Related Experiment Video
Updated: Sep 6, 2025
Author Spotlight: High-Resolution Imaging of Mouse Neonate Brains – A Micro-CT Protocol with Lugol's Solution Contrast Agent
Published on: May 19, 2023
Comparative Study of Brain Size Ontogeny: Marsupials and Placental Mammals
Carmen De Miguel1, Arthur Saniotis1,2, Agata Cieślik2
1Biological Anthropology and Comparative Anatomy Research Unit (BACARU), School of Biomedicine, The University of Adelaide, Adelaide 5005, Australia.
Abstract:
There exists a negative allometry between vertebrate brain size and body size. It has been well studied among placental mammals but less is known regarding marsupials. Consequently, this study explores brain/body ontogenetic growth in marsupials and compares it with placental mammals. Pouch young samples of 43 koalas (Phascolarctos cinereus), 28 possums (Trichosurus vulpecula), and 36 tammar wallabies (Macropus eugenii) preserved in a solution of 10% buffered formalin, as well as fresh juveniles and adults of 43 koalas and 40 possums, were studied. Their brain size/body size allometry was compared to that among humans, rhesus monkeys, dogs, cats, rats, guinea pigs, rabbits, wild pigs, and mice. Two patterns of allometric curves were found: a logarithmic one (marsupials, rabbits, wild pigs, and guinea pigs) and a logistic one (the rest of mammals).
Related Concept Videos
02:24Comparative Excretory Systems
01:20Anatomy of the Brain: Major Regions
The cerebrum is the largest section of the brain and divides into left and right hemispheres, separated by a deep fissure. The cerebral outer layer of grey matter — the cerebral cortex — comprises elevations called gyri and shallow groves called sulci. The inner portion of white matter includes long nerve fibers known as axons, which connect...