Tuesday, March 23, 2010

Welcome, Seitaad!

ResearchBlogging.orgI am pleased to announce the publication in PLoS ONE of Seitaad ruessi, a new sauropodomorph dinosaur from the Lower Jurassic Navajo Sandstone of southern Utah. Sauropodomorphs are (mostly) herbivorous dinosaurs that lived from the Triassic all the way until the end of the Cretaceous. Although most people know the giant quadrupedal sauropodomorphs like Brachiosaurus and Apatosaurus ("Brontosaurus"), many of the early sauropodomorphs were bipeds smaller than humans. Seitaad fits in the latter category. For reasons explained below, this is a really cool little animal and a truly rare find.

I have a personal connection to this fossil on two levels. First, the authors of the article, Joe Sertich (at left, pictured with the specimen) and Mark Loewen, are good friends and colleagues of mine. So, I was really excited when they told me that they wanted to submit their manuscript to PLoS ONE (full disclosure: I am an editor there; for obvious reasons, someone else handled their submission). I'll confess that I did little to discourage them. Congratulations, Joe and Mark, on a great paper!

Second, I was one of the lucky people who got to carry the block containing Seitaad from its original resting place, way back in 2005. This thing was heavy! It took a crew of 12 people (8 carrying at a time, and 4 resting for rotation back in) to haul it out. After several years of preparation and study, the new animal is finally named!

I queried one of Seitaad's authors, Mark Loewen, for his thoughts on the find (Joe Sertich is out of the country, so wasn't able to contribute). Here's what Mark had to say.

Briefly, what is the most significant aspect of the new find reported in PLoS ONE?
Seitaad is the first dinosaur discovered from the Navajo Sandstone of Utah and one of the oldest known dinosaurs from Utah. The Navajo Sandstone is a dominant rock unit exposed all over the west. . .and is hiked by thousands of people every year. Fossils in this formation are extremely rare. Prior to its discovery our entire view of the fauna of the Navajo consisted of a partial tritylodont, three chunks of crocodylomorphs, parts of a small theropod, [and] two fragmentary sauropodomorphs. Seitaad is the most complete fossil from the Navajo and through comparisons with taxa across the world gives a much better picture of the largest herbivore in the sand seas of western North America at the same time that large true sauropods had evolved in other parts of the world.

How did you choose the name that you did?
Seitaad was found by Joe Pachak [pictured at left, with the specimen], a local archaeologist and artist from Bluff, Utah while hiking Comb Ridge to document petroglyphs and pictographs. He reported the specimen to the BLM, who alerted us at the Utah Museum of Natural History. We went down to check it out, and immediately started to excavate the specimen. With a crew of 12, including Andy Farke, we hauled out the jackets and began preparing them at the UMNH.

The area around Comb Ridge is covered with numerous archaeological sites and cliff dwellings from the ancestral Puebloan (Anasazi) culture. In fact, Seitaad was located directly below a dwelling called the Eagles Nest. The people who lived in the area at the time would have recognized the white bones of Seitaad eroding out of the cliff if they had seen them. A nearby cliff dwelling has a slab with a dinosaur track incorporated into the window sill. I’m confident that the person who [put] this stone into the window had awareness and appreciation for the fossils preserved in the Four Corners region.

"Seitaad" is derived from Seit’aad, a sand-desert monster from the Navajo (DinĂ©) creation legend that swallowed its victims in sand dunes. The skeleton of Seitaad had been "swallowed" by a fossilized sand dune. The [species name] "ruessi" is derived from Everett Ruess, the famous young artist, poet, historian, and explorer who disappeared in southern Utah in 1934. Ruess is celebrated for his love of the region, its people, and for his free-spirited and adventurous lifestyle. Everett Ruess loved the red rock country of Utah and spent a lot of time exploring the Navajo Formation, so we thought it was fitting to honor him in the taxonomic name.

Why did you choose PLoS ONE as a venue for your research?
We chose to submit to PLoS ONE for several reasons. The open-access format of PLoS ONE and rapid turn-around were major factors. Another factor was the opportunity to reach a broader audience and the rising impact and recognition of PLoS ONE within the paleontology academic community. Another consideration was the lack of limits to figures and unrestricted use of color. The unlimited use of color became a concern during the preparation of our manuscript, when it became clear that black and white photos were not revealing proper contrast between white bones of Seitaad and the pink sandstone of the Navajo Formation.

Is there anything about this find that didn't make it into the scientific paper?
When we first saw photos of the skeleton in the cliff wall we thought it was a pterosaur. The v-shaped ischia looked like dentaries. It wasn’t until UMNH preparators got into the block that we changed our identification to theropod. Then when we got to the hand, we know from the thumb claw that it was a sauropodomorph.

Mark Loewen with the skeleton of Seitaad ruessi

Check out the original article for free at the PLoS ONE website. As always, you can leave comments or rate the article there.

Sertich, J.J.W., & Loewen, M. (2010). A New Basal Sauropodomorph Dinosaur from the Lower Jurassic Navajo Sandstone of Southern Utah PLoS ONE, 5 (3) DOI: 10.1371/journal.pone.0009789

Other Readings
The paper is all over the news and blogosphere; check out Dave Hone and ReBecca Hunt's blogs for more.

Image Credits: Mark Loewen and Utah Museum of Natural History


Anonymous said...

Sigh. Yet another pterosaur lost to science by actually being a sauropodomorph. Third time this week...

Less frivolously, this looks like a cracking little specimen. Well done all round.

iPreparator said...

I'd like to know where I can meet that sexy silhouette being used for scale!

iPreparator said...

File also in the less frivolous dept: I appreciate in this paper the brief description of collection and prep methods, a point which I have begun harping on quite a bit of late. It needs to be reproducible to be science, and that means you have to bring ALL of your methods on the bus. Paleontology doesn't start at the photo stand.