Archive for May, 2012

Academics on archosaurs: Jerry Harris

Dr. Jerry D. Harris, Director of Paleontology, Dixie State College of Utah
Specialist in being as much of a generalist as possible.

1. What first got you interested or involved in your research field?

Dunno, exactly…I have very hazy memories of playing with a set of old Marx dinosaur toys in a room with gigantic paper cutouts of various dinosaurs in the early 1970s; my mom tells me I had those starting at age 2, so I have no idea what was my initial exposure. I also have (less hazy) memories as an older child poring over books such as McGowen’s Album of Dinosaurs and Craig’s Dinosaurs and More Dinosaurs in fascination. Of course, all of these books and toys are hopelessly outdated–even laughably so–by today’s standards, but they obviously piqued my interest. Somewhere amid all the baby/early childhood stuff my mom saved is something I wrote in second grade–this was on those gray, sideways, blue-lined pieces of paper on which children learn to print. The assignment clearly had been to respond to a question such as “If you could be any animal, what would you be and why?” My answer: Compsognathus. I don’t remember why. Spelled it correctly, too.

2. What is your favourite piece of research?

But…but…I love _all_ of my children equally!  In all seriousness, I have a particular fondness for some of the first papers I wrote, particularly the ones that describe the theropod track Saurexallopus, the pterosaur Kepodactylus, and a bunch of isolated dinosaur tracks from the Morrison Formation near Canon City, Colorado. Compared to what I think I could produce today, they’re not the greatest papers…in some ways, they are blatantly amateurish! But producing them having only a bachelor’s degree behind me was an extremely interesting, eye-opening process that really exposed me to what the meat of research paleontology really is, which is nothing like anything I’d ever seen in a book or TV show. Anyone seriously contemplating getting into paleontology should have this kind of experience at the undergraduate level. I have lots of fond memories of being surrounded by stacks of papers, in my apartment or a nearby coffee shop, trying to learn about so many different things, amalgamate and filter them, and apply them to resolve a problem. They’re not the greatest papers in the world, but they were the foundation of my education in how to be a research scientist and therefore are near and dear to my heart.

3. What do you think is the most interesting or important discovery in your field in recent years?

At the risk of psittaciforming Tom Holtz, feathered dinosaurs and the cementing of the birds-are-dinosaur-descendants theory (yes, theory…no longer a hypothesis). Of course, it opens up all kinds of new questions about how far we can push inferences about dinosaurs based on extant bird physiology/anatomy/behavior/etc., but that’s also a great thing–gives us paleontologists something to do! Also, the increasing application of all kinds of technologies to resolve paleontological problems. In particular, increasingly high-resolution CT scanning has provided some really interesting insights into aspects of dinosaur paleobiology that I bet no one thought we would ever be able to tackle even a generation or two ago. (On a tangential note, the increasing prevalence of 3D digitization and rapid prototyping will, in the not-too-distant future, make possible comparing specimens in far-flung reaches of the globe easier and cheaper than traveling a lot). Lastly, I’d say that the (again increasing) realization that non-avian dinosaurs don’t really have any modern analogs in terms of anatomy, physiology, and ecology–and that dinosaurs aren’t the big, sluggish, swamp-dwelling reptiles I grew up with–makes working on them so much more fun and exciting because it allows us to see where principles we think we understand from extant organisms aren’t broad enough to encompass much of the past, and try to figure out more inclusive principles as well as all the variables that made the past unlike the present and tease out their effects.

