Anonymous request: Peacock-colored Rahonavis preening its feathers, with male and female variations.
Here’s a male tidying up his feathers a bit before putting on a show for the interested female.
Newly described basal therizinosaur Jianchangosaurus.
Pretty content with how it came out.
Today, after weeks of rampant internet speculation the new-look Spinosaurus was revealed. And it certainly didn’t disappoint: the paper by Ibrahim et al. musters a range of evidence from bone density, bone isotope data, facial innervation, osteology, etc., to suggest that Spinosaurus not only was a fish-eater (i.e. piscivorous) but was adaptive to that lifestyle to a greater degree than other known spinosaurids. Not only do they claim that Spinosaurus spent most of its life swimming in the water with adaptations that would rival early whales, but Ibrahim et al. specifically claim that the altered limb proportions would require Spinosaurus to have been an obligate quadruped on land, a first for a theropod. Unfortunately, there seems to be something fishy with those new proportions…
Finally it’s here!
The most important paleo-thing I’ve ever written since How to Properly Restore the Winged Arms of Aviremigians - Final Corrections. An entire post about pterosaur wings: shapes, colours, pycnofibres, thigh or ankle attachment, uropatagium and folding. Or, to put in another way: What You wanted to know about Pterosaur Wings but You’ve Never Asked!
You don’t have the faintest idea how much work did I put in it. Let’s just say that I published a rough version of it around early December. So, like 9-10 months in development. Of course it will be a huge amount of crap since I’m not a paleontologist, but I tried to do my best.
Try to enjoy it!
For the love of crocodylomorphs
by Darren Naish
Crocodiles, alligators and gharials are the modern members of a far grander, far more diverse clade of archosaurian reptiles termed Crocodylomorpha. It’s gradually becoming better known that, in additional to including amphibious, long-skulled taxa like the living ones, the group encompasses an incredible array of terrestrial and semi-terrestrial omnivores, herbivores, carnivores and insectivores.
(Read more → Tetrapod Zoology)
(Buy merch featuring the above image! → Darren Naish’s Redbubble shop)
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 the 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.
Stupendous illustration of an unenlagiine in a pond, surrounded by water lilies, by Christian Masnaghetti.