palaeontology

International Fossil Day!

How better to start this blog than with International Fossil Day? For those sadly bereft of the awareness of this grand occasion, yes it really is a thing. In fact it's two things, being that it covers the whole of the weekend of October 13th and 14th (palaeontologists not being renowned for having a good handle on short time intervals...). Two (other) things sadly prevented me doing something really good with this day: not noticing it was happening in time, and Storm Callum!

But here it is, and here we are, and I'm sitting in the 'shop' surrounded by fossils. Many of them are undescribed species (we're working on it... slowly!) Here, for example, is what's probably a new species of bryozoan, or moss animal:

 Undescribed species of bryozoan

It's a gorgeous thing, only 2cm wide, preserved with the calcite skeleton now replaced by iron oxides, probably as a result of the weathering of pyrite (fool's gold). These animals formed colonies, with an individual living in one of the tiny tubes that produce the saw-tooth edges. Bryozoans are very common animals today on modern strand lines (you've probably seen them washed up, and thought they were seaweed). The most abundant is Flustra foliacea, the Hornwrack, which is well illustrated by the incomparable Wikipedia:

Flustra foliacea (Creative Commons license)

(The observant will notice a second bryozoan nestled in the middle - I'm not sure what it is from here, but perhaps a Crisia species.)

Why start this blog with bryozoans? Well, there are several good reasons...

Partly because it illustrates our societal biases. How many people know what bryozoans are, despite them being such a major component of modern seaside communities, and such an important group in very many fossil assemblages (such as the famous Wenlock Limestone Formation)? They're a group that is often overlooked and forgotten, whether modern or ancient... and yet, that's our fault rather than theirs. Bryozoans are diverse, beautiful, and major components of many ecosystems... but in most cases, they can only be appreciated by those who take the time to look closely. They were really appreciated during the great age of microscopic discovery in the Eighteenth and Nineteenth centuries, and illustrated in numerous wonderful volumes, the drawings engraved onto lithographic limestone plates. Here, for example, is a Crisia species, C. denticulata from Lamouroux (1812):

Crisia denticulata (Lamouroux 1812)

Bryozoans are also, because they are so overlooked, an area we still know little about - at least for the early fossil ones. There are few specialist palaeontologists studying them, and they tend to prefer preservation in limestones, where the colonies can be sectioned at specific angles to see all the internal structures. For famous deposits like the Wenlock Limestone there have been monographs published that describe them all (I shared PhD time with Jo Snell, who made some ridiculous number of meaurements (was it 100,000?) over three years, to help her to classify and describe them in detail. These ones from deeper-water or non-limestone environments, though, are almost untouched; it's likely that most of what we find are new species. 

This is the real beauty of palaeontology as a subject: it's almost limitless. We will never know all there is to know, and dedicated fieldwork will produce new discoveries. The more we learn about fossils, the more questions there are. And all those hours sitting in damp quarries hammering..? Well, who remembers the discomfort when something like the bryozoan at the top of the page turns up?

 

Detail: Middle Ordovician (muchisoni Biozone, Darriwilian) of the Llanfawr Mudstones Formation; Builth Inlier, near Llandrindod (site under investigation for exceptionally preserved sponges, amongst other things). Unidentified (probably undescribed) species of fenestellid bryozoan, with zoecia opening on this side only (counterpart lacks openings); attached to poorly preserved orthocone nautiloid