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About Digital Art / Professional Core Member Scott HartmanMale/United States Recent Activity
Deviant for 11 Years
3 Month Core Membership
Statistics 229 Deviations 4,549 Comments 389,941 Pageviews

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Postosuchus big and small by ScottHartman Postosuchus big and small :iconscotthartman:ScottHartman 340 44 Dreadnoughtus - huge, but not the 'hugest' by ScottHartman Dreadnoughtus - huge, but not the 'hugest' :iconscotthartman:ScottHartman 253 62 Poposaurus gracilis sauntering along by ScottHartman Poposaurus gracilis sauntering along :iconscotthartman:ScottHartman 202 34 Teleocrater by ScottHartman Teleocrater :iconscotthartman:ScottHartman 208 46 Confuciusornis by ScottHartman Confuciusornis :iconscotthartman:ScottHartman 164 53 Ixalerpeton by ScottHartman Ixalerpeton :iconscotthartman:ScottHartman 159 27 Dawn 'bird' by ScottHartman Dawn 'bird' :iconscotthartman:ScottHartman 146 13 Jinfengopteryx elegans - the golden phoenix by ScottHartman Jinfengopteryx elegans - the golden phoenix :iconscotthartman:ScottHartman 136 22 Chinese Hunter by ScottHartman Chinese Hunter :iconscotthartman:ScottHartman 149 20 The not-so-gracile Leptoceratops by ScottHartman The not-so-gracile Leptoceratops :iconscotthartman:ScottHartman 146 39 Paleorhinus - not a croc! by ScottHartman Paleorhinus - not a croc! :iconscotthartman:ScottHartman 175 53 A big ichthyosaur by ScottHartman A big ichthyosaur :iconscotthartman:ScottHartman 167 70 Finally, an aetosaur! by ScottHartman Finally, an aetosaur! :iconscotthartman:ScottHartman 198 36 Granddaddy of the armored dinosaurs by ScottHartman Granddaddy of the armored dinosaurs :iconscotthartman:ScottHartman 179 41 Huayangosaurus - a primitive little stegosaur by ScottHartman Huayangosaurus - a primitive little stegosaur :iconscotthartman:ScottHartman 149 23 La Rioja's ponderous biped by ScottHartman La Rioja's ponderous biped :iconscotthartman:ScottHartman 131 42

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Bioluminiscent Pond by ChrisMasna Bioluminiscent Pond :iconchrismasna:ChrisMasna 273 39 Here Comes the Sun by ChrisMasna Here Comes the Sun :iconchrismasna:ChrisMasna 284 46 Quetzalcoatlus. The Stomping Land. 03 by Swordlord3d Quetzalcoatlus. The Stomping Land. 03 :iconswordlord3d:Swordlord3d 547 18 Tyrannosaurus. The Stomping Land. 02 by Swordlord3d Tyrannosaurus. The Stomping Land. 02 :iconswordlord3d:Swordlord3d 1,416 195 Slender tyrant by Dinomaniac Slender tyrant :icondinomaniac:Dinomaniac 640 22 Jurassic mother by dustdevil Jurassic mother :icondustdevil:dustdevil 129 18 Vivian' s Moving Castle by PrimevalRaptor Vivian' s Moving Castle :iconprimevalraptor:PrimevalRaptor 67 27 The More Accurate Utahraptor by EWilloughby The More Accurate Utahraptor :iconewilloughby:EWilloughby 634 109 Leaellynasaura by Apsaravis Leaellynasaura :iconapsaravis:Apsaravis 351 12 Plateosaurus by Apsaravis Plateosaurus :iconapsaravis:Apsaravis 450 23 Diatryma gigantea by MattMart Diatryma gigantea :iconmattmart:MattMart 223 66 Velociraptor mongoliensis by keesey Velociraptor mongoliensis :iconkeesey:keesey 136 23 PhyloPic T-shirt: Human Evolution by keesey PhyloPic T-shirt: Human Evolution :iconkeesey:keesey 51 10 Neovenator by pheaston Neovenator :iconpheaston:pheaston 226 33 Uteodon by pheaston Uteodon :iconpheaston:pheaston 140 9 Parasaurolophus cyrtocristatus by pheaston Parasaurolophus cyrtocristatus :iconpheaston:pheaston 170 15

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ScottHartman
Scott Hartman
Artist | Professional | Digital Art
United States
Current Residence: Wisconsin
Favourite genre of music: Anything but country!
Operating System: Windows 10, OSX, & Android
MP3 player of choice: Anything that can connect to Google Music
www.patreon.com/skeletaldrawin…
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Postosuchus big and small
For such an iconic Triassic archosaur, Postosuchus has proven lots of trouble when it comes to restoring what it looked like and how it got around. Getting the proportions right isn't a trivial matter, as none of the remains are so completely preserved/prepped/described that they can stand in for an entire skeleton. Simple cross-scaling of the specimens isn't possible, as they are of different sizes and exhibit allometric scaling (more on that in a sec).

