Skip to main content

Allosaurus fragilis 3: Allosaurus yet again...

Yes it is, it's Allosaurus fragilis yet again! The point is, Allosaurus is by far the easiest theropod to draw...I don't know why, but perhaps it's because you see images of Allosaurus skulls everywhere, being depicted as the "generic" theropod. Of course it is one of the most abundant theropods ever so we do have a good idea of its morphology and to a certain extent its ontogeny - the vast majority of fossils are of adults or subadults while juveniles and hatchlings are very rare.

I use Allosaurus when I am testing out new ideas, whether it be biomechanics or just new angles to draw...certainly this is the case of the latter. It's not entirely a ground-breakingly new angle at all but one that I have attempted in numerous previous accounts and have never really gotten right. Though, I think I've got it almost right this time. I find angled shots really difficult - as you may have noticed, most of my drawings have got the skulls captured in a lateral aspect or just slightly angled. Depth perseption in dinosaur drawings are quite hard - I find, at least...

Comments

Zach said…
I find depth troubling when drawing dinosaurs, too, especially for head-on views. You've got to give this allosaur some arms, brother! People underestimate how massive Allosaurus' arms were, especially its fingers. It's no spinosaur, but Allosaurus could hold onto stuff, and it had some kickass manual claws.
Otherwise the picture is quite good!

Have you read Bakker's paper (in "Feathered Dragons") about the paleoecology of Allosaurus and Ceratosaurus? He suggests that allosaurus was a specialized sauropod killer (not new), and that Ceratosaurus was a swimmer that went after lungfish. I was just reminded of that paper because you've drawn the two big Morrison theropods. :-)
Ironically, I've deliberately shrunken the arms after I thought, "wait a minute, they look too big"...although, you are right, I always am amazed how big and recurved allosaur manual claws are.

I haven't read his paper in Feathered Dragons but I have read his GAIA paper from '98 on Allosaurus as a sabre-tooth analogue...now, that was inspiring!
Sean Craven said…
I hear you about adding depth to reconstructions. My stuff tends to fall into three categories:

1) Strict profile based on photos and skeletal diagrams. This allows me to customize the poses while maintaining accuracy -- I build the skeleton one bone at a time, then flesh it out. These are flat and stiff and fail to get the sense of mass and depth that really delivers the animal.

2) Drawings based on photos of skeletal mounts. This restricts the poses available to me and gives me the creepy feeling that I'm vaguely plagiaristic.

3) Fakin' it. And you can really tell when I'm faking... This stuff looks awful.

At the end of the day I think this comes down to improving my drawing skills in general so I can learn to fake it better. Depressing, isn't it?
Zach said…
I'm in the same boat, Sean. :-)
Hi Sean,

With your criteria, my drawings would pretty much all be either 1, or 3 and most of them with any sort of posing would definitely be 3 - i.e. faked. Although, I would like to think that my detailed observations through my research have given me some good ideas of how they should look like...though that's where drawing skills become the limiting factor, I guess...

Popular posts from this blog

The difference between Lion and Tiger skulls

A quick divergence from my usual dinosaurs, and I shall talk about big cats today. This is because to my greatest delight, I had discovered today a wonderful book. It is called The Felidæ of Rancho La Brea (Merriam and Stock 1932, Carnegie Institution of Washington publication, no. 422). As the title suggests it goes into details of felids from the Rancho La Brea, in particular Smilodon californicus (probably synonymous with S. fatalis ), but also the American Cave Lion, Panthera atrox . The book is full of detailed descriptions, numerous measurements and beautiful figures. However, what really got me excited was, in their description and comparative anatomy of P. atrox , Merriam and Stock (1932) provide identification criteria for the Lion and Tiger, a translation of the one devised by the French palaeontologist Marcelin Boule in 1906. I have forever been looking for a set of rules for identifying lions and tigers and ultimately had to come up with a set of my own with a lot of help

R for beginners and intermediate users 3: plotting with colours

For my third post on my R tutorials for beginners and intermediate users, I shall finally touch on the subject matter that prompted me to start these tutorials - plotting with group structures in colour. If you are familiar with R, then you may have noticed that assigning group structure is not all that straightforward. You can have a dataset that may have a column specifically for group structure such as this: B0 B1 B2 Family Acrocanthosaurus 0.308 -0.00329 3.28E-05 Allosauroidea Allosaurus 0.302 -0.00285 2.04E-05 Allosauroidea Archaeopteryx 0.142 -0.000871 2.98E-06 Aves Bambiraptor 0.182 -0.00161 1.10E-05 Dromaeosauridae Baryonychid 0.189 -0.00238 2.20E-05 Basal_Tetanurae Carcharodontosaurus 0.369 -0.00502 5.82E-05 Allosauroidea Carnotaurus 0.312 -0.00324 2.94E-05 Neoceratosauria Ceratosaurus 0.377 -0.00522 6.07E-05 Neoceratosauria Citipati 0.278 -0.00119 5.08E-06 Ovir

Hind limb proportions do not support the validity of Nanotyrannus

While it was not the main focus of their paper, Persons and Currie (2016) , in a recent paper in Scientific Reports hinted at the possibility of Nanotyrannus lancensis being a valid taxon distinct from Tyrannosaurus rex , using deviations from a regression model of lower leg length on femur length. Similar to encephalisation quotients , Persons and Currie devised a score (cursorial-limb-proportion; CLP) based on the difference between the observed lower leg length and the predicted lower leg length (from a regression model) expressed as a percentage of the observed value. The idea behind this is pretty simple in that if the observed lower leg length value is higher than that predicted for its size (femur length), then that taxon gets a high CLP score. I don't particularly like this sort of data characterisation (a straightforward regression [albeit with phylogeny, e.g. pGLS] would do the job well), but nonetheless, Persons and Currie found that when applied to Nanotyrannus , it