Cabinet of Curiosities

Down To Earth

My collecting has gotten me into some strange places and tight squeezes over the years, but it is all such fantastic fun.

Head stuck in a hole
Quartz crystal cluster

I have always been absolutely fascinated by geology. Rocks are essentially combinations of minerals, which in turn consist of different elements blended together. Take granite as an example. This igneous rock is made up of three minerals namely quartz, mica and feldspar. Quartz is the commonest mineral on earth and occurs in most rocks. In granite it appears as small crystals that look almost like pieces of glass from a shattered windscreen. The mica is the laminated, shiny silver or blackish flecks and the feldspar forms the main matrix of the rock and comes in a variety of colours including grey, green, red and buff. It formed as molten rock or magma slowly cooled and solidified deep underground and around 420 million years ago this is how the granite that now makes up the bulk of the Dublin-Wicklow Mountains originated.

Selection of granites
Gneiss, Blacksod Bay, Co. Mayo

One of Ireland’s oldest is a metamorphic rock called gneiss. Found at a number of locations, including Blacksod Bay in Co. Mayo, it is a foliated rock, meaning that the different constituent minerals appear as a series of distinct layers or bands. The rock is around 1 billion years old and consists of quartz, mica and feldspar. This suggests that the gneiss may well be a much older metamorphosed granite.

The earth was dominated by dinosaurs, a diverse range of giant reptiles, for 180 million years. Among the earliest to be discovered, just over 200 years ago, was the iguanodon, the first specimen of which came to light in 1822 in Sussex, England. The name derives from the similarity in the morphology of their teeth with those of modern-day iguanas, a favourite haunt of which are the Galápagos Islands, off the Ecuadorian coast. Averaging 10 metres in height and weighing in at 4.5 tonnes they were an impressive animal and first appear in the early Cretaceous Period sometime around 140 million years ago. Their fore-feet were equipped with a feature we call a thumb-spike and this was probably put to use when the animal had to defend itself. On several sites the fossilised remains of numbers of iguanodons grouped together have been revealed and this suggests that they may have been a herd animal. Their fossilised remains are commonly found on the Isle of Wight, England.

Fossil tail vertebra of iguanodon, 125 million years old

Scientists calculate that the Earth formed around 4.6 billion years ago when our Solar System came into existence. Sometimes rock fragments originating in deep space manage to fall to Earth and these are known as meteorites. Each year tens of thousands of them enter our atmosphere, most mere dust particles, the majority of which melt away before reaching the ground or sea. They are visible as momentary bright trails streaking the dark night sky as they burn up and are known by the familiar name ‘shooting’ or ‘falling stars’. In 1576 a large meteorite was discovered by the Spanish Conquistadors in Argentina. They named the find spot ‘Campo Del Cielo’ – ‘Field of Heaven’. When it fell to Earth thousands of years ago it fragmented and so the surrounding landscape is pitted with impact craters from the individual pieces. Rich in iron, the meteorite had apparently been used by indigenous Indians as a source of metal. It is estimated to be around 4.5 billion years old. The fragment of this meteorite in my hand weighs 3 kgs.

Campo Del Cielo meteorite
Outdoor photographic studio

I have thoroughly enjoyed opening my Cabinet of Curiosities for you over the last couple of weeks and writing the daily blogs. I hope you found them a pleasant and welcome distraction each day from the challenging times we find ourselves in. The images were mostly composed on a makeshift outdoor photo studio, the background fabric of which you will readily recognise, and taken with my iPhone.  Appearing on occasion in the role of ‘specimen holder’ and ‘scale’, my wife Lindi has been an indefatigable help throughout the compilation of the series and my heartfelt appreciation is recorded here. Finally, thanks are due to you the reader, without whose continued interest the project would never have run its full course.



© Vincent Butler Heritage 2020

Cabinet of Curiosities

A Head Of The BEST

Brown long-eared bat

A total of nine different bat species are found in Ireland. These flying insectivorous mammals are a fascinating group. Fifty years ago, my wife Lindi was given a ‘stuffed’ brown long-eared bat by a then young medical student, David Barry, who had earlier practiced his dissection skills on the specimen. Stretched between its extremely long fingers is a web of skin which forms the wings. Leaving their roosts shortly after sunset, they feed on a range of invertebrates including moths, earwigs and spiders which are picked off the foliage of trees and shrubs, in addition to flying insects which are taken on the wing. They possess a formidable set of needle-sharp, pointed teeth which are ideal for seizing prey.

Brown long-eared bat dentition
Otter skull

My wonderful friend John ‘Squire’ Murray, while perambulating along the sylvan banks of the River Boyne some years ago, happened on the skeleton of an otter. Knowing that I was in the process of assembling an osteological comparative collection, he very thoughtfully bagged the specimen and it now resides in my lab in the ‘Carnivore’ section. Its prey consists primarily of fish including eel, salmon and trout. As a member of the Mustelidae family of mammals, which include badger, stoat, pine marten and mink, they possess a scent gland positioned at the anus. Each time the animal defecates, the droppings, known as spraints, are imbued with the scent and used to mark territories. Its Irish name ‘madra uisce’ means ‘water dog’ and they are one of our native species, having reached here around 10,000 years ago following the end of the Ice Age.

