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RE: Acamptonectes, new ichthyosaur in PLoS ONE



Darren already got his blog up about the beasty here 
http://blogs.scientificamerican.com/tetrapod-zoology/2012/01/03/cretaceous-ichthyosaur-revolution-part-i/

Quick on that, ain't it? For a rarity, Darren is discussing a taxon that has 
actually been published on the given date!

Cheers,

  Jaime A. Headden
  The Bite Stuff (site v2)
  http://qilong.wordpress.com/

"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)


"Ever since man first left his cave and met a stranger with a
different language and a new way of looking at things, the human race
has had a dream: to kill him, so we don't have to learn his language or
his new way of looking at things." --- Zapp Brannigan (Beast With a Billion 
Backs)


----------------------------------------
> Date: Tue, 3 Jan 2012 16:13:01 -0800
> From: bscreisler@yahoo.com
> To: dinosaur@usc.edu
> Subject: Acamptonectes, new ichthyosaur in PLoS ONE
>
> From: Ben Creisler
> bscreisler@usc.edu
>
> A new marine reptile paper in PLoS ONE:
>
>  Valentin Fischer, Michael W. Maisch, Darren Naish, Ralf Kosma, Jeff Liston, 
> Ulrich Joger, Fritz J. Krüger, Judith Pardo Pérez, Jessica Tainsh & Robert M. 
> Appleby (2012)
> New Ophthalmosaurid Ichthyosaurs from the European Lower Cretaceous 
> Demonstrate Extensive Ichthyosaur Survival across the Jurassic–Cretaceous 
> Boundary.
> PLoS ONE 7(1): e29234.
> doi:10.1371/journal.pone.0029234
> http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0029234
>
>
> Background
> Ichthyosauria is a diverse clade of marine amniotes that spanned most of the 
> Mesozoic. Until recently, most authors interpreted the fossil record as 
> showing that three major extinction events affected this group during its 
> history: one during the latest Triassic, one at the Jurassic–Cretaceous 
> boundary (JCB), and one (resulting in total extinction) at the 
> Cenomanian-Turonian boundary. The JCB was believed to eradicate most of the 
> peculiar morphotypes found in the Late Jurassic, in favor of apparently less 
> specialized forms in the Cretaceous. However, the record of ichthyosaurs from 
> the Berriasian–Barremian interval is extremely limited, and the effects of 
> the end-Jurassic extinction event on ichthyosaurs remains poorly understood.
> Methodology/Principal Findings
> Based on new material from the Hauterivian of England and Germany and on 
> abundant material from the Cambridge Greensand Formation, we name a new 
> ophthalmosaurid, Acamptonectes densus gen. et sp. nov. This taxon shares 
> numerous features with Ophthalmosaurus, a genus now restricted to the 
> Callovian–Berriasian interval. Our phylogenetic analysis indicates that 
> Ophthalmosauridae diverged early in its history into two markedly distinct 
> clades, Ophthalmosaurinae and Platypterygiinae, both of which cross the JCB 
> and persist to the late Albian at least. To evaluate the effect of the JCB 
> extinction event on ichthyosaurs, we calculated cladogenesis, extinction, and 
> survival rates for each stage of the Oxfordia
> t scenarios. The extinction rate during the JCB never surpasses the 
> background extinction rate for the Oxfordian–Barremian interval and the JCB 
> records one of the highest survival rates of the interval.
> Conclusions/Significance
> There is currently no evidence that ichthyosaurs were affected by the JCB 
> extinction event, in contrast to many other marine groups. Ophthalmosaurid 
> ichthyosaurs remained diverse from their rapid radiation in the Middle 
> Jurassic to their total extinction at the beginning of the Late Cretaceous.