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Mesozoic mammals from England
From: Ben Creisler
OK--not dinosaurs or birds--and based mainly on teeth--but theropods
and maybe pterosaurs ate these critters. Early mammals probably
competed with small or juvenile dinosaurs for insects and plants.
In the July 2012 issue of Palaeontology:
Brian M. Davis (2012)
Micro-computed tomography reveals a diversity of Peramuran mammals
from the Purbeck Group (Berriasian) of England.
The known sample of the important pretribosphenic mammal Peramus
tenuirostris, housed in the Natural History Museum (London, UK), was
imaged using micro-computed tomography (CT). Substantial morphological
diversity was discovered, prompting establishment (and resurrection)
of additional taxa from within the existing hypodigm of Peramus
tenuirostris: Peramus dubius comb. nov., Kouriogenys minor gen. nov.
and Peramuroides tenuiscus gen. et sp. nov. The Peramura are revised;
this group is restricted to taxa with clear evidence of a fully
functional upper molar embrasure for the dominant lower molar talonid
cusp (hypoconid), either through development of wear facet 4 or
through differentiation of a distinct hypoconulid. The Peramura are
the most likely sister taxon to the Tribosphenida (including living
marsupials and placentals) and represent a distinct molar morphotype,
transitional between primitive lineages characterized by dominant
orthal shear (e.g. dryolestoids) and those with modern,
multi-functional tribospheny. A very large masseteric foramen is
identified in peramurans, but this feature appears to be autapomorphic
and of uncertain function.