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Showing posts from February, 2008

Torvosaurus 3

Following yesterday's pencil sketch and digital line tracings, I've digitally colored in my Torvosaurus using Illustrator. I like Illustrator as it allows me to store the image in vector format thus I can scale it to any size without losing any resolution. Plus, more importantly, I can use layers to add different tones and texture. I guess you can do the same in Photoshop but I'm more used to Illustrator.

This one turned out to be a lot better than my Allosaurus as I've been spending the last two weeks preparing figures for my manuscript in preparation basically using pretty much the same technique but on photographs of skulls and reconstructing jaw muscles on them.

Torvosaurus 2

Line tracing with shadows of the same Torvosaurus drawing from the previous post, using Adobe Illustrator.

Torvosaurus

I initially named this sketch Megalosaurus but then remembered that I've been relying on the proportions of Torvosaurus for the reconstruction, so it's been renamed to Torvosaurus.Torvosaurus is a North American "megalosaur" popularly used to aid in the reconstructions of the English Megalosaurus mostly because the long-held assumption that these two taxa are closely related. However, more recent phylogenetic analyses show that the traditional monophyletic Megalosauridae does not seem to exist anymore but rather a paraphyletic "Megalosauridae" with a paraphyletic grade of "megalosaurs" leading up to the Spinosauridae. Or something like that...there seems to be quite a lot of confusion in this area of the theropod phylogeny probably because of the lack of good specimens. Although, in a consensus tree of published trees, a fair chunk of the traditional "megalosaurs" still seem to come together in a smaller but yet monophyletic Megalosaurid…

Olfactory capabilities in T. rex and birds

I’ve recently had the chance to review the literature regarding olfaction in birds and to my surprise found that there is little research done on the olfactory functions (e.g. olfaction threshold) and their relations to the olfactory bulbs. The main reason I got into this was primarily for the claim that T. rex had an acute sense of smell because of its enlarged olfactory bulbs. Now the latter part of this statement is obviously true. According to Brochu (2000), the olfactory bulb is 1.5 times as wide as the cerebral region of the endocast in T. rex. Following Bang and Cobb’s (1968) simple method, the greatest diameter of the olfactory bulb is about 41% of the greatest diameter (in this case the longest length) of the total brain. That’s higher than the largest proportion of olfactory bulb in modern birds according to Bang and Cobb (1968), which is as follows:

37.0% - Snow Petrel
33.0% - Wilson’s petrel
30.0% - Wedge-tailed Shearwater
30.0% - Greater Shearwater
29.5% - Dove Prion
29.0% - Bl…