which the (estimated) centre of gravity comfortably sits, when the legs are brought up, underneath the body, and out of the airflow.

Speculative illustration showing possible extent of contour feathers on Yi qi, and a possible centre of gravity. Note that the animal brings its legs in under itself, out of the airflow and therefore reduces turbulence. This also maintains a more-central centre of gravity. (Copyright © 2015 Gareth Monger)

Where the trailing edge of the membrane attaches (e.g., the body, or the hind limb) is not clear. Flying dinosaurs which use feathered wings benefit from legs which are independent of the wings. They can run into the airflow to achieve lift-off, or they can jump into the air, with the wings already committed to the flight strokes and not involved in the jump (compare pterosaur quad-launching). Having a skin membrane attached to the leg might be problematic since the legs (if not held out behind) would need to be elevated in order to maintain a level flight surface, and not one which partially faces into the airflow. However, that brings the leg and the membrane attached to it forward, reducing the tautness of membranous wing. Bearing that in mind, one might expect the membrane to attach on the body, somewhere in front of the hip, and not to the leg. The styliform element could work as a means by which the animal adjusts the tautness of the membrane, in a similar way to how a pterosaur is thought to do so with its apparent ankle attachment. Without that extra strut, the animal might enjoy less control and increased flutter in the membranes.

Yi qi in flight. (Copyright © 2015 Gareth Monger)

One of the key questions raised by this is why would a theropod go the route of developing a membranous flight surface when so much experimentation with flight (and there seems to be a lot of it!) is concerned with forming a continuous flight surface from elongated feathers? A major difference between scansoriopterygids and other, flighted, theropods is their elongated third digit. As suggested earlier on, it could be that this is an adaptation towards an arboreal lifestyle, enabling the animal to climb trees and other steep surfaces more easily. And it could be that selective pressures favoured the extension of the postpatagium instead of the feathers present on the arms. Whatever the case, feathers for flight persisted, and the theropodan flight membrane proved an evolutionary dead-end. Hopefully, additional specimens will come to light, adding to our understanding of this weirdo dinosaur.

Many thanks go to Mike Boyd for enabling me to write this particular article.

Speculative Palaeoart: Pterosaur Embryos

This micro-project was born out of one of those Facebook art challenges which I tried (and failed) to ignore, and for which I was nominated by Bob Art Models's Bob Follen (remember him from this post?) and Palaeoplushies's Rebecca Groom. The 'rules' of this particular Facebook challenge were pretty simple: produce three pieces of art for five days. That was it. It didn't specify whether they were to be new pieces, or whether they had to be posted over five consecutive days.

It started well enough as I paved the way to its inevitable non-completion with the usual good intentions. In fact, it's not abandoned, just hard to complete, what with everything else I've got going on. Given that I've got a fairly sizeable pterosaur project in the works, I figured it would make sense to stay close to this subject, and I was inspired to try my hand at portraying pterosaur embryos as close as possible to how extant animal embryos are.

It started with a quick mooch around Google, looking at photos of embryos of familiar animals, to get an idea of general bauplans. Most people are used to the proportions of young animals, with their disproportionately large eyes and heads, and comparatively short bodies and small limbs, but embryonic animals, depending upon their stage of development, can look altogether different to how they will appear at the time of their birth. Indeed, in the early stages, many disparate lineages' embryos may look broadly similar to one another. The diagram below shows representatives of the major vertebrate groups.

A selection of early-stage embryos, representing the major vertebrate groups. (Copyright © 2015 Gareth Monger)

You'll no doubt have seen versions of this line-up. I've opted to cut out most of the internal detailing so common to this style of diagram since I'm only dealing with external features in the pterosaur embryos I'm illustrating. It's easy to appreciate the broad similarities in this selection. The embryos, although perhaps not quite the same age, are at a very similar developmental stage, which shows how vertebrates follow a similar pattern of development in their earliest stages before they begin to specialise. As you can probably appreciate, there's not much point in producing a speculative, days-old pterosaur embryo to add into the above line-up as it won't look significantly different enough to add anything to the subject. The extant maniraptor in that diagram doesn't exactly scream 'DINOSAUR!', or at least not to this non-embryologist.

