Diagnostic anatomical reconstruction of Deinonychus antirrhopus, intended loosely for Wikipedia but also as an experimental piece to show pretty much exactly how I believe this animal looked in life.
This was largely inspired by an interesting Facebook discussion with paleoartist Julius Csotonyi about arm-folding in paravian dinosaurs. It occurred to me that people seldom reconstruct paravians, particularly dromaeosaurs, with their arms folded in a reasonable and accurate way. Julius made the fair point that these animals probably didn’t carry their arms out in front of the body, as is so often depicted (in skeletals and otherwise — it makes sense in skeletals, to adequately show the hand and arm anatomy), because such an awkward orientation would leave the hand and arm feathers open to damage and breakage. But they also can’t fold them tightly against the breast or back like birds do, because they lack the mobility to do so.
So how did Deinonychus normally carry its arms? Senter’s 2006 paper on forelimb function in Deinonychus and Bambiraptor shows that the humerus couldn’t rotate much past the horizontal with respect to the scapula. In addition, Sullivan et al. 2010 — winningly translated to layman coherency by Matt Martyniuk — shows that wrist mobility in many paravians is much less than you might expect, given their similarity to birds. The wrist of Deinonychus antirrhopus specifically would not have allowed it to bend its hands even 90° with respect to the arm!
Given these limitations, most of the flexion would have to occur at the elbow, but a fully flexed elbow would mean that the hands would be hanging below the body, not held sleek and secure alongside the body. The arm orientation in my illustration above is based on what I think is probably the perfect configuration for carrying the arms: a fully-flexed shoulder, a fully-flexed wrist, and a nearly fully-extended elbow. A few other people have drawn their dromaeosaurs with the same arm configuration, like Smnt2000 and Pilsator, so kudos to them.
Illustration based on the papers linked above as well as Scott Hartman's beautiful skeletal. Gouache on 12” x 20” hot-pressed illustration board.
“If you were asked to name a dinosaur, the chances are you would give a foreign example, such as Tyrannosaurus rex, despite the term dinosaur’ having been conceived by a British palaeontologist for fossils found in England. In fact, the British Isles have their own tyrannosaurs! The very first descriptions of dinosaurs in the early-mid 1800s were all based upon remains discovered in England. Since their initial discovery, dinosaur fossils have been documented at numerous locations across the British Isles, in England, Wales, Scotland and Northern Ireland. Indeed, the Isle of Wight is often referred to as the dinosaur capital of Europe. British dinosaur diversity is rather high, with theropods, sauropods, ornithopods and thyreophorans (stegosaurs and ankylosaurs) all represented. Remains found across the British Isles represent fragments to complete individuals, comprising unique examples. Following a foreword by the leading British dinosaur scientist Dr Paul Barrett (Natural History Museum, London), the authors summarise what is known about the history of every dinosaur species discovered within the British Isles. They include photographs of hundreds of fossils, many of which are usually hidden from view behind the scenes in various museum collections. These are supplemented by scientifically accurate skeletal reconstructions and vivid life reconstructions of how some of the animals most probably appeared when alive. This book is truly unique, providing the first comprehensive account on the dinosaurs of the entire British Isles. It will be of interest to a broad audience, from academics to those with a general interest in fossils. It will no doubt form, in part, the early inspiration for some readers to consider palaeontology as a future career.”
another practice sample from my illustration class. Watercolors are the only traditional color medium im actually somewhat confident with. Even though I layer like no ones business instead of making pretty, artsy washes like normal people do. Anyways, I never got around to doing my own, but here’s my Deinocheirus. cheers!
John Conway Leaellynasaura From the book All Yesterdays 
This is the small Australian ornithischian, Leaellynasaura, reconstructed as a furball using its tail for show.
All Yesterdays was originally a presentation I made at 2011 Symposium of Vertebrate Palaeontology and Comparative Anatomy in Lyme Regis. The central idea of the presentation was that prehistoric animals may have been stranger than we imagine, and to present some outlandish, but not necessarily wrong reconstructions.