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Early dung beetles may not have fed on dinosaur dung

Ben Creisler

A recent paper that may be of interest and not mentioned yet:

Dirk Ahrens, Julia Schwarzer, and Alfried P. Vogler (2014)
The evolution of scarab beetles tracks the sequential rise of
angiosperms and mammals.
Proceedings of the Royal Society B: 281 (1791) 20141470
doi: 10.1098/rspb.2014.1470

Extant terrestrial biodiversity arguably is driven by the evolutionary
success of angiosperm plants, but the evolutionary mechanisms and
timescales of angiosperm-dependent radiations remain poorly
understood. The Scarabaeoidea is a diverse lineage of predominantly
plant- and dung-feeding beetles. Here, we present a phylogenetic
analysis of Scarabaeoidea based on four DNA markers for a
taxonomically comprehensive set of specimens and link it to recently
described fossil evidence. The phylogeny strongly supports multiple
origins of coprophagy, phytophagy and anthophagy. The ingroup-based
fossil calibration of the tree widely confirmed a Jurassic origin of
the Scarabaeoidea crown group. The crown groups of phytophagous
lineages began to radiate first (Pleurostict scarabs: 108 Ma;
Glaphyridae between 101 Ma), followed by the later diversification of
coprophagous lineages (crown-group age Scarabaeinae: 76 Ma;
Aphodiinae: 50 Ma). Pollen feeding arose even later, at maximally 62
Ma in the oldest anthophagous lineage. The clear time lag between the
origins of herbivores and coprophages suggests an evolutionary path
driven by the angiosperms that first favoured the herbivore fauna
(mammals and insects) followed by the secondary radiation of the dung
feeders. This finding makes it less likely that extant dung beetle
lineages initially fed on dinosaur excrements, as often hypothesized.

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