Today, the only flying vertebrates are birds and bats, and since only bats and pterosaurs share a membranous wing, I chose to look at bat embryos. Of course, bats and pterosaurs are not particularly closely related, having both developed flight apparatus independently, separated by an enormous chunk of time. (View this illustrated lineage at Phylopic to see just how distantly-related they are.) The framework on which they support their wing membranes is different, too, with pterosaurs using an enormously-elongated fourth finger and an internal network of aktinofibrils to stiffen the wing, while bats support a comparatively loose membrane on an enormous, five-fingered hand. Presumably this is the trade-off: pterosaurs have a skeletal scaffold reduced to a single spar, but there's more going on in the membrane and the skeletal mechanism by which they fold the wing away may not be as effective as that of at least some bats.

Embryos of the black mastiff bat (Molossus rufus), showing various stages of forelimb development. Compare 1's short manual digits with those of 2 and 3. (Copyright: Dorit Hockman. Used with permission)

This photo of three black mastiff bat embryos, courtesy of award-winning Dorit Hockman, a junior research fellow at Oxford, shows clearly the embryo pups' 'hands' and dactylopatagia (interdigital wing membranes) which are relatively small compared to those of newborn pups. Roll back several days in these animals' development, and at some point the animals' limbs will appear somewhat unspecialised, without any suggestion of the flighted animal to come. It was this intermediacy which I wanted to explore in my pterosaur embryo illustrations.

There's probably not too much that bat embryology tells us about pterosaurs; after all, bats are altricial and, although relatively well-developed at birth, are unable to fly until they are several weeks old, so there is a period of development and growth during this period. Some exceptionally well-preserved pterosaur fossils suggest that they are precocial, to the point that they can probably even fly within a very short time of hatching. It's reasonable to expect this to be reflected in the anatomy of their embryos and that their embryos go through a stage of rapid development before hatching, at which point they are essentially miniature adults. Unfortunately, early-stage embryo skeletons comprise a lot of cartilage which doesn't often fossilise well anyway, hence the speculative nature of illustrating pterosaur embryos.

A relatively-quick digital 'sketch' of a pterodactyloid embryo, with large head, closed eyes and stubby wings. 10a scalpel blade for scale. (Copyright © 2015 Gareth Monger)

It's difficult to make any scientific claims as to the accuracy of these illustrations, given the lack of direct evidence, which is why I tend towards filing these under 'speculative palaeoillustration'. That's also why I don't feel comfortable tying these down to too specific a taxon, leaving it as loose as 'pterodactyloid'. Other than full-term pterosaur foetuses illustrated to support fossil finds, there doesn't appear to be much in the way of palaeoart for prenatal pterosaurs. It's probable that, owing to the lack of any physical evidence, and the fact that the embryonic/foetal stage is comparatively brief, it's simply not important enough to necessitate producing illustrations of an animal at a point in its development where nothing would see it anyway, particularly when the adult reconstructions are being reviewed and refreshed as frequently as they are.

Another generalised pterodactyloid pterosaur embryo, with wing-digit and brachiopatagium beginning to develop. (Copyright © 2015 Gareth Monger)

So, in short, I don't think this is necessarily a critical aspect of palaeoart, but as science and scientific art, including photography, creeps further and further into our lives, whether that be online or through television or in print, the previously-hidden lives of vertebrates become more familiar to us. It makes some sense for palaeoartists to let themselves be influenced by this.

Biggest of thanks go to Dorit Hockman for letting me use her photograph of the bat embryos, which greatly influenced the final look of my pterosaur embryos. View her professional profile here.

Mesozoic Marine Menu: Bone

A little over two years ago, I was contacted by science blogger, Gavin Hubbard, who, knowing I liked to illustrate palaeontological organisms, was interested to see if I had any marine reptile illustrations available to use in a planned article he was in the process of completing. Now, this wasn't an example of how well-known I had become, nor how targeted networking can result in commissioned work. Gavin and I were classmates at an East Anglian primary school from 1984 to '87 and he had remembered my enthusiasm for dinosaurs from then. Now, save for the briefest of encounters in a Wisbech pub circa 1999, I hadn't actually seen Gavin since 1987, when we were both seven years old, so it was touching that he'd remembered me for all the right reasons when he was writing this particular article.

