Posts Tagged 'biology'

An appeal for data on dinosaur tail data

Regular readers should be familiar with my 2012 paper on the lengths of tails in non-avian dinosaurs (those who you who missed it, for shame! can catch up with my post here). In this I looked at the general lack of complete tails in the fossil record, but also showed that tail length varies considerably in dinosaurs, and thus should not be included in length estimates or mass estimates derived from length.Collecting data for the paper I scoured a number of museum collections, went through as much of the dinosaur literature as I felt able, and also contacted numerous researchers and curators to ask for any ideas and things I might have missed or undescribed specimens hidden in basements and drawers. Many people were generous with their time and knowledge and by the end of it, I was really pleased with what I had in terms of a dataset.

Almost inevitably though, without hours of publication and my blog post on the subject, people started contacting me with new leads. Many were things I had looked at and decided were not complete, but some were things I had missed and represented additional data. Great though this was, there was not a lot I could do with even a handful of new data – the paper was done. However, inspired I did dive back into the literature and had another look and did find a few more and as you may have guessed, have now got as far as I, or rather we, can. This time out I’m collaborating with Scott Persons (who has been doing a lot of his own tails stuff) and a mathematically inclined colleague Steve Le Comber.

Scott and I have pooled our resources and have now found nearly 50 dinosaur specimens with complete tails, though we have this time out also been including specimens with ‘nearly’ complete tails. Obviously subjective, but we’re working on that.

Anyway, we’re appealing for more data. If you are aware of a dinosaur that has a truly complete (every single caudal vert, down to the last nub) tail, that’s not on the list, then do please let us know. If you know of something that’s near complete (maybe just a tip missing, or a couple in the middle or similar) do also let us know. Please be as specific as possible – “I think I saw a hadrosaur with a good tail in the AMNH” isn’t going to win you any prizes or get us anywhere, and we have at this point checked out a lot of material. On that note, all we can really offer is a mention in the acknowledgements for good leads that yield datapoints, and this may also include some limited measure of gratitude, or even a pint at the next conference where you catch us. Maybe.

Here are the lists of what we have to date.

Complete tails:

Othneilosaurus SMA 0010
Jeholosaurus IVPP V 12529
Scleidosaurus NHM R1111
Scutellosaurus MNA PI. 175
“Saichania” MPC 100/1305
Pinacosaurus PIN 614
Dyoplosaurus Arbour et al., 2009
Dryosaurus YPM 1884
Tethyshadros Dalla Vecchia, 2009
Edmontosaurus Lull and Wright, 1942
Lambeosaurus ROM 1218
Corythosaurus ROM 845
Hadrosauridae indet TMP 1998.58.01
Centrosaurus Brown, 1917
Psittacosaurus Sereno, 1987
Psittacosaurus IVPP V 120888
Coelophysis AMNH 7229
Sinocalliopteryx JMP-V-05-8-01
Gorgosaurus Currie, 2003
Gallimimus Osmólska et al., 1972
Ornithomimus TMP 1995.11.001
Caudipteryx IVPP V 12430
Nomingia Barsbold et al., 2000
Microraptor IVPP V 13352
Mei Xu and Norell, 2004
Jinfengopteryx CAGS IG 040801
Archaeopteryx Wellnhofer, 1974
Epidexipteryx IVPP V 15471
Lufengosaurus Young, 1941
Camarasaurus Gilmore, 1925
Opisthocoelicaudia Borsuk-Bialynicka, 1977
Protoceratops Fastovsky et al. 2012
Protoceratops Fastovsky et al. 2012
Leaellynasaura Herne pers comm
Chasmosaurine Mallon, 2010
Stegosaurus SMA 0092
Archaeoceratops IVPP V11115
Parksosaurus ROM 804
Anchiceratops CMN 8547
Microraptor Li et al 2012
Anchiornis IVPP
Sinusonasus Xu & Wang 2004
Spinophorosaurus Remes et al 2009
Kentrosaurus Holotype
Ornithomimid TMP 90.26.01
Tenontosaurus OMNH data

Near complete tails:

Epidendrosaurus IVPP V 12653
Sinornithoides IVPP V9612
Ceratosaurus USNM 4735
Khaan IGM 100/1127
Corythosaurus Lull & Wright, AMNH 5240
Anatosaurus Lull & Wright 8399
Anatosaurus lull & wright
Tianyuraptor Zheng et al 2009
Apatosaurus Gilmore 1936
Juravenator Chiappe & Goehlich, 2010
Sciurumimus Rauhut et al 2012
Psittacosaurus sinensis IVPP V 738
Psittacosaurus IVPP V14341.1
Psittacosaurus IVPP V14341.2
Psittacosaurus IVPP V14341.3
Psittacosaurus IVPP V14341.4
Sinocalliopteryx Ji et al 3007
Sinosauropteryx Currie & Chen 2001
?Heterodontosaurus MCZ 4188

Any other suggestions (specimens or papers), please do add them to the comments below. All help is most gratefully received.

