RE: Malawania, new "old-fashioned" ichthyosaur from Iraq

[Ben Creisler <bcreisler@gmail.com>]

From: Ben Creisler
bcreisler@gmail.com


The paper is now out:

Valentin Fischer, Robert M. Appleby, Darren Naish, Jeff Liston, James
B. Riding, Stephen Brindley, and Pascal Godefroit (2013)
A basal thunnosaurian from Iraq reveals disparate phylogenetic origins
for Cretaceous ichthyosaurs.
Biology Letters 9(4):  20130021
doi:10.1098/rsbl.2013.0021
http://rsbl.royalsocietypublishing.org/content/9/4/20130021.abstract

Cretaceous ichthyosaurs have typically been considered a small,
homogeneous assemblage sharing a common Late Jurassic ancestor. Their
low diversity and disparity have been interpreted as indicative of a
decline leading to their Cenomanian extinction. We describe the first
post-Triassic ichthyosaur from the Middle East, Malawania anachronus
gen. et sp. nov. from the Early Cretaceous of Iraq, and re-evaluate
the evolutionary history of parvipelvian ichthyosaurs via phylogenetic
and cladogenesis rate analyses. Malawania represents a basal grade in
thunnosaurian evolution that arose during a major Late Triassic
radiation event and was previously thought to have gone extinct during
the Early Jurassic. Its pectoral morphology appears surprisingly
archaic, retaining a forefin architecture similar to that of its Early
Jurassic relatives. After the initial latest Triassic radiation of
early thunnosaurians, two subsequent large radiations produced
lineages with Cretaceous representatives, but the radiation events
themselves are pre-Cretaceous. Cretaceous ichthyosaurs therefore
include distantly related lineages, with contrasting evolutionary
histories, and appear more diverse and disparate than previously
supposed.