Things to Do
We’re edging ever closer to a real, live analysis! In the meantime, there are four big tasks that remain for all of us:
- Double-check the taxonomic assignments of specimens, and make sure that they are up-to-date.
- Create a full listing of the ages of all included taxa.
- Finish the phylogeny.
- Weed out composite, juvenile and taxonomically indeterminate specimens.
You can help out with any of those – right now! I’ll write about each topic in more detail below, including what you can do to help.
But first, I would like to thank ODP volunteer Dave Dreisigmeyer for some major-time database coding work that he has done. Many of our specimens have measurements for individual elements identified as right, left, or unspecified. For instance, a specimen of Iguanodon might have published measurements for both the left and right humeri. We need to average those out to get a single value for just the humerus as a whole. This could have been time-consuming (and error-prone) work, but Dave wrote a nifty little script to do this automagically. The result is available for download here.
On to the tasks. . .
The original version of the database only used the published genus and species for each specimen. As taxonomy changes, these identifications must be updated. In some cases, it’s straight-forward. For instance, the animal formerly known as Yandusaurus multidens is now called Hexinlusaurus multidens. But, some areas are pretty messy – there are almost certainly too many named species of Psittacosaurus, but there isn’t a good published summary of the up-to-date taxonomy for this genus. In the end, it will require personal opinion (unfortunately).
What to do to help: I’ve started the work for some of this, but now we need to get it polished up a bit more. To make things easier, please use the Google document posted here (it’s the same one we’ll use for noting ages, too). If a name needs to be fixed, just mark it in the appropriate column. The project heads (Farke, Wedel, and Taylor) will have ultimate authority in the event of any disputes.
For the analysis focusing on morphological disparity (i.e., how different are the dinosaur limbs from each other), we will also want to look at the time component (see Randy Irmis’s guest post for more on this). So, we need to know how old all of our dinosaurs are. Fortunately, Rob Taylor has gotten a great head-start on the issue, and we’ve posted his file for you to add to it. Use published references whenever possible (see the document for more instructions).
What to do to help: Using the peer-reviewed literature (with references and page numbers, please), help fill out the table posted here (Google Document). The Dinosauria (2004 edition) is quite helpful. Also, many of the papers that published the original specimen descriptions can also help (especially for newer taxa).
Finish the Phylogeny
I spent my spare moments today drafting a phylogeny on which to hang our analysis. In an upcoming post, I’ll provide a few more details on what/how to contribute to this effort.
Weed Out Composite/Juvenile/Indeterminate Specimens
I’ve already removed specimens based on isolated elements (because they’re not a lot of good for comparison). For various statistical reasons (and because animals change body proportions as they grow), we also want to remove most of the juveniles from our analysis (although we may keep a few key players in there, especially if they’re from poorly represented portions of the family tree). Composite specimens (e.g., those made of multiple individuals, as happen in some museum mounts from bonebeds) also need to be excluded, because we have no idea if they accurately represent individual proportions. Finally, if we can’t identify a specimen (i.e., it’s listed just to the family level), it should also be removed.
What to do to help: Take a look at the trimmed-down spreadsheet of measurements (available here as an Excel spreadsheet). If you see a specimen that you think should be excluded, please mention it in the comments for this post.
Image credits: Original by Nobu Tamura, as posted at Wikimedia Commons. This file is licensed under the Creative Commons Attribution ShareAlike 3.0 License. In short: you are free to share and make derivative works of the file under the conditions that you appropriately attribute it, and that you distribute it only under a license identical to this one. Official license
NOTE: Co-authorship on the first major resulting full paper is offered for those who contributed measurement data, and also will be offered for other contributions at the discretion of the project heads (Farke, Taylor, and Wedel). However, those who help but do not have co-authorship will receive a place in the acknowledgments for the final paper. Please make sure you mark your contributions in the appropriate place, in order to receive credit.