Re: Pliosaurus, new giant species from England

["Matt Dempsey" <primevaldude@virginmedia.com>]

I remember seeing the giant skull mounted in Dorset and being suspicious 
that it looked like a large Pliosaurus sp., as the mandible greatly reminded 
me of the P.macromerus mandible that was on temporary display in London. 
Chuffed to see that my suspicion was correct!

-----Original Message----- 
From: Ben Creisler
Sent: Friday, May 31, 2013 10:32 PM
To: dinosaur@usc.edu
Subject: Pliosaurus, new giant species from England

From: Ben Creisler
bcreisler@gmail.com


New in PLoS ONE:

Roger B. J. Benson mail, Mark Evans, Adam S. Smith, Judyth Sassoon,
Scott Moore-Faye, Hilary F. Ketchum, and  Richard Forrest (2013)
A Giant Pliosaurid Skull from the Late Jurassic of England.
PLoS ONE 8(5): e65989.
doi:10.1371/journal.pone.0065989
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0065989


Pliosaurids were a long-lived and cosmopolitan group of marine
predators that spanned 110 million years and occupied the upper tiers
of marine ecosystems from the Middle Jurassic until the early Late
Cretaceous. A well-preserved giant pliosaurid skull from the Late
Jurassic Kimmeridge Clay Formation of Dorset, United Kingdom,
represents a new species, Pliosaurus kevani. This specimen is
described in detail, and the taxonomy and systematics of Late Jurassic
pliosaurids is revised. We name two additional new species, Pliosaurus
carpenteri and Pliosaurus westburyensis, based on previously described
relatively complete, well-preserved remains. Most or all Late Jurassic
pliosaurids represent a globally distributed monophyletic group (the
genus Pliosaurus, excluding ‘Pliosaurus’ andrewsi). Despite its high
species diversity, and geographically widespread, temporally extensive
occurrence, Pliosaurus shows relatively less morphological and
ecological variation than is seen in earlier, multi-genus pliosaurid
assemblages such as that of the Middle Jurassic Oxford Clay Formation.
It also shows less ecological variation than the pliosaurid-like
Cretaceous clade Polycotylidae. Species of Pliosaurus had robust
skulls, large body sizes (with skull lengths of 1.7–2.1 metres), and
trihedral or subtrihedral teeth suggesting macropredaceous habits. Our
data support a trend of decreasing length of the mandibular symphysis
through Late Jurassic time, as previously suggested. This may be
correlated with increasing adaptation to feeding on large prey.
Maximum body size of pliosaurids increased from their first appearance
in the Early Jurassic until the Early Cretaceous (skull lengths up to
2360 mm). However, some reduction occurred before their final
extinction in the early Late Cretaceous (skull lengths up to 1750 mm).