25 October 2013

Taxonomy check

If you teach a student foram taxonomy, and then they go off and make all sorts of taxonomic decisions you wouldn't have made yourself, does that mean you've not taught them well enough, or does it mean you taught them too well?

We had a MRes student (one could say,  a MSc student with PhD icing) in Plymouth who did foram counts on the intervals I hadn't covered, to see if anything happened in the time periods they represented. And now she's done! Next month is her viva (thesis defense; they have to do that for an MRes). And in the meantime, we incorporate her work into our project.

And then it's suddenly not so practical that we're most of the country away. In order to merge her counts and mine, we need to call the same thing the same thing. And you can't easily keep an eye on that with a 6 hour train ride in between. So we had gone through the taxonomy together before I left, but since then she checked her taxonomy with one of the chaps from Geology, who was another one of her supervisors. And he knows his stuff! He learned from the best. But he's not me. And in a case like this, it's actually more important your identifications are consistent than that they are correct.

 The rather pretty foram that had remained ignored

When we received her thesis and combined the data in it with mine, we saw that it was clear we did NOT use the same taxonomy. There was one species, that I had in most of the samples,  and that was absent in her counts. And some of her species were consistently more numerous in her samples than in mine. So we had to clear that up!

By sheer coincidence, our student was about to visit her brother who lived nowhere other than in York. That was convenient! She popped by at my office to hand over her slides with foraminifera. I was a bit disheartened when she told me she had lumped all different species of the two main genera present in the slides. This meant I would have to separate them myself in order to re-count the assemblages!And her counts suggested that 65% of all little critter fell in that category. So I was handed 6359 calcareous remains of marine organisms, of which 51% was not identified at species level at all, and another 14% had been identified at species level, but had been placed in the microslides in big heaps of the same genus. Oh dear...

 How I received the slides

What they look like when I'm done with them

I'm well on my way sorting this out by now. And I have found out that the geologist had not recognised the allegedly absent species. I am surprised to have the idea to know better than an expert! And we don't agree on taxonomy. My counts are different. So I now spend my days going through every slide, and picking up every single foram and placing it in a square with only what I think are its mates of the same species. And I line them up, so they're easy to count. As I write this I've done 1680. Another 4679 to go...

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