Avimimus portentosus
"portentous bird mimic"

Avimimus portensosus was aptly named, and not only in the sense Russian paleontologist Sergei Kurzanov intended. The name literally translates as "portentous bird mimic" (portentous in the sense of overdramatically important), but it also has the ring of "portent" to it. Often overlooked, Avimimus was in fact the fist traditional, non-avialan dinosaur recognized to have had feathers. True, direct impressions of true feathers didn't come until nearly twenty years after its 1981 discovery, in fossils of its close relative Protarchaeopteryx (described in 1997). However, Kurzanov did note the presence of a strange ridge along the back of the arm, as well as quill knobs, the anchor points for large wing feathers in modern birds. Because of this, and a suite of other bird-like features not seen before in dinosaurs, Avimimus became the first dinosaur commonly depicted with a full compliment of feathers. In fact, the tail of Avimimus has not yet been recovered, and early illustrations depicted it as having no bony tail at all, in the style of modern pygostylian birds. However, given how closely it is probably related to short-tailed primitive oviraptorosaurs, and characteristics of the hip, it almost certaily had at least a short tail, possibly capped by a fan of feathers as seen in its relatives, the Caudipterids.

As in caudipterids, I've drawn Avimimus with a large fan of primary feathers. Unlike caudipterids, I've also granted it secondaries along the upper arm, as evidenced by the quill knobs. Still, I made the primaries much longer and more striking on comor, given that they were probably used mainly for display in these primitive ground birds. Some other unique characteristics of Avimimus are the very large feet, relatively short arms, and the small 'dome' on the skull above the eyes. This dome is present only in a skull referred to this species, not the type specimen. Phil Currie reported the discovery of an Avimimus bonebed in 2008, and if these specimens turn out to have a non-domed skull, or have domes but differ from the type specimen in other ways, the species drawn here will likely be given a new name.

Another unique feature, hard to see in the image here (though I restored it as best I could at this scale), is the beak, which bore coarse serrations along its tip, sort of like pseudo-teeth. A few other flourishes however, such as the pheasant-like tail feathers and black display crest, are purely artistic license.

Avimimus comes from the Nemegt Formation of Mongolia, which at the end of the Cretaceous period would have been sort of a wetter, more forested version of the arid, sandstorm-prone dune fields of earlier Mongolian habitats, when relatives like Oviraptor lived. The presence of Avimimus here, and its similarity to caudipterids (not to mention its long toes, usually indicative of a marshy habitat), may mean that Avimimus and relatives were a wetland-loving bunch, unlike the desert-dwelling oviraptorids.

For more on Avimimus, including a modified, more conservative version of this drawing, see the Wikipedia article I helped edit.

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Image Details:
Media: Graphite, digital coloring in Adobe Photoshop CS using WACOM Graphire 3
License:
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