Feathers

Finally its time to show our Pachycephalosaurus!  Being one of our four playable dinosaurs we really took our time designing this animal.  We are very pleased to finally show him off and hope you guys enjoy it as much as we do.

Okay yeah it’s actually based on the fact that there isn’t much evidence for them being pack hunters in the first place 

The only evidence we have is A) the fossils of Deinonychus associated with the Tenontosaurus and B) some fossil footprints that may be from raptors walking together in formation 

Now the latter is actually pretty good evidence, but we only have one example of it, and if all raptors - and there were a lot of them - were pack hunters, we’d expect more evidence than just on track way. 

As for the former, it is possible that they were hunting in a pack, however it is equally possible that they were associating for convenience - flocking and then hunting - or just all gathering around a carcass and scavenging on it. 

Meanwhile, we don’t have a lot of other fossil evidence of raptors associating with each other. 

The pack hunting hypothesis was mainly proposed by individuals such as Jack Horner (who, I will remind everyone, is the literal worst,) in order to emphasize how dinosaurs were not “cold booded dumb giants” during the Dinosaur Renaissance. It’s why it was depicted in Jurassic Park - he was the primary paleontology consultant on that movie - it’s all part of his schemes to change the public’s opinion of dinosaurs by using wild speculations in addition to new data to emphasize this paradigm shift. He’s done it, for example, with other animals, saying that Tyrannosaurus was without doubt a scavenger - even though that issue is still up for scientific debate. 

He based this hypothesis on the assumption that raptors and modern-day wolves shared a similar ecological niche - and wolves pack hunt. However, there aren’t really any species of birds that pack hunt - and those animals are much more closely related to raptors and also could have had similar ecological niches (for example, vultures and birds of prey.) In fact, birds hardly ever form really purposeful groups together; rather, they flock together for convenience and do form mated pairs. It seems fairly unlikely that raptors would have shown completely different behaviors - given how closely related they are to birds - when there’s nearly no fossil evidence for it. 

Additionally, raptors weren’t actually very fast - their legs were much too short to be so - and they couldn’t use their famous sickle-claws to slash at prey. Rather, they were designed to strategically strike at vulnerable places on a prey’s body - something that would be kind of hard to do in a pack. I mean, you’d all be aiming for the exact same spot. 

I explain even more reasons why not (and provide sources) in my post about Velociraptor; additionally, you can look at my other raptor posts (anything on my page tagged “raptor”) for more information. 

True, these days I take his utterances outside of peer review with the appropriate amount of sodium chloride but I’d think it more forthcoming to name who actually started those notions about dromaeosaurid social hunting and leave someone admittedly roughshod when in the function of science communicator to his irrelevance in the matter. Here are the papers you alluded to:

Roach, B. T.; D. L. Brinkman (2007). “A reevaluation of cooperative pack hunting and gregariousness in Deinonychus antirrhopus and other nonavian theropod dinosaurs”. Bulletin of the Peabody Museum of Natural History 48 (1): 103–138.doi:10.3374/0079-032X(2007)48[103:AROCPH]2.0.CO;2. 

Li, Rihui; Lockley, Martin G.; Makovicky, Peter J.; Matsukawa, Masaki; Norell, Mark A.; Harris, Jerald D.; Liu, Mingwei (2007). “Behavioral and faunal implications of Early Cretaceous deinonychosaur trackways from China”. Naturwissenschaften 95 (3): 185–91. doi:10.1007/s00114-007-0310-7. 

Now on the first one you’ll note that it was Ostrom, the original author describing Deinonychus, who proposed social hunting for it. Further digressions of mine on the subject here. I think you’re confusing John R. Horner with Robert T. Bakker. The latter was the one who proposed the most far-fetched ideas within the Dinosaur Renaissance: you can read about one of them on print page 125 of the first scientific article. Horner at that time was busying himself with dinosaur nests, namely those of Maiasaura and Troodon (the latter initially misidentified as those of Orodromeus), so as a consultant for Jurassic Park he more than likely bridged the gap for the film crew regarding the then cutting edge of the scientific literature and mentioned interesting ideas for a cinematic context though perhaps not the most scientifically probable.

Artist Portfolio

Chuang Zhao is pretty much the artist who reconstructs the Chinese dinosaurs these days. His works have a vague semblance to the art of Luis Rey and Julius Csotonyi in their use of photocomposition to create colourful and ultrarealistic artwork. Recent reconstructions include Huanansaurus, Qianzhousaurus, and Ikrandraco.

