[Rockhounds] 75-million-year old eggshells suggest most dinosaurs were warm-blooded Read more: https://www.newscientist.com/article/2233396-75-million-year-old-eggshells-suggest-most-dinosaurs-were-warm-blooded/#ixzz6Dxua9ZJE

[Kreigh Tomaszewski]

An analysis of fossil eggshells may have settled a long-running debate
about dinosaurs, suggesting that all species were warm-blooded.

This also means the ancestors of dinosaurs must have been warm-blooded too,
says Robin Dawson at Yale University, who led the research.

It is now mostly agreed that the feathered dinosaurs called theropods that
gave rise to birds
<https://www.newscientist.com/article/2184040-birds-have-their-dinosaur-ancestors-to-thank-for-their-colourful-eggs/>
were
warm-blooded, but there is still a debate about whether other groups of
dinosaurs
<https://www.newscientist.com/article/dn25945-feathersaurus-plant-eating-dinos-had-plumage-too/>
were
too. Until recently, we had only indirect methods of working out the body
temperature of ancient animals
<https://www.newscientist.com/article/2187399-fossil-blubber-shows-ichthyosaurs-were-warm-blooded-reptiles/>,
so there was no way to be sure.

There is a way to work out the temperature
<https://doi.org/10.1016/j.quascirev.2011.09.001> at which organic matter
forms inside bodies based on carbon and oxygen isotopes. This technique can
be applied to eggshells to reveal the body temperature of the mother when
the shells formed.


Read more:
https://www.newscientist.com/article/2233396-75-million-year-old-eggshells-suggest-most-dinosaurs-were-warm-blooded/#ixzz6DxuQGItU