Name:
Pliosaurus
(More lizard).
Phonetic: Ply-oh-sore-us.
Named By: Richard Owen - 1841.
Synonyms: Liopleurodon rossicus,
Plesiosaurus giganteus, Plesiosaurus recentior, Spondylosaurus,
Stretosaurus, Strongylokroptaphus .
Classification: Chordata, Reptilia,
Sauropterygia, Plesiosauria, Pliosauridae.
Species: P. brachydeirus (type), P. almanzaensis, P.
brachyspondylus, P. carpenteri, P. funkei, P. kevani, P. macromerus, P.
patagonicus, P. portentificus, P. rossicus, P. westburyensis.
Diet: Carnivore.
Size: Some species up to 10 meters long, with
skulls
approximately 2 meters long. Largest species, P.
funkei
estimated at between 10-12.8 meters long.
Known locations: England - Kimmeridge Clay
Formation, and Norway, Svalbard, Spitsbergen. Possibly also France,
Poland and Russia, depending upon the validity of all species.
Time period: Kimmeridgian to Tithonian of the
Jurassic.
Fossil representation: Numerous specimens.
Originally
described as a species of
Plesiosaurus, this
was the first pliosaur ever named which is why Pliosaurus
is used as
the type genus of the Pliosauridae.
Related to the long necked
plesiosaurs
the pliosaurs adapted to fill a range of different predatory niches
with some like Pliosaurus itself being hunters of
other marine
reptiles. Such prey preference is indicated by the large teeth as
much as thirty centimetres long and jaws which would have been okay on
small prey like fish, but
devastating against large prey like plesiosaurs,
ichthyosaurs,
smaller pliosaurs and quite possibly giant fish such as Leedsichthys.
Because
of its long history a large number of remains under many different
species have been attributed to the genus, but the list of valid
names has now been greatly reduced as a result of more intensive study
of the fossils. The earlier attribution of fossils under multiple
species names is known as the wastebasket effect, and is something
that happened to almost all early discovered prehistoric creatures
including the plesiosaur Plesiosaurus,
the dinosaurs Megalosaurus
and
Iguanodon,
as well as the pterosaurs
Pterodactylus
and Rhamphorhychus.
Special note upon Pliosaurus
funkei, a.k.a. Predator X.
In
2006 highly fragmentary remains of a marine reptile were found,
and in 2008 an effort began to recover the fossils from the island
of Spitsbergen in the Svalbard archipelago. These fragments
numbered around 20,000 pieces in number, and took a long while to
piece together, though like a 3D jigsaw, they slowly came
together to form a particularly huge pliosaur that was subsequently
dubbed 'Predator X'. Predator X quickly
caught the attention of the news and popular science media, and was
even a focus animal in an episode of the well-made dinosaur documentary
series Planet Dinosaur, and all before this
individual had even been
granted an official binomial name. Today, Predator X is known
within scientific circles as Pliosaurus funkei
which is the official
descriptive name for this pliosaur that was granted in 2012.
When
P. funkei was still only known as Predator X, it
was initially
thought to have possibly been as much as 15 meters long. Now that
the fossils of this pliosaur have been reconstructed more, studied
and identified as a species of Pliosaurus, more
accurate
reconstructions have now been put together. This has seen the
speculated size of Predator X, now as Pliosaurus funkei,
estimated
at somewhere between 10 and 12.8 meters long. Unfortunately
this revision has still gone unnoticed by some who still credit
individuals as being 15 meters long, in a similar manner to how
another pliosaur named Liopleurodon
is still being credited as
being 25 meters long by some even though the largest known
specimen is a little over 6 meters in length.
At
the time of writing the only known fossils of Pliosaurus
funkei include
a partial skull, a flipper and a few additional post cranial remains
such as vertebrae. These remains are what were used to establish the
new size ranges for this pliosaur, though it is quite conceivable
that should a second specimen ever be found the size range may be
revised to be smaller, or even a little larger to what it currently
stands at. Even at ten meters long, however, P. funkei
will
still be comparable to other large species of Pliosaurus,
as well as
other large pliosaur genera such as Kronosaurus
and
Brachauchenius.
Like with its relatives, individual P.
funkei
would have been specialised predators of other large marine organisms.
Further reading
- Two new pliosaurs from the lower Volgian tier of the Volga region
(right bank) - Doklady Akademii Nauk SSSR 60:115-118 - N. I. Novozhilov
- 1948.
- A review of Upper Jurassic pliosaurs - Bulletin of the British Museum
(Natural History), Geology Series 14(5):147-189 - L. B. Tarlo - 1960.
- A new species of Pliosaurus (Sauropterygia:
Plesiosauria) from the
Middle Volgian of central Spitsbergen, Norway - Norwegian Journal of
Geology 92 (2–3): 235–258 - Espen M. Knutsen, Patrick S. Druckenmiller
and J�rn H. Hurum - 2012.
- A taxonomic revision of the genus Pliosaurus
(Owen, 1841a) Owen,
1841b - Norwegian Journal of Geology 92 (2–3): 259–276. - Espen M.
Knutsen - 2012.
- A giant pliosaurid skull from the Late Jurassic of England - PLoS ONE
8(5) - R. B. J. Benson, M. Evans, A. S. Smith, J. Sassoon, S.
Moore-Faye, H. F. Ketchum & R. Forrest - 2013.
- A new species of Pliosaurus (Sauropterygia,
Plesiosauria) from the
Upper Jurassic of northwestern Patagonia, Argentina". Ameghiniana. 51
(4): 269–283. - Z. Gasparini & J. O'Gorman - 2014.
- A new Pliosaurus species (Sauropterygia,
Plesiosauria) from the Upper
Jurassic of Patagonia: new insights on the Tithonian morphological
disparity of mandibular symphyseal morphology. Journal of Paleontology
92(2):240-253. - J. P. O'Gorman, Z. Gasparini & L. A. Spalletti
- 2018.
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