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APPENDIX 1.

Selected measurements of specimens examined during this study (.xls). (Available in zipped file.)

 

APPENDIX 2.

Discussion of character and taxon scoring changes from past analyses.

Our phylogenetic analysis was based on the matrix developed by Moon (2017) and modified by Maxwell et al. (2019). In addition to rescoring Hauffiopteryx, we made the following revisions to characters and scoring:

Character 50: The position of the parietal foramen is more complex than initially captured in this character. We divided state (1) into two separate states. Rescoring affected only Ichthyosaurus.

Character 50 Parietals - location of the parietal foramen: (0) contact between the left and right parietals present anteriorly, frontal excluded from the parietal foramen; (1) on the frontoparietal suture; (2) entirely surrounded by the frontals (modified from Motani 1999c, character 19).

Character 89: The transverse flange of the pterygoid (character 88) is absent in most ichthyosaurs (Maisch and Matzke, 2000), which are scored as “poorly developed” in the matrix of Moon (2017: character 88). We therefore rescore character 89 as ‘-‘ in these cases.

Characters 165, 166: In the analysis of Moon (2017), characters 165-166 are duplicated as currently organized (i.e. a sacrum is present by definition only if differentiated sacral ribs are present). Moreover, no taxa in the sample have a sacrum as defined by character 165 (ribs sutured to ilium). For that reason, we restructure characters 165-166 as follows:

Character 165: Sacrum (0) present (at least one morphologically differentiated sacral rib can be observed), (1) absent (no truly sacral ribs are present)(Motani, 1999 character 104 [part]).

Character 166: Sacral ribs (0) two with distal expansion, (1) one with distal expansion, (2) present and morphologically distinct [see character 165] but no distal expansion present. This character is treated as ordered.

Character 210: As scored by Moon (2017), this character is uninformative. This character was rescored based on pers. observ. of specimens at the SMNS and from the NHMUK digital collections interface, and such a notch separating the radial and ulnar facets of the distal humerus was observed in T. trigonodon, T. platyodon, and S. integer. Because such a notch may exist even in the presence of a humerus-intermedium contact, character 210 was scored for all taxa.

Character 221: A small interosseous foramen is present between the radius and ulna in T. trigonodon, T. platyodon (see McGowan, 1979), and Suevoleviathan. This character was rescored accordingly.

Character 240: In basal ichthyopterygians, metacarpal V is much larger than distal carpal IV, whereas in more derived forms these elements are subequal or metacarpal V may be lost entirely (Maisch and Matzke 2000b, character 100). In the character list Moon (2017), the character states were incorrectly transcribed. We have edited this error; the character-taxon matrix was not affected.

Mixosaurus kuhnschneyderi: Rescored for character 118.

Guizhouichthyosaurus wolonggangense: The following characters were rescored based on reinterpretation of forelimb homologies in the original description, in which digit I is absent (and therefore metacarpal V is present): 217, 219, 229, 233, 236, 237, 240, 243, 247, 248. Characters 35-45 were also rescored based on the description of the type specimen.

Guizhouichthyosaurus tangae: character 35, 41, 229 rescored based on type description.

Callawayia neoscapularis: characters 35, 43, 229 rescored.

Ichthyosaurus communis and I. larkini: Scoring corrected for Characters 42 and 43 (temporal process of the frontal absent).

Protoichthyosaurus prostaxalis and Protoichthyosaurus applebyi were scored based on Lomax and Massare, 2018; Lomax et al., 2017, 2019a,b.

Temnodontosaurus trigonodon: Rescored for character 219, since a postaxial manual accessory digit is absent.

Temnodontosaurus crassimanus was rescored for characters 47-48, 54, 73, 204, 207, 209, 214, 219, 226, 230, 240, 243 based on Melmore (1930). Additionally, we assume that Melmore (1930) misinterpreted the anterior-posterior polarity of the hind limb. This results in rescoring of characters 273 and 284.

Temnodontosaurus azerguensis was rescored for characters 227, 229, and 250 based on the figures and description of the holotype (Martin et al., 2012); characters 259 and 263-264 were scored based on the same.

Wahlisaurus massarae: Scoring for character 48 was corrected.

Leptonectes moorei: rescored for character 32, 233 based on pers. observ. of the holotype material.

Eurhinosaurus longirostris: Characters 20, 36, 53, 167 rescored and character 97 scored based on pers. observ. of specimens at the SMNS.

Excalibosaurus costini: Character 249 (number of phalanges) rescored based on the holotype specimen, characters 167, 217 rescored based on McGowan (2003).

Malawania anachronus: Characters 152, 219, 233 scored based on morphology illustrated in Fischer et al. (2013).

Stenopterygius quadriscissus: Characters 5, 9, 20, 32, 44, 61, 87, 152, 233 rescored based on pers. observ; character 82 rescored based on pers. observ.

Stenopterygius triscissus: Characters 5, 20, 152 rescored based on pers. observ; character 82 scored based on pers. observ.

Stenopterygius uniter: Characters 5, 9, 20, 152, 241 rescored based on pers. observ; character 82 rescored based on pers. observ.

Stenopterygius aaleniensis: Scoring of character 241 changed to ‘?’ as the metacarpal row is not preserved in this taxon; character 5 (subnarial process) also rescored based on pers. observ.

Chacaicosaurus cayi: Characters 233, 247-248 rescored based on Fernández (1994).

Ophthalmosaurus icenicus: Character 41 rescored as present, based on the separation of the postfrontal from the parietal in dorsal view by a process of the frontal.

Caypullisaurus bonapartei: Scoring for character 247-248 changed, as manual metacarpal V is present in these taxa (Fernández, 2001).

Arthropterygius chrisorum: Character 177 changed to ‘?’ as the caudal region is not well-enough preserved to evaluate this character.

Paraophthalmosaurus kabanovi: Scoring for character 247 changed to ? because the limb is incompletely preserved in this specimen.

Muiscasaurus catheti: rescored as ‘?’ for characters 11-12, since the maxilla-lacrimal suture is unclear.

Sveltonectes insolitus was rescored for character 227.

REFERENCES

Fernández, M.S. 1994. A new long-snouted ichthyosaur from the Early Bajocian of Neuquén Basin (Argentina). Ameghiniana, 31:291-297.

Fernández, M.S. 2001. Dorsal or ventral? Homologies of the forefin of Caypullisaurus (Ichthyosauria: Ophthalmosauria). Journal of Vertebrate Paleontology, 21:515-520.

Fischer, V., Appleby, R.M., Naish, D., Liston, J., Riding, J.B., Brindley, S., and Godefroit P. 2013. A basal thunnosaurian from Iraq reveals disparate phylogenetic origins for Cretaceous ichthyosaurs. Biology Letters, 9:20130021. https://doi.org/10.1098/rsbl.2013.0021

Lomax, D.R., and Massare, J.A. 2018. A second specimen of Protoichthyosaurus applebyi (Reptilia: Ichthyosauria) and additional information on the genus and species. Paludicola, 11:164-178.

