The Amber Ant of Mysteries (Taxonomy Fail, updated)

Well. Raising a holy hullabaloo on the internet pays dividends. Vincent Perrichot, one of the authors on the contested PNAS paper, has sent along another aspect of the mystery fossil:

Having trouble?  I’ve arranged a Formica specimen to model the pose:

In the comments below, Vincent provides his perspective:

Well, sounds that the ant nature of our fossil is getting much controversy here! I understand that the photograph provided in our paper is not very clear, so I’d like to clarify things and try to convince everyone. First of all the photograph you are commenting on was published here and by Wired Science in reverse position. It should be viewed at 180º to give at least a better idea.

I’ve sent a picture to Alex, which might help if he wants to post it on his blog. Now, the fossil is preserved enrolled and contrary to extant specimens, it is impossible to unroll, which makes its study much more difficult. Plus, anyone having tried to image some amber fossil one day knows that it is very challenging to obtain a good, well-focused, picture. So here I totally agree with one of my co-author Matthias Svojtka that it is very speculative to reject a determination based on a single photograph. Even with the specimen under your steromicroscope you will need time to figure out how this specimen is preserved and what it actually is.

I’ve been examining and working on thousands of amber arthropods in the last 11 years and my first thought when I discovered this one was: “what the hell is this?”. It is only after a careful examination that I was able to see by transparency the antennae, a part of the mandible, and the petiole. So yes, it’s actually an ant!! No wing, no elytra… Sorry that the photo is not speaking better by itself. When it’s viewed on the correct position, the head is on the top with the right eye small, darkened. The vertically oval structure on the bottom right is the gaster with apex pointing upward, touching and overlying the mouthparts. The petiole appears cylindrical between the gaster and the legs that are mostly folded over the mesosoma and run on the left side of the pic.

Our PNAS article is an overview paper of the amber deposit, thus it was not the purpose to describe the fossils in detail (will come elsewhere) and the space is too limited to justify our determination (otherwise I would have had to do so for each of the 30 arthropods). There are 12-segmented geniculate antennae with a very long scape, mandibles triangular to falcate, with a multi-toothed masticatory margin, a metapleural gland opening, a well-defined (although unusual) petiole, forelegs with a calcar spur… For now I am unable to tell what subfamily it belongs to (except it is not a sphecomyrmine) because too many characters are hidden by the legs and gaster, as preserved. This is why I am currently making a 3D reconstruction using high-resolution X-ray synchrotron imaging. The reconstruction of the specimen has been completed only very recently, which explains why such image was not provided in our paper but only the stereomicroscopic photo. The detailed study will be published elsewhere ASAP and you will understand that I cannot provide this reconstructed image here. Still, the diagnostic features are hidden on this view, so I am now
working on a virtual dissection (e.g., reconstruction of the head alone, of the alitrunk alone. etc…) to access all characters. This is a long work on which I and two colleagues from the synchrotron are working for several months, so be patient and you’ll see a true ant! 🙂

Ok, I see it now. Anyone else?