Fish are the most diverse animals with backbones – that is, vertebrates – living today. Bone and teeth of fishes abound in the fossil record, from the armour-plated, primitive fishes of the Devonian, through the cartilaginous sharks with their shiny dagger-like teeth, to the bones of advanced ray-finned teleosts related to modern carp and cod.
Along with other marine fossils, fossil fishes were once used as ‘proof’ of the biblical deluge, for example, the fabulous Cretaceous fossil fish deposits of Lebanon. Gayet et al. (2012) recorded that, in the third century, the Bishop of Palestine wrote:
“That Noah’s Flood covered the highest mountains is for me the truth, and I say that the witness of my eyes confirms it: for I have seen certain fishes, which were found in my lifetime on the highest peaks in Lebanon. They took stones from there for construction, and discovered many kinds of sea fishes which were held together in the quarry with mud, and as if pickled in brine were preserved until our times, so that the mere sight of them should testify to the truth of Noah’s Flood”.
Hugh Miller, in his book Foot-prints of the Creator (Miller, 1849), mentioned that amateur geologists of Caithness and Orkney would refer to one particular fossil in the Old Red Sandstone, presumably relatively common, as ‘petrified nails’ (Fig. 1). These are, in fact, the central processes of the median dorsal plate of the large placoderm fish, Homosteus milleri. Note that Miller erroneously referred to them as a part of the hyoid plate of another fish, Asterolepis (Fig. 2). It is not known whether the name ‘petrified nail’ was a simple allusion to the nail-like shape of the fossil or signified a belief that they were ancient nails entombed in rock.
Toadstones are the button-shaped fossil teeth of the Jurassic–Cretaceous fish, Lepidotes (Figs. 3 and 4). In folklore, they were once thought to have come from the heads of living toads. Toads were of particular interest to medical practitioners during the seventeenth century (Baldwin, 1993), when it was believed that concoctions made from pulverised toads could provide protection against bubonic plague if placed in an amulet and worn around the neck or wrists. This was justified on several grounds, notably that the toad’s warty skin resembled the carbuncles and spots developed by plague victims.
Much has been written about toadstones. They are mentioned in literature as far back as the Roman scholar, Pliny the Elder, who died in the famous AD 79 eruption of Mount Vesuvius that destroyed Pompeii. In fact, it has been suggested that the legends about toadstones originated with the name ‘Batrachites’ (frogstone) given to them by Pliny (Lankester, 1920). Lankester stated that they were so-named because their drab colour resembled that of a toad. Subsequently, the vivid imaginations of medieval physicians may have been responsible for myths about the origin and mystical powers of toadstones.
The naturalist, Robert Brookes (1763, p. 162), described the colour and shape of toadstones, remarking that:
“… some suppose it to be the tooth of a fish; but this does not seem to agree with its shape”.
Toadstones were even alluded to by William Shakespeare in As You Like It, Duke Senior saying in Act 2, Scene 1:
“Sweet the uses of adversity. Which, like the toad, ugly and venomous, Wears yet a precious jewel in his head”.
But how could toadstones be obtained? Topsell (1608) gave instructions on the extraction of the stone from the toad, which had to be alive at the time for the stone to retain its powers. The toad should be placed on a red cloth to act as a distraction and, while it ‘played’, the stone would fall from its head. Lupton (1627) suggested an equally imaginative way of extracting toadstones, which involved putting the toad into an earthen pot on an ant hill and covering it with earth. The ants would eventually eat the toad, leaving its bones and the toadstone in the pot to be collected.
Toadstones were once widely employed in jewellery. Several toadstones formed part of the famous Cheapside Hoard, a mass of Elizabethan and Jacobean jewellery discovered in 1912 by workmen in the City of London. Their use was not only for aesthetic reasons, but also because they were believed to counteract poison and be efficacious against epilepsy. It was thought that a toadstone set in an open ring would give off heat to the finger on which it was worn when poison was detected (Kunz, 1917). Kennedy (1976) suggested that toadstones were believed to change colour if a poison was present. The use of toadstones against all kinds of poisons was mentioned by Lupton (1627), who noted that:
“A Tode stone (called Crapaudina) touching any part be venomed, hurte or stung with Ratte, Spider, Waspe or any other venomous Beasts, ceases the paine or swelling thereof”.
The early literature also records medicinal uses for toadstones as cures for sores, fever, bowel problems and labour pains (Fig. 5).
‘True’ toadstones comprising Lepidotes teeth were sometimes substituted in Scotland by brown-coloured pebbles, which, like Lepidotes teeth, were often set in rings.
What kind of fish was Lepidotes? Sometimes written Lepidotus, Lepidotes was a primitive bony fish related to modern gars. Inhabiting both freshwater lakes and shallow seas, species of Lepidotes could grow to over two metres in length (Fig. 6). The body was covered with thick, enamel scales. Batteries of peg-like teeth (Fig. 7) – the toadstones – enabled Lepidotes to crush the shells of its molluscan prey. Interestingly, the remains of Lepidotes have been discovered alongside those of the Early Cretaceous dinosaur, Baryonyx, suggesting that it, in turn, was preyed on by this fish-eating giant.