Electronic supplementary material

Guang-Hui Xu¹, Li-Jun Zhao² and Chen-Chen Shen¹

²Zhejiang Museum of Natural History, Hangzhou, Zhejiang 310014, China

1. 
   Methods
   

‘Thoracopterus’ wushaensis [5] is a recently reported thoracopterid on the basis of five specimens from the same fossil beds as those of Potanichthys xingyiensis [2]. The fossil locality of ‘Thoracopterus’ wushaensis is about 5 km away from the type locality of Potanichthys in Xingyi, Guizhou Province, China. Both taxa are ‘four-winged’ thoracopterid gliders because they have wing-like paired fins and an asymmetrical caudal fin with the lower caudal lobe noticeably larger than the upper lobe, resembling Thoracopterus and Gigantopterus [6]. Comparison within the Thoracopteridae, ‘Thoracopterus’ wushaensis [5] and Potanichthys [2] are more closely related to Gigantopterus than to Thoracopterus in having an almost naked body. ‘Thoracopterus’ wushaensis should be moved out of the genus Thoracopterus; it is probably a younger synonym of Potanichthys xingyiensis. However, a detailed comparison between these two taxa is still difficult, because the holotype of ‘Thoracopterus’ wushaensis was poorly preserved and incompletely described ([5]; see below); a morphological redescription and a taxonomic revision of this taxon are pending. Thus, ‘Thoracopterus’ wushaensis has not been included in this analysis.

Supplementary Figure S1. Holotype of ‘Thoracopterus’ wushaensis (from [5]).

Supplementary Figure S2. Strict consensus of six MPTs (TL=142 steps, CI= 0.6127, RI= 0.7901, RC= 0.4841), illustrating phylogenetic positions of Wushaichthys and Peripeltopleurus within the Neopterygii. Character changes indicated with solid circles are unique.

BMNH, Natural History Museum, London, UK;

IVPP, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, China

PIMUZ, Paläontologisches Institut und Museum, Uiversität Zürich, Zürich, Switzerland

ZMNH, Zhejiang Museum of Natural History, Hangzhou, China
Amia calva: Grande and Bemis [7]

Lepisosteus osseus: Grande [8]

Exocoetus and Cypselurus: Breder [9]

Dapedium: Patterson [10,11]; Thies and Herzog [12]

Dorsetichthys (Pholidophorus) bechei: Patterson [11]; Arratia [13]

Leptolepis coryphaenoides: Patterson [11]; Arratia [14]

Perleidus: BMNH P16247, 16248, 19580–19584, 19587–19592, 19595–19599, 19603–19620, 19622, 19623; Lehman [15]; Patterson [11]

Semionotus elegans: Olsen and McCune [16]; Cavin [17]; López-Arbarello [18]

Watsonulus eugnathoides: Olsen [19]; Grande and Bemis [7]

Peltopleurus rugosus: Bürgin [20], PIMUZ T2904

Gigntopterus teller: Griffith [6]

Luganoia lepidosteoides: Bürgin [20]

Peripeltopleurus vexillipinnis: Bürgin [20], PIMUZ A/I 3687, T4332, 193, 473, 495, 718, 737, 1136

Peripeltopleurus hypsisomus: Bürgin [20], PIMUZ T1211, 2150, 2869

Potanichthys xingyiensis: Xu et al. [2]

Thoracopterus niederristi: Griffith [6], Lehman [21], BMNH P1098

‘Thoracopterus’ martinisi: Tintori and Sassi [22]

1. 
   Skull: no more than one-fourth of total length (0); roughly one-third of total length (1).
   
2. 
   Post-temporal fossa: rudimentary (0); well developed (1); lost (2).
   
3. 
   Sub-temporal fossa: present (0); absent (1).
   
4. 
   Dilatator fossa above hyomandibular facet: absent (0); present (1).
   
5. 
   Lateral cranial canal: absent (0); present (1).
   
6. 
   Posterior myodome: present (0); absent (1).
   
7. 
   Posterior myodome: paired (0); enlarged into a median cavity (1).
   
8. 
   Anterior myodome: present (0); absent (1).
   
9. 
   Number of anterior myodome: paired (0); a median single (1).
   
10. 
    Parasphenoid/basioccipital contact: absent (0); present (1).
    
11. 
    Basipterygoid process: present (0); absent (1).
    
12. 
    Internal carotid foramen on parasphenoid: absent (0); present (1).
    
13. 
    Efferent pseudobranchial foramen on parasphenoid: absent (0); present (1).
    
14. 
    Pterotic: present (0); absent (1).
    
15. 
    Intercalar: present (0); absent (1).
    
16. 
    Extrascapular: present (0); absent (1).
    
17. 
    Sphenotic with small dermal component: absent (0); present (1).
    
18. 
    Rostral as a discrete element: present (0); absent (1).
    
19. 
    Shape of rostral: as a deep cap on snout apex (0); reduced to a narrow tube (1).
    
20. 
    Rostral/frontal contact: absent (0), present (1).
    
21. 
    Anteriormost lacrimal: as part of orbital ring (0); anterior to orbital ring (1).
    
22. 
    Tube-like canal bearing anterior arm of antorbital: absent (0); present (1).
    
23. 
    Foramen for olfactory nerves on premaxilla: absent (0); present (1).
    
24. 
    Peg-like anterior process of maxilla: absent (0); present (1).
    
25. 
    Nasal involvement of anterior border of orbit: present (0); absent (1).
    
26. 
    Antorbital involvement of anterior border of orbit: present (0); absent (1).
    
27. 
    Posttemporal: contacts extrascapular anteriorly (0); contacts the extrascapular anterolaterally and separates this bone from contact with its counterpart (1).
    
