You're Doing It Wrong #1: Archaeopteryx

Above: What has mankind done to deserve this?

Sorry for the lack of posts lately. Just moved countries again (itchy feet need scratching) and settling into a new full-time teaching job. Also, any free time I've had over the last week or so has been spent on drawing, rather than blogging, dinosaurs. Rest assured those two will overlap. I've been meaning for a while to put together a guide to the wing anatomy of Mesozoic birds which will probably first appear on DinoGoss. This is for the good of the world, since it's insanely rare even in this day and age of the exquisitely preserved Jehol biota to find amateur (or sometimes professional!) paleoartists getting prehistoric birds right. I think they suffer from 'background syndrome'--birds, like pterosaurs, usually appear in the background in paintings starring more glamorous megafauna. Thus artists don't pay them much attention, thus they're prone to getting basic details wrong, which everyone else copies.

Actually, maybe that's the more important point. The copying, that is. Google Image Search syndrome is plaguing paleoart. Do a search for any prehistoric bird/basal aviremigian, and the first page of hits will all be inaccurate drawings. People looking for references but not wanting to do actual research will copy those mistakes, and they keep getting perpetuated, which keeps the same inaccuracies on the top Google hits, forever. Depressing, no? For example, on one forum, a young artist recently showed off a really well made, life-sized sculpture of Caudipteryx. Unfortunately, his research was obviously done by browsing Google, and he used this terribly inaccurate illustration as the basis for the model.

Thus, the reason for this new series, "You're Doing It Wrong." That and it's something I can write up quickly using only Google research. I'll start with one of the worst dinobird Google offenders, and the one for which there is the absolute least amount of wiggle room for excuses: Archaeopteryx.

1. How Bad Is It?

Google Image search "Archaeopteryx," and of the first 18 hits, 5 are photos of specimens, 2 are diagrams with labelled anatomy, and the rest are artist's impressions. Of those 11 illustrations, 0 are anatomically accurate. Count 'em: ZERO! That's pretty bad you guys.

2. What's the problem?

Some are better than others. Three of the images, one by pro Todd Marshall, get minor details wrong. In the Marshall one, all the proportions looks correct, it's just that the primary feathers seem to be coming off the wrist rather than the finger. This is a common mistake, but at least an entire, ill-proportioned, scaly hand isn't poking anteriorly from a feathered wing where the feathers apparently anchor to nothing, like some of the other results. The second "ok" one has the same problem, plus the presence of tertial feathers. If you're posing your Archie with an outstretched humerus, there should be a gap in between the wing and the body. This is even true of most modern birds! Yet it's probably the number one common mistake in drawing Mesozoic avialans. The third, by T. Mike Keesey, has the arms lifted too high above the body, an anatomical impossibility.

This model, from Wikipedia, is pretty good minus the naked legs. We know now that Archie actually had quite long feathers on the legs down at least to the ankle. (UPDATE: I had originally included "blue iridescent color on the head" as an error here. However, recent research suggests that the apparent filamentous nature of the contour feathers in many fossils is probably a taphonomic artifact, so it's entirely possible Archie had pennaceous body and head feathers, allowing iridescence and other structural colors).

Some suffer from more than minor inaccuracies. Images like those above should not be allowed in the 21st Century. Reversed hallux, hands decoupled from the wing, scaly head and neck, etc. Then there's this one, that even says Archaeopteryx had a horny beak... wtf?

3. What's the excuse?

There isn't one. Entire papers have been published explaining the anatomy and plumage of Archaeopteryx in great detail. It's one of the best-studied, if not THE best-studied, Mesozoic bird, period. Aside from color, we know just about everything there is to know about this creatures appearance. Not to mention, one of the top Google hits is a fairly acceptable diagram showing how the feathers attached and the proportions of all the bones. Of course, this is counter-acted by a completely crap diagram further down the page that barely looks like a theropod, let alone Archaeopteryx. Of course, this is on a much more popular web page, and ostensibly an "educational" one, Enchanted Learning.

