Fiona L. Gill, JÃrgen Hummel, A. Reza Sharifi, Alexandra P. Lee & Barry H. Lomax (2018)
Diets of giants: the nutritional value of sauropod diet during the Mesozoic.
Palaeontology (advance online publication)
A major uncertainty in estimating energy budgets and population densities of extinct animals is the carrying capacity of their ecosystems, constrained by net primary productivity (NPP) and its digestible energy content. The hypothesis that increases in NPP due to elevated atmospheric CO2 contributed to the unparalleled size of the sauropods has recently been rejected, based on modern studies on herbivorous insects that imply a general, negative correlation of diet quality and increasing CO2. However, the nutritional value of plants grown under elevated CO2 levels might be very different for vertebrate megaherbivores than for insects. Here we show plant speciesâspecific responses in metabolizable energy and nitrogen content, equivalent to a twoâfold variation in daily food intake estimates for a typical sauropod, for dinosaur food plant analogues grown under CO2 concentrations spanning estimates for Mesozoic atmospheric concentrations. Our results potentially rebut the hypothesis that constraints on sauropod diet quality were driven by Mesozoic CO2 concentration.
Claudia InÃs Serrano-BraÃas, Belinda Espinosa-ChÃvez & S. Augusta Maccracken (2018)
Insect damage in dinosaur bones from the Cerro del Pueblo Formation (Late Cretaceous, Campanian) Coahuila, Mexico.
Journal of South American Earth Sciences (advance online publication)
Insect boring traces are first described on dinosaur bones from Coahuila, Mexico.
Seven trace boring patterns were recognized, including a new Cubiculum ichnospecies.
The borings were likely produced by dermestid beetles and possible termites.
Evidence suggests that the insect invasion was performed on a dry hadrosaur carcass.
This study represents the first description and analysis of insect borings on hadrosaur bones (Dinosauria: Hadrosauridae) from the Late Campanian Cerro del Pueblo Formation (CdP) of the State of Coahuila, Mexico. Here we describe seven different trace patterns that include a new Cubiculum ichnospecies and possible termite damage. The insect bone borings include holes, notches, chambers, furrows, tunnels and rosettes. Transitional structures can also be observed in the hadrosaur bones. Comparisons of these trace morphologies with extant necrophagous insect groups suggest that the CdP borings were likely the result of dermestid beetle larvae and possible termite osteophagy on a dry hadrosaur corpse prior to burial.