Eagerly Awaited and Sailing Your Way

[Jaime Headden <qi_leong@hotmail.com>]

Surprised no one's mentioned this (that I know of):

http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0025693

Butler, R. J., Brusatte, S. L., Reich, M., Nesbitt, S. J., Schoch, R. R. & 
Hornung, J. J. 2011. The sail-based reptile *Ctenosauriscus* from the latest 
Early Jurassic of Germany and the timing and biogeography of the early 
archosaur radiation. _PLoS ONE_ 6(10):e25693. doi:10.1371/journal.pone.0025693

Abstract:
Background
Archosaurs (birds, crocodilians and their extinct relatives including 
dinosaurs) dominated Mesozoic continental ecosystems from the Late Triassic 
onwards, and still form a major component of modern ecosystems (>10,000 
species). The earliest diverse archosaur faunal assemblages are known from the 
Middle Triassic (c. 244 Ma), implying that the archosaur radiation began in the 
Early Triassic (252.3–247.2 Ma). Understanding of this radiation is currently 
limited by the poor early fossil record of the group in terms of skeletal 
remains.

Methodology/Principal Findings
We redescribe the anatomy and stratigraphic position of the type specimen of 
*Ctenosauriscus koeneni* (Huene), a sail-backed reptile from the Early Triassic 
(late Olenekian) Solling Formation of northern Germany that potentially 
represents the oldest known archosaur. We critically discuss previous 
biomechanical work on the ‘sail’ of *Ctenosauriscus*, which is formed by a 
series of elongated neural spines. In addition, we describe 
*Ctenosauriscus*-like postcranial material from the earliest Middle Triassic 
(early Anisian) Röt Formation of Waldhaus, southwestern Germany. Finally, we 
review the spatial and temporal distribution of the earliest archosaur fossils 
and their implications for understanding the dynamics of the archosaur 
radiation.

Conclusions/Significance
Comprehensive numerical phylogenetic analyses demonstrate that both 
*Ctenosauriscus* and the Waldhaus taxon are members of a monophyletic grouping 
of poposauroid archosaurs, Ctenosauriscidae, characterised by greatly elongated 
neural spines in the posterior cervical to anterior caudal vertebrae. The 
earliest archosaurs, including *Ctenosauriscus*, appear in the body fossil 
record just prior to the Olenekian/Anisian boundary (c. 248 Ma), less than 5 
million years after the Permian–Triassic mass extinction. These earliest 
archosaur assemblages are dominated by ctenosauriscids, which were broadly 
distributed across northern Pangea and which appear to have been the first 
global radiation of archosaurs.

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)