Tuesday, April 28, 2009

Aucasaurus


A medium sized abelisaur from the late cretaceous of South America. Very similar to Carnotaurus but with no 'horns'. Around 13-15 feet long, and found at the bottom of an ancient lake. Some skin impressions were found around the pelvis area, but I can't find any pictures on it online (I did find a picture of dinosaur skin, but no named along with it.)

Best,

Brett

Unnamed Carcharadontosaur


I'm not quite sure what to do with this guy. I drew it when some late Cretaceous carcharadontosaur teeth were found in South America. But another study claims they might in fact be abelisaur teeth that mimic carcharadontosaurs... Sooo, this might be entirely wrong, but it was based on only a few teeth so it wouldn't be that accurate to begin with, just me having some fun;)

Best,

Brett

Saturday, April 25, 2009

Becklespinax


Known from only 3 vertebrae, the rest of this restoration are purely conjecture. Found in England from rocks dating to the early Cretaceous. It's though to be related to either the sinraptors or Acrocanthosaurus. I drew it more like Acro due to the elongated nature of the 3 vertebrae.

I've been having problems with Blogger not telling me things are spelled wrong and even keeping them wrong AFTER I have corrected them. My spelling is horrible to begin with so you might not notice;)

Best,

Brett

Friday, April 24, 2009

Spinosaurus aegyptiacus

The ever popular Spinosaurus. Originally found in the desert near Egypt (mid Cretaceous rocks) at the beginning of the 20th century, all the original material was lost during the bombing of Germany during WWII. We are lucky to have drawing of the material so all was not lost! The original material which consisted of the front part of the lower jaw, a few neck vertebrae, a few tail vertebrae, and most of the back vertebrae with the elongated neural spines. The original restoration was of a giant allosaur with a sail, like this drawing. The exact size of is hard to pinpoint. The original material appears to not have been fully grown. Sizes from 50 to 65 feet have been offered, but we'll have little to no idea until a new skeleton is found.

For a long time that was the restoration, until the 80's, when Baryonyx was found. It was quickly discovered that the 2 species were very similar, that gave us our first decent peek at what a spinosaur looked like. In this restoration I bulked up the skull a bit, the lower ends shortly after the tip, but the back of the jaw bone looks very robust. So I toyed with the idea that Spinosaurus was sort of returning to a more predatory dinosaur, Baryonyx was considered a fish eater (even though iguanadon bones were found in it's stomach contents, along with fish scales) so the skull was more delicate.
In 2003 it was suggested that Spinosaurus was actually a chimera (made up of more than on animal) since it was found in a bone bed with other animals. The jaw belonging to a spinosaur, the neck to a relative of Acrocanthosaurus. The back to a sauropod (all of the three major dinosaur branches produced a 'fin' back.) I actually like the idea (I suggested a hadrosaur for the backbone since the older adults bones seem to mimic theropods, something I didn't know until I saw Valley of the T. rex with Jack Horner. But a sauropod would explain the great size) I liked the idea of a chimera, the sail would be a great hindrance to an active predator. But science changes and moves on...

It was reported that a new skull was found earlier this decade, something that would have been around 8 feet long. Now there was/is a possible relative of Spinosaurus, or in this case a subspecies, also found in Africa, this was dubbed Spinosaurus marocannus. Only the front part of the upper jaw was found, it was very delicate. But this new skull, seemed to link the 2 species/subspecies together, the new skulls teeth matched the original lower jaws teeth so it appears that the more robust skull I drew was wrong, so this drawing was done.


This is the most recent drawing, based on all the info I could find online. It looks like Spinosaurus is actually closely related to the South American spinosaur Irritator. At first Irritator was thought to be a pterosaur (it's skull is really strange even for a spinosaur,) but the new skull material for Spinosaurs matches it rather closely, even similar in tooth count.

What appears to be emerging is a very different animal than originally described. Long and lean, the nostril s far back on the skull, the neck designed for a more heron like attack. It appears to be a giant fish eater, perhaps it was forced to the water as it's great length wouldn't protect it from the other giant theropods that shared it's environment? (Carcharadontosaurus, Deltadromeus and possibly a few others, the remains are too scrappy.)

But what of the sail? It's been theorized that it was for fat storage, but the spines are very thin, I doubt they could have supported much weight. Possibly for cooling? Other theropods with similar size didn't have one, but maybe it helped when fishing in the afternoon, it does get hot inthe sun. I've also heard it was used as an actual sail for swimming... We know theropods could swim, we have 'foot' prints, really just nail prints;) But none of the other spinosaurs with associated skeletons show aquatic adaptions.. So I had an idea. It might be wrong, but what about a shade for hunting in the sun? Something to keep the glare of the sun off the water so it can see the fish below? Or maybe a combination of these? That's the most plausible scenario seeing as most parts of the body preform several functions.

Best,

Brett

Thursday, April 23, 2009

Tyrannotitan

A large early carcharadontosaur from South America. Not much is known about this animal yet. It's clearly large, around 40 feet, and the arms are very small (thus the name.)

Even though only a small amount of the animal is known, it's enough to give you a basic idea of what it looked like. Besides the small arms, it is also known to have a deep tail, so it's assumed that swimming would have been possible. Of course with all those horrors of the deep swimming around I don't think theropods would have ventured far into the water;)

Tuesday, April 21, 2009

Albertosaurus Attack!

A quick shot of a sub adult Albertosaurus attacking a Struthiomimus, both from Canada. Albertosaurus grew to around 30 feet and Struthiomimus got to around 15 feet. Paleontologists are still not sure what the orstich mimic dinosaurs ate, everything from filter feeders to omnivors have been proposed.

Best,

Brett

Suchomimus

So this is an older shot of Suchomimus. As you can see I don't really like drawing backgrounds, since I don't actually get paid for doing these drawings, I tend to just concentrate on the animal.

Found in Africa, this animal is considered a close relative of Baryonyx (the first good specimen of a spinosaur found.) The skeleton that was found was of a sub adult and it was 36 feet long, so this animal might have gotten to the 40+ foot size range. There are teeth from this line of spinosaurs (Spinosaurus and Irritator are on a second branch, they have less teeth and a more pterosaur like head) from Europe, weather this is a third species is unknown right now.

Best,

Brett