It’s funny that I say all that because, at heart, I’m still a “let’s go dig up something new and describe it” kind of guy, which has increasing risk of obsolescence…

4. What do you think is the biggest unanswered question in your field right now?

The biggest question is: who the heck is going to employ the vast numbers of paleontologists coming out of schools these days?!? …OK, so that’s not really it. The biggest question is: when are physicists going to get off their collective gluteals and invent time machines that will allow us to go back and observe dinosaurs firsthand?!? …OK, so that’s not really it, either. Actually, I don’t know that I can answer this one–there are so many huge questions, none more important than the other! For example, why did ornithuran dinosaurs survive the K-Pg extinction event but no others did? Why don’t ornithischians show any osteological hallmarks of having pneumatic diverticula, and how did they effectively compete against saurischians without them? Why are the footprint records of many dinosauromorph groups so strangely different than the body-fossil records? When will someone reconcile opposing molecular and fossil-based phylogenies? What’s it gonna take before everyone on the planet realizes that everything tastes like basal saurischian dinosaur, not chicken, and that eggs demonstrably came first? …OK, so I’m getting off track here…

5. What advice would you give to students about research?

As a teacher of scientific writing, and as someone who learned via trial-by-fire under the tutelage of someone unafraid to rip my writing to shreds, I have a personal interest in good writing. It’s also something I consistently fail to see from students, and something I see with alarmingly decreasing frequency in the literature. Frankly, if you want anyone to take your research seriously, write it correctly: use words properly and to maximum effect, structure sentences properly, use parallel structure throughout and across paragraphs and paper sections, and perhaps above all else, learn how to explain your reasoning in a clear, logical fashion.

Beyond that pet peeve, obviously doing careful research is key. Often, that means doing detailed work, not glossing over various details that you think are unimportant, or that aren’t usually talked about in other papers. You never know what will be important in the future! Doing careful research also means examining all issues from multiple angles–these days, phylogenetics seems to be the favorite perspective, but functional morphology, paleoecology, sedimentology, stratigraphy, paleobiogeography, etc. all contribute valuable information. Be holistic, not narrowly focused…maybe not all in a single paper, but in approaching any specific problem. (Plus, this gives you ample opportunity to beef up your CVs!).

Academics on archosaurs: Tom Holtz

Dr. Thomas R. Holtz, Jr., Univeristy of Maryland
Specialist in theropod paleobiology, with special concentration on/obsession with/affection for the Tyrannosauroidea

1. What first got you interested or involved in your research field?

As a young kid (about 3 years or so) I got two different toy dinosaurs: a Tyrannosaurus and a “Brontosaurus“. I asked my mom what they were, and she said “dinosaurs”. I apparently was very skeptical, because how could these two animals which looked SO different from each other both be called the same thing, when horses and cows (which looked a lot more similar) had their own names. So she bought a copy of the How and Why Wonderbook of Dinosaurs and read to me from it. At that point I decided I would grow up to be a dinosaur. Somewhat later (when my parents convinced me that this was not going to happen), I decided I would be a paleontologist.

2. What is your favourite piece of research?

I think my favorite pieces of research include: establishment under a phylogenetic context that tyrannosaurs were coelurosaurs (already suggested since the early 20th Century, and independently developed by Currie, Novas, and Sereno while I was doing my work); functional anatomy of the arctometatarsus (again there had been previous work on the subject, but by giving the structure a name it seems to have attracted more rigorous studies (e.g., various papers by Eric Snively); and the critical analysis of the obligate scavenging hypothesis for Tyrannosaurus and kin.

3. What do you think is the most interesting or important discovery in your field in recent years?

Feathers. Feathers galore. Feathers on fairly basal coelurosaurs, and maybe deeper. (However, I would also say that work on growth rates in dinosaurs and the revolution in studies of respiration and air sacs in archosaurs are also revolutionary for the field).

4. What do you think is the biggest unanswered question in your field right now?

How basal were feathers? Or, to put this a different way, are the elements in Tianyulong, coelurosaurs, and/or pterosaur pycnofibres homologous? Towards this end, dinosaur fossils in lacustrine or lagoonal deposits of the Late Triassic and Early Jurassic are greatly to be desired!

5. What advice would you give to students about research?

So many important things to suggest here…

One: Read the older literature! Just because a work wasn’t published since 2000 doesn’t mean that it doesn’t have great observations.

Two: Don’t be afraid to be wrong. Science is all about reducing the error bars over time, so don’t expect the first paper in a field to be the last word!

