Chenendopora michelinii, sponge

Fossil specimen known as Chenendopora michelinii HindeIn this section of the online exhibition we explore Parkinson the geologist. One of the founding members of the Geological Society of London in 1807, Parkinson assembled a large and important collection of fossils and published the results of his palaeontological researches in the pioneering work, Organic remains of a former world, which is featured later in this section of the online exhibition.

The fossil featured here was once part of James Parkinson’s own collection, which was housed in his practice premises at 1 Hoxton Square. It is the specimen from which the frontispiece to volume 2 of Organic remains is derived.

Fossil specimen known as Chenendopora michelinii HindeFrontispiece to volume 2 of Organic remains of a former world, showing a specimen placed within the genus of sponges, called Chenendopora LamourouxThe second of these three volumes is devoted to ‘fossil zoophytes’. These are animals which were thought to be plant-like because of their sessile and invertebrate characteristics. They often had a branching or radiating structure comparable to the organisms which make up coral, which were also called ‘animal flowers’.

Of this specimen Parkinson says:

The fossil animal body which is here represented is of the genus Alycyonium. Bodies of a similar form and structure are found in various parts, but nowhere in greater quantities than the neighbourhood of Touraine, in France, and in Wiltshire … The original animal fibres are now entirely silicious; and the interstices are filled with carbonate of lime.  

At the time he was writing the sheer variety of species in this genus defied systematic classification:

Analogy, indeed, proves their existence to have depended on the powers of animal life, but it seldom helps us any further; since, with respect to many of them, we can find no corresponding species or genus, under which, known human beings are disposed, which will allow of their admission.   

With a cup-shaped body that tapers below to an elongated cylindrical or compressed stem, this specimen is now placed within the genus of sponges called Chenendopora Lamouroux. On ‘minute examination’ of its external surface Parkinson observed that:

a …rather porous substance is discoverable; some of the pores appearing to be the result of a peculiar reticulated texture; whilst others, of rather an oval form, may be supposed to be the openings of ramifying tubuli … The examination of its internal structure is prevented by a friable matter, which appears to be partly calcareous and partly silicious, with which the cavity is nearly filled.

In the frontispiece to volume 2 of Organic remains, reproduced to the left here, the whole structure is magnified compared to its appearance to the naked eye. The outer surface is rendered in striking detail, the artist emphasising its gnarled and finely textured trabeculations.

The images of fossils in this section are displayed courtesy of the Natural History Museum, London.

They are used in accordance with a Creative Commons licence.

Further information

For further information please contact us ›