You may have seen the Museum’s work in the news recently, when our scan of a catshark helped University of Sheffield researchers understand how shark teeth evolved. In this blog, Brett Clark from the Museum’s Vertebrates Palaeobiology department shows us the method used.
Our research, led by Dr Zerina Johanson, investigates the evolution and development of teeth in jawed vertebrates – in particular, the tooth arrangement of present day sharks.
Earlier in the summer I tweeted a picture of a microfossil slide I made in 1997. On the back I had written that it was made while I was listening to England bowl Australia out for 118 in a cricket test match at Edgbaston, Birmingham.
The slide got me thinking about more important hidden notes I have found recently that relate to historical events and provide a context to the microfossil collection. This post examines evidence of a collector’s escape from a disintegrating ice floe, attempts to cover-up a major disagreement between two scientists and the sad end for a laboratory that led to my first job as a curator.
When I first came to the Museum I dreamt that one day someone would bring something in for identification that I would recognise to be a really important find. The contents of a consultancy sample back in 2005 helped to make my wish come true. This post tells of the discovery and subsequent publication of a significant species of early fossil fish from Oman that provides information on the origins and evolution of life on our planet, one of the main focus areas of Museum science.
Very occasionally I get consultancy rock samples sent to me for dissolving to find microfossils. This is so that we can provide the age for a rock formation or details about fossil environments or climate. And so it was that Alan Heward, then of Petroleum Development Oman (PDO), sent me a sample in 2005 for analysis to try to find age diagnostic conodonts. Conodonts are extinct phosphatic microfossils that look like teeth and are used extensively for dating rocks that are roughly 500-205 million years old.
Some meteorites, called CI chondrites, contain quite a lot of water; more than 15% of their total weight. Scientists have suggested that impacts by meteorites like these could have delivered water to the early Earth. The water in CI chondrites is locked up in minerals produced by aqueous alteration processes on the meteorite’s parent asteroid, billions of years ago. It has been very hard to study these minerals due to their small size, but new work carried out by the Meteorite Group at the Natural History Museum has been able to quantify the abundance of these minerals.
The minerals produced by aqueous alteration (including phyllosilicates, carbonates, sulphides and oxides) are typically less than one micron in size (the width of a human hair is around 100 microns!). They are very important, despite their small size, because they are major carriers of water in meteorites. We need to know how much of a meteorite is made of these minerals in order to fully understand fundamental things such as the physical and chemical conditions of aqueous alteration, and what the original starting mineralogy of asteroids was like.
Last month a new temporary display featuring some of our foraminiferal specimens and models was placed in the Museum gallery. This features real microfossils on one of our foraminiferal Christmas card slides alongside 20 scale models, part of a set of 120 models generously donated to us last year by Chinese scientist Zheng Shouyi.
As a curator dealing with items generally a millimetre or less in size I have not often been involved in developing exhibits other than to provide images or scale models like the Blaschka glass models of radiolarians. Displaying magnified models is one of the best ways to show the relevance of some of the smallest specimens in the Museum collection, the beauty and composition of foraminifera and to highlight our unseen collections.