Name:
Megalosaurus
(Great lizard).
Phonetic: Meg-ah-lo-sore-us.
Named By: William Buckland - 1824. Full name
species
Megalosaurus bucklandii by Gideon Mantell - 1827.
Classification: Chordata, Reptilia, Dinosauria,
Saurischia, Theropoda, Megalosauridae.
Species: M. bucklandii (type).
Diet: Carnivore.
Size: Roughly estimated at around 9 meters long.
Known locations: England.
Time period: Bathonian of the Jurassic.
Fossil representation: Partial remains of the
skull, mandible and post cranial skeleton, possibly also footprints.
The Introduction of Megalosaurus
to Science
Megalosaurus
was the dinosaur that started a great many things including the science
of palaeontology, the debate about if dinosaurs should be called
names that end with 'saurus' because they are not 'lizards',
to lifetimes of fascination about the creatures that once walked the
Earth when we ourselves were an evolutionary dream.
What
is thought to be the first fragment of Megalosaurus
was discovered way
back in 1676, and was recovered from a limestone quarry in
Oxfordshire. Although only drawings of this bone exist today it was
described at the time as part of a femur by Robert Plot, a chemistry
professor at Oxford University. However due to the unprecedented
nature of the find, he declared it to belong to a giant human,
citing the mention of giants in the bible as a reference.
In
1763 the bone was given the name 'Scrotum humanum' by Richard
Brookes, due to the rather crass yet accurate appearance of the end
of the bone to a human scrotum. However this name was never formerly
accepted by any scientific body, and has always been interpreted as a
description of the drawing of the bone, and was never put forward to
represent the binomial name. Today the ICZN, the body that governs
the
naming of animals, has not made any special
effort to protect the name Megalosaurus as they
insist it is the
correct and valid name for the genus, and that Brookes's name is not
valid.
The
man most often associated with Megalosaurus is the
Rev. William
Buckland who had acquired further fossil material from the same
location as the 'first' bone in 1815. Buckland continued to
puzzle over what animal these bones belonged to until Georges Cuvier,
the first man to correctly identify Pterodactylus
as a flying
reptile, declared the bones to belong to some kind of giant
lizard-like creature. Compiling and describing as many fossils as
he could, Buckland wrote a paper titled 'Notice on the
Megalosaurus or great Fossil Lizard of
Stonesfield'. You have to
remember that the title dinosaur would not be created until 1842 by
Richard Owen.
Megalosaurus
- The Dinosaur
Early
reconstructions depicted Megalosaurus more as a
quadrupedal reptilian
bear rather that the bipedal theropods that everyone is familiar with
today. As far as the people reconstructing it were concerned
'Megalosaurus was a big lizard, so we'll build a
big lizard'.
The out-dated reconstruction of Megalosaurus can
be seen at Crystal
Palace, London, and although grossly inaccurate it has become a
landmark in itself. A famous drawing by �douard Riou from the era
also shows two giant quadrupedal lizards identified as Megalosaurus
and
Iguanodon
(the second dinosaur ever discovered)
tearing chunks of
flesh out of each other in some primordial battle. Needless to say
this is also inaccurate as not only were they not reconstructed
correctly, Iguanodon was a herbivore and would
not think to bite a chunk
out of a Megalosaurus.
Eventually
further theropod discoveries from different parts of the world towards
the end of the nineteenth century resulted in what were more accurate
reconstructions, although by modern standards they were still
inaccurate. Megalosaurus was now depicted as a
large bipedal
theropod, one of and possibly the largest one active in Europe during
the Jurassic.
Because
Megalosaurus remains are so often associated with
marine deposits the
suggestion can be made that Megalosaurus frequent
coastal regions at
least some of the time, and from this a number of lifestyles can be
inferred. One is that Megalosaurus was just like
any other
carnivorous theropod, hunting inland and only being on the cost
coincidentally. The second is that Megalosaurus
may have been taking
advantage of special types of prey such as small plesiosaurs that were
resting on the land. The third is that Megalosaurus
was a beach
comber, scavenging washed up bodies or visiting tidal pools for
trapped fish. The fourth and probably most likely is all of the
above.
Megalosaurus
was a large theropod and would have needed to make use of every
available source, especially when you consider that the higher ocean
levels of the Jurassic turned Europe into a chain of Islands that
significantly reduced the available land mass for supporting
terrestrial animals. Also Megalosaurus probably
did not stick to one
kind of prey of food source throughout its entire life, and probably
changed its behaviour and strategy during different stages of its life.