Three: Always keep in mind: if you were wrong, how would you know it? In other words, be clear as to what your hypotheses really are.

and a big one:

Four: Read outside your field! Be aware of research done in other disciplines, from functional anatomy to sedimentology and stratigraphy to ecology and so forth. Don’t get pigeon-holed into a single particular topic.

Academics on archosaurs

I have been delighted with the response to the (theoretically at least) ongoing series of palaeoart interviews. People seem to really enjoy them, and having a whole series with the same questions has enabled readers to cross compare ideas and see a little of the mechanics of the minds of the artists. Now while I do love good palaeoart, but I do want the focus of the Musings to be more about the science and recently I have started to wind down a bit. However, a solution to both issues popped into my head just the other day – to interview my colleagues about their research.

Now the obvious problem is that a good interview digs deep into the workings of a researcher’s field, how they work, how things intertwine, and can go back and fourth to develop ideas. That means a long and involved process and I’m no skilled interviewer and moreover, few people will want to take that kind of time and effort. My solution therefore is to pose just a few short and simple questions that will be quick and easy to answer and hopefully encourage people to take part and yet by focusing them on their own research themes, provide contrasting and expansive answers.

In short I hope to build up a body of these that will get a wide range of researchers to talk about their work and interests and provide a much broader picture of the state of archosaurian science than just reviews of papers and new discoveries, and to get a chance to hear from a lot more people than just those of us who blog or comment regularly. We’ll see how it goes of course, but I do already have a few lined up and a bunch of feelers out there. This will hopefully therefore become a frequent, if irregular, new theme on the Musings and so I’ve put up a new category to cover it.

The first proper interview will follow very shortly, stay tuned!

Pterosaur ontogeny

 Not too long ago, Matt Wedel had an SV-POW! post that talked about ways of diagnosing an adult vs non-adult sauropod. Inspired by this and the fact that I have recently been playing around with issues of ontogeny in pterosaurs, I decided to write something similar for the non-avian Mesozoic fliers. If you have a pterosaur specimen in front of you, just how do you know if it’s an adult or not?

Obviously there are some general indicators that are pretty good for vertebrates as a whole that will get you quite a long way (even if this is a new species). Size is obviously rarely a great indicator, but if you have a pterodactyloid with a 20 cm wingspan then it’s going to be a juvenile, and likewise if you have a rhamphorhynchoid coming in close to the 2 m mark it’s very unlikely to be anything but a big adult. Young animals (and especially very young animals) tend to have big heads compared to their body and especially very big eyes compared to the size of the head. A bunch of fusions are absent in young pterosaurs that are present in adults too, just as you’d expect for most animals. The sutures between the centrum and neural arch of the vertebrae will be open in juveniles and closed in adults, and similarly the elements of the pelvis and sacrum, and the scapula and coracoid will be separate in young animals and fused together in adults.

Pterosaurs also have some characters of ontogenetic change that are rather more peculiar to them than vertebrates in general. Very young pterosaurs also tend to have a very grainy texture to the surfaces of their longbones, despite the fact that even embryonic pterosaurs have a pretty ossified set of bones (unlike many young animals). Smaller pterosaurs also tend to have various parts of the skeleton being less ossified and rather amorphous compared to those of adults. The tarsals are often not well ossified and can be missing (well don’t preserve) and if present may be very simple shapes. The carpals tend to look more ‘blobby’ and lack the detailed morphology seen in adults and will be separated into multiple elements whereas in adults the wrist will primarily be formed of just two massive elements (plus the pteroid). Finally, while obviously you would expect skulls to fuse up during ontogeny, pterosaurs do tend to take it one step further than most. Rather like birds, in adult pterosaurs the sutures all but disappear, or even go entirely, such that the skull looks like a single smooth piece of bone. Also as in some birds, bigger pterodactyloids have a notarium and this only fuses up and fully develops in adults. Similar to the point above about absolute size, the presence and development of some form of head crest is indicative, but not a great indicator of age. Yes a massive and elaborate crest in an animal is indicative that it’s an adult, but there could be a fairly well developed crest in an animal that is close to becoming and adult and of course there are taxa without crests and in at least once case it appears that females don’t have crests.

