The evolution of maximum body size of terrestrial mammals.
The extinction of dinosaurs at the Cretaceous/Paleogene (K/Pg) boundary was the seminal event that opened the door for the subsequent diversification of terrestrial mammals. Our compilation of maximum body size at the ordinal level by sub-epoch shows a near-exponential increase after the K/Pg. On each continent, the maximum size of mammals leveled off after 40 million years ago and thereafter remained approximately constant. There was remarkable congruence in the rate, trajectory, and upper limit across continents, orders, and trophic guilds, despite differences in geological and climatic history, turnover of lineages, and ecological variation. Our analysis suggests that although the primary driver for the evolution of giant mammals was diversification to fill ecological niches, environmental temperature and land area may have ultimately constrained the maximum size achieved.
Department of Biology, MSC03 2020, University of New Mexico, Albuquerque, NM 87131, USA. fasmith@unm.edu
Felisa A
FA
Smith
Alison G
AG
Boyer
James H
JH
Brown
Daniel P
DP
Costa
Tamar
T
Dayan
S K Morgan
SK
Ernest
Alistair R
AR
Evans
Mikael
M
Fortelius
John L
JL
Gittleman
Marcus J
MJ
Hamilton
Larisa E
LE
Harding
Kari
K
Lintulaakso
S Kathleen
SK
Lyons
Christy
C
McCain
Jordan G
JG
Okie
Juha J
JJ
Saarinen
Richard M
RM
Sibly
Patrick R
PR
Stephens
Jessica
J
Theodor
Mark D
MD
Uhen
D000818:Animals; D001272:Atmosphere; D005075:Biological Evolution; D049628:Body Size; D017753:Ecosystem; D004777:Environment; D053476:Extinction, Biological; D005580:Fossils; D005843:Geography; D008322:Mammals / Q000033:anatomy & histology* / Q000145:classification / Q000254:growth & development; D008954:Models, Biological; D010100:Oxygen; D010802:Phylogeny; D013696:Temperature
D010100:Oxygen