28. 
    Parietal as a discrete element: present (0); absent (1).
    
29. 
    Nasal process of premaxilla that tightly sutured to frontals: absent (0); present (1).
    
30. 
    Premaxillae: paired (0); fused (1).
    
31. 
    Number of lacrimal bones: single (0); two or more (1).
    
32. 
    Vomers in adults: paired (0); fused (1).
    
33. 
    Frontal: elongated (0); laterally expanded (1).
    
34. 
    Supraorbital sensory canal: ending at frontal (0); ending at parietal (1).
    
35. 
    Infraorbitals posterior to antorbital and below dermosphenotic: two or three elements (0); four or more elements (1).
    
36. 
    Supraorbitals (including adnasal): absent (0); present (1).
    
37. 
    Number of supraorbitals between adnasal and dermosphenotic: single (0); two or more (1).
    
38. 
    Suborbitals: present (0); absent (1).
    
39. 
    Number of suborbitals: single element (0); two or more (1).
    
40. 
    Dermohyal: present (0); absent (1).
    
41. 
    Mobile premaxilla: absent (0); present (1).
    
42. 
    Maxilla free from preopercle: absent (0); present (1).
    
43. 
    Mobile maxilla in cheek: absent (0); present (1).
    
44. 
    Supramaxilla: absent (0); present (1).
    
45. 
    Number of supramaxilla: one (0); two (1).
    
46. 
    Supra-angular: present (0); absent (1).
    
47. 
    Coronoid process: absent (0); present (1).
    
48. 
    Suspensorium angle: acute (0); nearly vertical (1).
    
49. 
    Symplectic: absent (0); present (1).
    
50. 
    Symplectic involment of jaw joint: absent (0); present (1).
    
51. 
    Quadratojugal: present (0); absent (1).
    
52. 
    Shape of quadratojugal: plate-like (0); splint-like (1).
    
53. 
    Uncinate processes on epibranchials: absent (0); present (1).
    
54. 
    Number of hypobranchials: three (0); four (1).
    
55. 
    Opercle: larger than subopercle (0); roughtly equal to or smaller than subopercle (1).
    
56. 
    Shape of preopercle: boomerang-shaped (0); narrow and vertical, bearing a tapering anterior process (1); oval-shaped (2); crescent-shaped (3); L-shaped (4).
    
57. 
    Hinge position of jaws: far backwards from posterior margin of orbital (0); near or well anterior to post margin of orbital (1).
    
58. 
    Suborbital/maxilla contact: absent (0); present (1).
    
59. 
    Interopercle: absent (0); present (1).
    
60. 
    Median gular: present (0); absent (1).
    
61. 
    Lateral gular: present (0); absent (1).
    
62. 
    Presupracleithrum: present (0); absent (1).
    
63. 
    Posterior margin of maxilla: straight or slightly convex (0); concave with a posterior maxillary notch (1).
    
64. 
    Clavicle: present (0); absent (1).
    
65. 
    Clavicle: large, cap anterior end of cleithrum (0); reduced into small plates on postbranchial lamina of cleithrum (1).
    
66. 
    Fringing fulcra: absent (0); present (1).
    
67. 
    Pectoral fin enlarged as wing: absent (0); present (1).
    
68. 
    Diural caudal skeleton: absent (0); present (1).
    
69. 
    Division of hypurals into dorsal and ventral groups (a gap between hypurals 2 and 3): absent (0); present (1).
    
70. 
    Dorsal and anal fins: rays more numerous than radials (0); rays and radials equal (1).
    
71. 
    Pelvic fin enlarged as wing: absent (0); present (1).
    
72. 
    Dense lepidotrichial segments of pectoral fin rays between innermost principle pectoral fin ray and body: absent (0); present (1).
    
73. 
    Anal fin: larger than or equal to dorsal fin (0); smaller than dorsal fin (1).
    
74. 
    Hooklets on anal fin of supposed male: present (0); absent (1).
    
75. 
    Dorsal and anal fin rays: segmented throughout length (0); segmented distally (1).
    
76. 
    Caudal fin: forked (0); unforked (1).
    
77. 
    Caudal fin: lower lobe slightly shorter than or equal to upper lobe (0); lower lobe longer than upper lobe present (1).
    
78. 
    Uroneural: absent (0); present (1).
    
79. 
    Median caudal neural spines: absent (0); present (1).
    
80. 
    Body scales: body fully covered (0); reduced to a few (no more than four) rows of scales in caudal region (1); entirely lost (2).
    
81. 
    Scale shape: rhomboid (0); circular to cycloid (1).
    
82. 
    Dorsal ridge scales (with posteriorly directed spines): absent (0); present (1).
    
83. 
    Horizontal row of scales along lateral line: slightly deeper than those scales above or below lateral line (0); much deeper than those scales above and below lateral line (1); lost (2).
    
84. 
    Ossified vertebral centra: absent (0); present (1).
    

‘T’. magnificus and ‘T’. martinisi respectively represent ‘Thoracopterus’ magnificus and ‘Thoracopterus’ martinisi. The states of three characters (nos. 4, 7, 58) are constant throughout the selected taxa and are not included when performing this phylogenetic analysis.

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