National Fossil Day 2011

As you all know, Wednesday is National Fossil Day in America, not that a national day is needed to wax lyrical about the brilliant things that are fossils of course. If we’re celebrating it doesn’t that make it International Fossil Day? In celebration of one of the better National Days I’ve decided to write about my favourite fossil at the Grant Museum.

Although it is a zoology collection first and foremost, the collection does contain a number of fossil specimens and at one point was lauded by the Lancet in 1835 for being “almost the only comprehensive and accessible source of information in this subject in the English language” after Grant introduced ‘fossil zoology’ to courses at UCL. Presumably, this meant that at one point, the collection contained an excellent fossil series but they were presumably transferred to other institutions or lost because the current collection is a real mix and the fossil collection is on my “to curate properly” list. Big acquisitions in the 80s and 90s as well as the relatively liberal movement of material in between institutions in the past has meant that the fossil collection needs a large amount or sorting; the kind of slow, methodical and satisfying work that I often end up delegating to volunteers to do. In the past we have had some super star volunteers recruited form UCL Earth Sciences including a certain Emma-Louise Nicholls who documented the fossil fish collection and Debi Linton who went through our marine reptile collection, both of whom went on to hold posts at the Museum..

Until our fossil collection is fully explored, identified, catalogued and added to our online database I’d like to highlight my favourite fossil specimen at the Grant Museum.

My first role at the Grant Museum, despite being trained as a palaeobiologist was to document the entomology collection. Whilst in this role, I came across this lovely specimen of Protolindenia wittei from the Solnhofen Plattenkalk Lagerstätte (a Lagerstätte is a fossil deposit that shows extraordinary fossil preservation), a locality I was fortunate enough to excavate at during my undergraduate degree. The reason why I love this specimen so much is because it sums up why I decided to study palaeobiology.

At a glance this beautiful fossil is easily identifiable as a flying insect despite being around 150 million years old. We are fortunate that this specimen even exists, the chances of this particular dragonfly dying and being preserved in such exquisite detail are astronomical.

This insect already beat the odds by making it to an adult. As an egg it could have been eaten by a passing fish or washed away into waters that would have dissolved it or blown away to dry out on a riverank, never fulfilling its potential. As a nymph any number of creatures, amphibians, fish or other insects could have eaten our dragonfly. Even after it left the water and took to the air as an adult it could have been snapped up by a Jurassic predator (Archaeopteryx perhaps?) and perished. Upon death this insect could have been scavenged by ants, decomposed by bacteria or fungus or simply have fallen to pieces and been dispersed by the wind and rain.

Soft tissue rarely preserves in the fossil record because in a number of minutes, once living tissue starts to degrade and decompose. The preservation of the fine wing veins seen in this specimen indicate to us that this dragonfly must have been sealed in a preserving environment very near to or even before the point of death. This organism defied chance by being preserved in such good condition in the first place but even rarer still has survived millions of years of Earth history. If this insect had been preserved at a different place the rock it was preserved in could have been exposed and weathered away, destroyed by volcanic activity, stretched or squeezed into an amorphous smear or subducted back into the core of the Earth through the movement of the tectonic plates. As if that wasn’t enough once fossilised it was then subsequently excavated in one piece, perhaps by a fossil hunter or quarryman and fortunately not destroyed by a pick axe, hammer or pneumatic drill or misplaced or destroyed after its discovery.

You can see that the probability of that tiny egg hatching, the larva reaching adulthood and then being perfectly captured in the rock record, excavated and eventually ending up on display at the Grant Museum is statistically so slim as to be impossible. For me this is what makes every fossil, from the complete skeletons of dinosaurs through to a humble dragonfly, truly remarkable. That we know what we know about the history of Earth and the life on it from the scientific study of fossils really is working with miracles.