4. What's to be done?

Research, I should hope! Get a good photo of the fossil, or even better, a copy of Christiansen & Bonde's 2004 paper "Body plumage in Archaeopteryx: a review, and new evidence from the Berlin specimen." Stop copying the images done in the past, even if by notable artists--they're probably wrong in at least some minor respect. And study the drawings done by Reichel in the 1940s, which are still extremely accurate, especially in terms of plumage arrangement.

Till next time gosshounds!

On the structure of hind wings

Above: Anchiornis model from NatGeo. Something is wrong with those foot feathers...

With all the recent hubbub over Anchiornis and its coloration, have come several pretty cool life reconstructions showing the animal as it would, supposedly, look in life. I posted one in my blog yesterday on the topic, and NatGeo has a cool 3D model on their site, here (and figured above).

One thing I've noticed about all these images is the very... standard rendering of the infamous hind wings (shared with Microraptor and Pedopenna). Much debate has surrounded these appendages, mainly relating to their ability to glide. A whole Nova special was made showing different attempts to reconstruct gliding posture, from biplane-like, to sprawled-out-sideways, to rear-swept canopy. And especially in that special, the same thing bugged me about the hind wings:

Every configuration required the primary foot feathers to emerge at a different angle from different parts of the limb!

It shouldn't be so hard to figure out how these feathers attached, which would help us suss out their potential uses. First of all, the reconstruction of Anchiornis above, and by extension reconstructions of Microraptor with the legs sprawled out, make little anatomical sense to me. Maybe I'm mistaken, but I think we should look to the example of how front wings are put together to inform on this, as developmentally the two are almost certainly related.

Above: Incorrect, pronated-handed Velociraptor skeletal by Frederik Spindler, licensed. Just where are those primary feathers supposed to be attaching? To the underside of the fingers?

Back in the days of pronated theropod hands, many similary ridiculous renderings of feathered theropods were made, many by me. Of course, we all know how wings 'look' when folded - primary and secondary feathers swept back along the side of the body. The problem is that, if the hand is incorrectly shown as pronated, this arrangement makes no sense. On a pronated hand, the feathers emerge laterally from the edge of the finger and hand, and from the lateral side of the ulna. Only when the hand is not pronated does the proper wing configuration emerge. If real wing anatomy were taken into consideration, artists of bunny-wrist theropods would show the primary feathers sicking out to the side of the animal, not flush with the body, when the arms are folded. Otherwise, the feathers would be attached to the palm of the hand, which is ridiculous.

Above: Probably incorrect rendering of Microraptor. Just how is this animal supposed to sit down?

So why isn't this also true of the foot? My guess: it is. For all intents and purposes, the foot is the same configuration as the hand, only it really is pronated. The toes and metatarsals are equivalent to the fingers and metacarpals. I'll put this to the experts out there, because it's something I've never seen addressed and makes no sense to me. If the hind wing feathers projected posteriorly from the metatarsals, how are these animals supposed to have sat, or brooded their eggs? We have several fossil examples of theropods sitting, sleeping, or brooding, all with metatarsals fully in contact with the ground. If there were very large, rigid feathers pointing straight down from the foot, that would be impossible. Furthermore, developmentally, it seems we would expect the legs to mirror the arms, with primary leg feathers articulating from the top of pedal digit 2 and metacarpal 2. Therefore, sticking straight out to the side when standing.

Above: An animal capable of sitting, with sticky-out hind wings. AMNH.

Now, maybe I missed something so please correct me if any of my reasoning is wrong. But in short, I believe the biplane or semi-biplane model is the only one anatomically feasible, barring some novel adaptation like feathers with a hinge at their base to allow them to deploy outward like an X-Wing from Star Wars. The pedal primaries have to have pointed out to the side, while the tibial primaries of the lower leg would still point backward, as in the model above. So all those recons purporting to show Anchiornis as it really was miss a pretty important point. Not to mention the naked, beak-like snout, doesn't anybody look at fossils anymore? ;)

Above: This pigeon with sticky-out, biplane configured foot feathers is apparently able to sit down.

Another note on this--maybe my whole reasoning about comparing the front to hind wings is off. Can't we then compare to modern hind winged animals? Like the one pictured above? Those foot feathers do not point backward and, as you can see, the animal is therefore able to sit. Imagine those feathers configured like the Anchiornis model at the top of this post. It just doesn't work.

In other news... Anchiornis now in full color!