Dino Dossier

Zhenyuanlong suni _is a new large basal microraptorian dromaeosaurid theropod from the Early Cretaceous Jehol Biota of China. Its extensive preservation of feathers on various parts of its body, combined with a strange short-armed physique, reveal new insights about microraptorian evolution. The discovery of _Zhenyuanlong revives the debate of whether feathers evolved for flight or display, and increases homoplasy amongst Liaoning dromaeosaurs.

Reconstruction Critique

**Wing Structure. **Whilst _Zhenyuanlong _had a complicated arrangement of primaries, secondaries, coverts, and retrices, here the feathers on the arm are represented as a simple fan.

**Pronation. **Even though this isn’t Jurassic Park Velociraptor-like full on bendy wrist pronation, this posture is still unlikely and will cause wrist breakage.

**Leg Feathers. **Here Zhenyuanlong is depicted with vestigial _Microraptor-_like hindlimb feathers, whereas the actual fossil lacks any feathers around the hindlimbs. This may be a taphonomic artifact, but speculation isn’t a good way to go for a reconstruction. 

**Shrinkwrapping. **It may be a matter of texturing, but the feet of _Zhenyuanlong _are horrendously wrinkled in this reconstruction. This is not that major a problem for the rest of the body.

**Posture. **The right leg is bent at a crude, almost painful angle. This certainly calls into question how the hips of this thing even work.

**Coloration. **Having this flashy coloration may not necessarily be the best choice for an active predator. On the other hand, this may be intended to be for display. In either case, however, the colour is not what we would expect for this animal.

Mostly consisting of valid criticism I do share as well. Here are my two cents:

Wing Structure: My primary criticism. This is especially embarrassing considering the primary and secondary remiges, along with their coverts, are so blatantly obvious and well-preserved on the specimen (and clearly show primary attachments along manual digit 2) that there is no excuse for these mistakes. On top of that, both the paper and the article focus a substantial amount of time on wing structure and its clearly preserved primary feathers that makes seeing a faulty reconstruction with omitted primaries alongside the article mindbogglingly painful.

Pronation: I have to admit that I did not notice this first time around. At a second glance, however, I do see some degree of pronation on the right manus’ posture. This is inconsistent and especially confusing considering the posture of the more easily visible left manus seems to be in order.

Leg Feathers: Here, I have to contradict your criticism. It is true that the specimen featured no preserved filament along its hindlimbs. However, it is important to note that the hindlimbs were part of the second, non-feather-bearing slab that was completely absent of any filament impressions. If you take a second look at the fossil with the slabs in mind, you can see that the preserved feather imprints of the rectrices and secondary remiges suddenly stop along the edges in transition to slab 2. To help locating the slabs, here is a quick image I prepared that visualize the three main slabs: This is also mentioned in the paper: "However, it must be noted that the hindlimbs are part of the second major piece of the slab and no feathers are visible on this piece, whereas numerous feathers are seen on pieces one and three. The lack of feathers on the second piece could be an artifact of taphonomy or have been erased during preparation. Therefore, it cannot be totally ruled out that hindlimb feathers were present in life." (Lü & Brusatte, 2015) That said, please note that I am not saying that Zhenyuanlong definitely had hindlimb feathers: I am merely emphasizing that there is a definite possibility and reconstructions that render Zhenyuanlong with present hindlimb feathers aren't automatically to be considered faulty.

Shrinkwrapping: I agree. Although, compared to most other points of criticism regarding this particular reconstruction, this seems to be a mere minor nitpick. However, I do remember somebody commenting on the texture of the feet in this reconstruction, saying how they appear as if they were made out of rotten wood, which I found to be mildly amusing.

Posture: Most of the anatomy of the right leg is obscured by the wing, which makes it difficult to tell.

A large, short-armed, winged dromaeosaurid (Dinosauria: Theropoda) from the Early Cretaceous of China and its implications for feather evolution

The now-iconic “stand down” scene from Jurassic World, with Blue, Charlie, and Delta portrayed here by some more-accurately sized Utahraptor ostrommaysorum. 

T-rex and Velociraptor

Because, in the Jurassic World aftermath, it’s always a good thing to remind ourselves raptors were actually feathered. This doodle is based on a photo of the set from the original Jurassic Park movie.

Free to reblog. Do no steal.

On March 31 the Swedish Museum Of Natural History opens a new exhibition called Fossils & Evolution. My part of this production was to provide illustrations of the animals in their natural environment. With permission from the museum, I’m releasing the material on my website. I couldn’t have done these images without the help from the following people at NRM: 

Thomas Mörs - Senior Curator, Fossil Vertebrates 

Stephen McLoughlin -Senior Curator, Paleobotany

Christian Skovsted - Senior Curator, Fossil Invertebrates

Daniella Kalthoff - Curator, Zoology

Tove Frambäck - Producer

For the full series, go here.