That is the geochemical question.

I've collected concretionary rock samples from the fossil locality in central-western Queensland I'm studying, and am now in the process of (partially) destroying them. Why/how/WHAT?

Well, I want to examine the types of minerals in the rocks, including their structure and chemical composition, because we don't know much about the depositional environment under which dinosaur, fish, and crocodile remains were fossilised. Due mainly to the fact that no-one has investigated it yet, but also because there is very little outcrop at the site. Which means I won't be constructing a nice long stratigraphic section, which is normally used to conduct facies analysis, which in turn indicates the likely depositional environment (i.e. deep sea, or river channels, or floodplains and so on). Instead, I'm relying on geochemical indicators of environment.

The analyses I'm undertaking are destructive or partially destructive. Polarised light microscopy, scanning electron microscopy (SEM), and electron microprobe analyses, although non-destructive, require thin sections or small stub samples from sliced-up rock. X-ray diffraction (XRD) requires samples that are crushed into a fine powder. Inductively coupled plasma atomic emission spectrometry (ICP-AES) and stable isotope analysis require dissolving the rock in acid which becomes, in the case of ICP-AES, atomized into a mist-like cloud.

These rocks, having survived 101 million years of erosion and a ~1000km car ride back to Brisbane, are now literally dust.

For Science!

But seriously, this is work that absolutely has to be undertaken, to understand how and under what conditions these dinosaur, crocodile, and fish remains became fossilised.

Confession time.

I've not been writing very much about my PhD here lately. 

The reason? Fear of being scooped. 

Which is a little bit hilarious, because on the one hand I suffer from imposter syndrome, but on the other hand I must think my ideas are *so* brilliant that they would be stolen the minute they're posted online.

After attending the 14th Conference on Australasian Vertebrate Evolution, Palaeontology & Systematics (CAVEPS) last week, and talking to a few people who said my blog was more about research techniques and technology than actual palaeo research, it's time to mend my ways. Even if it means my ah-mah-zing ideas are up for grabs, it's better to practice pitching them and getting some feedback. And it'll be a hell of a lot more interesting for you, dear reader.

So, it's time for more palaeontology, more taphonomy, more dinosaurs!

Sometimes accidents happen. Sometimes, those accidents are preserved in the fossil record, And sometimes, we're lucky enough to find those fossils and ponder over the fate of those poor individuals. In the case of the amphibian Sclerocephalus haeuseri, shown in the image below, it had literally bitten off more than it could chew.

Ahem.

This particular specimen appears to have died while eating another smaller amphibian (possibly a smaller S. haeuseri). If you look at the images below, the skull of the smaller individual can be seen in the larger individuals throat region. I've gotta say it again... I love taphonomy! But I would urge caution, as perhaps these carcasses merely laid on top of one another and rotted together. Or some other taphonomic oddity merged the two skeletons together. It's hard to tell without close examination.

Unfortunately, this slab (which includes a small fish fossil - possibly Paramblypterus gelberti - completely ignored by the press, poor thing!) is going to be auctioned off by Heritage Auctions on the 19th/20th October, 2013. If it ends up in the hands of a private collector, any research conducted on that fossil cannot be included in a published paper, as journal guidelines often stipulate that fossils studied must be housed in publicly accessible institutions (most often, museums).

Some might argue that a private collector can allow access for researchers to the fossil; however, what if they change their mind? And will their heir allow access? Or their heir's heir? Will it still be accessible in 100 years time? Given that this fossil came from a 'Private San Francisco Collection' (according to the auction website), this probably explains why this specimen has not been included (to my knowledge) in a scientific publication thus far.

At least the auction house admits that "Because of changes in German law, collecting of these specimens is no longer permitted." Phew! Similar laws restricting collection and sale of fossils are in place in other countries; however, this doesn't stop illegal collection and auction, and only with a lot of campaigning are these auctions halted (like the cancellation of a Tarbosaurus bataar fossil auction earlier this year).

