Supplementary Information for “The Evolution and Extinction of the Ichthyosaurs from
the Perspective of Quantitative Ecospace Modelling”
Authors: Daniel G. Dick and Erin. E. Maxwell
Supplementary Tables:
Supplementary Table 1: All genera, ecospace variables, and codes included in this article.
The data in Table 1 was used for the non-metric Multidimensional Scaling and Ward’s
Method Cluster Analysis seen in Figure 1 of the text.
Genus
Suction/RamTeeth Absent/Present
Size
Cartorhynchus
0
0
Utatsusaurus
1
1
Parvinatator
1
1
Grippia
1
1
Chaohusaurus
1
1
Cymbospondylus
1
1
Mixosaurus
1
1
Besanosaurus
1
1
Phalarodon
1
1
Xinminosaurus
1
1
Thalattoarchon
1
1
Shonisaurus
1
0
Shastasaurus
1
0
Toretocnemus
1
1
Macgowania
1
1
Guizhouichthyosaurus 1
0
Qianichthyosaurus
1
1
Suevoleviathan
1
1
Leptonectes
1
1
Eurhinosaurus
1
1
Excalibosaurus
1
1
Temnodontosaurus
1
1
T. azerguensis
1
0
Stenopterygius
1
1
Ichthyosaurus
1
1
Ophthalmosaurus
1
1
St. aaleniensis
1
1
Brachypterygius
1
1
Platypterygius
1
1
Caypullisaurus
1
1
Sveltonectes
1
1
Simbirskiasaurus
1
1
Pervushovisaurus
1
1
Maiaspondylus
1
1
Aegirosaurus
1
1
Sisteronia
1
1
Callawayia
1
1
Cryopterygius
1
1
Mollesaurus
1
1
Acamptonectes
1
1
Palvennia
1
1
Janusaurus
1
1
St. cayi
1
1
Undorosaurus
1
1
Hauffiopteryx
1
1
Habitat
0
2
1
1
0
3
1
3
1
1
4
4
4
2
2
4
1
3
2
3
3
4
4
2
0
2
2
3
3
3
2
3
3
3
1
2
2
3
2
2
3
2
2
2
2
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Ambush/Pursuit
Guild: Cut/Other
Teeth Heterodont/Homodont
Guild: Smash/Other
Guild: Pierce/Other
Guild: Crunch/Other
Period
0
0
1
0
0
0
0
0
0
0
0
0
0
0
1
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
1
1
0
0
0
0
0
0
0
0
1
0
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
0
0
0
1
0
1
0
0
0
1
0
1
0
0
0
1
0
1
1
0
0
1
0
1
1
0
0
1
0
1
0
0
0
1
0
1
1
0
0
1
0
1
0
0
1
1
0
1
1
0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
1
1
0
0
0
1
0
1
0
0
0
1
0
1
1
0
0
1
0
1
1
0
0
1
0
1
1
0
0
1
0
1
1
0
0
1
0
1
0
0
1
1
0
1
0
0
1
1
0
1
1
0
0
1
0
1
0
0
0
1
0
1
1
0
1
1
0
1
0
0
1
1
0
1
0
0
1
1
0
1
1
0
0
1
0
1
1
0
0
1
0
1
0
0
1
1
0
1
0
0
1
1
0
1
1
0
0
1
0
1
1
0
0
1
0
1
1
0
0
1
0
1
1
0
0
1
0
1
1
0
0
1
0
1
0
0
1
1
0
1
1
0
0
1
1
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
3
3
3
3
3
3
3
3
4
4
4
4
4
4
4
4
4
4
4
2
4
4
4
4
4
4
4
3
Explanation of Variables in Supplementary Table 1:
Suction/Ram: One of two variables used to characterize feeding strategy. Based on published
material (see Appendix 1) and the relationship between rostral morphology and body shape.
Specifically:
-
Suction (Code: 0): Robust mandible and hyoids, relatively short (amblygnathic)
snout, and complete edentulism.
-
Ram/Raptorial (Code: 1): The shape of the rostrum and teeth is what separates
specific instances of this variable; small hyoids, extended rostra imply inability to
produce suction, and they are thus interpreted as ram/raptorial feeders.
Ambush/Pursuit: One of two variables used to characterize feeding strategy. Based on
published material (see Appendix 1) and the relationship between body shape and swimming
speed. Specifically:
-
-
Ambush (Code: 0): Anguilimorph swimming style (based on vertebrae shape), which
results in slow constant swim speeds, with the capability to generate short bursts of
high speed. Suitable for ambushing prey; indicates majority of the diet included fish or
other slow-moving prey.
Pursuit (Code: 1): Thunniform swimming style (based on vertebrae shape and tail
morphology), which allows for relatively high sustained swimming speeds. Suitable
for chasing or ramming fast moving prey; indicates majority of the diet included
cephalopods or other fast-moving prey.
Dental Guild Categories: Based on Massare 23, with some modifications. A new guild was
added for some Early-Mid Triassic forms; “Heterodont (Smash-Crunch)” which has been
suggested to imply a generalist diet with facultative durophagy 25. Additionally, given their
ecological synonymy, Massare’s 23 Pierce II and Smash guild were categorized together as
“Smash”; this is due to their overlap in Massare’s 23 initial description, and that both imply
effectively the same diet and feeding strategy (ram/raptorial consumption of soft-bodied prey
[cephalopods] and fish). Their use to separate ichthyosaur species into “unique niches” as has
been practiced in the literature is here argued to be over-splitting, given their minimal
differences.
-
Teeth: Absent/Present (Absent = 0, Present = 1)
Teeth: Heterodont/Homodont (Heterodont = 0, Homodont = 1)
Guild: Cut/Other (Cut = 1, Other = 0)
Guild: Smash/Other (Smash = 1, Other = 0)
Guild: Pierce/Other (Pierce = 1, Other = 0)
Guild: Crunch/Other (Crunch = 1, Other = 0)
Size: Body length: Code 0 (Very Small) = < 1m, Code 1 (Small) = 1-2 m, Code 2 (Medium) =
2-5 m, Code 3 (Large) = 5 - 8 m, Code 4 (Very Large) = > 8 m.
Habitat: Refers to an organism’s occupation with reference to three dimensional space.
Demersal (Code: 0), refers to near shore, shallow water feeders (currently only includes
Cartorhynchus) 38. Potentially amphibious, these organisms were capable of both twodimensional movement (terrestrial crawling) and three-dimensional swimming 38. Pelagic
(Code: 1), refers to open water swimmers, capable of only three-dimensional swimming.
Based on limb/fin morphology.
Results of the cluster analysis used to determine ecotypes:
-
Calculated using PAST 3.06 16.
Different sized symbols represent the same ecotype at different body sizes. Letters
correspond to the letters used in the text to refer to ecotypes.
Cophenetic correlation: 0.7509
Distance: Euclidean
Ward’s Method (Bootstrap n = 10,000)
Non-metric Multidimensional Scaling Analysis settings and results:
-
Distance: Euclidean
Coordinate 1: Mainly capturing variation in body size.
Coordinate 2: Capturing variation in the other ecological variables.
Settings for MDA 41:
-
Rarefaction Bootstrap: n = 200
Confidence Intervals: 90%
Supplementary Information for Figure 1:
-
The visualization of the non-metric MDS analysis displayed in Figure 1 was created
using PAST 3.06 16.
APPENDIX 1:
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