Geoscience Reference
In-Depth Information
enjoyed only six years of marriage before he died following complica-
tions with his urinary system.
The earlier reference to Plot's infamy derives from his interpre-
tation of various English fossils which he described and illustrated for
the first time in his two county topics. Today young students of
palaeontology find these accounts fanciful, amusing, even startling.
Plot described 'screw-stones', 'bulls' hearts', 'horses' heads' and 'star-
stones' as well as a variety of other petrifactions, now known to be
the fossilised remains of once living marine organisms. He attributed
their formation to some 'plastic force' and did not regard them as being
of organic origin. His 'screw-stones' are either Lower Carboniferous
crinoid stems or the internal moulds of turritellid gastropods; his
'bulls' hearts', or Bucardites as he called them, are the internal mould
of the bivalve Protocardia; the 'horses' heads' or Hippocephaloides are
internal moulds of another bivalve, Myophorella hudlestoni,fromthe
Jurassic rocks at Headington near Oxford; and his 'star-stones' are
colonial corals. However, before condemning Plot for his ludicrous
conclusions, one should look at the material: when viewed from a
particular angle, some of the internal moulds do look like horses'
heads or hearts. With nothing with which to compare the material, it
is not surprising that he reached the conclusions and attributions
he did. Plot was important in the history of palaeontology as he brought
this material to the wider public and thus instigated a debate on the true
nature of the material, this at a time when the organic origin of such
curiosities was beginning to be appreciated across Europe. He also
illustrated in his Oxfordshire treatise what he thought was the petrified
thigh bone of a giant man. Nearly ninety years later in 1763, Richard
Brookes redescribed Plot's specimen, which he named Scrotum
humanum - no guessing what portion of the human he thought it
represented. Today, we know that this bone is the lower portion of a
thigh bone from the dinosaur Megalosaurus. This animal, first described
by the later Oxford academic William Buckland, was the first dinosaur to
be given a name. Recently, it was suggested by the palaeontologists
and historians of science Bill Sarjeant and Beverly Halstead that in fact
