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Paleocene placental mammals--phylogenetic relationships (free pdf)



Ben Creisler
bcreisler@gmail.com



Out yesterday but now in open access:


Thomas J. D. Halliday, Paul Upchurch and Anjali Goswami (2015)
Resolving the relationships of Paleocene placental mammals.
Biological Reviews (advance online publication)
DOI: 10.1111/brv.12242
http://onlinelibrary.wiley.com/doi/10.1111/brv.12242/abstract

Free pdf:
http://onlinelibrary.wiley.com/doi/10.1111/brv.12242/pdf



The ‘Age of Mammals’ began in the Paleocene epoch, the 10 million year
interval immediately following the Cretaceous–Palaeogene mass
extinction. The apparently rapid shift in mammalian ecomorphs from
small, largely insectivorous forms to many small-to-large-bodied,
diverse taxa has driven a hypothesis that the end-Cretaceous heralded
an adaptive radiation in placental mammal evolution. However, the
affinities of most Paleocene mammals have remained unresolved, despite
significant advances in understanding the relationships of the extant
orders, hindering efforts to reconstruct robustly the origin and early
evolution of placental mammals. Here we present the largest cladistic
analysis of Paleocene placentals to date, from a data matrix including
177 taxa (130 of which are Palaeogene) and 680 morphological
characters. We improve the resolution of the relationships of several
enigmatic Paleocene clades, including families of ‘condylarths’.
Protungulatum is resolved as a stem eutherian, meaning that no
crown-placental mammal unambiguously pre-dates the
Cretaceous–Palaeogene boundary. Our results support an
Atlantogenata–Boreoeutheria split at the root of crown Placentalia,
the presence of phenacodontids as closest relatives of Perissodactyla,
the validity of Euungulata, and the placement of Arctocyonidae close
to Carnivora. Periptychidae and Pantodonta are resolved as sister
taxa, Leptictida and Cimolestidae are found to be stem eutherians, and
Hyopsodontidae is highly polyphyletic. The inclusion of Paleocene taxa
in a placental phylogeny alters interpretations of relationships and
key events in mammalian evolutionary history. Paleocene mammals are an
essential source of data for understanding fully the biotic dynamics
associated with the end-Cretaceous mass extinction. The relationships
presented here mark a critical first step towards accurate
reconstruction of this important interval in the evolution of the
modern fauna.


News:

This news item mentions another paper in the Biological Journal of the
Linnean Society, but that paper does appear to be available yet
online.

http://phys.org/news/2015-12-mammal-diversity-immediately-dinosaur-extinction.html