Dessicated lesser spotted dogfish
Dogfish egg capsules (‘mermaid’s purses’)

The lesser spotted dogfish (Scyliorhinus canicula) is a member of the shark family and sports the characteristic features of its relations. They are found in the Atlantic, Mediterranean and North Sea and, in common with other species of shark, have a sandpaper feel to their skin due to the tooth-like projections on the scales called denticles. Living on the sea bottom, they feed on crustaceans, molluscs and small fish. The individual eggs are contained in a protective, rectangular capsule equipped with tendrils at each of the corners which wrap around seaweeds and so safely anchor it until the young fish emerge. Often found washed ashore, the empty egg capsules are holed and indicate the point where the tiny dogfish emerged. They are known by the fanciful name of ‘mermaid’s purses’.  You may have at some point enjoyed lesser spotted dogfish with chips in the guise of ‘rock salmon’.

Irish hare scull

The Irish hare (Lepus timidus hibernicus) is a native species and bone evidence indicates that it has been here for a long time. Herbivorous, it is aptly equipped with a set of chisel-like incisors which it uses to nibble on grasses, gorse, heather, and other plants. As far as dining is concerned, hares make sure to get value for money! They consume their own droppings, a kind of ‘second-helping’ so to speak, in order to absorb the maximum amount of nutrients from the food. This digestive technique is called ‘refection’.

Barn owl scull

The barn owl (Tyto alba) hunts mainly mice, rats and shrews. Its sharp, hooked upper beak is perfectly designed for snagging prey which is swallowed whole. The undigestible parts, the hair and bone, are later regurgitated and expelled from the mouth. These small ‘packages’ are known as pellets. Active at night, barn owls on occasion emit a high pitched, unnerving screech, earning it the Irish name Scréachóg reilige, ‘the graveyard screecher’. Hanging out in graveyards, their silent flight and light colouration give the bird something of a ghostly appearance. 

The European mole

The European mole (Talpa europaea) never made it as far as Ireland following the melting of the ice sheets. The slick muscular body, dense velvety coat and powerful, clawed front feet are designed for tunnelling and the animal possesses consummate skills in this art. Each mole patrols its own system of tunnels as it hunts for earthworms, grubs, beetle larvae, and slugs. This specimen was discovered in a box of junk in a flea market in Brussels in 1980 and having just reread Kenneth Grahame’s wonderful book ‘The Wind in the Willows’, I felt compelled to purchase it!



© Vincent Butler Heritage 2020

Cabinet of Curiosities

Crystal Clear

I found my first fossil when I was ten years old, a gastropod embedded in a piece of Carboniferous limestone. This marked the beginning of my collecting, so it would be remiss of me, even disrespectful, if I were not to highlight this wonderfully interesting sedimentary rock. Around 340 million years ago a sub-tropical sea existed which supported a myriad of marine life including corals, molluscs and sea-lilies. Layers of calcium-rich sediment were accumulating on the seabed and as the corals and other creatures died their remains became incorporated in it. Over millions of years these sediments were transformed into layers of solid rock that we now call limestone and the shells and other hard parts of the marine organisms were preserved as fossils. It makes up around 60% of Ireland’s bedrock.

Fossil solitary coral, Carboniferous Period

Limestone can sometimes be fossiliferous, meaning rich in fossils. These provide us with valuable information about the complex prehistoric marine ecosystem. Corals are a fascinating group of small invertebrates. Each of these soft-bodied animals, known as a coral polyp, secretes calcium carbonate or lime from which it constructs a hard protective exoskeleton. Coming together in large numbers they create individual colonies and when these coalesce form coral reefs. A specimen of a solitary coral still stands upright as it had in life 340 million years ago on the bed of the Carboniferous Period sea.      

Fossil Brachiopod

Although superficially resembling bivalves, brachiopods are a separate group of shellfish. They first appeared in the Cambrian Period some 540 million years ago and at various times in the geological past were extremely common. The lower and larger of its two shells had a round opening at the posterior tip through which a fleshy pedicle or stalk protruded. The animal used this to attach itself to the seabed. Around 200 species are still found today. Perfectly preserved fossil brachiopods sometimes just pop out of the limestone when lumps are broken open, as was the case with the specimen here.

Calcite is the crystalline or pure form of calcium carbonate, the main constituent mineral of limestone. It occurs as veins within the rock, sometimes in large enough concentrations to justify commercial mining.


When rain falls it absorbs carbon dioxide gas from the air and forms a weak carbonic acid which chemically reacts with the limestone, slowly dissolving the calcium. Filtering down through the body of the rock, the water becomes saturated with this mineral. On contact with air when it seeps into an underground passageway or cave, some of the carbon dioxide is released. As a result of this, each drop of water that forms on the roof deposits minute crystals of calcite and over time a downward tapering feature known as a stalactite develops. Where drops splash consistently on the same spot of the floor a stumpy upward growing stalagmite forms.

Another mineral sometimes found in Carboniferous limestone is fluorspar. Also known by the name ‘Blue John’, it was mined at one time in the Burren, Co. Clare. It was used as a flux in the production of iron and was a main ingredient in the manufacture of hydrofluoric acid which among other things, was used for etching glass.

Piddock bored limetone

Piddocks are a group of marine bivalves who bore into rock. Tell-tale signs of their presence are small circular holes peppering the surface of the rock or the larger chambers that they excavate by rasping with the sharp edges of the shells. Each piddock is condemned to serving a life-sentence, incarcerated in its self-made stone-walled cell. The wrinkled rock borer or red nose (Hiatella rugosa) bores a flask-shaped chamber and these are a common find in rocks along the shore in areas of limestone.



© Vincent Butler Heritage 2020