Sunday, 5 June 2011

Anomalocaridids ahoy!

Fossils by hallucygenia
Fossils, a photo by hallucygenia on Flickr.

It seems that the Famous Fezouata Biota of Morocco is turning up the goods again. Hot on the heels of last year's announcement of just how good these rocks in southern Morocco are turning out to be (, here's another paper in Nature by Peter Van Roy and Derek Briggs:

We should say that we're not overly surprised. In fact, this is what we've been telling you all we can't tell you about, ever since we came back from the last fieldtrip. Now, however, the work is done, the cat is out the bag, and we're free to put up silly photos. The cat in question is among the largest arthropods ever found: a monstrous, primitive creature with grasping appendages and a pineapple-ring mouth... yes, it's everyone's favourite: an anomalocaridid!*

What you see before you is an array of pieces of anomalocaridid in the hotel restaurant in Zagora. It turns out there are probably pieces of 6 specimens in this unceremonious pile, and you can see in the biggest ones the wide segments going across the body. You might also notice that they're all bits... there's not a single complete one amongst them (I know they're a metre long, but even so... shouldn't we have made the effort?).

All these specimens were found in a small area, in drainage channels down the side of a hill. How long they had been weathering there is anyone's guess... but a good while. The anomalocaridids were preserved whole inside huge nodules (silica-iron-manganese, apparently), and as the hillside weathered in, they broke off, piece by piece. So, finding them took some trawling up and down the channels, and sticking them together was perhaps the best jigsaw I've ever had the pleasure to have a go at. It's a shame someone lost half the pieces. Still, you take what you can get in this line of work.

So why is this find important? Well, it's big and scary (bigger and scarier than any known before, in fact), and it's also the youngest example. These monster predators (probably the only larger animals in the Cambrian seas were sponges) were thought to have gone extinct in the Cambrian. The Fezouata Biota is showing that these survived into the Ordovician along with everything else, and indeed were positively thriving. The number of specimens in a small site is startling, the size is disconcerting... just think what it would have been like swimming amongst them and trying to avoid being eaten...

*If the word "dinosaur" appeared in your mind at this point, however briefly, go home and meditate on your iniquity until suitably chastened. Yes, you, Neil.

Friday, 3 June 2011

Another swallowtail

Papilio polytes by joe with a camera
Papilio polytes, a photo by joe with a camera on Flickr.

This is a swallowtail butterfly feeding on a pomegranate tree, photo taken by Joe at Xuanwu Lake, near the institute. We went to have lunch by the lake a few days ago, saw this flying around and, after some chasing, got this photo. The butterfly's wingspan is roughly 10 centimetres, to give you an idea of size. The photo hasn’t been manipulated apart from being cropped; the background looks odd because the photo was taken against the sky using flash.

We're off back to the UK for six weeks of fieldwork this weekend. We're hoping to be able to keep the blog updated fairly regularly, although we won't have internet access for at least some of the time.