Acheroraptor

Here's my rendition of the new Hell Creek velociraptorine dromaeosaur. It's known only from the maxilla and dentary, so I decided to only draw the business end of the animal (that, and I didn't really have the time for a full reconstruction). It's depicted staring at a hispine beetle, of which there is abundance evidence (Johnson et al 2000) from Hell Creek ichnofossils.

The animal has been known from teeth for many years, and was only recently finally given a name, Acheroraptor temertyorum, after the underworld Acheron of Greek mythology (Hell Creek reference and so on). Phylogenetic analysis recovers it as a velociraptorine, the most basal member of the group containing Velociraptor, Adasaurus and Tsaagan.

I had a bit of consternation on whether or not to depict the animal with lips: the original version lacked full lips, and I drew the upper teeth overlapping the dentary. Ultimately I decided to add lips and the result is the above image. The original can be seen to the right.

Evidence for lips on theropods is still debated, but it seems to be mounting over time. I've been wishy-washy about lips: my preferred state of depicting dromaeosaurs, at least, was with a sort of "in-betweenish" lip situation, where lips covered around half the vertical distance of the upper teeth, but the upper teeth still overlapped the dentary somewhat. Jaime Headden has a great post on the complexities of dinosaur lips and why some options aren't really satisfactory without more information.

Photoshop CS4, ~2-3 hours

All Your Yesterdays!

Every other paleo-nerd with a blog is posting about this, so I guess I'll join the bandwagon!

All Your Yesterdays, a new book by C.M. Koseman of Irregular Books, has just been released and is now available for download! Brought to you by the same group that published the game-changing paleoart book All Yesterdays (see my review of that book here), All Your Yesterdays is a compilation of paleoart from dozens of different artists that seek to explore unusual aspects of rational paleontological speculation. I have three pieces in the tome: two Microraptors doing unusual but plausible things, and a Utahraptor being unusual just by virtue of not trying to kill anything. Many other aspiring and talented paleoartists have tackled such scenarios as lactating stem-mammals, polycephaly and cancer in dinosaurs, and many unusual - though often quite reasonable - display structures.

The book is available for free download, but please consider donating to keep the fine folks at Irregular Books producing fabulous work!

Deinonychus Family

This is a very small watercolor "sketch", part of which was for a friend, and the scene inspired by Jon's novel-in-progress...

Obviously this is a very speculative scenario, perhaps a bit All Yesterdays-esque, and is speculative in a number of ways:

1. Family groups in dromaeosaurs are definitely not outside the realm of possibility, and may be more likely than the tired "pack" scenario, at least until the young disperse (fledge? Wean?). Here, the male and female are depicted in a monogamous pair-bond, and jointly care for the young.

2. The male is the more brightly-colored of the two, and the female is similarly-colored but a bit duller, and with more banding. The display feathers in the male are green due to a pigment molecule similar to the pigment turacoverdin, the only known green pigment in birds, and the pigment responsible for the green coloration in turacos. There is evidence to suggest that turacoverdin - or a molecule structurally very similar to it - arose at least twice in modern birds, once in turacos and once in the northern jacana, a totally unrelated bird. Therefore it's not totally outside the realm of possibility that a similar compound evolved independently in dromaeosaurs as well. Turacoverdin is copper-based porphyrin and turacos derive their copper from the fruit they eat, but Deinonychus could derive its copper from the livers of its prey, which is also high in copper.

3. The female is carrying its young on its back, much in the same way that some waterbirds like loons and grebes, as well as crocodilians, do with their young. The idea is that Deinonychus occupies a large territory and would needing to constantly hunt to feed the brood, and would be moving location too frequently for young to easily follow on foot. Here, one chick is using WAIR to climb up its father's back, which is something that some modern young birds also do.

4. The chicks are patterned similar to baby ratites, which are often streaked or spotted until they get older.

5. The feathery toes, while not terribly unique due to finds like Anchiornis, are loosely based on Matt Martyniuk's new post on dinosaur foot scales, which indicates that scutes may have evolved from feathers, rather than the opposite. The chicks here don't have feathery feet because the animals would have evolved from an ancestor that had pebble-scaled feet without feathers or scutes, and ontogeny occasionally very loosely recapitulates phylogeny. (Alternately, I could have depicted the chicks with voluminous legwings, since legwings may have been an intermediate stage between pebble-scale feet and scuted feet).

The Most Accurate Inaccurate Utahraptor

This is a commission of a Utahraptor "reference" for a friend. It is entirely based only on material that is currently-published, and is therefore technically inaccurate considering the existence of unpublished material. However, my client wanted an image of Utahraptor that is "as accurate as possible" based on the knowledge we've had on the critter up to this point. Once the new material is released to the public, this image will be modified to reflect the updated anatomy, and will therefore serve as an interesting "before" and "after" for the animal.

Anatomy is based on Scott Hartman's technically-outdated Utahraptor skeletal diagram.

New website for my art

As of yesterday, the official website for my illustration work is up! My dear friend and brilliant web-developer did a marvelous job, and I’m really happy with it. From here on out, this will be my official platform for displaying my professional work, as well as a hub for selling items (check out the Store section for prints, merchandise, and a handful of originals). I’ve also written a fairly expansive “about” section that talks about why paleoart is so important to science and society, if you’re into that sort of thing.

→ Emily Willoughby Art ←
I will still post to Blogspot, DeviantArt and everywhere else, but I’ve been wanting a professional portfolio site for a long time and it’s been a long time coming. Check it out and tell your friends and stuff!

The Velociraptor Hunting Dance

This is the famous Velociraptor mongoliensis in its native late Cretaceous Gobi Desert. Velociraptor was a small dromaeosaur, or raptor dinosaur, and contrary to its most famous depictions was almost certainly feathered from head to tail. This is no longer based merely on phylogenic evidence, either - as of 2007, reanalysis of the fossil has shown that its posterior forearm contains quite obvious quill knobs.

Velociraptor surely went after larger prey like Protoceratops at least occasionally, as we have fossil evidence that it certainly did so. However, like many modern mid-sized carnivores, its diet probably consisted of a large proportion of much smaller animals, which it may have ambushed or sniffed out of crevices. I imagine such a predation event would have been rather felid in nature, wherein the animal displayed a curious mixture of predatory grace and pure silly ridiculousness as it bounced and flailed after a frantic prey animal. In this case the prey in question is Zalambdalestes, a small shrewlike eutherian from the Djadochta Formation of Inner Mongolia.

The Many Meals of Microraptor

As a lot of you will already know by the time of reading this, a recent publication in the journal Evolution demonstrates that the four-winged, tiny dromaeosaur Microraptor was at least occasionally in the habit of ingesting fish. Scales and portions of several disarticulated skeletons of the osteoglossiform Jinanichthys were found fossilized in the specimen's gut. The authors do not discount the possibility that the fish were scavenged, but considering other known habits of the four-winged wonder, it seems at least reasonably likely that it caught the fish itself - and unlike previous known gut contents, it couldn't have taken this meal in the trees (though it's hard to know what the nay-sayers will claim next...).

Xing et al 2013 describes fish remains in the gut of a Microraptor specimen
This newest study is another piece in the puzzle of Microraptor's ecology - a puzzle which is looking more complete as time goes by. With over 300 undescribed specimens, at least three perserved meals (all different), a color study, conflicting scleral ring studies, and a myriad of biomechanical research, we now know a tremendous about this animal (at least for being dead 120 million years).

But can we extract a reasonable approximation of its diet and lifestyle from the available information? To answer that, one option is to look towards modern birds. But first, let's look at what we do know.