Figure 2.

Sampling of the beetle fossil record. (a) Proportion of families known to range through each 25 Myr interval that are actually sampled within that interval. When split by type of deposit, the proportions of range-through taxa preserved in amber (yellow, lower line) or non-amber (blue, upper line) deposits are depicted. The dashed line shows the proportion in either deposit, and is coincident with the non-amber line prior to the Cretaceous, because there are no beetle-containing amber deposits older than the Cretaceous. (b) Number of genus-level occurrences within 25 Myr intervals. The numbers of occurrences from amber deposits (yellow, upper portion) are stacked on those of non-amber deposits (blue, lower portion). (c) Number of families sampled only from amber deposits (yellow, uppermost portion), only from non-amber deposits (blue, lowermost portion) or from both amber and non-amber deposits (green, middle portion) within 25 Myr intervals. (d) The number of occurrences per family from amber (yellow, lower line) or non-amber (blue, upper line) deposits within 25 Myr intervals. (Online version in colour.)