With a bit of care I've managed to pull together a reasonable composite based on (and scaled to the size of) the type specimen, TTU-P 9000. One of the larger sticking points (in part related to getting the proportions correct) has been if and to what degree Postosuchus was bipedal. While the forelimbs are robust for their size, recent work has noted that the forelimbs are substantially shorter than the hind limbs, which at least in the type specimen I heartily agree with.

One thing that is interesting, however, is that the smaller paratype specimen TTU-P 9002 has different limb proportions - the forelimbs are quite a bit longer relative to the hind legs, and in fact are nearly as long as in the substantially larger type specimen. I've scaled down the skull and axial skeleton to match the limbs of 9002 in the smaller skeletal above. It's tempting to infer that the young of Postosuchus were quadrupeds (or at least were _more_ quadrupedal), and as they grew Postosuchus spend more time on its hind legs alone.
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Dreadnoughtus - huge, but not the 'hugest'
Massive props to the authors of the Dreadnoughtus papers, this has to be one of the best documented and figured sauropods of all time, and in quite a short span of time (the specimen was just named four years ago!).

Of course what everyone wants to discuss is the size of Dreadnoughtus. The mass has been downsized a few times since the initial description's claim of 59 tonnes; I don't have anything new to add other than what has been said previously (i.e. it wasn't as big as Argentinosaurus, Patagotitan, the Mexico "Alamosaurus" or Puertasaurus).

Length-wise I get 23 meters along the curve of the back, a bit shorter than the 26 meters in the original paper. Most of that is due to my interpreting a large cervical as the 10th rather than the 9th cervical. Doing so has a knock-on effect that shortens the estimate for most of the cervical vertebrae. It's still got a heck of a long neck, even for a titanosaur. I'd be remiss not to point out that there's no way to tell which position is correct at this point - we will need more Dreadnoughtus cervicals to know for certain, but in the absence of any additional data I'm going with the more conservative interpretation.
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Poposaurus gracilis sauntering along
The eponymous poposaurid (a group of croc-line archosaurs), it sorta parallelled theropods in becoming bipedal, but was also quite different from theropods in other ways.
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Walker's heavy claw (2018)
2018 Update: Some more revisions in preparation for tackling other spinosaurids (hopefully!) in the coming year. I've decided that there is probably less missing from the incomplete femur (missing a section out of the middle) than before, which brings the femur more into line in terms of how robust it is relative to its length. I updated the scaling of the incomplete lower limb elements to reflect his. I also updated the vertebral column somewhat, reducing the rate at which the neural spines increase in height in the mid-posterior dorsals. Along this line, I've seen some internet hacks of my skeletal (note: please don't hack up or modify my skeletal reconstructions and post them!) that restore the last dorsal as having a very short neural spine; the neural spine of the last dorsal is obviously broken and is clearly labeled as such in the classic Charig & Milner description, so there's no reason to try and force it to have a really short neural spine. Finally, I've raised the neck a bit - not due to any changes in the anatomy, but to put it more in line with the semi-flexed pose I use on other theropods, and because I think it will make a more useful comparative pose in its relatives. For posterity I've left the previous updates below.


2016 Update: I updated the presacral series to reflect the new identifications of Evers et al. 2015 in their Sigilmassasaurus description. This has the effect of putting a stronger S-curve back into the neck, but it still leaves us with a hangdog angle for the skull. Interestingly, the neural spine morphology suggests the building up of axial muscles or nuchal ligaments (or both) along the back of the neck and front of the dorsal column, which is not unlike what Andre Cau has suggested for Spinosaurus, and would make it analogous to what we see in Deinocheirus as well (but on a smaller scale than either of those taxa).

