Please welcome Mirarce eatoni
November 13, 2018
Skeletal reconstruction of Mirarce by Scott Hartman (Atterholt et al. 2018: fig. 19). Recovered bones in white, missing bones in gray. The humerus is 95.9mm long.
Today sees the publication of the monster enantiornithine Mirarce eatoni (“Eaton’s wonderful winged messenger”) from the Kaiparowits Formation of Utah, by Jessie Atterholt, Howard Hutchinson, and Jingmai O’Connor. Not my critter, not my story, but it is SV-POW!-adjacent. (Just here for the paper? Here’s the link.)
Xiphoid process of sternum of Mirarce (Atterholt et al. 2018: fig. 5). Scale bar = 1cm.
As of this past summer, I knew that Jessie had a prehistoric monster coming out soon, and I knew that Brian Engh liked bringing prehistoric monsters to life, and I suspected that if the two reagents were combined, the rest of us might get something cool out of it.
Jessie and Brian talking about Mirarce, Utah for scale. July 13, 2018.
I did some heavy eavesdropping while the three of us were stomping around southern Utah looking for dinosaurs, so I got to hear Jessie and Brian batting ideas back and forth. By the end of our Utah trip Brian had sketches, and not long after, finished art (his post on Mirarce, including process sketches, is here). If you’ve seen one of my talks in the last month or so, you’ve gotten a teaser (with Jessie’s and Brian’s permission), and I know the piece got shown around a bit at SVP, too. You’ve waited long enough, here you go:
Not that the art is the whole story! Mirarce is a legitimately awesome find and Jessie and her coauthors poured a ton of work into the description. I’d tell you all about it, but much more capable and bird-fluent folks are on that already, and I have spinal cord and brainstem lectures to polish. So I’m gonna leave you with some links, which I’ll try to keep updated as different outlets get the story out:
- Berkeley News
- National Geographic
- Independent
- Gizmodo
- PeerJ Blog – a guest post in which Jessie herself explains what’s cool about the find
Reference
Atterholt, J., Hutchinson, J.H.., and O’Connor, J.K. 2018. The most complete enantiornithine from North America and a phylogenetic analysis of the Avisauridae. PeerJ 6:e5910 https://doi.org/10.7717/peerj.5910
Sauropod Vertebra Picture of the Week 
November 13, 2018 at 2:46 pm
Bird skeletons are ridiculous. It’s perfectly obvious that Mirarce is way front-heavy, and would be incapable of standing without falling on its face. Sorry, bird fans, but it’s the truth and you know it.
November 13, 2018 at 3:47 pm
Everybody knows that pygostyle mass is about half of whole body.
November 14, 2018 at 4:04 pm
Ah, that rings a bell — aren’t they formed from neutron-star material or something?
November 14, 2018 at 4:12 pm
Ha, no, nothing so exotic. Just regular run-of-the-mill nickel-tungsten alloy. I believe that Midwest Tungsten carries a complete line of tungsten pygostyles “to meet the diverse enantiornithine-balancing challenges of the 21st century”.