Plesiosaur Bites
Mine’s bigger than yours! The Monster of Aramberri, Predator X, and other monster pliosaurs in the media
During the past decade several dramatically named giant pliosaurs
have hit the mainstream media, many claiming to be the biggest yet
discovered. But only a trickle of peer-reviewed literature has been
published to accompany these news stories. The lack of published data
makes it really difficult to sift the facts from the fiction, and it’s
easy to get the different stories muddled up, especially in the case of
two identically sized congeneric pliosaur specimens from Svalbard: ‘The
Monster’ and ‘Predator X’. So in an attempt to iron out the details and
assess what we really know about all these specimens, here’s a short
summary of the main players.
The Monster of Aramberri
Hit the mainstream media: 2002.
Estimated length in media: 18 m.
Conservative estimated length 15 m.
Material: Partial vertebral column, proximal end of a
femur, part of the pelvic girdle, and cranial fragments. The fragment of
rostrum collected in 1985 is now lost.
Where: Aramberri, Mexico.
Excavation: The original excavation in 1985 yielded a partial
rostrum and vertebral column. The excavation site was reidentified in
2001 and additional material was collected during 2001 and 2002.
Peer-reviewed scientific references: Buchy et al. (2003).
Notes: The material was collected over a period of several
years, but the discovery only hit the mainstream media in 2002 when more
substantial pieces of the skeleton were discovered. An excellent
account of the ‘Monster of Aramberri’ is given here by Richard Forrest.
Buchy et al. (2003) described UANL-FCT-R2, the partial vertebral column
discovered in 1985 [pictured below], but the majority of the skeleton
has not been described and is in the process of being prepared. I’ve
confirmed with Marie-Celine that the vertebrae described in 2003 are
part of the ‘Monster of Aramberri’, but it is worth noting that the 2003
paper doesn’t explicitly mention ‘The Monster of Aramberri’ by name.
Originally referred to
Liopleurodon, it isn’t considered so any more (Buchy & Frey, 2003).
Part of a figure from Buchy et al. (2003) showing some of the vertebrae and girdle elements of 'The Monster of Aramberri' of the
The Monster
Hit the mainstream media: October 2006
Estimated length in media: 15 metres
Conservative estimated length: 13-15 m
Material: anterior part of rostrum, two cervical and numerous
dorsal vertebrae, a nearly complete coracoid and right forelimb, and
several dorsal ribs and gastralia.
Where: Svalbard, Norway.
Excavation: Discovered in 2006 and excavated in 2007.
Peer-reviewed scientific literature: none.
Notes: ‘The Monster’, not to be confused with ‘The Monster of
Aramberri’, was the first pliosaur from Svalbard to be excavated and the
first to make the news. A second giant pliosaur (‘Predator X’, see
below) was discovered at the same time, but was excavated the following
season.
Richard Forrest’s 2008 article on the plesiosaurs from svalbard
provides a thorough discussion, including comments on ‘The Monster’,
but it was written before the second pliosaur hit the mainstream media.
Partial forelimb of 'The Monster'
Predator X
Hit the mainstream media: March 2009
Estimated length in media: 15 m
Conservative estimated length: 13-15 m
Material: Partial skeleton including posterior skull region and anterior cervical vertebrae.
Where: Svalbard, Norway.
Excavation: Discovered in 2006 and excavated in 2008.
Peer-reviewed scientific literature: none.
Notes. The fossil material attributed to this pliosaur
was first mentioned in stories covering “The Monster” in 2008, but the
name ‘Predator X’ was coined after the specimen was excavated and it hit
the media in 2009. According to an SVP poster by Knutsen
et al.
(2009) both ‘The Monster’ and ‘Predator X’ belong to the same taxon –
they are congeneric and they are closest in their anatomy to
Pliosaurus.
They are both estimated to be the same size, and they are also both
from the same geological formation, so with all these similarities it’s
easy to confuse the two. ‘Predator X’ inspired the cover story for the
31 October 2009 issue of New Scientist, and was the main subject of a
recent History Channel documentary of the same name, which also featured
another giant pliosaur – the Weymouth Bay pliosaur. ‘Predator X’ will
also appear in the BBC’s upcoming series
Planet Dinosaur. Despite its widespread presence in the news and on TV, I was unable to find a suiatable photograph of the actual material.
The Weymouth Bay pliosaur
Hit the mainstream media: October 2009
Estimated length in the media: 16 m
Conservative estimated length: 12 m.
Material: skull and mandible (missing the tip of the manibular symphysis).
Where: Weymouth Bay, Dorset, UK.
Excavation: Discovered in pieces over a period of time –
specific details unclear. The specimen was purchased by Dorset County
Museum in Dorchester.
Peer-reviewed scientific literature: none.
Notes: There is an excellent
account of the Weymouth Bay pliosaur here by Richard Forrest. The skull as preserved is 2.1m long.
The Weymouth Bay pliosaur and Richard Forrest
So there we have it, four mega-pliosaurs making big news in the space
of a decade. All of them have conservative and realistic length
estimates around the 15m mark, with the Weymouth Bay pliosaur possibly
slightly smaller and ‘The Monster of Aramberri’ possibly slightly
larger. But all the estimates are way too wooly to take seriously just
yet. So all these monsters will remain jostling for top spot until the
scientific papers are published, and until we have a better
understanding of pliosaurid proportions.
There are or course plenty of other giant pliosaurs, which frequently
pop up in discussions too, including additional real contenders for
‘biggest pliosaur ever!’. While I do plan to write more on giant
pliosaurs in the future, I’ve stuck to the ones in the mainstream media
for now. You might have noticed that
Liopleurodon was
conspicuously omitted from this post. Well, although it is entirely
relevant to the present topic, it hasn’t been in the news recently so I
decided to leave the magical
Liopleurodon alone this time
around. It will be nice to write about a pliosaur with an actual
scientific name for a change, even if that’s opening a can of worms in
itself!
References
Buchy, M.-C. & Frey, E. 2003. Was it really eating granite? We’re searching hard: history of the Monster
of Aramberri (and stories about it). First meeting of the EAVP – abstracts, 39.
Buchy M.-C., Frey E., Stinnesbeck, W. ; López-Oliva J.G. 2003. First
occurrence of a gigantic pliosaurid plesiosaur in the Late Jurassic
(Kimmeridgian) of Mexico. Bulletin de Societe géologique de France, 174,
271-278.
Knutsen, E., Druckenmiller, P., Hurum, J., Nakrem, H. 2009.
Preliminary account of new Late Jurassic pliosaurid material from
Svalbard, Norway. Journal of Vertebrate Paleontology, 128A.
Noè, L. F., Smith, D. T. J. & Walton, D. I. 2004. A new species
of Kimmeridgian pliosaur (Reptilia; Sauropterygia) and its bearing on
the nomenclature of Liopleurodon macromerus. Proceedings of the
Geologists’ Association 115, 13-24.
fonte: http://plesiosauria.com
Os paleontologistas encontraram os ossos na vila de Krzyżanowice, perto das montanhas Świętokrzyskie. Nos
dias do pliosaurus, essa parte da Polônia era um arquipélago de ilhas
tropicais, com lagoas quentes e reservatórios marinhos, onde os animais
marinhos viviam. 
As criaturas podem atingir mais de 10 m de comprimento e pesar várias dezenas de toneladas. 
Os ossos pertencem tanto ao pilossauro quanto às criaturas que ele comeu. 
