Showing posts with label warm blooded. Show all posts
Showing posts with label warm blooded. Show all posts

Saturday, 14 June 2014

Dinosaurs 'neither warm nor cold blooded'

12 June 2014 Last updated at 21:41

By Jonathan Webb
Science reporter, BBC News

Dinosaurs fit in an intermediate class between warm and cold blooded animals, a study in the journal Science claims.

Scientists compared the growth rates of hundreds of living and extinct species, using growth rings and bone size to calculate the rates for dinosaurs.

They linked growth rate to metabolic rate, the measure of energy use that divides warm and cold blooded animals.

The study suggests that the dinosaurs fall into a middle category, in a fresh contribution to an enduring debate.

Warm blooded animals, like mammals and birds, need a lot of fuel and use that energy to their advantage, including faster movement and boosted brain power. In burning all that food they also maintain a high, stable body temperature.

Cold blooded animals are more economical, but lack those advantages.

Saturday, 30 June 2012

Dinosaurs Were Warm-Blooded Reptiles: Mammal Bone Study Sheds Light On Dinosaur Physiology


ScienceDaily (June 28, 2012) — A study with extant mammals refutes the hypothesis on which the assumption that dinosaurs were ectotherms was based.

The work was carried out by researchers from Institut Català de Paleontologia (ICP) and Universitat Autònoma de Barcelona (UAB). It has been published in Nature.
The study analysing the lines of arrested growth (LAG) in the bones of around a hundred ruminants, representative of the specific and ecological diversity of that group of mammals. The results show that the presence of these lines is not an indicator of an ectothermic physiology (does not generate internal heat), as had previously been thought, since all warm-blooded mammals have them. The study therefore dismantles the key argument of the hypothesis that dinosaurs could have been cold-blooded reptiles.
The work was carried out by Meike Köhler, ICREA researcher and ICP palaeontologist; Ronny Aanes, researcher from the Norwegian Polar Institute; Nekane Marín, PhD student at the UAB and Xavier Jordana, lecturer of postgraduate studies at same university.

Related Posts with Thumbnails

ShareThis