Lomax, D.R., Massare, J.A., and Evans, M. 2019a. New information on the skull roof of Protoichthyosaurus (Reptilia: Ichthyosauria) and intraspecific variation in some dermal skull elements. Geological Magazine. https://doi.org/10.1017/S0016756819001225

Lomax, D.R., Porro, L.B., and Larkin, N.R. 2019b. Descriptive anatomy of the largest known specimen of Protoichthyosaurus prostaxalis (Reptilia: Ichthyosauria) including computed tomography and digital reconstruction of a three-dimensional skull. PeerJ 7: e6112. https://doi.org/10.7717/peerj.6112

Lomax, D.R., Massare, J.A., and Mistry, R.T. 2017. The taxonomic utility of forefin morphology in Lower Jurassic ichthyosaurs: Protoichthyosaurus and Ichthyosaurus. Journal of Vertebrate Paleontology 37:e1361433. http://dx.doi.org/10.1080/02724634.2017.1361433

Maisch, M.W., and Matzke, A.T. 2000. The Ichthyosauria. Stuttgarter Beiträge zur Naturkunde Serie B (Geologie und Paläontologie), 298:1-159.

Martin, J.E., Fischer, V., Vincent, P., and Suan, G. 2012. A longirostrine Temnodontosaurus (Ichthyosauria) with comments on Early Jurassic ichthyosaur niche partitioning and disparity. Palaeontology, 55:995-1005. https://doi.org/10.1111/j.1475-4983.2012.01159.x

Maxwell, E.E., Cortés, D., Patarroyo, P., and Parra Ruge, M.L. 2019. A new specimen of Platypterygius sachicarum (Reptilia: Ichthyosauria) from the Early Cretaceous of Colombia and its phylogenetic implications. Journal of Vertebrate Paleontology, 39: e1577875. https://doi.org/10.1080/02724634.2019.1577875

McGowan, C. 1979. A revision of the Lower Jurassic ichthyosaurs of Germany with descriptions of two new species. Palaeontographica Abt. A, 166:93-135.

McGowan, C. 2003. A new specimen of Excalibosaurus from the English Lower Jurassic. Journal of Vertebrate Paleontology, 23:950-956.

Melmore, S. 1930. A description of the type-specimen of Ichthyosaurus crassimanus, Blake (Owen MS.). Annals and Magazine of Natural History Series 10, 6:615-619.

Moon, B.C. 2017. A new phylogeny of ichthyosaurs (Reptilia: Diapsida). Journal of Systematic Palaeontology, 0:1-27. https://doi.org/10.1080/14772019.2017.1394922

Motani, R. 1999. Phylogeny of the Ichthyopterygia. Journal of Vertebrate Paleontology, 19:473-496.

APPENDIX 3.

Character list, copied directly from Moon (2017). Text in red corresponds to changes to the original character list that were introduced in Maxwell et al. (2019); text in blue indicates characters that were modified for the current study (characters 50, 165-166 only). See Appendix 2 for discussion and references. Characters 100, 107, 153, 166, and 219 are treated as ordered.

Skull

Character 1 Snout - extremely slender premaxillary segment, < ¼ the maximum lateral width of the posterior of the skull: (0) absent (1) present (Motani 1999c, character 34). This is modified from Motani’s (1999c) character 34 by defining a specific boundary of ‘slender’. Motani’s original character separates several taxa, especially his ‘Eurhinosauria’. To maintain this distinction this character is defined as the width of the snout where the premaxillae exclude the nasals from dorsal view - the nasals anteriormost dorsal exposure - compared to the maximum width of the post-narial skull.

Character 2 Premaxilla - supranarial process: (0) present (1) absent (modified from Maisch and Matzke 2000b, character 9; and Maxwell 2012, character 1).

Character 3 Premaxilla - size of supranarial process: (0) large, extending > ⅓ of the external

narial length (1) small, extending < ⅓ of the external narial length (modified from Maisch and Matzke 2000b, character 9; and Maxwell 2012, character 1).

Character 4 Premaxilla - subnarial process: (0) absent (1) present (modified from Maisch and Matzke 2000b, character 10; and Maxwell 2012, character 1).

Character 5 Premaxilla - size of the subnarial process: (0) small, extending < ⅓ of the external

narial length (1) large, extending > ⅓ of the external narial length (modified from Maisch and Matzke 2000b, character 10; and Maxwell 2012, character 1).

Character 6 Premaxilla-palatine - contact in ventral view: (0) absent (1) present, relatively broad (Druckenmiller and Maxwell 2010, character 15).

Character 7 Maxilla - reduction: (0) absent, ≥ ½ of the length of the snout (1) present, < ½ the length of the snout (modified from Sander et al. 2011, character 106). The reduction of the maxilla is defined more specifically than Sander et al.’s (2011) character 106. While this is defined relative to the length of the snout as a whole, the dorsoventral exposure and contribution should also be considered (see character 9).

Character 8 Maxilla - bearing teeth: (0) present (1) absent. See character 7.

Character 9 Maxilla - location of the laterally exposed greatest dorsoventral extent: (0) posterior to the external naris (1) ventral or anterior to the external naris (modified from Druckenmiller and Maxwell 2010, character 4). State one has been modified to include ‘ventral to the external naris’.

Character 10 Maxilla - length of the premaxillary process: (0) short, extends approximately one or less narial lengths anterior to the external naris (1) long, extends approximately 1.5 or more narial lengths anterior to the external naris (Maxwell 2012, character 2).

Character 11 Maxilla - postnarial process exposed laterally: (0) present (1) absent (modified from Maisch and Matzke 2000b, character 11). The postnarial process of the maxilla is a dorsal extension of the maxilla posterior to the external naris, this is the processus postnarialis of Maisch and Matzke (1997a); it is equivalent to the dorsal lamina of Motani (1999c).

Character 12 Maxilla - size of the postnarial process exposure: (0) large (1) tiny (modified from Maisch and Matzke 2000b, character 11). Clarified that this refers to exposure of the postnarial process.

Character 13 Maxilla - size of the jugal process: (0) long, extending as far under the orbit as the lachrymal in lateral view (1) short, hidden in lateral view by the jugal (Maxwell 2012, character 3).

Character 14 Maxilla - contacts prefrontal: (0) absent (1) present (Maisch and Matzke 2000b, character 12).

Character 15 Maxilla - contacts external naris in external lateral view: (0) present (1) absent (modified from Fernández 2007a, character 2; after Fischer et al. 2011, character 9; and Fischer 2013, character 9).

Character 16 Nasal - anteroposterior extent of dorsal exposure in the prenarial rostrum: (0) substantial, over 40% (1) reduced, less than 40% (Maxwell 2012, character 4).

Character 17 Nasal posterior extent: (0) reaches back to the orbit (1) reaches distinctly over the orbit (Maisch and Matzke 2000b, character 14).

Character 18 Narial shelf: (0) absent (1) present (Jiang et al. 2006, character 4). This narial shelf is anterior to the external naris, bordered medially by the nasosupraorbital ridge (Jiang et al. 2006).

Character 19 Nasal - borders external naris: (0) present (1) excluded (Sander 2000, character 7).

Character 20 Nasal - descending process on the interior posterior border of the nares: (0) absent (1) present (Fernández 2007a, character 2).

Character 21 Nasal-postfrontal - contact: (0) absent (1) present (modified from Nicholls and Manabe 2001, character 3).

Character 22 Nasal-postfrontal contact - size: (0) small (1) extensive, separating frontals and prefrontals in dorsal view (modified from Nicholls and Manabe 2001, character 3).

Character 23 Excavatio internasalis: (0) absent (1) present (Maisch and Matzke 2000b, character 16).