2015 Updated: After nearly a decade and a half here is the overhauled skeletal. The overall proportions aren't all that different, but some of the details are. The midline crest has been moved back above the lacrimal, and I can now confirm that the odd downcurving neck seems to be a real thing, although it also uses some upwardly deflected almost cervicalized anterior dorsals to achieve it. The gray portion of the ilium is the part that was preserved as an imprint (i.e. there is no surviving bone from those parts) and so its accuracy depends entirely on the observations of the original excavators.

Original description: Baryonyx wasn't the first spinosaurid found, but it went a long ways in clarifying what these sorts of theropods looked like and ate. And it turns out they ate fish - although like modern crocodilians, Baryonyx almost certainly ate anything else it could get a hold of too (both fish scales and iguanodont bones were found in its stomach).
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Hello DAers!

My long absence due to multiple projects (and teaching, and graduate school) is probably a month away from coming to an end. I apologies for those who sent me IMs and didn't hear back, sometimes for months. If there is a rush it's almost always better to contact me through my website contact form, as I'll see that right away.

Also, I should have lots of fun skeletals to show off in the coming months (and years) thanks in part to the work I put in over the last 9 months. I look forward to chatting with you all again in a few weeks!

-Scott
Hello DAers!

My long absence due to multiple projects (and teaching, and graduate school) is probably a month away from coming to an end. I apologies for those who sent me IMs and didn't hear back, sometimes for months. If there is a rush it's almost always better to contact me through my website contact form, as I'll see that right away.

Also, I should have lots of fun skeletals to show off in the coming months (and years) thanks in part to the work I put in over the last 9 months. I look forward to chatting with you all again in a few weeks!

-Scott

Comments


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:icondovahkiinhu3br:
DovahkiinHU3BR Featured By Owner Jun 9, 2018
Dr. Hartman, do the ceratopsian footprints tell us about large ceratopsians like Triceratops ran? Like if the maximum they did was trotting (like elephants and hippos) or if they actually ran trough a series of small jumps (like rhinos)?
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:iconhublerdon:
HUBLERDON Featured By Owner Edited May 22, 2018  Hobbyist General Artist
Hey Scott, can you help me with a Velociraptor I'm designing? I noted you on the subject.
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:iconhublerdon:
HUBLERDON Featured By Owner May 23, 2018  Hobbyist General Artist
Thanks for the help. I was mostly worried about the uppermost version, as that's the one I wanted to see sevbut wasn't sure if it was accurate. Could it really curve like that?
Reply
:iconaction-figure-opera:
action-figure-opera Featured By Owner Apr 25, 2018
Going way out on a limb since Jurassic Park's design team has never cared much about anatomical accuracy: Have there been recent discoveries regarding the shape of allosaurus's head? I ask because the toys for the previous Jurassic World movie featured a relatively accurate allosaurus. The species itself makes no appearance in that movie (as far as I know). However, the species does make an appearance in the new movie Jurassic World Fallen Kingdom, and its skull seems to be almost completely wrong. It doesn't even read like an allosaurid. It has a really fat head like a sperm whale. Its lower jaw is far too thick. The top of its head is flat. And the horns on its head point completely backward, rather than up. They don't even have a shallow upward curve. Is any of this consistent with new allosaur studies?
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:iconscotthartman:
ScottHartman Featured By Owner May 2, 2018  Professional Digital Artist
No, it's just the overactive imaginations of the toy developers.
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:icongigaboss101:
GigaBoss101 Featured By Owner Apr 21, 2018  Hobbyist Traditional Artist
What species of Mammuthus is portrayed in your 2011 skeletal?
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:iconscotthartman:
ScottHartman Featured By Owner May 2, 2018  Professional Digital Artist
M. primigenius.
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:icondinopithecus:
Dinopithecus Featured By Owner Edited Apr 9, 2018
Given the known skull material from Ceratosaurus dentisulcatus, how long/large do you think its skull was?

Also, just to be sure, is C. dentisulcatus likely synonymous with C. nasicornis? I remember hearing such an idea before, but I don't think I've ever read why.
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:iconkukuvitza:
Kukuvitza Featured By Owner Edited Mar 27, 2018
Sheesh, why do you keep logging in everyday and staying online for hours on DA, considering you don't do anything at all and you get no new notifications? Don't you have other and better things to do in your time than sitting infront of the computer?
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:iconaction-figure-opera:
action-figure-opera Featured By Owner Apr 25, 2018
"infront" isn't a word. Also, you're an idiot.
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