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Early evolution of ray-finned fishes (free pdf) + tetrapodomorph from Devonian of Iran



Ben Creisler
bcreisler@gmail.com


Recent non-dino papers that may be of interest:



Matt Friedman (2015)
The early evolution of ray-finned fishes.
Palaeontology (advance online publication)
DOI: 10.1111/pala.12150
http://onlinelibrary.wiley.com/doi/10.1111/pala.12150/abstract
Free pdf:
http://onlinelibrary.wiley.com/doi/10.1111/pala.12150/pdf

Ray-finned fishes (Actinopterygii) constitute approximately half of
all living vertebrate species. A stable hypothesis of relationships
among major modern lineages has emerged over the past decade,
supported by both anatomy and molecules. Diversity is unevenly
partitioned across the actinopterygian tree, with most species
concentrated within a handful of geologically young (i.e. Cretaceous)
teleost clades. Extant non-teleost groups are portrayed as ‘living
fossils’, but this moniker should not be taken as evidence of
especially primitive structure: each of these lineages is
characterized by profound specializations. Attribution of fossils to
the crowns and apical stems of Cladistia, Chondrostei and Neopterygii
is uncontroversial, but placements of Palaeozoic taxa along deeper
branches of actinopterygian phylogeny are less secure. Despite these
limitations, some major outlines of actinopterygian diversification
seem reasonably clear from the fossil record: low richness and
disparity in the Devonian; elevated morphological variety, linked to
increases in taxonomic dominance, in the early Carboniferous; and
further gains in taxonomic dominance in the Early Triassic associated
with earliest appearance of trophically diverse crown neopterygians.

==============

Donald Davesne, Jorge Mondéjar-Fernández, Vachik Hairapetian, Martin
Rücklin, Jobst Wendt & Gaël Clément (2015)
A new large tetrapodomorph sarcopterygian from the Late Devonian of Iran.
Paläontologische Zeitschrift (advance online publication)
DOI: 10.1007/s12542-015-0255-7
http://link.springer.com/article/10.1007/s12542-015-0255-7



Remains of a large sarcopterygian were collected in the Middle-Late
Devonian Zarand Formation of Southeastern Iran. These remains consist
of incomplete jaw bones of uncertain identification, preserved in a
dense and heterogeneous rock matrix. The use of CT scan
microtomography and 3D visualization enabled unraveling their overall
anatomy as well as the microstructure of one tooth. This large tooth
shows eusthenodont-type plicidentine, found only in Devonian
tetrapodomorph sarcopterygians and more specifically suggesting
affinities with the family Tristichopteridae. This discovery
constitutes the first occurrence of a large tetrapodomorph in the
Devonian of Iran and the Middle East.