Also, ignore the media's label of 'crocodile' when referring to these specimens: they are crocodile-like in shape, I guess, but any reference to crocodiles just confuses the issue! They are amphibians, not reptiles. It would be like calling a bee a 'bird' because they both have wings.

Last week, Flinders University hosted the 14th Conference on Australasian Vertebrate Evolution, Palaeontology and Systematics (CAVEPS 2013) in Adelaide, SA. What a week! It was a great opportunity to catch-up with old friends from CAVEPS 2011 and make some new contacts too. The conference was extremely well organized by Gavin Prideaux and his team, and enjoyed by all.

There were pre- and post-conference field trips to Kangaroo Island and the Lake Eyre Basin respectively, and a series of phylogenetic, dating, fossil preparation and scientific illustration workshops on the first day of the conference. The main conference symposia and general sessions ran from Tuesday through to Friday, topics including:

• Stirton Symposium: on R. A. Stirton's trips to Australia in the 50's and 60's. Many speakers sung Stirt's praises, which got a little repetitious towards the end ("He preferred to be called 'Stirt' " was mentioned in at least 5 different talks). Apparently Stirt discovered almost half of all known mammal fossil sites in Australia, which led to an intriguing suggestion by Tom Rich that more fossils could be found in, for example, fissure fill or impact crater fill, and we just need to go out and find them! If we all had the time and money, I think we would.

• Phylogenetics Symposium: molecular data versus morphological data (old summary of what this is/why it matters here). I'll admit up-front that I've done little phylogenetic work myself, so this symposium was very educational. Johannes Müller started by suggesting that although molecular techniques can produce some unorthodox hypotheses about the evolution and relatedness of taxa, instead of dismissing them outright, morphologists should see this as an opportunity to test the new theories. The following presentations were a mixture of pro-molecular or pro-morphology analyses, with some integration of the two. Obviously still some disagreements in this field...

• Palaeoecology Symposium: comparing modern ecosystems with ancient ecosystems. Lee Lyman began by reminding us all that conservation targets shouldn't be static - there isn't a magic number or distribution of species that is 'correct', as they have and will naturally change all the time regardless of human impact. Evidence for this is in the fossil record, with other speakers expanding on what that evidence is: mesowear, trace elements, and isotopes in teeth, pollen preserved in stalactites and stalagmites, ancient DNA and stable isotopes from eggshell, body fossils, and mathematical models (such as GRIWM).

• General sessions: ranging from megafauna to dinosaurs, fossils to footprints. Presentations included topics on functional morphology and ecology, faunal response to quaternary climate change, early vertebrate evolution (including Devonian placoderm fish), dinosaur fossils and ichnofossils, and new Cenozoic taxa. The majority of presentations focused on mammalian and marsupial palaeontology. There were a few archaeology presentations, including one very interesting talk by Silvana Tridico on the form and function of mammoth hair (it was blonde/translucent in colour, not red, by the way).
  

I presented a talk in a general session titled, "Dinosaurs (and croc taphonomy)" on, you guessed it, crocodile taphonomy. This session was held on the last day of the conference, right before lunch, so I had all week to stress and feel nervous about the talk! Right before the talk began, I told myself, "You're not feeling stressed or nervous, you're feeling excited to tell everyone about your research", which seemed to work quite well.

I explained the results of my decay experiments, that croc carcasses allowed to decay in water will float, and disarticulate upon sinking, even in the absence of water currents or large scavengers. It was well received, with lots of chats about taphonomy at the lunch break afterwards. It may be obvious to you all, but it is now abundantly clear to me: if you want an easier time networking at conferences, present a talk or poster!

I was very fortunate to take out the prize for 'Best Student Oral Presentation' along with Shimona Kealy (a UNSW Honours student who presented a very impressive total evidence phylogeny of Dasyuromorphia). Go us! I received a lovely trophy (pictured above) which showcases examples of vertebrate fossils found in Australia (including a Thylacoleo tooth, crocodile scute, turtle plastron, dinosaur bone, shark teeth etc...) as well as funds for research related activities. I already have a plan for the prize winnings: funding my trip to NAPC in Florida next February. Bring on more conference talks and networking!