Above: Left - so close, yet so far away. Right: The actual colors of a dinosaur.

Oh man, I was SO CLOSE! And I've been planning a new digipainting of this guy too, but was hesitant to do so figuring the color would be worked out in a few months. You can all thank me for summoning this study with mind bullets. Thanks to Ed Young pointing this out on his blog!

Li et al. 2010. Plumage Color Patterns of an Extinct Dinosaur. Science http://dx.doi.org/10.1126/science.1186290

P.S. How flipping beautiful is this new specimen? Go to hell Berlin Archaeopteryx specimen ;)

Above: Awesomeness.

Banji the Hunted

Above: Possible extents of oviraptorid beaks, from Jansen's thesis.

Recently, some of my adventures on Wikipedia have addressed the question of oviraptorid beaks. Now, contain yourselves, I know this sounds a little too exciting. But it's really a very rarely addressed topic. It's obvious that oviraptorids had beaks of some kind, with their strong, toothless, pointy jaws that don't quite close right when unsheathed by rhamphotheca (the keratinous covering that forms the beak). But just how these beaks looked and to what extent they covered the jaws hasn't been studied in a lot of detail.

I asked about this a few times back on the old version of dinoforum, and some commentors there (especially oviraptorer Jaime Headden) were very helpful in pulling educated guesses based on modern analogues. Jaime's conclusion, IIRC, was that most oviraptorids have been constructed with beaks that are too large or, more specifically, cover too much of the skull and jaws. You can see the difference in two versions of my own ovi profile drawings, old one here with extensive beaks, new one with corrected beak after Headden here. Note also the more subtle difference--the beaks on the newer version meet flush, without the upper beak overlapping the other (what use would that be?) and the beak does not incorporate the nostril, which is the exception, not the rule in modern beaked animals like birds and turtles.

The first real scientific work on this topic has not yet hit the official literature, but an unpublished phD thesis by Stig Jansen addresses this topic. Jansen also has a similar unpublished paper floating around for ornithomimid beaks, I'm sure you're Google-fu will turn it up.

Jansen's thesis comes to essentially the same conclusions as Headden did, and presents two potential extremes for the extent of oviraptorid beaks, illustrated by him above. Interestingly, one of the options has a keratin-less crest. Traditionally, crested oviraptorids or those with tall, pronounced skulls have been restored with horny, cassowary-like casques, though there was never any direct evidence for this, and they could just as well have been covered in skin or feathers.

Above: Skull reconstruction of Banji, note the striations on the crest. Fig. 2 from Xu & Han 2010.

Well, most of them, but maybe not a newly described genus of oviraptorid (named Banji long, or "dragon with striped crest"... this is, incidentally, another case of bad grammar in a binomial. The specific name is supposed to be an adjective, not a noun, which makes for very awkward translations like Mei long, or "dragon, comma, soundly sleeping". Also, it sounds like Benji.). Anyway, Banji reserves some unique vertical striations on its crest. The implications of this feature aren't discussed in the paper, but the first thing that jumps to my mind is that these may form the bases of more pronounced striations in an overlying keratinous crest. As Jansen shows, underlying bony features of a bak often subtly reflect larger features of the keratin, like the keratinous pseudo-teeth on the beaks of some oviraptorids. A future paper will describe Banji and its implications in more detail, so we'll see if this ends up supported by actual study of the fossils, but right now it's a very interesting possibility that may argue for the more extensive beak suggested by Jansen's thesis.

Haplocheirus, the (or one of the?) Jurassic alvarezsaur(s)

Above: Illustration of Haplocheirus, from Stone 2010 (intro article published in Science)

Those coelurosaur ghost lineages just keep getting filled in lately. Today sees the publication of Haplocheirus sollers, the first Jurassic alverezsaur. Unlike its later brethren, this doesn't look very alvarezsaurian at first glance, more like you're typical generic coelurosaur. As Tom Holtz said o the DML, this is the first alvarezsaur that "looks normal"!

