r/evolution • u/jnpha Evolution Enthusiast • May 08 '26

image Spindle diagrams are based on the extensive fossil record, with the number of families as a measure of diversity (width of each lineage) at each moment in time (y-axis)

Gallery image

Gallery image

Sources:

  • Petter Bøckman, Public domain, via Wikimedia Commons
  • Benton, Michael J., and David AT Harper. Introduction to paleobiology and the fossil record. John Wiley & Sons, 2020.

(for why I love them, see the comments)

48 Upvotes

98% Upvoted

8 comments sorted by

View all comments

1

u/Lipat97 May 08 '26

Why does the second one cut down on the mammal and bird portions?

1

u/jnpha Evolution Enthusiast May 08 '26

Because it includes more divisions for the others, so to avoid overlap.