As in mammals, but unlike dinosaurs and birds, pterosaur also have epiphyses. The growing plates at the ends of the long bones physically separate the main shaft of the bone from the proximal and distal ends, so things like the femur can appear to be in three pieces. Obviously as growth slows towards maturity these epiphyses slowly disappear as they fuse into the single element that you would expect to see.

So in short, something that is small, with grainy textured bones, a big head, with big eyes, unossified tarsals, amorphous carpals, no crest, clear sutures in the skull, no notarium, and separated scapulocoracids, pelvis, epiphyses and neurocentral sutures is going to be a young juvenile. And the close these various features get to the opposite condition the closer the animal is likely to be to adulthood.

As ever with such things these are not absolutes, but merely guides. Good guides, certainly – you simply won’t see a notarium in a very young pterosaur, or open neurocentral arches in a big, old adult. However, in terms of determining more subtle difference in age it will be tricky – one animal may have fused up the notarium, but may have incompletely ossified tarsals and another could have the reverse. Although at least some characters do seem to have a bit of a pattern (the scapulocoracoid seems to fuse pretty early in most things) a general lack of numerous specimens of different ages makes it hard to do any more detailed analysis. Still, in terms of gross age (hatchling – young – adolescent – adult) even for a specimen of a previously unknown species with no obvious close relatives, it should be relatively easy to determine the approximate age of the animal.

Catch 22

While the aquatic dinosaurs nonsense certainly united palaeontologists in their dismissal of the ‘hypothesis’ it also caused something of a split. Discussions both public and private went around about how to deal with such an issue. It’s a fundamental problem with bad science and anti-science and while it’s a fairly obvious one, it is worth laying it out. In short, once the proverbial cat is out of the bag and has spread to a significant number of the public via the media, there is no obviously good way of tacking the problem.

Option 1 is quite simple – ignore it. It’s bad science, it’s wrong. Sooner or later most people will simply forget and move on and many will recognise it as being wrong.

Option 2 is to counter it. Show why it’s wrong and why the good science is right.

This all sounds rather reasonable and not too tricky and either way, the good science should shine through. The reality though is all too different and in fact dealing with it is a catch 22. Follow option 1 and you will find a good number of people will, years later, still think this thing was true. They heard it, absorbed it, heard nothing to contradict it and so assumed it was right. Even if it sounded dodgy, they do now have two (or more) competing ideas in their heads and might not be able to say which is right or better supported. If you do nothing then bad ideas can fester and it can be triumphed by some as a victory with the scientists too cowed to reply.

Acting may not help much however. Assuming you can even reach many or the same people as the original story (the media rarely publish retractions, don’t tend to give replies the same airtime or print space, and will come later) you may convince few. Simply continuing the discussion gives a sense of validity to an idea that it shouldn’t have simply by arguing with it and keeps things going longer than they should.

So it is a damned if you do and damned if you don’t. Some favour the ‘let it lie’ approach and others the ‘get good info out there’ (like this for the aquatic dinos at least). Not surprisingly I tend to favour the latter with my overall approach and attitude to science communication, but it’s not a blanket one. There’s no need to devote time and effort to disprove every bit of silliness that appears online and in the media, if no one has seen it, it’s not even an issue. But for me, major stories do have an impact and I’ve too often seen people cling onto things and think of them as genuine simply because they were reported and while it might give a nonsense piece a little of the oxygen of publicity, providing a well-directed and decent sized dose of science will probably reach a few more people and more than offset the damage.

The real solution of course is for idiots to spot pushing BS as science, the media to stop reporting BS as science and to make everyone scientifically literate so they know BS when they see it. In the absence of solutions to those trivial problems however, we have to do the best we can, even if we can’t always agree on the best way to do it.

Book review: When Dinos Dawned….