However, telltale signs (such as downward-flared basipterygoid processes on the skull) and a phylogenetic analysis shows that this is the earliest and most primitive member of the group. It comes from the Late Jurassic of China, and falls out as a basal maniraptoran, which jibes with the placement of alvarezsaurs in many recent studies, not avialan or ornithomimosaur as previously suspected by some. Interestingly, the teeth are heterodont, which seems to me to give weight to the reent hypothesis that all maniraptorans are ancestrally omnivorous. It's also the largest nkown alvarezsaurid known from good material, indicating that these guys may have started out fairly big and later shrunk to the diminutive sizes seen in the likes of Parvicursor.

But, is this really the earliest alvarezsaur on the radar? Some goss fans may have heard of a supposed alvarezsaur from the Tiaojishan Formation, preserved with feathers, mentioned at last year's SVP. That ain't this, though it would be from roughly the same time period (about 60 Ma ago). Depending on how similar the two species are, we might be looking at a ghost lineage that goes even further back than before, rther than being clipped to the mid-Jurassic. Time will tell.

The White Stripes

Back in August, I posted about a study by Vinther and colleagues looking at fossil bird feathers in an attempt to not only determine color patterns in life, but the actual colors constituting those patterns. That study looked only at Cenozoic birds, but tantalizingly, Vinther and co. promised follow-ups looking at Mesozoic birds and other feathered or proto-feathered dinosaurs.

Well, somebody has beat them to it (though, interestingly, Vinther has responded with skepticism to this newest study which has beat him to the punch though appears to use similar methods, as reported by Ed Young). Specifically, Zhang and colleagues have an online-first paper out in Nature today reporting the presence of melanosomes (pigmentation-bearing cell bits) for the first time in protofeathers. The team looked at Sinosauropteryx, Sinornithosaurus and Confuciusornis, and found pigment in all of them.

This is interesting for a few reasons, not the least of which that children's books can now officially limit their audiences imaginations by saying "no, little Billy, dinosaurs weren't whatever color you can dream of, this one here for example was black with shades of red and white patches thrown in." Firstly, this whole color-patterns-in-dinos thing was (as far as I know) first officially brought up by Nick Longrich at SVP 2002. Longrich pointed out that the thing everybody noticed about Sinosauropteryx (the stripey tail) was not an artifact of preservation, as the describers suggested, but reflected color, in the same way that prehistoric insects and fish fossils can show patterns. Based on Longrich's conclusions, I did the painting of Sinosauropteryx shown above, and this has proven largely correct (I lightened the color a bit to seem lighter browning orange, but the original was pretty close if I may say so!).

Unfortunately, being a Nature publication, this announcement comes with high prestige and itty bitty page count. The authors here promise more detailed follow-ups with more specific color patterns, and presumably Vinther et al. are also still working on their studies. Vinther's objection, which I mentioned above, is that as they had pointed out, really deciphering fossil animal colors requires a thorough understanding of how different pigment structures create color in modern birds, which is barely understood. So new discoveries with modern animals could overturn some or all of this. But, for now, all good paleoartists will reconstruct Sinosauropteryx as red-brown with a striped tail, and if Longrich was right about the rest, a bit of counter-shading.

Interestingly, the Sinosaur the new study uses is an undescribed specimen. In some news reports like this one, it is stated that Sinosauropteryx had only a feather fringe along the back, implying a partly scaly body. Now, other specimens have shown evidence of feathers on at least the lateral torso, but could this new one show evidence of a more Juravenator-type scalation on the legs and tail base (as I also restored above)? We'll see...

NY Daily News Staff Writers Are Dumb As Bricks

Above: Maybe venomous, but NOT a spitter!

Check out this short piece "attempting" to condense the recent story on potentially venomous sinornithosaurs. The piece was written by New York Daily News staff writer Ethan Sacks, who does not understand one word of the subject he's covering.

The headline:
"Venomous velociraptor: Scientists discover sinornithosaurus dinosaur spit poison at prey"

*HEADDESK*

I can guarantee you with 100% certainty no scientist or press release even remotely said anything like this.

What they probably told him/what he probably read on other news sites: "The dinosaur Sinornithosaurus, a relative of Velociraptor, was venomous, like the spitting dinosaurs in Jurassic Park."

What Sacks heard: "Velociraptor's relatives were venom-spitting dinosaurs, like in Jurassic Park!"

Way to make the world a dumber place, Ethan Sacks.