
This Article From Issue
July-August 2014
Volume 102, Number 4
Page 244
DOI: 10.1511/2014.109.244
To the Editors:
In the article “On the Trail of the First Placental Mammals,” by Maureen A. O’Leary in the May–June issue, a figure caption refers to the ancestral placental mammal, which is still unknown to the fossil record, as “rodent-sized.” This wording is exceedingly imprecise.
Present-day rodents range in size from extremely small mice, weighing less than 10 grams, through squirrels, woodchucks, and beavers, and up to the largest living rodent, the capybara, one example of which appears to have exceeded 90 kilograms in weight. At least one extinct rodent, Josephoartigasia monesi, reached the size of a rhinoceros.
Ronald H. Pine
University of Kansas
American Scientist Comments and Discussion
To discuss our articles or comment on them, please share them and tag American Scientist on social media platforms. Here are links to our profiles on Twitter, Facebook, and LinkedIn.
If we re-share your post, we will moderate comments/discussion following our comments policy.