Gavin's blog, aptly named 'ScienceHubb', offers commentary on subjects as disparate as they are interesting, from immunisation to the defensive strategies of moths, and he delivers it in an engaging and humorous way. As a box-ticking exercise, that's pretty much all I want in a blog, and I get to learn something as well. Back in March 2013, Gavin was dealing with a little-known organism going by the name of Osedax, which is a genus of polychaete which invades the bones of 'whalefall', that is, dead whales which die and come to rest on the seabed. Many of us are familiar with deep-sea footage of dead cetaceans being scavenged by crabs, hagfish and sleeper sharks, but often these programmes stop short of documenting what happens after the whale has been reduced to a seemingly-clean skeleton, and the last of the hagfish have swum off to choke some sharks to death.

Don't eat the yellow ones: from lion of the sea to fertiliser for bone-eating snot-flowers. The route by which a Mesozoic marine reptile might find its way to its permanent place on the seabed. (Copyright © 2015 Gareth Monger)

Osedax is the genus name, but these things also answer to 'boneworm', 'zombie worm' and, in case you've not met your word-count, 'bone-eating snot-flower worm'. So, what do these worms want with a whale skeleton? (I'll keep it short since Gavin's already said it perfectly well.) After the removal of all the obvious soft tissues, whalebone is still rammed full of nutritional amazingness, if you're equipped to get to it. Osedax secrete an acid which dissolves the bone mineral, allowing them to 'take root' in its surface. They then utilise their symbiotic chums, a type (or types) of bacteria, to digest the lipids and proteins within the bone; they have to do this since they possess neither stomachs nor mouths. It's not certain if they are specialised cetacean scavengers, or if they will colonise other skeletons and that whales just happen to be longer-lasting on the seabed, easier to find and, therefore, study. Towards the end of Gavin's article at ScienceHubb, he speculated as to whether Osedax's ancestors may have colonised the skeleton's of the Mesozoic's array of large, marine reptiles.

Main illustration: a pliosaur skeleton, representing 'plesiosaurfall'. Inset: an Osedax individual, established on a pliosaur vertebra. (Copyright © 2013 Gareth Monger)

So, in order to illustrate his point, he wanted an existing image of a pliosaur. As it happened, it was my day off, so I had some time to throw something together, rather than reuse an illustration. 'Thrown together' is probably about right. The inset image was easy-enough to sort out, as there was plenty of reference. The main illustration started out as an A3 print of an old illustration of 'Rhomaleosaurus' (now Meyerasaurus), which I photographed at a jaunty angle, reprinted, sketched out, and painted in gouache. (Richard Forrest, at Plesiosaur.com, later pointed out that this particular skeleton was found correctly oriented, but erosion had damaged some of the dorsal features, and the preparators had flipped the specimen onto its back in order to display its better-preserved ventral side!)

Roll on a couple of years, and researchers Silvia Danise and Nicholas Higgs have published a study showing how some Mesozoic marine reptile bones display the telltale signs of Osedax activity, down to the signature cavities produced by their chemical bone-boring. The study demonstrates that Osedax (or at least Osedax's ancestors - I guess we cannot be sure it's the same genus) did not initially co-evolve with cetaceans, but already existed in the Mesozoic, survived the KPg extinction event, and exploited other organisms' skeletons immediately after the Mesozoic reptiles went extinct. They also speculate that snot-worm activity may be responsible for the destruction of skeletons before fossilisation can take place so, presumably, they won't find their way onto the Palaeontology's Favourite Pets list any time soon. It's good to see Gavin Hubbard's speculation justified by a solid scientific study and, personally, it's nice to have provided an illustration for it.

References:

• Higgs, N and Danise, S (2015) Bone-eating osedax worms lived on Mesozoic marine reptile deadfalls. The Royal Society, volume 11, issue 4.
• Hubbard, G (2013) Osedax: Ancient Bone Eaters. http://sciencehubb.co.uk/osedax-ancient-bone-eaters/

LATE EDITION:

A Pteroformer article gets the majority of its hits in its first day, so I've not got long to add in this snippet of maximum importance.

Love In The Time Of Chasmosaurs's blogger, David Orr, and his wife, Jennie, have written 'Mammoth Is Mopey', a children's alphabet book which utilises illustrations of extinct taxa which are rendered as accurate caricatures. That is, they're caricatures, but they're not wrong. Pronunciations are explained, background info is supplied, and the illustrations are fun and engaging. And, let's face it, it'll appeal to the adults who look back at their own childhoods with a hint of sadness at having not had a book like this.