Character 24 Lachrymal - anterior extent: (0) reaches external naris (1) is excluded from the external naris by the dorsal process of the maxilla and/or the ventral process of the nasal (Sander 2000, character 10). The polarity of this character was reversed by Maxwell (2012, character 5).

Character 25 Lachrymal - numerous small-to-medium-sized nutritive foramina: (0) absent (1) present (Sander et al. 2011, character 111). This character refers to millimetre-size nutritive foramina that perforate the lachrymal and are only recorded in Shastasaurus.

Character 26 External nares - shape: (0) small, round to ovate (1) elongate (2) elongate and complexly lobate (Sander 2000, character 8). As this character defines shape, states one and two are considered suitably different that this should not be coded with reductive methods.

Character 27 External nares - orientation: (0) dorsolateral (1) lateral, scarcely visible in dorsal view (Motani 1999c, character 4).

Character 28 Jugal - shape: (0) triradiate (1) lunate or J-shaped (Motani 1999c, character 24). Compare this with character 31.

Character 29 Jugal - anterior margin shape: (0) tapering, running between the lachrymal and maxilla (1) broad and fanlike, covering a large area of the maxilla ventrolaterally (Druckenmiller and Maxwell 2010, character 6).

Character 30 Jugal - extent of anterior margin: (0) terminates posterior to the anterior end of the lachrymal (1) reaches or surpasses the anterior end of the lachrymal (Roberts et al. 2014, character 11).

Character 31 Jugal - dorsal ramus shape: (0) well-developed and strongly curved dorsally (1) poorly developed, jugal essentially straight (Maxwell 2012, character 8). This character is exclusive of character 28: poor development of the dorsal ramus does not preclude a J-shaped or triradiate jugal, although this may be less apparent.

Character 32 Jugal - contact between the postorbital process and the squamosal: (0) absent (1) present (Sander 2000, character 31).

Character 33 Jugal-quadratojugal - external contact: (0) absent (1) present (Motani 1999c, character 23). This was included as a new character by Roberts et al. (2014), who explicitly included the postorbital to separate the jugal and quadratojugal.

Character 34 Jugal-quadratojugal notch - deep, forming a pronounced ventral emargination of the cheek: (0) present (1) absent (Jiang et al. 2005, character 24). This character is exclusive of character 79 as the ventral margin of the quadratojugal may be concave without forming a distinct emargination of the cheek.

Character 35 Prefrontal - dorsal exposure: (0) broadly exposed (1) present, but limited by the anterior process of the postfrontal and posterior process of the nasal (2) little to none (modified from Maxwell 2012, character 12).

Character 36 Prefrontal-external naris - contact: (0) absent (1) present (Druckenmiller and Maxwell 2010, character 7).

Character 37 Prefrontal-postfrontal - contact: (0) absent, the dorsal margin of the orbit is formed by the frontal (1) present, eliminating the frontal from the dorsal margin of the orbit (Motani 1999c, character 8). This character incorporates the revised interpretation of the skull of Ichthyosaurus and Stenopterygius (Motani 2005), but character states may have been revised. This also applies to subsequent skull roof characters.

Character 38 Prefrontal and postfrontal - high supraorbital crest: (0) absent (1) present (Maisch and Matzke 2000b, character 22).

Character 39 Frontals - dorsal view: (0) strongly convex at the anterior edge of the parietal foramen (1) flat to concave, overlapped by surrounding elements (Maxwell 2012, character 13). Overlapping by surrounding elements may be separated into another character, however, this has not clearly been seen to warrant this distinction.

Character 40 Frontal - location of the widest exposure: (0) located posteriorly (1) at nasal suture (Motani 1999c, character 15).

Character 41 Frontal - temporal process: (0) absent (1) present (Fischer et al. 2011, character 14).

Character 42 Frontal - participates in the supratemporal fenestra in dorsal view: (0) absent (1) present (modified from Druckenmiller and Maxwell 2010, character 9; and Fischer et al. 2011, character 14). This and the next character are separated for reductive coding.

Character 43 Frontal - size of participation in the supratemporal fenestra: (0) small (1) extensive (modified from Druckenmiller and Maxwell 2010, character 9).

Character 44 Frontal and parietal - relative dorsal exposure size: (0) frontal as large or larger than the parietal (1) frontal smaller than the parietal (Maisch and Matzke 2000b, character 17).

Character 45 Parietal - dorsal view contribution to the anterior margin of the supratemporal fenestra: (0) no contribution (1) minor contribution (2) large, almost completely excluding the postfrontal from contact (modified from Maxwell 2012, character 14).

Character 46 Parietal ridge: (0) absent (1) present (Motani 1999c, character 17).

Character 47 Parietal shelf - orientation (0) obliquely oriented; (1) horizontally oriented (modified from Nicholls and Manabe 2001, character 8).

Character 48 Parietal shelf - size: (0) large (1) reduced (modified from Nicholls and Manabe 2001, character 8).

Character 49 Parietals - separation of anterior processes of the right and left: (0) narrow, forming parietal fork, and frontal dorsally visible along the pineal foramen (1) widely open, resulting in absence of clear fork (Motani 1999c, character 19). This character may be coded as inapplicable if the anterior processes of the parietals contact (character 50).

Character 50 Parietals - location of the parietal foramen: (0) contact between the left and right parietals present anteriorly, frontal excluded from the parietal foramen; (1) on the frontoparietal suture; (2) entirely surrounded by the frontals (modified from Motani 1999c, character 19).

Character 51 Parietals - anterior fork elevated: (0) absent (1) present (Nicholls and Manabe 2001, character 10). This character is coded as inapplicable if no anterior parietal fork is present (character 49).

Character 52 Postparietals - additional bone separating the parietal and supratemporal: (0) absent (1) present (modified from Thorne et al. 2011, character 18).

Character 53 Parietal - size of the supratemporal process: (0) short (1) long (modified from Thorne et al. 2011, character 18).

Character 54 Parietal foramen - anteroposterior position: (0) approximately equal to the anterior edge of the supratemporal fenestra (1) well anterior to the anterior edge of the supratemporal fenestra (Maxwell 2012, character 15).

Character 55 Postfrontal - size of the posterior flange: (0) delicate and narrow, not extending ventrally to the posterior orbital rim (1) robust and triangular, approaching posterior orbital rim (Druckenmiller and Maxwell 2010, character 12). The posterior flange on the postfrontal is found in all ichthyosaurs (Motani 1999c; Thorne et al. 2011), but the size of this varies (Druckenmiller and Maxwell 2010).

Character 56 Postfrontal-postorbital - size of contact: (0) narrow (1) broad (Roberts et al. 2014, character 16).

Character 57 Postfrontal-supratemporal - contact: (0) absent (1) present (Sander 2000, character 28). This is exclusive of character 55 as contact between the postfrontal and supratemporal may be made whether the posterior flange is large or small.

Character 58 Postorbital - shape: (0) triradiate (1) lunate, without posterior process (Motani 1999c, character 11).

Character 59 Postorbital - size: (0) broad (1) narrow (Fernández 2007a, character 7).

Character 60 Postorbital - participates in the supratemporal fenestra: (0) present (1) absent (Motani 1999c, character 12).

Character 61 Postorbital-supratemporal - contact in external view: (0) present (1) absent (Maxwell 2012, character 6).

