Friday, May 21, 2010

A Phylogenetic Inferrence Too Far?


I tip my hat once again to the incomparible Lukas Panzarin, who I think is the most talented paleo-artist working today. I don't particularly like the fact that he's been commissioned to basically make up McDonald et al.'s new duckbill, Jeyawati, from the new issue of JVP. Look at the known bones. Look at all the unknown bones. I feel like we've got another Masiakasaurus here. Phylogenetic inferrence is great, but it's being taken to an unfortunate extreme here. This reconstruction is just begging to be falsified.

However, I must once again stress that I LOVE Lukas' work.

11 comments:

Dinogirl said...

A very cool new species! But what does "Jeyawati" mean exactly??? Hasn't the same man named another dinosaur "Glishades" a week ago? I didn't understand that name either..."Hades" has something to do with "Hell" (Hell Creek?), I guess, but I don't recognize the "glis" part at all! On some German site they said it was Latin for "edible dormouse" but that can't be the explanation, or can it???

nick gardner said...

The authors of the papers on Jeyawati and Glishades are not the same people at all. A quick search on Google could have cleared that up, but see the end of my comments as well.

Glishades "concealed in mud" (Latin glis for Mud, Greek hades for Unseen), in reference to the material being found in sedimentary strata and also in reference to referring to the world beneath the surface where fossils are found(1).

Jeyawati is from the Zuni words for "grinding mouth" (Zuni jeya-/u for grind, awati for mouth) (2).

Now, onto the actual post. What exactly is wrong with how they restored the missing elements, Zach? The missing elements were restored after Protohadros and Eolambia, two related North American hadrosauroids, and the missing elements are restored extremely conservatively.

The only way you're going to falsify the reconstruction is to find more material, which I don't think anyone would complain about, Zach.

I don't think what Lukas has done here is any worse than another paleo-artist who's sketched in rough lines for missing elements...

1) Prieto-Márquez, A. 2010. Glishades ericksoni, a new hadrosauroid (Dinosauria: Ornithopoda) from the Late Cretaceous of North America. ZooTaxa 2452: 1-17. Link1 Link2

2)McDonald et al. (2010). A new basal hadrosauroid (Dinosauria: Ornithopoda) from the Turonian of New Mexico. JVP 30(3): 799-812. Link3

Mike Keesey said...

Isn't every reconstruction begging to be falsified?

Brad said...

How far off can it be? I challenge you to draw a Jeyawati skull that looks as little like that one as possible, within the limits of the known morphology. :)

lantaro said...

It looks like a sock puppet!

qilong said...

I think Zach is worried that, with such an incomplete skull, the restoration by Panzarin was "wasted" on something so incomplete, instead of turning this technique onto more complete material, especially where the inferrence of denticulated rhamphotheca might be more viable.

Zachary said...

Yes, what Quilong said.

Trish said...

Those are a lot of assumptions being made with, what, five bones? The art is lovely, and probably a decent guess, but for all we know, the animal had a massive underbite and a unicorn horn. Or five unicorn horns...

So, what's all this about DireStraitsCrazyTeethasaurus? XD

Zachary said...

Masiakasaurus is a relatively small noasaurid abelisaur from Madagascar. It's skeleton is well represented, as if the dentary, which has, as you say, crazy teeth. The maxillas are known, but the rest of the skull is unknown. So we don't know how the premaxillary bones "matched up" with the anterior end of the dentary. And it might've had crests or horns or rugosities like every other abelisaur.

But paleo-artists continue to draw the thing with a fairly standard "theropod" head. It bothers me.

Anonymous said...

"But paleo-artists continue to draw the thing with a fairly standard "theropod" head. It bothers me."

Not everyone does. Luis Rey did a particularly nice drawing of a Masakiasaurus with a freaky upper jaw that looked like spinosaurid meets Rhamphorhyncus.

Anyway, you probably know this already, but I wanted you to know that it seems that ceratopsian book that you've been waiting for, is supposed to come out early! As in next week/month or something! Apparently the reason they delayed it was because they were fitting many of the newly discovered ceratopsian taxa (read: Medusaceratops, Coahuilaceratops) into the book.

TriPARROTops said...

While we're on the subject of horned dinos, someone tell me why so many depictions of Triceratops in popular culture give it such a small face and huge frill/brow horns? This must be a hard dinosaur for most people to draw, because they cannot seem to get the head proportions correct. The Jurassic Park movies, the Dino Crisis videogames, and even google image results repeat this mistake over and over. Examples:
http://animals.nationalgeographic.com/animals/printable/triceratops-horridus.html
http://www.fossilsasart.com/desc_image/triceratops.jpg