I would have put the full title of the book in the title of of the post, but frankly I thought it might end up filling the whole page. “When Dinos Dawned, Mammals got Munched & Pterosaurs took Flight: a Cartoon Prehistory of Life in the Triassic” is probably one of the longest titles going, but this is perhaps the only real criticism I can have of this book.

This entry is the latest in a series for National Geographic by author / artist Hannah Bonner. It’s aimed at children quite clearly, but I think there’s enough depth to be of interest to adults and bring a little enlightenment to even knowledgeable readers. The science is basically perfect, and the material is presented in a fun and accessible manner. The drawings are simple in style, but extremely accurate in terms of anatomy and settings and nicely executed – there are ‘cartoon’ style animals for various panels, but the majority of the content is more like the cover shown here.

The Triassic is of course a time when lots of interesting things were happening. While perhaps understandably most books like this would focus on dinosaurs and by extension the Jurassic and Cretaceous, there is a lot more to the Mesozoic than just dinosaurs and the Triassic has most of that covered. Odd crocs, aetosaurs, phytosaurs, the first pterosaurs, the first icthyosaurs, prolacertiforms and the weirdness that is things like Longisquama. A lot of these are unlikely to be on the radar of a young dinosaur enthusiast, so this really helps fill in the picture of what was going on in terms of evolution and the changing faunas.

Obviously the reptiles get to dominate this, but mammals, insects and even plants get a decent look-in and are put in context of what was going on. It was also good to see lots of more obscure things get a look in – even books that do cover aetosaurs or the like will often include a token animal – I certainly can’t think of any previous effort that covered three (count them!) drepanosaurs. When the rhynchosaurs, Panphagia, Lotosaurus, Odontochelys and Proterosuchus also get a mention and are illustrated, well it’s just lovely.

At this point I should probably note that I’m reviewing this because I was lucky enough to be sent a preview copy. My colleague Corwin Sullivan played a major role as a consultant on this book given his work on various Triassic critters and Hannah also contacted me during her research (but I don’t recall even giving her any specific help in the end). Still, she was kind enough to arrange for me to get a free copy and I’ll gladly cover it here (especially after I spotted a reference to the Musings in a list of useful websites in the back). Certainly the accuracy is to Corwin’s credit for his advice and to Hannah’s for taking it, and the book certainly benefits as a result.

Overall though this is an excellent effort with much to recommend about it – good science, nice art, a great theme and well written. While I’d imagine the market is a little limited, this is going to go down very will with all kinds of kids who like their dinosaurs and other prehistoric beasties but want to know more and have more than enough books discussing Diplodocus and Tyrannosaurus. Great stuff.

Butterflies & moths

Another little display from the Carnegie I’ve had sat in my files for too long. OK so there’s nothing here that’s linked to archosaurs, or even evolution in general. But what it does do is address just the kind of question that often bugs people. I think a very big proportion of the public would recognise that moths and butterflies are close relatives and that they are different, but aside from the diurnal / nocturnal split and the fact that butterflies tend to be more colourful, they would probably struggle to say how you could tell them apart, or for that matter what linked them together.

My experiences with Ask A Biologist suggest this kind of thing is really common. People have bits of knowledge and part of the full picture, but don’t realise they have only part of the story and even if they did, don’t know how to go about filling in the gaps or putting their knowledge into context. In the case of AAB, someone has realised that don’t know the full picture, or has had their interest piqued by some incident.

In the case it’s actively prompting people – it’s easy to imagine someone looking at this and thinking “Oh yeah, what *is* the difference?”. The headline is a nice attention grabber and it’ll get people to read the short captions below and, hopefully, get them thinking a little more about taxonomy and diversity (if not in those terms) and the world around them. In short, neat idea, well done. I can easily see this being a nice series too – a line of panels of ‘What’s the difference between a shark and a fish?’ or frogs vs toads, newts vs salamanders, goats vs sheep and the like.

What is also nice about this is how much that is conveyed in such a small amount of space and few words. Maximum communication but without filling the place or making people struggle through dense text to get the message across, and all the time filling in other gaps in their knowledge with little extras like the addition of skippers or the relative numbers of species. Great stuff.

