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.


Drawing by Mick Ellison of the American Museum of Natural History, NYC. 

When: Early Cretaceous (~125 million years) 

Where: Liaoning, China

What: Mei is a paravian dinosaur. Paraves is the clade comprised of birds and two families of non-avian dinsaurs; Troodontidae and Dromaeosauridae. As Mei is a fairly basal member of the troodontids, it is not very far removed from the common ancestor of all paravians. Its bird-like heritage can be easily seen in this extraordinary articulated fossil shown above. This specimen was found in a sleeping pose, which is very much like the resting posture of many modern birds, with the legs folded underneath the body and the head folded back and resting on the shoulder.  It is this pose that gives the taxon its full name:  Mei long, which translates to ‘sleeping dragon’. This animal is a sub-adult, determined via the ends of its bones not yet being fused, and would be roughly 21 inches (~53 cm) long, if it was not curled up as it is.  

 The find of a basal troodontid in this pose gives us far more information than just when the sleeping posture was adapted by this clade. It has been determined that modern birds commonly sleep like this to preserve their body heat, covering up the areas that are most prone to radiating heat. If Mei long  and its kin were not 'warm blooded’ than there would be no benefit to sleeping in this pose. Thus, this provides another compelling bit of evidence that the 'warm bloodedness’ of modern birds was present in their mesozoic non-avian relatives. 

A second concept art for my thesis and paleo art practice! Sketched a bunch of dynamic poses my friends looked over and gave me feedback on, and finally decided on a bathing Deinonychus one!

Once again thank you so much to Xane and Emily for their patience and feedback! And everyone else who gave me awesome feedback and motivation looking over the first concept I submitted!


Who was the earliest bird: Archaeopteryx, as has long been thought, or Aurornis, a newly-described Chinese paravian? Nature News explores this issue in a new article that features this illustration of these two dinobirds facing off in a conceptual battle for status.

Contra the Nature article, and while the true phylogenetic position of Archaeopteryx is certainly a fascinating issue and deserves resolution, the reality is that it does not matter whether good ol’ Archie was a bird or something very, very similar to a bird. Modern phylogenetics has rendered the distinction logically irrelevant: whether Archaeopteryx is the first “bird” is now an issue of semantics more than one of science. So let’s try to cut back on the uproar over who was truly the earliest bird—there are enough worms to go around.

Gouache on artboard, 16" x 20", processed in CS4.
Available as a print.

Also pictured: Kulindadromeus, a basal neornithischian covered in voluminous feather-like structures, and Zanabazar, a late Cretaceous Mongolian troodontid.

Somehow I had never drawn an archaeopteryx.  I know, I’m as surprised as you are.  So of course I decided to draw it while at work without a reference because why not.  Turns out it’s supposed to have weirdly long wing coverts.  Like, almost as long as the primaries.

Someone please tell me how we’ve had a fully-feathered, fully-winged dinobird for 150 years, and yet it wasn’t until the freaking 80s that birds being dinosaurs started to become fully accepted.

Palaeopteryx thomsoni

Source: thewoodparable​, again, because he’s a saint 

Name: Palaeopteryx thomsoni 

Name Meaning: Ancient Wing

First Described: 1981

Described By: Jensen

ClassificationDinosauria, Saurischia, Eusaurischia, Theropoda, Neotheropoda, Averostra, Tetanurae, Orionides, Avetheropoda, Coelurosauria, Tyrannoraptora, Maniraptoriformes, Maniraptora, Pennaraptora, Paraves

Palaeopteryx is a potentially non-existent (meaning, once again, we have a dubious genus here folks) dinosaur from the Kimmeridgian age of the Late Jurassic, about 153 million years ago (hey guys, isn’t it nice I made that geologic time scale? Now you have an easily accessible post on my blog that showcases when all these things lived! Hooray!).  It was found in the Morrison Formation in western Colorado. Originally named as a bird older than Archaeopteryx, it has now been described as an indeterminate paravian, and shows some of the earliest maniraptoran traits. It was fairly small, but I could not find a full size estimate, only the length of the leg bon (4.5 cm, which can still give you some idea). 


Shout out goes to paleobiology!

P.S. There’s an important addition to my blog page explaining why I do not do my own illustrations. You can find it under the Donate Button. 

The foot feather, Pedopenna (2005)

Phylum : Chordata
Clade : Avialae
Genus : Pedopenna
Species : P. daohugouensis

  • Late Jurassic (164 - 152 Ma)
  • 1 m long and 4 kg (size)
  • Daohugou beds, China (map)

Pedopenna is a genus of small, feathered, maniraptoran dinosaur from the Daohugou Beds in China. It is possibly older than Archaeopteryx, though the age of the Daohugou Beds where it was found is debated. A majority of studies suggest that beds probably date from between the late Middle Jurassic and early Late Jurassic Period.

The name Pedopenna refers to the long pennaceous feathers on the metatarsus; daohugouensis refers to the locality of Daohugou, where the holotype was found. Pedopenna daohugouensis probably measured 1 meter or less in length, but since this species is only known from the hind legs, the actual length is difficult to estimate. Pedopenna was originally classified as a paravian, the group of maniraptoran dinosaurs that includes both deinonychosaurs and avialans (the lineage including modern birds), but some scientists have classified it as a true avialan more closely related to modern birds than to deinonychosaurs.


The Temporal Paradox.

Wanna know why?

For those who don’t know, the Temporal Paradox is a reasoning against birds being dinosaurs, on the basis that all of the most bird-like dinosaurs (ie dromaeosaurs) came AFTER birds.