The live fauna of Dinosaur Provincial Park

In addition to the actual fossils, I do have a decent record of seeing live animals while out in the field, and the DPP and environs of the Tyrrell were no exception. The dinosaurs are of course, awesome, but it’s nice to see some wildlife too. Mark Graham had mentioned in his guest post that I’d been snapping some of the fauna, so now seemed a good time to bring them out

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First off is the easy one, these ground squirrels infest the area around the Tyrrell and this guy was literally sat on the front steps begging for food. While I didn’t give him any, the pot belly on this one and those that were hanging around make it quite obvious that plenty of people do, though just a few yards away other locals were much more shy and sveldt.

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Just traces here, but quite cool that you have coyote and deer (presumably mule deer given their abundance) going in opposite directions, though of course who knows how far apart in time. The canid also has some nice overprinting going on such that the two feet have left what appears to be one large, but rather odd, footprint.

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And here’s a pronghorn. A male rather obviously, and something I’d long wanted to see. I didn’t realise their range was this far north, so were a complete surprise to me when we came across a small group and I’ve got some nice photos of them mooching around.

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And here are some of those mule deer. This was part of a herd of a dozen or so, though there were plenty of odd ones or pairs seen from time to time in various places both around the museum and out into the wilds. I did see white-tailed deer too, but didn’t get any great photos.

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A real prize for me, a nice big bunny. I assume this is a jackrabbit, but I don’t actually know. I really like rabbits in general and have seen desert hares a couple of times in the wilds of China, but they tend to explode out of cover and vanish over the horizon before I realise I’ve spooked one, whereas this one was kind enough to move not too fast and stop a couple of times allowing me to get decent snaps (though out of tons that are out of focus or suffering from motion blur).

IMG_2807And finally a chipmunk, one of many hanging around in the woods near Don Henderson’s house, though I was also surprised to see them out in boulder fields too. I saw traces of activity from beavers and porcupines on several trees (and a couple of roadkill of the latter) but sadly no live ones were around. I think pretty much all of these bar the chipmunk were new to me, not just in the wild, but in zoos too. Perhaps as they are considered too ‘boring’ or ‘normal’ for most collections, and if the US doesn’t bother, then they’re not too likely to end up in Europe or Asia either, so this was really a pretty good haul by my standards.

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Palaeocasting

I do have a couple of bits lined up for the Musings over the next week or two, including my traditional end-of-year roundup. The Lost Worlds has been rather more quiet of late than I’d have liked owing to massive teaching commitments. These have finally cleared up, leaving me time to err, catch up on all the work I’ve let drag owing to the teaching commitments, so blogging is still a bit behind.

On the upside, I did find time recently to record an interview with the Palaeocast guys and you can catch it all here. It’s a potted history of my research and with some thoughts about sexual selection, feeding behaviour in theropods, the great rush of Chinese fossil discoveries and sci comms material like Ask A Biologist. So in the absence of more text-based stuff, drop on over there and have a listen.

Issues on understanding evolution

A couple of things intersected over the last week or so that have had me thinking a bit more about evolution and how it’s presented. More specifically, I’ve increasingly noticed a phenomenon that seems to get little attention and might be worth a bit more consideration. In short, there do seem to be a good number of people who, for whatever reason, are really quite happy with the concept of evolution as a whole (species arise, natural selection happens, common ancestry etc.) but seem to profoundly misunderstand how and why it works.

It’s perhaps understandable that a lot of focus goes into winning over the people who don’t accept that evolution even exists, but we should not ignore those who are happy enough with the idea, but actually don’t understand it at all well. After all, they might well be vulnerable to misinformation or further misunderstandings, when in fact they should be the kind of people who would be resistant to such things. I’ve heard or come across all sorts of basic mistakes and misunderstandings like the idea that evolution is directed (or has some predetermined outcome), that mankind is all but inevitable, that evolution occurs at the individual level, that X is the exact and direct ancestor of Y and so on.

All of these things are the kinds of fallacies that creationists use to undermine evolution or promote confusion about how it really operates, yet these are also errors made by those who have no problem with the concept. While these mistakes are not ignored when it comes to public outreach in science, I do wonder if in part, we are paying too little attention to a sizable number of people who would benefit from knowing more and having a better understanding and appreciation of evolution, and likely be interested in learning more. We’re not talking about deep and complex evolutionary theory, merely some fairly basic concepts that should be easy and simple enough to explain quickly and effectively, the question is, are we doing that for the people who need it?