Character 62 Supratemporal - enlargement: (0) small, minimal posterior exposure (1) moderate, forming posterior border of the supratemporal fenestra (2) strongly enlarged, forms significant portion of the posterior and lateral borders to supratemporal fenestra and skull roof (modified from Sander 2000, character 26). The definitions for ‘small’ and ‘enlarged’ are clarified.

Character 63 Supratemporal - anterodorsal sheet overhanging the supratemporal fenestra: (0) absent (1) present (Maisch and Matzke 2000b, character 25).

Character 64 Supratemporal - size of the descending ramus: (0) pronounced, reaching at least half of the total height of the quadrate (1) reduced, a small process medial to the quadrate articulation (Maxwell 2012, character 17).

Character 65 Supratemporal-stapes - contact: (0) absent (1) present (Fischer et al. 2013, character 52).

Character 66 Sagittal eminence: (0) present (1) absent (Fischer et al. 2011, character 13).

Character 67 Supratemporal - orientation of parietal ramus in dorsal view (0) oblique, (1) horizontal. This character may not be independent from the orientation of the parietal shelf, but can be scored in the absence of a clear parietal shelf.

Character 68 Supratemporal - relative anterior extent of the lateral and parietal rami in dorsal view (0) subequal, (1) lateral ramus extending much further anteriorly.

Character 69 Squamosal: (0) present (1) absent. This character is added, and characters 70 to 72 are modified, and which may be coded as inapplicable, for reductive coding.

Character 70 Squamosal - shape: (0) triangular (1) squared (Fischer et al. 2011, character 16).

Character 71 Squamosal - posterior descending process: (0) absent (1) present (modified from Fernández 2007a, character 4). The absence of the squamosal is coded separately (character 69).

Character 72 Squamosal - participates in supratemporal fenestra: (0) present (1) excluded by supratemporal and/or postfrontal (Nicholls and Manabe 2001, character 6).

Character 73 Supratemporal fenestrae - width in dorsal aspect: (0) posterior half narrower than anterior half (1) anterior and posterior halves approximately equal in width (Druckenmiller and Maxwell 2010, character 11).

Character 74 Anterior terrace of the supratemporal fenestra: (0) absent (1) present (modified from Motani 1999c, character 14).

Character 75 Anterior terrace of the supratemporal fenestra - extent: (0) small, reaching the posterior part of the frontal anteriorly (1) large, reaching the nasal anteriorly (modified from Motani 1999c, character 14). See character 74.

Character 76 Skull roof - posterior margin indented in dorsal view: (0) deep (1) moderate (Maisch and Matzke 2000b, character 27).

Character 77 Quadratojugal - location of the main body: (0) laterally (1) posteriorly (Maisch and Matzke 2000b, character 28).

Character 78 Quadratojugal - exposure: (0) broad in lateral view (1) narrow and most extensively exposed in posterior view (Maxwell 2012, character 8).

Character 79 Quadratojugal - shape of the ventral edge: (0) concave (1) ventral edge straight or entirely covered by the jugal (Maxwell 2012, character 9). See also character 34.

Character 80 Quadratojugal - distinctly offset quadrate process: (0) present (1) absent (Maisch and Matzke 2000b, character 29).

Character 81 Quadrate - dorsal articulation location: (0) enclosed laterally by the squamosal (1) articulates dorsomedially with the supratemporal only (Maxwell 2012, character 11). This character may be coded as inapplicable if the squamosal is absent (character 69), although this implies state (1).

Character 82 Quadrate - location of the stapedial facet on the posterior surface: (0) ventral half (1) dorsal half (Druckenmiller and Maxwell 2010, character 21).

Character 83 Orbit - shape of the anterior margin: (0) irregular (1) regularly rounded (2) angled (modified from Maisch and Matzke 2000b, character 23). The additional state ‘angled’ is added for the condition in e.g. Cryopterygius kristiansenae.

Character 84 Postorbital skull - length compared to orbital diameter: (0) > ⅓ (1) < ⅓ (Jiang et al. 2005, character 7).

Character 85 Cheek - orientation: (0) mostly lateral (1) largely posterior (Motani 1999c, character 25).

Character 86 Interpterygoidal vacuity: (0) present (1) absent (modified from Motani 1999c, character 27). Other characters referring to a ‘closed palate’ (Jiang et al. 2005, character 12) and exposure of the basis cranii (Maisch and Matzke 2000b, character 44) are included within this. This character is modified into a simple presence/absence dichotomy.

Character 87 Palatine - contributes to subtemporal fenestra: (0) posteriorly forms anterior edge (1) posteriorly excluded from the subtemporal fenestra (Maxwell 2012, character 25).

Character 88 Pterygoid - transverse flange: (0) well-developed (1) poorly developed (modified from Motani 1999c, character 26). The development and orientation of the transverse flange of the pterygoid are separated for reductive coding (characters 88 and 89).

Character 89 Pterygoid - orientation of the transverse flange: (0) anterolateral (1) posterolateral (modified from Motani 1999c, character 26). See character 88.

Character 90 Pterygoid - posteromedial process: (0) present (1) absent (Maisch and Matzke 2000b, character 35).

Character 91 Vomer - number of dorsal processes: (0) one (1) two (Druckenmiller and Maxwell 2010, character 17). The vomer, particularly dorsally, is poorly known; while this character is included, its coding completeness is low.

Character 92 Epipterygoid - ossified: (0) present (1) absent.

Character 93 Basis cranii - largely formed by: (0) parasphenoid (1) basisphenoid (Maisch and Matzke 2000b, character 41).

Character 94 Basioccipital - shape of the condyle: (0) flat or slightly concave (1) hemispherical (Motani 1999c, character 31).

Character 95 Basioccipital - notochordal pit on the condylar surface: (0) absent (1) present. See character 96.

Character 96 Basioccipital - location of notochordal pit on the condylar surface: (0) central (1) dorsal.

Character 97 Basioccipital peg: (0) present (1) absent (Fischer et al. 2011, character 20).

Character 98 Basioccipital - prominent ventral tubers separated by a deep notch: (0) present (1) absent (modified from Maxwell 2012, character 24). This character has been simplified to presence/absence.

Character 99 Basioccipital - extracondylar area: (0) present (1) absent. This character is added as, in some taxa, the extracondylar area may be entirely lost. This is incorporated into Fischer et al. (2013, character 20).

Character 100 Basioccipital - size of the ventral extracondylar area: (0) larger than the dorsoventral height of the condyle (1) smaller than the condyle but still extensive (2) reduced to a thin strip (Maxwell 2012, character 23). This is similar to Fischer et al. (2013, character 20). This character is treated as ordered.

Character 101 Basioccipital - contribution to the floor of the foramen magnum: (0) absent, excluded by the exoccipitals (1) present, the portion contributing being flat, or concave, and covered in finished bone (Maxwell 2012, character 21).

Character 102 Parabasisphenoid - base of basipterygoid processes in dorsal or ventral view: (0) offset and anteroposteriorly narrow, much less than half the anteroposterior length of the parabasisphenoid (1) markedly expanded, forming approximately 50% or more of the anteroposterior length of the parabasisphenoid.

Character 103 Carotid foramen - pairing: (0) paired (1) unpaired (modified from Maisch and Matzke 2000b, character 42; after Maxwell 2010, character 10). These two characters are joined, as they are slightly different versions of each other.