Variation and selection

Well hey, another little leftover from the Carnegie I should have mentioned before.

There are of course a multitude of ways of presenting ideas in museum exhibits. This one is not only well done (showing the natural variation present in a selection of specimens of one species alongside male and female differences and by extension a little of the diversity and variation seen between species) but has a little resonance for me as it combines two other displays I have seen and commented on before. Tokyo has a nice cabinet showing the diversity seen in a single species (mentioned here, but not shown I’m afraid) and Oxford commented on the diversity of beetles with this lovely effort.

In all three cases the message is simple, but a profoundly important part of biology as a whole and the mechanics of evolution specifically. Communicating that quickly, effectively, simply but with maximum impact and interest is a real challenge and whoever came up with these various cabinets deserves much credit for having done so.

Yet more hadrosaur heads

The Musings seems to be have been on a bit of an unintentional roll for hadrosaur heads recently. There were some Lambeosaurus heads to go with Nipponosaurus but now here’s something of a flood. Steve Cohen, who kindly supplied a bunch of AMNH pterosaurs, has sent in this set of heads from the halls of the AMNH and it’s a nice example of the variety of crests and expansions seen in the group.

While some of these genera have made appearances on these pages before (like this Corythosaurus and while not shown here, don’t forget the amazing Tsintaosaurus) this is good chance to smush them all together and make them much easier to compare and contrast. A couple have also been flipped to put everything in left lateral view, though this means that the nicely labelled Saurolophus as the bottom is now covered in mirror writing.

Here then are (in order): Corythosaurus, Hypacrosaurus, Kritosaurus, Lambeosaurus, Prosaurolophus and finally Saurolophus.

Google Scholar citations

A combination of a post by Andy Farke on the metrics of PLoS ONE and a comment thread over on SV-POW has turned me to looking at the citation metrics of Google Scholar for various articles and indeed, authors. I don’t think there’s any disagreement that Scholar gives rather higher values than do set-ups like Web of Knowledge, but what is behind this? (And yes, for the record I still don’t like ranking things in general, and nor do a lot of people).

The general answer is ‘blog posts get counted’ and while some certainly do sneak in, in my experience it’s not massive. I certainly have picked up a few hits from blog posts, but not many. What I have got rather more of though is hits from less well-known journals and indeed book chapters – things that don’t always flag up on WoK indices and the like.

This to me is a much more significant issue. While there are papers that are unreviewed papers out there in some (even good) journals, and some good and bad books (and indeed grey literature) there are plenty of good papers in minor journals and book chapters. While I think it would be reasonable that some things should be excluded from such metrics (unreviewed letters and comments and replies I don’t think should count), any paper has potentially good science in it and if it’s building on your work, you should be credited with it. (Essentially this is the approach now being pushed by the Wellcome Trust – it’s not the journal the paper is in but the paper that has the merit).

In short, while GS might well be overstating things, WoK and the like and also probably understating. I looked at a few of my papers in more detail to highlight a couple of things I found.

WoK gives my paper on the soft tissue of Jeholopterus just 10 citations, but GS some 23! That’s a massive difference. But looking over the latter in detail, it’s not massively overstated. There is a duplication in there (so the same paper appears twice for some reason), and one is from a student thesis, and one citation is from a review from the Chinese Academy of Sciences journal (so not really a formal paper, but at the same time not quite irrelevant either and are certainly not blog posts or media bits). So we can certainly remove two of these, and arguably another two. That drops it down to 19, but this is still almost double the 10 citations of WoK. All the other 9 ‘extra’ citations are in published, peer-reviewed journals (well, as far as I can tell). Oddly, WoK also has once citation GS doesn’t, from the little editorial review at comes at the front of the volume in which this paper appeared, which I would hardly count as a scientific use of the work.