Here's the really important bit: this is a crowd-funded project. And it's all or nothing. Jennie and David are sixty-five percent of the way to their goal of $10K, needed in order to get this thing to press. There's a fortnight left. Two weeks to get the remaining three-and-a-half thousand dollars OR IT DOESN'T HAPPEN. So, if you've not looked at their page at Indiegogo, take a look now. If you've looked but not contributed, please consider contributing. Not your thing? Share the link - it'd help! But seriously, take a look at all the lovely, lovely incentives they offer! Fifteen dollars (what's that in pounds? A tenner?) gets you a book! That's a niece's or nephew's birthday gift sorted! So click the link ->> this one <<- and have a gander. Thanks.

In From The Cold: The Return Of Brontosaurus

I daren't let this story rumble on by without throwing in some of my own observations. Indeed, Brontosaurus was an important dinosaur during my early flirtations with dinosaurology when, perhaps, the palaeontologists of the early '80s would rather it hadn't been - or at least not by the that name. This is such a big story right now, that it's barely worth summarising it yet again, but for the benefit of someone finding this article out of the context of the media 'frenzy', we're talking about the the issue of the genus erected for a fossil sauropod discovered by Othniel Charles Marsh in 1879. In 1903 Brontosaurus was reclassified as a species of Apatosaurus, but despite this, the name Brontosaurus stuck fast. Whatever the actual reason, or reasons, it's not hard to see the appeal of Brontosaurus. It's the 'Thunder Lizard', a veritable superhero of the Mesozoic world, splitting the rocky ground upon which it walked and announcing its approach long in advance of its arrival. Apatosaurus, well, it just sounds kinda vague. Less thunder and more rain: A-pitter-patter-saurus. Apatosaurus is Betamax.

Exactly how it happened. (Copyright © 2015 Gareth Monger)

Back then, and compared with Brontosaurus, Apatosaurus lacked airtime. The authors of the kids' books I owned didn't really imbue it with any personality - if they mentioned it at all. Also discovered by Marsh, and only a couple of years earlier, Apatosaurus ajax shares the same overall 'layout' as Brontosaurus excelsus, being a heavy-set quadruped with an enormously long neck and tail. It's slightly stockier than Diplodocus and holds itself more-or-less horizontally, especially when compared with that other famous sauropod, Brachiosaurus. Certainly in the popular children's books of the '70s and '80s, Brontosaurus was depicted as Diplodocus's squatter cousin, and much of the scientific laziness can probably be attributed to their authors simply taking their lead from existing books they were hoping to emulate and, if only in terms of style, update. The reasoning behind the pair rarely receiving the same attention in the same book probably boils down to the simple reason that since both animals share very similar bauplans, why include both? After all, dinosaur-overview books tend to focus on the most famous and the most disparate forms.

Old and new (and old again). Interesting news but, unfortunately, it won't create much new work in the palaeoart community. (Copyright © 2015 Gareth Monger)

So what does this mean for Brontosaurus's future, as far as its ranking as a kids' favourite? Based on my horribly vague recollections of my friends' dinosaur knowledge in the mid-'80s, if I'd taken a poll and asked my five-year-old friends to name five dinosaurs, you'd almost certainly hear Tyrannosaurus (never "T. rex" back then), Brontosaurus, Triceratops, Stegosaurus and perhaps Diplodocus - and probably not much else. Of course, if you asked the same demographic now, there'd be a whole host of new names, minus Brontosaurus. To be fair, it's to be expected, and for all the obvious reasons: new discoveries, better restorations, better reach, and everything in between - and several years of authors honouring Brontosaurus's 1903 reclassification. But for today's younger dinosaur enthusiasts, they may only have come across Brontosaurus whilst reading about Apatosaurus. For them, Brontosaurus is just an interesting little quirk of the scientific process recorded in the footnotes of an Apatosaurus profile. Whether it recovers its position as a firm favourite with the next generation of dinosaur fans remains to be seen. Can Brontosaurus bounce back from its second extinction?

Read the paper by Tschopp, Mateus and Benson here. It's got all the science bits I ignored in it.