Megalosaurus
- The Wastebasket
Megalosaurus
quickly captured the attention of the public and
even pop culture when it got a brief reference in the Charles Dickens'
classic Bleak House. However Megalosaurus
ended
up being a victim of
its own fame and success, with subsequent theropod discoveries being
assigned to it upon the basis of, 'its an unidentified theropod,
we'll chuck it in with Megalosaurus'. The same
thing happened to
other extinct animals such as Pterodactylus, and
was a practice born
out of a lack of understanding. Back in the early days of
palaeontology there was no internet, books on the subjects of extinct
animals were very basic, and only a small number of people had access
to scientific papers that detailed new discoveries, and these were
often months or even years old when they became available to people on
the other side of the world.
This
is why the vast majority of fossils once attributed to Megalosaurus
have since been reclassified into different genera and species, some
including very familiar names such as Dilophosaurus
and
Carcharodontosaurus.
The advent of new diagnostics techniques, air
travel, increased understanding of biology, and the internet which
allows scientific papers to be downloaded within seconds of their
publication has allowed many of the previous mistakes to be corrected,
although the process of making sure that everything is correct as well
as processing new discoveries continues to this day.
Further reading
- Notice on the Megalosaurus or great Fossil Lizard
of Stonesfield -
Transactions of the Geological Society of London. 2 1 (2): 390–396. -
W. Buckland - 1824.
- Illustrations of the geology of Sussex: a general view of the
geological relations of the southeastern part of England, with figures
and descriptions of the fossils of Tilgate Forest. - London: Fellow of
the Royal College of Surgeons. p. 92. - G. Mantell - 1827.
- Report on British fossil reptiles, part II - Report of the British
Association for the Advancement of Science 11: 32–37. - Richard Owen -
1842.
- List of extinct Vertebrata, the remains of which have been discovered
in the region of the Missouri river, with remarks on their geological
age - Proceedings of the Academy of Natural Sciences of Philadelphia 9:
89–91. - J. Liedy - 1857.
- On the upper jaw of Megalosaurus - Quarterly
Journal of the
Geological Society 25: 311–314. - T. Huxley - 1869.
- On the reptile fauna of the Gosau Formation preserved in the
Geological Museum of the University of Vienna - Quarterly Journal of
the Geological Society of London 37: 620–707. - H. G. Seeley - 1881.
- On the dinosaurs from the Maastricht beds - Quarterly Journal of the
Geological Society of London 39 (1–4): 246–253. - H. G. Seeley - 1883.
- On a skull of Megalosaurus from the Great Oolite
of Minchinhampton
(Gloucestershire) - Quarterly Journal of the Geological Society of
London 66 (262): 111–115. - A. S. Woodward - 1910.
- Carnivorous Saurischia in Europe since the Triassic - Bulletin of the
Geological Society of America 34: 449–458. - F. von Huene - 1923.
- On several known and unknown reptiles of the order Saurischia from
England and France - Annals and Magazine of Natural History. 9 17
(101): 473–489 - F. von Huene - 1926.
- Scrotum humanum Brookes 1763 - the first named
dinosaur - Journal of
Insignificant Research 5: 14–15. - L. B. Halstead - 1970.
- Megalosaurids from the Bajocian (Middle Jurassic) of Dorset -
Palaeontology 17 (2): 325–339. - M. Waldman - 1974.
- Scrotum humanum Brookes - the earliest name for a
dinosaur - Modern
Geology 18. pp. 221–224. - L. B. Halstead & W. A. S. Sarjeant -
1993.
- Material Referred to Megalosaurus (Dinosauria:
Theropoda) from the
Middle Jurassic of Stonesfield, Oxfordshire, England: one taxon or two
- Proceedings of the Geologists' Association 115 (4): 359–366.- J. J.
Day & P. M. Barrett - 2004.
- Megalosaurus chubutensis del Corro: un posible
Carcharodontosauridae
del Chubut - Ameghiniana. issue 41 - F. Poblete & J. O. Calvo -
2004.
- The taxonomic status of Megalosaurus bucklandii
(Dinosauria,
Theropoda) from the Middle Jurassic of Oxfordshire, UK - Palaeontology
51 (2): 419–424. - R. B. J. Benson, P. M. Barrett, H. P. Powell
& D. B. Norman - 2008.
- A redescription of 'Megalosaurus' hesperis
(Dinosauria, Theropoda)
from the Inferior Oolite (Bajocian, Middle Jurassic) of Dorset, United
Kingdom - Zootaxa 1931: 57–67. - R. B. J. Benson - 2008.
- An assessment of variability in theropod dinosaur remains from the
Bathonian (Middle Jurassic) of Stonesfield and New Park Quarry, UK and
taxonomic implications for Megalosaurus bucklandii
and Iliosuchus
incognitus - Palaeontology 52 (4): 857–877. - R. B. J. Benson
- 2009.
- A description of Megalosaurus bucklandii
(Dinosauria: Theropoda) from
the Bathonian of the UK and the relationships of Middle Jurassic
theropods - Zoological Journal of the Linnean Society 158 (4): 882. -
R. B. J. Benson - 2010.