Similarly the paper describing Shaochilong gets 11 vs 8 with the 3 extras in GS all coming from proper papers. The paper on sauropod necks is more of a problem – fully 3 of the 5 citations assigned to it by GS are from blog posts. But the others are from Lethaia and Biological Reviews – both well-known journals with proper Impact Factors and the rest. One papers is properly published and the other is ‘in press’ (but an accepted version, formatted etc. and with a DOI and has been out online for 6 months now) yet only 1 is picked up by WoK. Either it’s slow (not great but not the end of the world) or not counting ‘in press’ papers (which seems odd, and in the electronic age, a bit of a weak excuse) or it’s simply not counting them all.

Finally I also know I’m missing some citations even on GS (or at least by their standards). The Beijing Flugsaurier meeting had extended, reviewed, abstracts published in one of the normal Chinese journals – a far from major international journal and probably little known, but a bona fide research, reviewed journal. Even so, I have picked up a couple of citations from this volume of abstracts – but not all of the ones I should get (since it’s easy enough to flick through and check) and indeed one of my pieces in there isn’t even recorded on the list of things I have written. So clearly GS is recording some of the abstracts as papers and citations but not others.

In short, GS does indeed overcount a bit. But having had a good look through my records at least, not that much and yet I know I’m still ‘owed’ a few more which would compensate at least a little for this. And moreover WoK is so massively undercounting that in terms of what my ‘true’ citation record is, I think it’s likely closer to GC than WoK. Now obviously I still don’t like these ranks in general, and this is not an especially detailed look at only my own situation which could be very unrepresentative, but overall I don’t think either is especially good and I must say I can’t find much to really recommend WoK in any particular way over GS. It’s certainly more widely used and respected, but speaking for my record it doesn’t seem to be any more accurate or representative of how my work is being used and cited and in fact, probably less so.

Orange & white

Every now and then I’ve sneaked a little commentary on colour into my posts and it’s time for another one. This time it’s on the delightful orange with white trim pattern that seem to turn up on occasion. While there are plenty of orange-red animals out there (tigers, orangs, maned wolves, foxes, coati) and at least a few of them with white parts, the ones I’ve been thinking about are the red river hog, congo buffalo and bongo. All three are fairly large herbivores (OK the hog less so, but it’s not a small animal) and all live in fairly dense forested environments in the Congo area. All three are predominantly orange with white ear tips and white ‘trim’ (white stripes for the bongo and hog, white tails for the hog and buffalo) and for the record all three have rather dark lower legs.

Some colour combinations or patterns are pretty obvious and have a clear function. Dappled coats are common in forests where they match the light pattern through the leaves. Desert animals tend to be pale and sandy colours, those in grasses tend to have stripes and so on. What I find interesting here is that you do have a set of species with relatively similar habits living in a similar environment and they have all convergently struck on a very similar coat pattern.

White ear tassels and tails are often considered signalling structures which makes sense in a dark environment. But why orange and the dark legs? It seems too much of a coincidence (but of course still could be) that they all share this coat colour pattern given the shared behaviour and environment, but I can’t think what it might be. I’ve had a chat to a few colleagues and no one seems to have any concrete ideas but it’s something that’s been buzzing in my brain for a while and features several of my favourite animals, so it’s a good excuse to put these up and muse a little on colour patterns.

Intraspecific variation

There have been a couple of posts on here before on this subject. A good long time ago now I put up a post on intraspecific variation and the implications for taxonomy, and I also had a post on variation in coat colour in deer. Fine though that was, colour is not the best example to use when talking about vertebrate palaeontology, some kind of nice osteological feature is what you really want.

And here is one – horns of the addax, taken at Marwell zoo. Horns can be notoriously screwy in captive animals and you can see whole herds of things like bongo with barely a one having the ‘normal’ horn shape for the species. While that effect is probably a bit at play here you can see variation in the curvature of the horns between the different animals, not to mention the one with a really screwy (and presumably trimmed) horn.

Plus, well, I like addax and hadn’t managed to include them in the zoo review.

@Dave_Hone on Twitter

Enter your email address to follow this blog and receive notifications of new posts by email.

Join 503 other followers