And man, this really bothered me throughout high school and college. I was starting to get interested in all these birdy dinosaurs running around, except how the hell could birds have come from dinosaurs if the most bird-like dinosaurs came AFTER birds?

Except UNLIKE most anti birds-are-dinosaurs arguments, this one is SO SIMPLE TO DEBUNK.


Birds and dromaeosaurs are SISTERS, they BOTH evolved from PARAVIANS. Which–oh snap!–came before either of them.

Debunking most of the other BANDit arguments can be kind of confusing and requires ten-minute explanations of feather development and frame-shift genetics and whatnot, but this one is SO SIMPLE ARGH. HOW DID I NOT LEARN THIS UNTIL LAST YEAR.

Eosinopteryx brevipenna


Name: Eosinopteryx brevipenna

Name Meaning: Dawn Chinese Wing

First Described: 2013

Described By: Godefroit et al. 

ClassificationDinosauria, Saurischia, Eusaurischia, Theropoda, Neotheropoda, Averostra, Tetanurae, Orionides, Avetheropoda, Coelurosauria, Tyrannoraptora, Maniraptoriformes, Maniraptora, Pennaraptora, Paraves, Eumaniraptora, Averaptora, Avialae

So science is constantly changing things. Like Eosinopteryx. Which was originally classified as a troodontid, so I put it in my list for ADAD. But then it got reclassified as an avialan, So today’s dinosaur is a bird! Hooray! If it was not an avialaen, it could have been a primitive paravian as well, which is the group we begin today now that we’re done with oviraptorids. It is only known from one fossil specimen, so the confusion on its classification is fairly standard. It lived in the Oxfordian age of the Late Jurassic, about 160 million years ago. It was found in the Tiaojishan Formation of Liaoning Province, China. It was about 30 centimeters long, making it quite small if it wasn’t an avialan. The tail was fairly short and the wings were the same size as Anchiornis huxleyi, and it had hind wings on its lower legs and feet. This could mean that the origin of flight is a much more complex phenomenon than archaeopteryx -> birds; however, given various dinosaurs such as Microraptor, this is not much of a surprise.

Shout out goes to jamesz3!

Pedopenna daohugouensis


Name: Pedopenna daohugouensis

Name Meaning: Foot Feater

First Described: 2005

Described By: Xu & Zhang

ClassificationDinosauria, Saurischia, Eusaurischia, Theropoda, Neotheropoda, Averostra, Tetanurae, Orionides, Avetheropoda, Coelurosauria, Tyrannoraptora, Maniraptoriformes, Maniraptora, Pennaraptora, Paraves, Eumaniraptora, Averaptora, Avialae

Pedopenna is another small, feathered dinosaur whose classification is questionable. It was found in the Daohugou Beds in China, about 164 million years ago in the Callovian age of the Middle Jurassic. It had large pennaceous feathers on its legs, and it has been classified both as a paravian (so a dromaeosaur, troodontid or avialan) or just an avialan. It was probably about 1 meter long, but it is only know from its hind legs, and thus true estimation is difficult. It had shorter feathers overlying the long foot feathers, showing the presence of coverts like in modern birds. It had fewer aerodynamic adaptations and they were less stiff, so whatever aerodynamic properties it had were weaker than in Microraptor. They could have been ornamental. 


Shout out goes to karladon!

Epidexipteryx hui


Name: Epidexipteryx hui

Name Meaning: Display Feather

First Described: 2008

Described By: Zhang et al. 

ClassificationDinosauria, Saurischia, Eusaurischia, Theropoda, Neotheropoda, Averostra, Tetanurae, Orionides, Avetheropoda, Coelurosauria, Tyrannoraptora, Maniraptoriformes, Maniraptora, Pennaraptora, Paraves, Sansoriopterygidae 

Epidexipteryx is a very distinctive genus paravian dinosaur due to its characteristic ornamental tail feathers. It was found in the Daohugou Beds of Inner Mongolia, China, dating back to the Middle or Late Jurassic Period, about 164 million years ago, literally on the boundary between the Oxfordian and Callovian ages of the Jurassic. Given its elaborate plumage, a lot of the early analyses of its phylogenetic position put it closer to birds; however, it has since been placed as a basal paravian in a recent 2012 study. There is a chance, however, that they are actually pennaraptorans, a sister group to the oviraptors. More fossils once again are required to know more about where this animal falls in the dinosaurian tree. 


However, the skeleton it is known from is very well preserved specimen. It was about 25 centimeters long in body length, but the tail feathers made it 44.5 centimeters long. It was a very early paravian, and might have used its long tail feathers like a peacock, displaying to members of the species for attracting mates. It lacked wing feathers and could not fly, and it also had teeth only in the front of the jaw and angled forward. If it had wing feathers at any point, it subsequently lost them, and the tail feathers remained for display. 


Shout out goes to nailpolishremoverr!

Pneumatoraptor fodori


Name: Pneumatoraptor fodori 

Name Meaning: Air Thief 

First Described: 2010

Described By: Õsi, Apesteguía & Kowalewski

ClassificationDinosauria, Saurischia, Eusaurischia, Theropoda, Neotheropoda, Averostra, Tetanurae, Orionides, Avetheropoda, Coelurosauria, Tyrannoraptora, Maniraptoriformes, Maniraptora, Pennaraptora, Paraves

Pneumatoraptor was another small paravian, about 70 centimeters long, from the Csehbanya Formation of Hungary. It lived in the Santonian age of the Late Cretaceous, about 85 million years ago. It is only known rom fragmented remains, but the fossils had a lot of air cavities, leading to this guy’s name. Its uncertain, however, if it belongs to a more advanced paravian group, or which one if it does. 


Shout out goes to kingofkrakens!