Tuesday, May 19, 2009

Four Wings Bad, Two Wings Good?

While helping to review a painting of Velociraptor posted to Gondolend, the artist brought up an outdated drawing of Sinornithosaurus she'd found among the top hits on Google, showing generally poor drawing skills and a likely inaccurate frond-tail of feather extending all the way to the hip (dromaeosaurs all seem to have had only a spray of vaned feathers at the tip of the tail, the rest being covered in down). This drawing is one of mine. As I've been updating my web site, I figured Sinornithosaurus should go to the top of the list for things to take a second stab at illustrating.

But how? In his book Dinosaurs of the Air, Greg Paul gave his sinornithosaurs something no fossils of them preserve--Microraptor-like wings on the back legs. It's a close relative of Microraptor, sure, but why do this with no evidence? In the travelling Feathered Dinosaurs exhibit I was lucky enough to see at the AMNH, the Liaoning diorama also contained a sinornithosaur with small, microraptorian hind wings. I checked the fossils again. Was I missing something? It seemed like a consensus was emerging with no published evidence. Sounds like some juicy behind the scenes goss was at work here.

It was. I present to you an unpublished specimen (NGMC 00-12-A, from Ji's thesis) of Sinornithosaurus (EDIT: Or is it a large, old Microraptor? See Mickey Mortimer's comments below) with what looks to be small wings on the hind legs.
Not only that, but as predicted by GSP and the AMNH model, it also appears to have full wings with primary (not just secondary as suggested by the preservation of the "Dave" specimen) wing feathers.

But... is it real? A few posters to DinoForum have admitted tentative wariness about even the hind-wing sporting Microraptor. After all, portions of the published Micro specimens are known to have been, ah, "enhanced" to make them more appealing to fossil collectors on the secondary fossil market (which is like half the Chinese economy and is only illegal in name). Sure, many specimens of Microraptor have been found with hind wings, but only two have been published on, and all came from private collectors. Specimens dug up by pros have lacked this feature, but are also more poorly preserved.

In the photo above, you can see that the feathered portion of the leg is on a separate piece of rock from the rest. Granted, specimens like this, at this size, are generally pretty fragmented, but it also gives fakers leeway to swap pieces in and out in order to make the piece more attractive. This practice isn't necessarily malicious, the enhancers just want to create a more artistic piece with no concern for science. Nor is it limited to China (remember Irritator? It got that name for a reason). Still, it's very prevalent there, to the point where many "museums" (mostly private collections that admit the public like the old Cabinets of Curiosity) contain mostly faked fossils. Professional museums in China, like the IVPP, are mainly clean from what I've heard. The pros are aware of this problem and I'd like to think most specimens that hit press are properly vetted, especially in the aftermath of Archaeoraptor. But when it comes to unpublished specimens, all bets are off, so be careful out there, paleoartists!

Long story short, I'll be re-illustrating Sinornithosaurus, but the hind wings will go in a separate layer, just in case...

[Top image: Very old, outdated Sinornithosaurus drawing by yours truly. All rights reserved.]
[second image from top: Sinornithosaurus by FunkMonk, lisenced.]


  1. hey just found your site. it is pretty awesome.

    i love your bio, i too fall more into that dino-groupie category then pretend researcher.

    as for your drawings i don't think it was that bad (some of them on wiki are much worse). you should check out the new online palaeo art community at ART Evolved. They are looking for more dino inclined people to participate in their online galleries.

    anyways can't wait to see more posts!

  2. That unpublished specimen is probably a Microraptor instead. As I write on my website-

    "Ji (2002) described a dromaeosaurid (NGMC 00-12-A) found in 2000 as Sinornithosaurus sp.. This was based on several characters, which are all found in other microraptorians. The unserrated premaxillary teeth, posteriorly bifurcated dentary, prominent obturator process and subarctometatarsalian metatarsus are also present in Microraptor, the U shaped furcula is present in all microraptorians, while the extremely short manual phalanx III-2 relative to III-1 is even more similar to Microraptor than Sinornithosaurus. The ischium is more similar to Microraptor than Sinornithosaurus in being slender shafted with a more proximally placed distodorsal process, and the maxillary teeth are more like Microraptor in being mesially unserrated. NGMC 00-12-A seems to lack a pronounced biceps tubercle, but has a short first manual digit, bent pubis and curved tibiotarsus. Unlike Microraptor gui and the holotype and paratype of Cryptovolans, NGMC 00-12-A lacks a fused sternum (though it is the largest well described specimen). In a few proportions, NGMC 00-12-A is more similar to M. gui than Cryptovolans pauli, including the small sternum (53% of femoral length vs. 49% in gui and 60% in pauli), though in others it is more similar to C. pauli. The latter include the (originally supposed to be apomorphic for Cryptovolans) ratio between manual phalanx III-1 and III-3 (139% vs. 142% in pauli and 90% in gui). NGMC 00-12-A is more similar to the CAGS specimens than M. gui in its ulnohumeral ratio (89%) and manual phalanx III-1 compared to III-3, but more similar to M. gui in its short manual phalanx I-1 compared to metacarpal I (208%), and short manual phalanx II-2 compared to II-1 (101%). There are a few differences from smaller Microraptor specimens- more slender dentary, posterior dentary teeth serrated mesially, and taller posterior dorsal neural spines (last dorsal neural spine 72% taller than centrum compared to 63% in CAGS 20-8-001), longer pubofemoral ratio (86% vs. 71-77%), and shorter pedal phalanx III-2 vs. III-1 (59% vs. 78-83%). These are possibly due to age."

  3. Interesting, thanks Mickey. So this specimen has been published then? Is that paper available in English?

  4. Well, the paper is Ji's thesis. And no, it's in Chinese.

    Ji, 2002. New data of Early Cretaceous dromaeosaurs from Western Liaoning with comments on the origin of feathers. Unpublished Thesis. 94 pp.

  5. Which figure in Dinosaurs of the Air are you referring to? Sinornithosaurus is restored in figure 6.1 (page 118) as a "quadrupedal arborealist" without wings except for a shallow fringle along the forelimbs. Remember, this book came out way back in 2002!