@article {1876,
	title = {Catalogue of fossil Scarabaeoidea (Coleoptera: Polyphaga) of the Mesozoic and Tertiary},
	year = {2004},
	pages = {61},
	institution = {The Natural History Museum},
	address = {London},
	author = {Krell, Frank-Thorsten}
}
@article {1889,
	title = {Diel separation of Afrotropical dung beetle guilds - avoiding competition and neglecting resources (Coleoptera : Scarabaeoidea)},
	journal = {Journal of Natural History},
	volume = {38},
	number = {17},
	year = {2004},
	note = {823AIJ NATUR HIST},
	month = {Sep},
	pages = {2225-2249},
	abstract = {Dung beetle guilds of different competitive level coexist at high abundances in the forest - savanna mosaic of Ivory Coast. A total of 25 875 specimens was recorded from 90 samples of fresh buffalo dung exposed for 4- h periods over the day in the Parc National de la Comoe. Redundancy analyses show different patterns of the guild structure determined by time of day, and positive correlations of guild abundance with temperature. The competitively superior telecoprids ( rollers) have their abundance peak at midday when the high temperatures presumably enable them to perform their energetically costly rolling behaviour at greater speed. The competitively intermediate paracoprids ( tunnellers) and the competitively inferior endocoprids ( dwellers) have their peak around dusk when: ( 1) the superior competitors are not active, and ( 2) they can easily synchronize their flight activity using light intensity changes. During the two peaks of flight activity of the dung beetles, their abundance at the resource is very high, causing obvious competition. On the other hand, the resource is hardly used between 22: 00 h and 10: 00 h. This is probably due to physiological constraints ( high optimum temperature required for the diurnal species and dependence on light intensity patterns as a flight trigger of the nocturnal species, respectively). Shifting flight activity to these periods of low competition does not occur, resulting in a unequal level of competition over the day, thus periods of considerable competition within dung beetle assemblages alternate with vacant temporal refuges.},
	keywords = {{\textquoteright}, Cote d, Dung beetles, Ivore},
	url = {<Go to ISI>://000221581700007},
	author = {Krell-Westerwalbesloh, Sylvia and Krell, Frank-Thorsten and Linsenmair, K. Eduard}
}
@article {2032,
	title = {Linear and threshold-dependent expression of secondary sexual traits in the same individual: insights from a horned beetle (Coleoptera: Scarabaeidae)},
	journal = {Biological Journal of the Linnean Society},
	volume = {83},
	year = {2004},
	pages = {473-480},
	abstract = {Elaborate horns or horn-like structures in male scarab beetles commonly scale with body size either (a) in a linear fashion with horn size increasing relatively faster than body size or (b) in a threshold-dependent, sigmoid fashion; that is, males smaller than a certain critical body size develop no or only rudimentary horns, whereas males larger than the threshold size express fully developed horns. The development of linear vs. sigmoid scaling relationships is thought to require fundamentally different regulatory mechanisms. Here we show that such disparate regulatory mechanisms may co-occur in the same individual. Large males of the south-east Asian Onthophagus  ( Proagoderus ) watanabei  (Ochi \& Kon) (Scarabaeidae, Onthophagini) develop a pair of long, curved head horns as well as a single thoracic horn. We show that unlike paired head horns in a large number of Onthophagus  species, in O. watanabei  the relationship between head horns and body size is best explained by a linear model. Large males develop dispropor- tionately longer horns than small males, but the difference in relative horn sizes across the range of body sizes is small compared to other Onthophagus  species. However, the scaling relationship between the thoracic horn and body size is best explained by a strongly sigmoid model. Only males above a certain body size threshold express a thoracic horn and males smaller than this threshold express no horn at all. We found a significant positive correlation between head and thoracic horn length residuals, contrary to what would be expected if a resource allocation tradeoff during larval development would influence the length of both horn types. Our results suggest that the scaling rela- tionship between body size and horn length, and the developmental regulation underlying these scaling relation- ships, may be quite different for different horns, even though these horns may develop in the same individual. We discuss our results in the context of the developmental biology of secondary sexual traits in beetles.},
	keywords = {allometry, developmental constraint, developmental tradeoff, Onthophagus, scaling},
	author = {Moczek, Armin P. and Bruhl, Carsten and Krell, Frank-Thorsten}
}
