Gripe

Eventually, when I finish my current projects, I will get around to discussing conodonts, and their jaw-like … things. But for the moment, I’d like to call out to the various sources on the latest paper (not yet published in print in the journal Proceedings of the Royal Society, B: Biological Sciences, but available online, here) that has been receiving attention [Taylor Reint's consideration, a Nature blog, and a Scientific American blog treatment] due to the results of finite element analysis (FEA) on one of the posterior P elements of conodonts.

Enquilled

It’s kinda of a mystery, and I’m not sure I can solve it, but…

Buck Teeth? Wait a Minute….

New news of a new newsworthy theropod dinosaur in the presses. It’s not published in paper yet, although the journal has it available (free) on its website. Because it’s not published (on paper) I will refrain from discussing the taxon (or the paper) virtually at all.

A Little About Interdental Plates

Interdental plates represent another feature of variation in the dental row, and one generally taken for granted by most researchers, and the following illustration represents a crude way to encapsulate some of the variation that occurs in archosaurs. Because interdental plates appear virtually exclusively in crurotarsans and dinosaurs, I focus my attention on the subject to those groups where present.

Tooth Implantation – PiT#2

This is the second “Precision in Terminology” post

Tetrapods generally have only a few ways to affix teeth to their tooth-bearing bones. While most of you readers may be familiar with socket-toothed implantation (thecodonty), the range of dental attachment varies greater than that. Generally, then, there are three types:

A Definition for “Heterodonty”

Teeth in jaws are generally graded by a useage of “heterodonty” versus one of “non-heterodonty.” In some groups, teeth that are actually identical in two spectra (form and size) are termed isodont (literally, “same tooth”) and could reasonably pass for one another without any confusion. The opposite of isodont dentitions has been called “heterodont,” (literally, “different tooth”) but this is used in two ways.

Pubic Orientation — WP#8

One of the more interesting non-dental features of theropod dinosaur evolution is the orientation of the pubis. Historically, it was used to help affirm the transition of the modern bird form from that of particular theropod dinosaurs. Back then, it was Gauthier [1] and Ostrom [2] (and lesser known but nonetheless correct, Barsbold [3]) who tied retroversion of the pubis to birds and dromaeosaurid theropods, but this obscures that some historical perspectives, going back to Thomas Huxley of all people, correctly identified some features of the dinosaurian hip to that of birds. Of course, this was based on the occassional premise that Ornithischia (“bird-hipped ones”) was correctly named in more ways than one.

Therizinosaur Humerus – WP#7

The humerus (or the anterior propodium) is one of the most complex bones of the limb, next to the femur (or posterior propodium), and various carpal/tarsal bones as they are described in mammals (although that’s largely practical, rather than actual). I don’t come to this conclusion lightly, but based on the weight of the number of different features associated with it:

What – If Anything – is a Nomen Dubium?

Historically, taxonomy has been the playground of débutants and the workshop of balls-to-the-wall genetic systematics. It is the method by which names are applied to organisms, to distinguish concepts of how life can be categorized. We’ve seen different systems of nomenclature (the actual subject of names) applied to phylogeny (which together form taxonomy), and we’ve touched on the various ways in which taxa have been regarded as dubious, set aside, or expanded on the basis of the concept of the nomen dubium.

Problematically, there is no “one way” when it comes to regarding something as a nomen dubium, and the practice of regarding something as one, as how you treat it afterwards, has been variable historically. I’ve had plenty of opportunity to regard the various concepts, and their applications, and realized a few things about the phrase and label (and how its been differentially applied to various taxonomies).

Precision in Nomenclature #1 (Phalanges)

Yay! Another series, and more of a break. This time, it’s about terminology, one of my more favorite aspects of methodological science. Without knowing what to name stuff, we lapse into grunting and rude gestures, and nobody likes that. Well, I mean, I guess some of you do — perverts.

But terminology has two broad aspects, and in most cases, they are both highly useful, but you need to keep an eye on them.