Juan Manuel Usera

An iguanodon, a cetiosaurus, pteranodons… the old prints decorating Juan Manuel Usera’s office would be a delight for any kid. He is Full Professor of Palaeontology at the University of Valencia. There are stacks of papers everywhere, however, and they are a good example of the volume of work carried out from this reduced space in the department of Geology. This year, the specialist in foraminifera was in charge of the course opening of the University of Valencia with the master class «Palaeontology, Quo Vadis».

Why did you choose the future of palaeontology as the topic for your conference?
If the topic had been really scientific, it would have reached very few people. Talking about the development of palaeontology, I thought people would understand how ideas about fossils have changed since the times of ancient Greece until today. That is easy to capture by anyone in the audience.

And what can we glimpse of that future, in this moment of recession?
The fact is that today palaeontology is not just going out to the countryside looking for fossils. Now you take your fossil and you do all kinds of things to it: isotope analysis, microstructure analysis…

And do you need more resources for that kind of research?
This line of research is way more expensive than the other one. That other one was fieldwork, lab work and not much else. That is why I said in my conference that governments are the ones who could finance it.

Then is the work of a palaeontologist today more lab work than backpack and mountain?
Yes, there’s a lot of laboratory work. Although there is a whole generation of palaeontologists who prefer going to the field and mountains to find fossils.

When one thinks of palaeontology, it is easy to think of the great fossils of dinosaurs. You, however, are specialist in foraminifera, which are diminutive organisms. What peaked your interest for such small fossils?
Well, in geology we studied a subject called micropalaeontology, and nothing is more beautiful than a microfossil. The structures are spectacular…

I have to recognize that I googled for images of foraminifera and was surprise by their beauty.
Even other groups like radiolaria, silicoflagellates… are perfect structures that had been copied over and over again by architects, structures of enormous consistency. I don’t know if you have heard about Emiliano Aguirre, the discoverer of Atapuerca… He taught me Quaternary and Human Palaeontology. When I told him I wanted to devote my career to micropalaeontology, the topic of the Mediterranean Sea desiccation, the Messinian crisis, was on everyone’s lips, and he brought me some samples of marine clays from Niebla (Huelva) that belonged to that border of the Miocene. I prepared them, cleaned them and there were such beautiful groups, really beautiful, of foraminifera… some benthic, other planktonic… and I fell in love right there and then.

What can we learn from foraminifera? Why are they so important?
They are very specialized protists. The kind of pseudopods they have is very special, with microtubules in which currents form in such a way that all the food particles surrounding it move towards the digestive vacuoles. That is a unique feature of foraminifera. And then, they can have sex or not. In stable environments, they are sexless. As there is a lot of competence with other organisms, it keeps developing and growing, but it does not reproduce because there is not enough food for so many. When the environment is unstable, for example in marshes that dry up during the summer and fills again in winter, it uses sexual combination to get a wide range of new possibilities and always survive.

That is to say, they provide information not only about the age of the rocks but about the environment…
That would be another aspect, the age of the rocks. Mainly because there are some groups with a really fast evolution rate, and so many species are created in a brief period of geological time. At that point you can, by identifying each species, know in which layer and level you are.

Does micropalaeontology have any other practical applications?
Well, there is the one I talked about in the conference, dating in oil samplings, because drilling heads destroy all the macrofossils. Only sand comes out, and with it come microfossils. It was interesting to know the age of oil layers, which usually coincides with eras of bad ocean circulation. Anoxic environments are formed at the bottom of these layers. You need to drill to get there and, of course, each metre of survey costs millions in infrastructure… Therefore, you need formidable precision.

Up to which point did those economies contribute to develop the field?
An enormous lot. Labs were created all over the world and all of us worked there, in the oil industry. And, well, many journals emerged, some specialized, some group-specific or about micropalaeontology in general, and they carried out mainly taxonomy work, species identification in certain layers to serve as a guide and, as samples were extracted, know which era you were talking about. Then came high-resolution seismic, which shows the oil layer.