Supplementary material.
1. Rarefunction analysis to test for equal sampling efforts in Western and eastern
Australia.
We have conducted an individual rarefaction analysis with PAST (Hammer et al. 2001) to
compare the number of obtained Bennelongia species in the samples from different parts of
Australia. Following the instructions of PAST, we have used the rarefaction analysis based
on our samples from eastern Australia (with 208 sampled wetlands and ponds) and the
Northern Territory(with 27 samples; see Table 3 in the main text for more details) to estimate
the number of expected species from the 159 Western Australian samples. As the shape of the
rarefaction analysis for Western Australia shows (see Figure S1 below), our sample efforts
have reached a plateau and are thus comparable between eastern and Western Australia. The
higher number of Western Australian Bennelongia species can thus not be attributed to a
sampling artefact.
Figure S1: Individual rarefaction analysis of the number of taxa in Western Australian.
This rarefaction curve was extrapolated from the number of samples taken in eastern Australia and the Northern
Territory (see Table 2 in paper). A = number of extrapolated positive samples.
2. Obtaining relative age estimates with different molecular clocks
We conducted relative age estimates with two different clocks from Wilke et al. (2009) – (1)
with the GTR model (+ I + γ) as described in more detail in the paper with a rate of 1.76 %
per Myr and a 95% confidence interval of 0.66 %, and (2) with the slower clock of Wilke et
al. (2009) using the HKY85 model (+ I + γ) with a rate of 1.57 % and a 95% confidence
interval of 0.45%. As is obvious from Table S1 below, applying the slower clock did not
greatly affect our age estimates. Our main conclusions that Australian Bennelongia are
neither of recent nor of Godwanian origin are thus supported with both molecular clocks.
Table S1: Details of divergence time estimates with two different universal invertebrate
clocks by Wilke et al. (2009) for major splits among Bennelongia species from Western
and east Australia.
B = Bennelongia; Myr = millions of years; WA = Western Australia; EA = eastern Australia. / indicates
divergence into different lineages or species in the phylogenetic tree (Figure 1). Rows in normal font: age
estimates with the GTR + I + γ clock by Wilke et al. (200) as shown in the paper. Rows in italics: age estimates
obtained with the slower HKY + I + γ clock by Wilke et al. (2009).
Divergence
B. scanloni & B. timmsi/all other B.
Next major split leading to 3 different lineages
B. mckenziei & B.invae/B. calei & B.
dedeckkeri
Third major split leading to 2 different lineages
B. ivanae/B. mckenziei
B. nimala/harpago
B. tirigie/lineage with B. pinderi B. koendersae
B. spec. 15
B. regina/B. triangulata/ various B. species
B. calei/B. dedeckkeri
B. scanloni/B. timmsi
B. pinpi/B. strellyensis & B.kimberlyensis
B. pinderi/B. koendersae & B. spec. 15
B. gwelupensis/group with B. cuensis, B.
coondinerensis & B. lata
B. strellyensis/B. kimberlyensis
B. coondinerensis/B. lata
B. cuensis WA-EA
B. koendersae/B. spec. 15
B. dedeckkeri WA-EA
Mean age
(Myr)
16.82
19.57
15.52
18.11
13.21
15.54
12.01
14.03
10.90
12.75
10.85
12.74
9.74
11.74
8.91
10.45
8.02
9.47
7.44
8.84
7.43
8.61
6.62
7.85
5.89
6.98
5.12
6.11
3.98
4.72
2.64
3.17
2.08
2.49
0.05
95 % Highest Posterior
Density (Myr)
11.73 - 22.86
14.19-25.67
10.84 - 21.15
13.13-23.98
8.57 - 17.94
10.59 – 20.61
7.82 - 16.38
9.60 – 18.65
6.54 - 15.58
8.17 – 18.15
6.47 - 15.39
8.01 – 17.85
5.96 - 13.85
7.19 – 15.91
5.15 - 12.19
7.01 – 14.21
4.89 - 11.78
5.74 – 13.52
4.71 - 10.76
5.60 – 12.56
4.77 - 10.30
5.85 – 11.90
3.96 - 9.53
4.84 – 11.22
3.83 - 8.21
4.70 - 9.49
3.15 - 7.53
3.87 - 8.64
2.34 - 5.85
2.82 - 6.82
1.50 - 3.93
1.82 - 4.60
1.08 - 3.27
1.31 - 3.77
0.00 - 0.16
0.00 - 0.19
References of supplementary material
Hammer, Ø., , D.A.T. Harper & P.D. Ryan, 2001. PAST: Paleontological statistics software
package for education and data analysis. Palaeontologia Electronica 4(1): 9pp.
Wilke, T., R. Schultheiß & C. Albrecht, 2009. As time goes by: a simple fool's guide to
molecular clock approaches in invertebrates. American Malacological Bulletin 27: 25-45.