Spoils of something-or-other

Protospongia? sp., a photo by joe with a camera on Flickr.

Well, we survived the trip, and very successful it was too. We actually found enough for several papers, and are working hard on them even now (well, more or less - we have just had dinner, and we've got to be in early to use the electron microscope).

This one is a rather stunning specimen of Protospongia - or something very like it, but I think it really is Protospongia, unlike most of the species that have been called it in the past. The grid is made up of cross-shaped spicules, which would have been made of opal (probably, but that's another story) when alive. It was buried in quite unpleasant, anoxic mud, and the spicules have been replaced by pyrite (fools' gold). It's very common for spicules to be replaced like that; it's not at all common for the skeleton to be preserved beautifully intact. This is only a fragment, but the field of view is about 7 cm across. the complete sponge would have been a delicate, bowl-shaped thing with the wall consisting of a single layer of spicules, surrounded by soft tissue, the entire sponge probably a good half a metre in diameter.

Now, isn't that cute?