Thursday, 16 April 2015

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.

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