Unlabeled

Average brain size of 12 species of fossil human relatives, by fossil age

About 1.8 million years ago in East Africa, Homo rudolfensis skulls averaged 772 cm³ and Paranthropus boisei skulls 492, not far above the 428 of Australopithecus afarensis 1.4 million years earlier.

What does this axis measure?
What does this axis measure?
Average brain size of 12 species of fossil human relatives, by fossil age: 12 points, a scatter chart.
Reveal the axesHide the axes
y ↑
Brain size (cm³)
x →
Fossil age (million years)
Show the story, the data and the sourceHide the story, the data and the source
The data: 12 points
Fossil age (million years)Brain size (cm³)
0.5491,187.1
0.8251,001.8
1.665805.6
1.698604.9
1.718492
1.765642.7
1.892771.9
1.967605.6
1.977420
2.155450.5
2.401475.4
3.152428.4
Source
Du, Zipkin, Hatala, Renner, Baker, Bianchi, Bernal and Wood (2018), Pattern and process in hominin brain size evolution are scale-dependent, Table S1, Proceedings of the Royal Society B, via The Royal Society (figshare); species averages calculated by Unlabeled
Licence
CC BY 4.0 (the file as read, from the Royal Society's figshare record); the same file is CC0 1.0 on the authors' Dryad deposit (doi:10.5061/dryad.c30g9)
Read
2026-11-10
Drawn
12 points as the puzzle showed them · scatter
  • Ran in puzzle #48 on November 13, 2026. Play it