 

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.

Animals Inside Out

Friday night saw me being lucky enough to get into the superb new exhibit at the Natural History Museum. Featuring plastinated animals and anatomical dissections, this is an amazing looking inside both some well-known and unusual animals. Since I’m not really one for great anatomical details on the blog and the fact that there is a very good slide-show here online, I’ll stop here for any great analysis.

Suffice to say though, that if you are interested in anatomy or biology in general, then this really is a must. It does show things nor normally seen (even to those familiar with dissections and anatomical books and papers) and gives a greater appreciation and understanding of how things fit together. Even jaded experts seemed quite thrilled with some things like the ‘exploded’ elephant and the sectioned giraffe.

If there is a complaint it’s the almost complete lack of signs and explanation of things. I suspect too many people will look at things and say ‘cool’ but come away with very little increased knowledge and understanding of what they saw, even if they have got a much great appreciation and love of the beauty of nature.

Anyway, for those who can go, go. For those who can’t, well, at least there are some pictures.

Osteological correlates

I’ve now passed the 500 odd post mark (if you include all the old stuff on DinoBase) and frankly it’s getting hard to remember what I have and have not said before. While I don’t think this post is a real repeat of anything I’ve said before I’ll be surprised if I’ve not mentioned it at least in passing and may well have gone into some detail. Since I try to avoid covering ‘new’ things to do with archosaurs, and focus on the basics palaeontology and the mechanics of research on archosaurs I don’t really have the luxury of always ‘moving forwards’. As such it’s really only a matter of time before I end up completely repeating myself in a post or two (or three).

However, I’m working under the assumption that this is unlikely to be a problem. New readers will not necessarily have read my whole back catalogue (though I would ask, if not, why not? It’s all great, honest.) and regular readers won’t necessarily remember what I said two years ago (since I can’t, I doubt they can). Should this end up repetitive then consider it like revision – something rarely stays in the mind permanently after one round, so a little brush up, or re-examination of an old topic is hardly a disaster. With that in mind, onto the largely (I think) uncovered world of osteological correlates and their place in palaeontology.

Continue reading ‘Osteological correlates’

Attenborough on Wallace

attenboroughFor those who missed it at SVP, or indeed missed SVP, Sir David Attenborough FRS gave a public talk on Alfred Russel Wallace and the birds of paradise. Sir David has a particular interest in these avians so it was a real pleasure to hear him speak on the subject and to answer questions at the end of the talk – he’s a quite exceptional lecturer. For those who want to hear him, the talk was one of a series celebrating 100 years of the University of Bristol, and the whole thing is available to watch online here, so go and enjoy it.

(Image taken from the UoB site).

Taxonomy

Time for another ‘science basics‘ post and this time out I’m tackling the often complex and misunderstood field of taxonomy, quite simply the naming of things. It is quite possibly the most fundamental and important part of biology as a field and yet seems to be glossed over in the few undergraduate courses that even bother to mention it, which is both a shame and a worry. Why is it so fundamental? Well for the quite simple reason that if you do not know what species any given organism belongs to, then it becomes very hard to say anything meaningful about it. How do you protect a given species if you don’t even know what is and what is not a member of that species? Want to treat a snake bite? What species was it? Got a new drug from a rare frog, great! What frog was it? Are you working on a single species of a bunch of them in your lab that have just not been revised properly? You can see the issues – there is a basic one of clarity (all scientists want to be able to communicate clearly about what they are dealing with) but the consequences of making sure that is the case go far beyond that and touch every branch of biology.

Continue reading ‘Taxonomy’

Systematics vs Taxonomy

There are a wealth of posts on their way on syatematics and especially taxonomy on the Musings (just as soon as I find the time to get them up and clear out all the backlog) and this seemed like a good opportunity to drop in a very quick post about the two and what they actually mean and relate to. It seems to me that often in the literature researchers refer to ‘systematics and taxonomy’ as almost a single entity and while they are certainly incredibly closely related, they are separate fields and I suspect the odd reader on here is not aware of the difference.

To put it as simply as possible, taxonomy is the science of naming organisms, and systematics the science of working out their relationships to each other. (And cladistics which is oft mentioned here is the method primarily used in systematics). So there you go, one half puts names on the things and makes sure they are different, the other tries to put them in order.

It should therefore be quite obvious to see how they interlink, and not surprisingly a great many researchers do both (though each side has it’s specialists). Of course a taxonomist could quite happily go though the whole of life (as in organisms, rather than that of the researcher, though I guess this is also true) and name every single species without ever actually worrying about who was related to what, but systematics would really struggle without definitions of species to tell them what they were actually working on.


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