Character 104 Carotid foramen - location: (0) basioccipital and (1) parabasisphenoid (modified from Maisch and Matzke 2000b, character 42; after Maxwell 2010, character 10).

Character 105 Parasphenoid - shape of the base of the cultriform process: (0) wide, gently grading into the basal plate (1) distinctly narrowed, well offset from the basal plate (Maisch and Matzke 2000b, character 43).

Character 106 Parabasisphenoid - shape in dorsal or ventral view: (0) anterior edge (including basipterygoid processes) less than 2/3 as long as posterior edge (1) anterior and posterior edges similar in length; (2) posterior edge less than 2/3 as long as anterior edge.

Character 107 Parabasisphenoid - location of the carotid foramen: (0) opening near the middle of the ventral surface, (1) opening on the posterior third of the ventral surface, (2) opening on the posterior surface [treated as ordered] (modified from Maisch and Matzke 2000b, character 42; after Maxwell 2010, character 10). See characters 103 and 104. In cases where the carotid foramen is on the basioccipital rather than the parabasisphenoid (character 104), character 107 is coded as inapplicable.

Character 108 Opisthotic - shape of the paraoccipital process: (0) short and robust (1) elongate and slender (Fischer et al. 2012, character 20).

Character 109 Supraoccipital - orientation of the exoccipital processes: (0) parallel (1) divergent (Maxwell 2012, character 19).

Character 110 Exoccipital - contribution to foramen magnum: (0) exoccipitals make up the largest lateral contribution (1) supraoccipital contribution almost equal to that of exoccipitals (Maxwell 2012, character 20).

Character 111 Stapes - size of the proximal head: (0) slender, much smaller than opisthotic proximal head (1) massive, as large or larger than opisthotic (Fischer et al. 2011, character 21).

Character 112 Stapes - relative size of heads: (0) lateral head less robust than the medial head (1) both medial and lateral heads robust (Maxwell 2012, character 18).

Character 113 Stapes - size of shaft in adults: (0) thick (1) slender and gracile (Roberts et al. 2014, characters 25).

Character 114 Lower jaw: (0) well developed (1) reduced relative to lower jaw (Maxwell 2012, character 26).

Character 115 Lower jaw - development: (0) normal (1) slender, reduced in diameter (Sander et al. 2011, character 108).

Character 116 Lower jaw - ventral margin in lateral view: (0) straight, or nearly so (1) markedly concave approximately ventral to the external nares (modified from Sander 2000, character 37).

Character 117 Dentary - labial shelf: (0) absent (1) present (Jiang et al. 2006, character 14).

Character 118 Surangular - makes up most of the posterior lateral surface of the lower jaw: (0) absent (1) present (Maisch and Matzke 2000b, character 38).

Character 119 Surangular - dorsal (paracoronoid) process just anterior to the jaw articulation: (0) absent (1) present (Sander 2000, character 42).

Character 120 Angular - extent of anterior lateral exposure: (0) much smaller than the surangular’s exposure (1) extensive, at least as high and anteriorly as the surangular’s exposure (modified from Motani 1999c, character 32; after Fischer et al. 2011, character 22; and Maxwell 2012, character 28).

Character 121 Angular - extent of posterior lateral exposure: (0) minimal, covers less than half of the lateral surface of the retroarticular process (1) extensive, surangular exposure reduced to a thin strip on the lateral surface of the retroarticular process (Maxwell 2012, character 29).

Character 122 Splenial - participation in the mandibular symphysis: (0) more extensive than the dentary (1) present but restricted to the posterior half (Maxwell 2012, character 27).

Character 123 Coronoid - ossified: (0) present (1) absent (modified from Maisch and Matzke 2000b, character 45). This character is separated for reductive coding (see character 124).

Character 124 Coronoid - shape: (0) laterally flattened (1) narrow and elongate (modified from Maisch and Matzke 2000b, character 45). May be coded as inapplicable if the coronoid is not present/ossified (character 123).

Character 125 Coronoid process: (0) flat (1) elevated (2) drawn into a pointed process (modified from Sander 2000, character 41). This refers to the true process on the coronoid, so may be coded as inapplicable if this is not present/ossified (character 123).

Character 126 Lower jaw glenoid - deeply excavated: (0) absent (1) present (Sander 2000, character 43).

Character 127 Articular - transverse width: (0) wide with dorsally deeply concave retroarticular process (1) narrow (Maisch and Matzke 2000b, character 47).

Character 128 Teeth: (0) present (1) absent (modified from Maisch and Matzke 2000b, character 4; after Fischer et al. 2011, character 4; and Sander et al. 2011, character 109). The presence/-absence of teeth is separated for reductive coding alongside character 129; subsequent dentition characters may become inapplicable in this case.

Character 129 Dentition - complete, well-developed dentition retained in adults: (0) present (1) strongly reduced (modified from Maisch and Matzke 2000b, character 4; after Fischer et al. 2011, character 4; and Sander et al. 2011, character 109). This character is separated from edentulism as it refers to the size and number of teeth (character 128).

Character 130 Dentition - tooth implantation after Motani (1997a): (0) subthecodont (1) thecodont (2) aulacodont (modified from Sander 2000, character 52). Here, ankylosed and ichthyosaurian thecodonty are separated into separate characters (character 131).

Character 131 Dentition - bony fixation: (0) present (1) absent (Motani 1999c, character 43).

Character 132 Plicidentine: (0) absent (1) present (Motani 1999c, character 36).

Character 133 Dentition - number of tooth rows: (0) one (1) two (2) irregular pavement (Sander 2000, character 50).

Character 134 Upper dental groove: (0) absent (1) present (modified from Motani 1999c, character 41). Motani’s (1999c) characters 41 and 42 have each been separated to form characters 134 to 137 by reductive coding. These are not excluded by edentulism (character 128): the dental groove may be retained.

Character 135 Upper dental groove - location: (0) throughout jaw margin (1) only anteriorly (modified from Motani 1999c, character 41). This character may be inapplicable if the upper dental groove is absent (character 134).

Character 136 Lower dental groove: (0) absent (1) present (modified from Motani 1999c, character 42). See character 134.

Character 137 Lower dental groove - location: (0) throughout jaw margin (1) only anteriorly (modified from Motani 1999c, character 42). This character may be inapplicable if the lower dental groove is absent (character 136).

Character 138 Dentition - number of maxillary positions ventral to the jugal: (0) less than three (1) four or more (Druckenmiller and Maxwell 2010, character 16).

Character 139 Palatine teeth: (0) present (1) absent.

Character 140 Pterygoidal teeth: (0) present (1) absent (Motani 1999c, character 44).

Character 141 Dentition - replacement: (0) irregular (1) regular (Sander 2000, character 51).

Character 142 Dentition - position of replacement teeth to the pulp cavity of the predecessor: (0) outside (1) inside (Motani 1999c, character 35).

Character 143 Dentition - ornamentation of the enamel: (0) prominent ridges and grooves (1) thin and smooth (2) thick and bumpy (Maxwell 2012, character 30).

Character 144 Dentition - shape of the root cross-section in adults: (0) rounded (1) quadrangular (modified from Fischer et al. 2011, character 3; after Fischer et al. 2012, character 3).

