Gateway to the Paleobiology Database
Basic options Subsampling options Raw data columns Subsampling columns Graphing options

Diversity curve request form

File name:
Required if you entered a name when you downloaded the data.
Time scale:
Bin size in millions of years:
Required if you selected one of the Neptune options above; otherwise ignored.
Taxonomic level:
If the family or order name is missing, use the immediate parent taxon's name instead? yes
Count references instead of taxa?
Range extant taxa through to the Recent? yes

This form allows you to request a diversity curve with assorted statistics.

  • A diversity curve shows the number of taxa that are counted in different time intervals such as epochs
  • You must download an occurrence data file before you submit this form
  • If you only want to see the raw data, press submit
  • To run a standardized subsampling analysis instead, fill out the required fields under "Subsampling options"
  • Subsampling methods and diversity measures are explained in Alroy 2010 (Paleontological Society Papers 16:55-80)
  • Note: our server is fast, but requests may still take a minute or two to process

Subsampling method:
Required for subsampling. See Alroy (2010) for a discussion of the alternatives.
Weighting exponent:
Required for occurrences-weighted subsampling, and otherwise ignored.
2.0 = occurrences-squared weighting; 0.0 = unweighted subsampling;
1.0 = simple occurrences-weighted subsampling.
Sampling quorum (for SQS) or quota of data records (for other methods):
Required for subsampling. A quorum is a fraction; a quota is a count.
Good's u options:
Count taxa     Ignore most common taxon?      Ignore largest collection?
Number of subsampling trials:
Required for subsampling.
Draw fewer collections from references yielding many of them? yes
Sampled item counts to report in subsampling curves:
Not required and can't be computed by SQS.
Print subsampling stats for intervals that do not meet the quorum or quota?
Not required.

Descriptive statistics
Base (Ma) Midpoint (Ma)
Collections Occurrences Occurrences-squared or exponentiated Specimens or individuals
Sampled taxa Two timers Three timers Part timers One-occurrence taxa One-reference taxa Good's u
Unbiased statistics (if sampling is already nearly uniform)
3T origination rate (Alroy 2008) 3T extinction rate
Three timer sampling stat (Alroy 2008) Three timer diversity estimate
Dominance Dominant taxon Evenness of occurrences (Hurlbert's PIE)
Biased statistics unless sampling is already complete)
Range-through taxa Boundary-crosser taxa Single-interval taxa
First appearances Last appearances BC origination rate (Foote 1999) BC extinction rate
Gap analysis sampling stat (Paul 1982) Gap analysis diversity estimate
Mean richness Median richness
Check all    Check counts    Check diversity estimates

Descriptive statistics
Base (Ma) Midpoint (Ma)
Items sampled Two timers Three timers Part timers
Subsampling results
Median sampled diversity 1-sigma CI Mean sampled diversity
3T origination rate (Alroy 2008) 3T extinction rate
Three timer sampling stat Three timer diversity estimate
Biased statistics
Range-through diversity Boundary-crosser diversity
First appearances Last appearances Single-interval taxa
BC origination rate (Foote 1999) RT origination percentage BC origination percentage (Alroy 1996)
BC extinction rate RT extinction percentage BC extinction percentage
Gap analysis sampling stat (Paul 1982) Gap analysis diversity estimate
Check all    Check counts    Check diversity estimates

Choose line colors and scalings for the variables you want to graph.

Sampled taxa
Range-through taxa*
Boundary-crosser taxa*
First appearances*
Last appearances*
Single-interval taxa*
Compute correlations between each pair of lines
*Biased statistic that should not be used in a publication.
See Alroy (2008, 2010a, b, c) and Alroy et al. (2008).