A new study that contrasts that of Brusatte et al. (2008), who had found a significant dropoff in pseudosuchian disparity through the end Triassic extinction.
Toljagić, O., and R. J. Butler.
2013 Triassic–Jurassic mass extinction as trigger for the Mesozoic radiation of
crocodylomorphs. Biology Letters 9: 20130095. http://dx.doi.org/10.1098/rsbl.2013.0095
Abstract - Pseudosuchia,
one of the two main clades of Archosauria (Reptilia: Diapsida), suffered a
major decline in lineage diversity during the Triassic–Jurassic (TJ) mass
extinction (approx. 201 Ma). Crocodylomorpha, including living crocodilians and
their extinct relatives, is the only group of pseudosuchians that survived into
the Jurassic.We reassess changes in pseudosuchian morphological diversity
(disparity) across this time interval, using considerably larger sample sizes
than in previous analyses. Our results show that metrics of pseudosuchian disparity
did not change significantly across the TJ boundary, contrasting with previous
work suggesting low pseudosuchian disparity in the Early Jurassic following the
TJ mass extinction. However, a significant shift in morphospace occupation
between Late Triassic and Early Jurassic taxa is recognized, suggesting that
the TJ extinction of many pseudosuchian lineages was followed by a major and
geologically rapid adaptive radiation of crocodylomorphs. This marks the onset
of the spectacularly successful evolutionary history of crocodylomorphs in
Jurassic and Cretaceous ecosystems.
17 hours ago in The Phytophactor