Herbivorous Mammals Have Bigger Bellies Than Their Carnivorous Counterparts, Says New Study

A team of researchers from the Technical University of Berlin and the University of Zurich (UZH) has revealed that herbivorous mammals have larger bellies compared with their carnivorous counterparts. For a long time, scientists have been of the view that plants are extra difficult to be digested than meats; however, there was no scientific evidence before this study.

The team examined the ribcage's shape in over 120 tetrapods belonging to both modern and prehistoric periods. They used computer imaging techniques and photgrammetry to build the bellies' 3-D models of all the species. Fossil records of extinct species were used to find out the volume of the body cavity based on pelvis size, rib cage, and spinal column.

The results clearly showed that the bellies of plant-eating mammals are almost twice the size of those of carnivorous mammals. This is the evidence of the first kind, which clearly shows that herbivorous mammals have bigger guts, said Marcus Clauss, professor at UZH.

He added that diet played an important role in determining the volume of the torso as the torso volume of herbivores is approximately 1.5 times bigger than carnivores. The foods of herbivorous mammals are not easily digested and need the presence of a huge number of gut microbes and a relatively long time for the digestion to take place with the help of these microbes.

A surprising fact, however, was that this arrangement was not seen among dinosaurs since there wasn't the slightest hint of any difference between plant-eating and animal-eating dinosaurs. The study took into account all kinds of fossilized species-right from the primitive amphibians to the biggest mammoths and dinosaurs.

Professor Clauss noted that it's difficult to reconstruct the skeletons of dinosaurs, which is why the results for these species aren't so reliable. The researchers are of the view that a varying respiratory system might be the reason for the conflicting effect of the food on the structure of the body in mammals and dinosaurs. The study was published in the Journal of Anatomy on Nov. 4, 2016.