Ammonoid recovery after the Permian–Triassic mass extinction: a re-exploration of morphological and phylogenetic diversity
patterns
Morgane Brosse
Arnaud Brayard
Emmanuel Fara
Pascal Neige
10.6084/m9.figshare.3453188.v1
https://geolsoc.figshare.com/articles/dataset/Ammonoid_recovery_after_the_Permian_Triassic_mass_extinction_a_re-exploration_of_morphological_and_phylogenetic_diversity___patterns/3453188
<p>The explosive ammonoid rediversification after the Permian–Triassic mass extinction is now well understood in terms of taxonomic
richness and biogeography. Using an updated dataset of Early Triassic ammonoids, we compare morphological disparity and taxonomic
richness patterns at the regional and global scales. Disparity evolved similarly at both scales, suggesting a global influence
of abiotic factors. Morphological diversification occurred early in the Smithian and a marked contraction of the morphospace
took place during the end-Smithian extinction. We confirm that trends in disparity and richness were decoupled during the
Griesbachian and Dienerian. Three macroevolutionary processes may be involved: (1) a nonselective extinction at the Permian–Triassic
boundary; (2) a Dienerian constrained radiation with several homeomorphic genera; (3) a potential deterministic extinction
during the end-Smithian crisis. We also demonstrate a superfamily imprint upon disparity for the Spathian when most superfamilies
occupied a restricted part of the morphospace. Sphaerocones were the most affected by the Dienerian and end-Smithian extinction,
but explanations remain elusive. On the one hand, this may be linked to widespread harsh conditions at those times. On the
other hand, as the sphaerocones occurred episodically during the Early Triassic, this might be explained by a relaxing of
ecological constraints or simply by convergent evolution.
</p>
2016-06-21 11:12:19
nonselective extinction
convergent evolution
ammonoid rediversification
Dienerian
abiotic factors
macroevolutionary processes
disparity
Ammonoid recovery
Morphological diversification
Triassic ammonoids
homeomorphic genera
Permian
phylogenetic diversity patterns
taxonomic richness
taxonomic richness patterns
Geology