Character 145 Dentition - dentine infolding (0) striations not externally visible basal to the crown in the apical third of the root; (1) forming prominent grooves and ridges basal to the crown in the apical third of the root.

Character 146 Dentition - dentine infolding (0) creating clear externally visible striations in the basal half of the root in functional teeth, (1) completely obscured by cellular cementum.

Character 147 Dentition - definition of the base of the enamel layer: (0) poorly defined or invisible (1) well defined and precise (Fischer et al. 2011, character 2).

Character 148 Dentition - horizontal section of the tooth crown: (0) circular (1) mesiodistally compressed (2) laterally compressed (modified from Motani 1999c, character 37). This has been restricted to the tooth crown only.

Character 149 Dentition - shape of the posterior tooth crown: (0) conical (1) rounded (2) flat (Motani 1999c, character 39).

Postcranial axial skeleton

Character 150 Atlas pleurocentrum - shape: (0) anteriorly convex (1) deeply concave (Maisch and Matzke 2000b, character 49).

Character 151 Atlas-axis: (0) separate (1) co-ossified in adults (Maisch and Matzke 2000b, character 50).

Character 152 Atlas-axis - neural spines: (0) completely overlapping, may be fused (1) functionally separate, never fused (Druckenmiller and Maxwell 2010, character 26).

Character 153 Presacral vertebrae - number: (0) n < 40 (1) 40 ≤ n < 55 (2) 55 ≤ n (modified from Motani 1999c, character 95). [treated as ordered]

Character 154 Central facets: (0) bulging (1) central face straight-sided (modified from Sander 2000, character 58).

Character 155 ‘Cervical’ vertebrae - diapophysis-neural arch contact extent: (0) up to middle dorsal region (1) anterior dorsal region (Fischer et al. 2011, character 23).

Character 156 ‘Cervical’ vertebrae - centrum to neural arch height: (0) < 2 (1) ≤ 2 (modified from Sander 2000, character 61). This has been simplified to a dichotomy.

Character 157 ‘Cervical’ centra - bicipital rib facet: (0) absent (1) present (Motani 1999c, character 99).

Character 158 Postcervical to presacral centra - number of rib articulations: (0) holocephalous throughout (1) dicephalous in posterior dorsal and anterior caudal region, remainder holocephalous (2) dicephalous throughout (Nicholls and Manabe 2001, character 38).

Character 159 Dorsal centra - increase in height from anterior to posterior: (0) absent (1) present (Sander 2000, character 55).

Character 160 Anterior dorsal neural spine - shape: (0) normal (1) narrow, high and straight (Motani 1999c, character 102).

Character 161 Anterior dorsal/thoracic zygapophyses - pairing: (0) paired (1) bilobate (2) unpaired (modified from Maisch and Matzke 2000b, character 51). The additional state ‘bilobate’ is added to separate when the two zygapophyses meet medially.

Character 162 Anterodorsal centra - rib facet position: (0) confluent with anterior face in at least some centra (1) not confluent in any (Motani 1999c, character 101).

Character 163 Anterodorsal centra - synapophysis shape: (0) symmetrical, hourglass-shaped (1) asymmetrical with irregular swellings and constrictions (modified from Nicholls and Manabe 2001, character 40).

Character 164 Posterior dorsal centra - outline: (0) ≤ 3.5× high as long (1) ≤ 4× high as long (Fischer et al. 2011, character 24). These codings are the reverse of Maxwell (2010, character 15), but direction is defined by the outgroup to the clade where the state changes.

Character 165 Sacrum: (0) present, at least one morphologically differentiated sacral rib can be observed (1) absent, no truly sacral ribs are present (Motani, 1999 character 104 [part]).

Character 166 Sacral ribs: (0) two with distal expansion, (1) one with distal expansion, (2) present and morphologically distinct [see character 165] but no distal expansion present. Is inapplicable when sacrum is absent/undifferentiated (character 165). [treated as ordered]

Character 167 Tail - length relative to precaudal body: (0) longer (1) shorter (Maisch and Matzke 2000b, character 65; Fischer et al. 2013, character 33).

Character 168 Tail - lunate tail fin: (0) none (1) well-developed (Maisch and Matzke 2000b, character 66).

Character 169 Caudal peak: (0) absent (1) present (Motani 1999c, character 96). This character is separate from character 168: the caudal peak is interpreted as an early modification of the tail to an aquatic lifestyle, with development of a tail fin (Motani 1999c; McGowan & Motani 2003).

Character 170 Caudal centra - mid-region height change: (0) gradual decrease (1) increase (2) sudden decrease (Motani 1999c, character 98).

Character 171 Caudal centra - elongation: (0) elongate (1) short (Maisch and Matzke 2000b, character 59).

Character 172 Anterior caudal vertebrae - neural arch to centrum height: (0) < 2 (1) ≤ 2 (modified from Sander 2000, character 63).

Character 173 Anterior to middle caudal centra - spinous process shape: (0) very long and slender (1) short and wide (Maisch and Matzke 2000b, character 61).

Character 174 Middle caudal centra - neural spine inclination: (0) distinctly anterior (1) vertical or posterior (Maisch and Matzke 2000b, character 60).

Character 175 Tail fin centra - shape: (0) strongly laterally compressed (1) as wide as high (Maxwell 2010, character 16).

Character 176 Chevrons - ossified: (0) present (1) absent.

Character 177 Chevrons: (0) present throughout caudal region (1) absent in apical region.

Character 178 Rib - cross-sectional shape at mid-shaft: (0) oval or with posterior groove (1) figure-of-eight (2) round with anterior and posterior flanges (3) (modified from Sander 2000, character 73). State three is added to code for the outgroup Hupehsuchus nanchangensis.

Character 179 Gastralia - V-shaped median element: (0) present (1) absent (modified from Sander 2000, character 75).

Character 180 Gastralia - lateral elements: (0) one lateral element per side (1) two lateral elements per side (modified from Sander 2000, character 75).

Appendicular skeleton

Character 181 Interclavicle - shape: (0) cruciform (1) triangular (1) T-shaped (Motani 1999c, character 45).

Character 182 Clavicle - expanded medial flange: (0) present (1) absent, clavicle slender and narrow medially (Maisch and Matzke 2000b, character 68).

Character 183 Coracoid - shape: (0) mediolaterally wider than anteroposteriorly long (1) approximately equidimensional (2) anteroposteriorly longer than mediolaterally wide (Maxwell 2012, character 32).

Character 184 Coracoid - medial margin: (0) well-rounded (1) straight symphysis (Maisch and Matzke 2000b, character 73).

Character 185 Coracoid - anterior notch: (0) present (1) absent (modified from Maxwell 2012, character 33).

Character 186 Coracoid - posterior notch: (0) present (1) absent (modified from Maxwell 2012, character 34).

Character 187 Coracoid - lengths of anterior and posterior extensions: (0) anterior extension longer than posterior (1) reduced anterior extension (Maisch and Matzke 2000b, character 74).

Character 188 Coracoid - anteromedial process: (0) present (1) absent (Fischer et al. 2011, character 29).

Character 189 Coracoid - glenoid and scapular facet sizes: (0) very small (1) enlarged (Maisch and Matzke 2000b, character 72).

Character 190 Coracoid - medial facet for the scapula: (0) absent (1) present (Arkhangelsky & Zverkov 2014, character 52).

