What Carbon Has To Do With It

This may go under the radar, so I consider it opportune to mention it. While it doesn’t directly consider fossil archosaurs in any fashion, or a ridiculously over-hyped but very popular group of bird-stem archosaurs, the study at hand does consider the methodology of 1) writing a good paper, 2) being exceptionally thorough in both summary of previous results and current methodology, and 3) analyzing a bulk of trends in consideration for how to assess diet when all you have are teeth.

The Next Step

While discussing lips in theropod dinosaurs is easy, and a bit dinosaur-centric (what about lips in nondinosaurian archosaurs?!), there are two major elements of the dinosaury that bear understanding: First, that ornithischians present an additional hurdle to overcome when discussing facial skin and its extent (i.e., the issue of “cheeks”) and sauropods present the interesting issue of what to do with large open spaces in the jaw. The latter issue is easier to deal with and represents the next step.

What Use A Perfect Specimen?

A holotype specimen is important in systematics when the taxonomist desires to use an ideal specimen upon which a new animal is created. It is the first, and best specimen, for future systematists to refer to when comparing other taxa. It bears the diagnostic criteria from which other specimens can be compared, and thus whether those specimens do or do not belong to the new name. Occasionally, the taxonomist has used a partial specimen, say fragments of the skull (Quaesitosaurus mongoliensis Kurzanov and Bannikov, 1983), a vertebra or a series of such (Titanosaurus indicus Lydekker, 1877 — where two vertebrae with varying morphologies form the holotype and paratype), or even just a tooth (Astrodon johnstoni Leidy, 1865). In other examples, the holotype is a juvenile (such as Apatosaurus ajax Marsh, 1877), and this raises another issue.

To Play Devil’s Advocate

Recently, Mike Taylor of University College London and Matt Wedel of the Western University of Health Services (both of  SV-POW!) and Rich Cifelli (of the Oklahoma Museum of Natural History) have published a paper describing a new taxon, Brontomerus mcintoshi (freely available from their website, or online from Acta Palaeontologica Polonica itself). They have produced several engaging and data filled posts at the SV-POW! blog, so check them out (including the magnificent photo gallery).

OTP: One True Posture

I’ll summate briefly:

Sauropod neck posture has been debated fairly aggressively among those narrow-discipline sauropod specialists (and occassional avocation biologists) for about a century. Speculation has permitted some people to put sauropods into “snorkel” position deep under water, extending their necks far above their bodies in near-vertical postures, and it has also caused some people to think sauropods were incapable of holding their necks at any real posture above the horizontal, and even then just barely. Attempts to discover the “true” posture has engrossed some researchers, who sought what may be the “Holy Grail” of sauropod neck attitude, the “One True Posture.”

I think they’re all wrong.

A Radical Idea

Or … maybe not so radical. It doesn’t change that much.

Some readers here will recall a small debate over at SV-POW! where I argued with Mike Taylor over the effective purpose and reason behind the recognition of the name Giraffatitan [1] (originally named as a subgenus of Brachiosaurus by Greg Paul [2]). In this work, Mike Taylor described the known material of Brachiosaurus altithorax (as recognized by Riggs [3]), and noted the distinctive qualities between Brachiosaurus altithorax and then-Brachiosaurus brancai, the latter a sauropod taxon recovered from the latest Jurassic of Tendaguru, Tanzania [4].

Sauropod Feeding Strategies #2

A more thorough version of my last post is presented. There is some confusion over what the papers presented below actually say, some of them very technical. A summary, which may certainly be wrong in some cases, is required.

Sauropod Feeding Strategies

Few studies have actively approached the premise of sauropod neck position from a purely biomechanical viewpoint. Those that do, however, tend to differ on their results. This is generally due to 1) taxon sampling, 2) methods used, or 3) how much of the biomechanical data was used in the conclusions phase of the work.