Character 191 Scapula - anterior expansion proximally: (0) present (1) absent (modified from Maxwell 2012, character 31). Maxwell et al.’s (2012) character is modified to presence/- absence of acromion process, with anterior expansion (states 1 and 2) separated into character 192.

Character 192 Scapula - prominent acromion process: (0) present (1) absent (modified from Maxwell 2012, character 31).

Character 193 Scapula - shape of the anterodorsal margin: (0) fan-shaped (1) emarginated (2) straight (Motani 1999c, character 46).

Character 194 Scapula - size of the glenoid contribution: (0) at least as large as the coracoid facet (1) markedly smaller than the coracoid facet (Fischer et al. 2012, character 27).

Character 195 Scapula - posterior process: (0) distinct and large (1) reduced (Maisch and Matzke 2000b, character 71).

Character 196 Scapula - blade shaft: (0) absent (1) present at least proximally (Motani 1999c, character 47).

Character 197 Scapula - angle subtended by the axis and glenoid facet: (0) nearly parallel (1) 60° or more (Motani 1999c, character 48).

Character 198 Humerus - differentiated and offset proximal head: (0) present (1) absent (Maisch and Matzke 2000b, character 75).

Character 199 Humerus - anterior margin: (0) straight, convex (1) with small central notch (2) markedly concave (modified from Maisch and Matzke 2000b, character 77).

Character 200 Humerus - anterior flange: (0) absent (1) present (modified from Motani 1999c, character 53).

Character 201 Humerus - anterior flange size: (0) large, complete (1) reduced proximally (modified from Motani 1999c, character 53). See character 200.

Character 202 Humerus - relative width at mid-shaft, exclusive of anterior flange: (0) more than twice as proximodistally long as anteroposteriorly wide (1) approximately equidimensional (Motani 1999c, character 54).

Character 203 Humerus - dorsal trochanter: (0) none or incipient (1) well-developed (Maisch and Matzke 2000b, character 78).

Character 204 Humerus - protruding deltopectoral crest: (0) absent (1) present (modified from Fischer et al. 2011, character 31; after Fischer et al. 2013, character 39).

Character 205 Humerus - development of protruding deltopectoral crest: (0) normal (1) large, matching the dorsal trochanter in height, and bordered by concave areas (modified from Fischer et al. 2011, character 31; after Fischer et al. 2013, character 39). See character 204.

Character 206 Humerus - relative anteroposterior width in dorsal view, excluding dorsal and ventral processes: (0) distal end wider than proximal (1) approximately equal or proximal end wider than distal (Fischer et al. 2011, character 32).

Character 207 Humerus - plate-like dorsal ridge: (0) absent (1) present (Druckenmiller and Maxwell 2010, character 31).

Character 208 Humerus - position of distal facets: (0) not terminal (1) terminal (modified from Motani 1999c, character 52).

Character 209 Humerus - relative size of radial and ulnar facets: (0) radial facet is larger than the ulnar facet (1) radial and ulnar facets approximately equal size (modified from Motani 1999c, character 52). See character 208.

Character 210 Humerus - separation of radial and ulnar facets: (0) continuous (1) separated by notch (Maxwell 2012, character 36). This is coded as inapplicable in taxa where the radial and ulnar facets are separated by e.g. the intermedial facet.

Character 211 Humerus - ulnar facet deflected posterodistally, distal facing radial facet: (0) absent (1) present (Fischer et al. 2012, character 34).

Character 212 Humerus - tuberosity at the anterodistal extremity: (0) present (1) absent, acute angle (Fischer et al. 2013, character 44).

Character 213 Humerus - anterodistal facet for sesamoid: (0) absent (1) present (Motani 1999c, character 57).

Character 214 Humerus - posterodistal facet for sesamoid: (0) absent (1) present (Druckenmiller and Maxwell 2010, character 36).

Character 215 Humerus-intermedium - contact: (0) absent (1) present (Fernández 2007a, character 16).

Character 216 Forelimb - epipodial and metapodial shape: (0) flattened and plate-like (1) strongly thickened (Maisch and Matzke 2000b, character 94).

Character 217 Forelimb - notching of anterior face on leading edge elements [in adults]: (0) present (1) absent (Fischer et al. 2011, character 37).

Character 218 Forelimb - notching of posterior face on trailing edge elements [in adults]: (0) absent (1) present.

Character 219 Forelimb - number of postaxial ‘complete’ accessory digits: (0) none (1) one (2) two or more (Fischer et al. 2011, character 38). This character is treated as ordered. See also characters 217, 283 and 284.

Character 220 Epipodials - relative size of anterior and posterior element: (0) radius/tibia much larger than ulna/fibula (1) equal in size (modified from Nicholls and Manabe 2001, character 24).

Character 221 Epipodials - interosseous space between ulna and radius: (0) present (1) small foramen (2) absent (Sander 2000, character 87).

Character 222 Radius - proximodistal length to anteroposterior width: (0) longer than wide (1) wider than long (Motani 1999c, character 61).

Character 223 Ulna - posterior margin: (0) concave (1) notched (2) straight or convex (modified from Motani 1999c, character 62). See character 199.

Character 224 Ulna - anteroposterior width: (0) proximal end narrower than distal (1) about equal widths (Maisch and Matzke 2000b, character 87).

Character 225 Ulna - shape of the posterior surface: (0) rounded or straight and nearly as thick as the rest of the element (1) concave with a thin, blade-like margin (Fischer et al. 2012, character 36, 2013, character 45).

Character 226 Manual pisiform: (0) present (1) absent (Motani 1999c, character 67).

Character 227 Manual pisiform 2 (neomorph): (0) absent (1) present (Jiang et al. 2006, character 20).

Character 228 Intermedium: (0) present (1) absent (modified from Motani 1999c, character 66).

Character 229 Intermedium-ulnare - relative size: (0) ulnare larger than intermedium (1) ulnare smaller than intermedium (modified from Motani 1999c, character 66). See character 228.

Character 230 Intermedium - location: (0) distal to the ulna (1) between radius and ulna (modified from Fernández 2007a, character 19).

Character 231 Intermedium - shape: (0) as wide or wider than long (1) longer than wide (modified from Jiang et al. 2006, character 22).

Character 232 Intermedium - proximal shape: (0) straight or notched (1) pointed (modified from Jiang et al. 2006, character 22).

Character 233 Intermedium - distal edge shape: (0) angular (1) flattened (Maxwell 2010, character 27).

Character 234 Intermedium - number of digits directly supported: (0) one (1) two (2) three (modified from Fischer et al. 2011, character 40). The intermedium must have substantial distal facets present for articulation with distal carpals, or contact a distal carpal over at least 30% of its proximal surface for a digit to be considered to be supported.

Character 235 Intermedium - size of distal facets: (0) subequal (1) one much larger than the other(s) (modified from Maxwell 2012, character 43).

Character 236 Ulnare - number of distal facets: (0) primarily supporting a single digit (1) a posteriorly oriented facet for articulation with metacarpal V at least half the length of the facet for mcIV (Maxwell 2012, character 44).

Character 237 Distal carpal - number: (0) five (1) four (2) three (3) two (modified from Sander 2000, character 92). This refers only to ‘true’ distal carpals, and not accessory elements in the distal carpal row (after Motani 1999a).

Character 238 Distal carpal 1-metacarpal V - relative size: (0) much smaller (1) similar size or larger (modified from Maisch and Matzke 2000b, character 95). This may be coded as inapplicable if either element is not present.

Character 239 Distal carpals 2-3-distal carpal 5 - relative size: (0) much smaller (1) of comparable size (Maisch and Matzke 2000b, character 96).

Character 240 Distal carpal 4-metacarpal V - relative size: (0) much smaller (1) comparable in size or larger (Maisch and Matzke 2000b, character 100).

Character 241 Manual digits - number of ossified elements in the metacarpal row: (0) four or fewer (1) five or more (Maxwell 2012, character 45).

Character 242 Manual preaxial accessory digit: (0) absent (1) present (Fischer et al. 2011, character 39).

Character 243 Manual digit V reduction: (0) none (1) reduced to small floating elements (modified from Fischer et al. 2013, character 55). The absence of digit five is removed from this character as it is coded by the loss of metacarpal V (character 247).

Character 244 Manual metacarpal I: (0) present (1) absent (modified from Motani 1999c, character 68).

Character 245 Manual metacarpal I - shape: (0) elongate (1) semilunate or rounded (modified from Maisch and Matzke 2000b, character 97).

Character 246 Manual metacarpals II-IV - shape: (0) elongate cylinder (1) rounded (Maisch and Matzke 2000b, character 98).

Character 247 Manual metacarpal V: (0) present (1) absent (modified from Maisch and Matzke 2000b, character 99).

Character 248 Manual metacarpal V - posterior margin: (0) convex (1) straight or concave (modified from Maisch and Matzke 2000b, character 99).

Character 249 Manual phalanges - maximum number in a single digit: (0) five or less (1) six or more (modified from Motani 1999c, character 77).

Character 250 Proximal manual phalanges - shape: (0) elongate or hourglass-shaped (1) mostly rounded (2) tightly packed rectangles/polygons (modified from Maisch and Matzke 2000b, character 102; after Fischer et al. 2011, character 42).

Character 251 Distal manual phalanges - shape: (0) elongate (1) rounded (Maisch and Matzke 2000b, character 101).

Character 252 Manual digital bifurcation: (0) absent (1) present in at least some individuals (modified from Fischer et al. 2011, character 43).

Character 253 Pelvic girdle - size: (0) normal-sized (1) moderately reduced (2) strongly reduced (Sander 2000, character 103).

Character 254 Ilium - blade shape: (0) with thick shaft (1) plate-like (2) narrow and styloidal (Motani 1999c, character 80).

Character 255 Ilium - anteromedial prominence: (0) present (1) absent (Motani 1999c, character 81).

Character 256 Ischium-pubis - medial fusion: (0) absent (1) present (modified from Maxwell 2012, character 50).

Character 257 Ischium-pubis - lateral fusion: (0) absent (1) present (modified from Maxwell 2012, character 51).

Character 258 Ischium and pubis - meet medially in well defined symphysis: (0) present (1) strongly convex medial margins (Maisch and Matzke 2000b, character 108).

Character 259 Ischium and pubis - relative size: (0) pubis larger than ischium (1) similar size or ischium larger (Maisch and Matzke 2000b, character 107).

Character 260 Ischium or ischiopubis - shape: (0) plate-like, flattened (1) rod-like (Fischer et al. 2011, character 45).

Character 261 Ischium - medial edge expansion: (0) great (1) little or none (Maxwell 2012, character 53).

Character 262 Ischium - acetabular contribution: (0) greater than pubis (1) subequal with pubis (Maxwell 2012, character 52).

Character 263 Pubis - obturator foramen: (0) present (1) absent (modified from Motani 1999c, character 84).

Character 264 Pubis - location of obturator foramen: (0) completely enclosed in pubis (1) mostly in pubis but open on one side (2) part of obturator fossa (Thorne et al. 2011, character 84).

Character 265 Pubis - distance between the obturator foramen[/incisure] and the pubic symphysis: (0) closer to the glenoid than the pubic symphysis (1) closer to the pubic symphysis than to the glenoid (2) obturator fossa open medially (modified from Maisch and Matzke 2000b, character 110).

Character 266 Femur - relative proximodistal length to anteroposterior width: (0) much (>2×) longer than wide (1) shorter and wider, with distinct medial constriction (Sander 2000, character 110).

Character 267 Femur - prominent, ridge-like dorsal and ventral processes demarcated from the head and extending up to mid-shaft: (0) absent (1) present (Fischer et al. 2011, character 46).

Character 268 Femur - ventral process size relative to dorsal process: (0) smaller (1) same size or larger, more prominent (Roberts et al. 2014, character 52).

Character 269 Femur - wide distal blade: (0) present (1) absent, subequal proximal and distal widths (Fischer et al. 2013, character 61).

Character 270 Femur - anterodistal facet for anterior accessory epipodial element anterior to the tibia: (0) absent (1) present (Fischer et al. 2011, character 48).

Character 271 Femur - tibial facet size relative to fibular facet: (0) larger (1) subequal (Maisch and Matzke 2000b, character 112).

Character 272 Tibia - proximodistal length to anteroposterior width: (0) longer than wide (1) wider than long (Motani 1999c, character 90).

Character 273 Tibia - anterior margin: (0) concave (1) notched (2) straight or convex (modified from Motani 1999c, character 92). See character 199.

Character 274 Tibia - posterior margin: (0) concave (1) notched (2) straight or convex (modified from Motani 1999c, character 91). See character 199.

Character 275 Tibia - proximodistal length relative to more distal elements: (0) approximately twice as long (1) only slightly longer (Maxwell 2012, character 55).

Character 276 Tibia and fibula - relative size: (0) tibia larger than fibula (1) approximately equal (2) tibia proximodistally and anteroposteriorly smaller (Maxwell 2012, character 56).

Character 277 Tibia and fibula - proximal contact: (0) absent (1) present (modified from Motani 1999c, character 88; after Maxwell 2012, character 57).

Character 278 Fibula - anterior margin: (0) concave (1) notched (2) straight or convex (modified from Maxwell 2012, character 59). See character 199.

Character 279 Fibula - position relative to femur: (0) not fixed, mobile relative to the femur (1) much posterior (2) about the same level (Motani 1999c, character 93).

Character 280 Astragalus - position: (0) between tibia and fibula (1) distal to tibia (Druckenmiller and Maxwell 2010, character 48).

Character 281 Distal tarsals - number: (0) five (1) four (2) three (Sander 2000, character 112).

Character 282 Pedal digit 1: (0) present (1) absent (Motani 1999c, character 89).

Character 283 Hindlimb - notching on anterior of leading edge metapodials: (0) absent (1) present (Maxwell 2012, character 60). See also characters 217, 218 and 284.

Character 284 Hindlimb - notching on posterior of trailing edge metapodials: (0) absent (1) present.

Character 285 Pedal postaxial accessory digit: (0) absent (1) present (Fischer et al. 2011, character 50).

Character 286 Metatarsals - shape: (0) elongate or hourglass-shaped (1) shortened and rounded (2) polygonal (modified from Maisch and Matzke 2000b, character 118).

Character 287 Pedal phalanges - shape: (0) elongate or hourglass-shaped (1) rounded (2) polygonal (modified from Maisch and Matzke 2000b, character 119). See character 286.

APPENDIX 4.

Character by taxon matrix for phylogenetic analysis (.nex). (Available in zipped file.)