Supplementary Information for ‘An exceptional Devonian
fish from Australia sheds light on tetrapod origins’
John A. Long1,2, 3, Gavin C. Young2, Tim Holland 1, 3, Tim J. Senden 4 and
Erich M. G. Fitzgerald 1,3
1, Museum Victoria, Melbourne, PO Box 666, Melbourne, Australia, 3001;
2, Dept. of Earth and Marine Sciences, The Australian National University,
Canberra, Australia, 0200;
3, School of Geosciences, Monash University, Clayton, Victoria, Australia,
3800;
4, Dept. of Applied Mathematics, Research School of Physical Sciences and
Engineering, The Australian National University, Canberra, Australia, 0200.
1. Methods and materials
A. Preparation
The specimen was a complete fish preserved in two limestone blocks, the
larger containing almost the entire head and body skeleton to the level of the
pelvic girdle (showing pelvic basal scutes), and the smaller block (which fitted
on to the posterior end of the main block) with an impression of the caudal fin
region. Preparation of the main block was by immersion in 10% acetic acid,
for 2 day intervals, followed by washing in water, air-drying and then
impregnation of the exposed bone surfaces using Mowital B30 (Clariant
Chemicals ) diluted with pure ethanol. Photographs of the specimen were
taken at each stage of preparation to document the exact position of bones as
they came out of the matrix. The tail was prepared by first embedding the
exposed surface in epoxy resin to retain articulation of the squamation and
posterior fin elements, and the resin block was then acid-etched using the
above method. Specimen preparation was carried out by JAL over the period
August 2005-February 2006.
B. Tomogram of Otico-occipital unit
High resolution X-ray tomography was conducted in-house (for details see
Sakellariou et al. 2004a, b) to explore the relationship between external
and internal structures at a spatial resolution of 13 microns.
The included animation shows the right posterolateral corner (quadrant) of
the otico-occipital. The dermal bone is depicted in translucent brown, and
endocranial bones rendered translucent beige. As the specimen rotates the
down-turned lamina showing the spiracular border can be clearly seen.
Following this rotation the dorsal surface is presented and the specimen is
progressively eroded towards the ventral surface. During the erosion we
see expression of the semicircular canals of the inner ear, finishing at the
floor of the fossa bridgei. All volume rendering and animation was done
using the freeware package, Drishti (http://sf.anu.edu.au/~acl900/Drishti/ ).
2. Determining the shape of the spiracular chamber
Supplementary Figure S1 shows the mesial view of the entopterygoid of the
new Gogonasus specimen, with the ridge defining the ventral margin of the
spiracular chamber clearly indicated. The shape of the spiracular chamber in
Gogonasus as in Figure 1h is clearly delineated by this ridge, following the
same method as used by Brazeau & Ahlberg (2006, ref. 9) to determine the
spiracular chamber shape for Eusthenopteron.
The hyomandibula, and its relationship and orientation with respect to the
braincase, were clearly figured by Long et al. (1997, ref. 2) in their Fig. 42G
and Fig. 44. The restoration shown in Fig. 60A of that monograph needs slight
modification as the opercular process of the hyomandibula sits more
posteriorly, taking into account cartilage pads on the synovial surfaces of the
hyomandibular facets. This brings into alignment the hyomandibular
opercular process and opercular pit on the mesial face of the opercular bone.
Nonetheless the actual orientation of the hyomandibula with respect to the
skull table is accurate, as verified by the new specimen, bearing in mind the
slight degree of vertical movement afforded by the cartilage articulatory
surfaces on the hyomandibular head.
3. Phylogenetic methods
Analysis protocol and results:
The character state scores for all taxa, except Gogonasus, Onychodus,
Marsdenichthys, and Medoevia, were adapted with modifications from
Ahlberg & Johanson (1998), Daeschler et al. (2006) and Shubin et al.
(2006). Marsdenichthys was scored, with modifications, from information
in Long (1985). Medoevia was scored, with modifications (JAL has
studied the original specimen) primarily from information in Lebedev
(1995), and for Eusthenopteron and Megalichthys characters were taken
from Andrews & Westoll (1970a, b), and Jarvik (1966) as well as personal
observation of material by one of us (JAL). Character data entry and
formatting was performed in MacClade (version 4.05) (Maddison &
Maddison 2002). The matrix includes 103 morphological characters in 12
taxa, of which 9 were based on fairly complete specimens with few
missing codings. All characters were treated as unordered, and all
characters were weighted equally. The data matrix was analysed with
parsimony using PAUP* (version 4.0b10) (Swofford 2002). The analysis
protocol consisted of a branch and bound analysis, with furthest addition
sequence, and multiple trees saved. Branches were collapsed if the
minimum branch length was zero (“amb-” option) (see Kearney & Clark
2003 for discussion). Where taxa were coded for multiple states, the
coding was interpreted as uncertainty. Where taxa were coded for gaps, the
gap coding was interpreted as an additional state. Character state
optimisation was ACCTRAN. Onychodus was employed as an outgroup,
and outgroup rooting was used.
The analysis of the data set found 2 shortest trees of 190 steps [consistency
index (CI) = 0.7526; retention index (RI) = 0.7902; rescaled consistency
index (RC) = 0.5947]. In both of the most parsimonious trees Gogonasus
is posited crownward of all other tetrapodomorphs usually referred to as
‘osteolepiforms’, and is the sister group of the elpistostegalians. Thus, this
analysis shows that Gogonasus is clearly not nested within the taxa
formerly referred to as ‘osteolepidids’, contra the hypothesis of Ahlberg &
Johanson (1998).
The clade consisting of Gogonasus + Elpistostegalia is diagnosed by the
following synapomorphies: wide spiracular notch (ch. 54: 1  2); short
ventral process on the entepicondyle is present (ch. 61: 0  1);
supracleithrum and postemporal are small, scale-like bones (ch. 69: 0 
1); body of humerus is flattened and rectangular (ch. 79: 0  1); and the
entepicondyle is narrow (ch. 82: 1  0). Notably, Eusthenopteron
occupies a basal position in the phylogeny presented here, being more
basal than Medoevia, Megalichthys, and Gogonasus. This is in stark
contrast to previous studies, which have posited Eusthenopteron (with
other taxa) in the clade Tristichopteridae as the sister group to
Elpistostegalia (Panderichthys, Tiktaalik + Tetrapoda) (e.g. Ahlberg &
Johanson 1998; Daeschler et al. 2006).
These results demonstrate, once again, that the ‘Osteolepididae’ and more
broadly the ‘Osteolepiformes’ are both paraphyletic groupings of
tetrapodomorphs as suggested by Ahlberg & Johanson (1998). Given the
importance of the ‘Osteolepiformes’ to understanding character evolution
in the fish-tetrapod transition (and palaeobiological issues therein), it is
critical that the question, “What, if anything, is an osteolepiform?” be
addressed through a thorough cladistic analysis of all relevant
tetrapodomorph taxa. Only then will it be possible to offer a cladistic
redefinition of ‘osteolepiform’ taxa. Such a study is beyond the scope of
this essay, but we acknowledge the problem here to highlight the need for
resolution of this issue.
References
Ahlberg, P. E. & Johanson, Z. Osteolepiformes and the ancestry of
tetrapods. Nature 395, 792-794 (1998).
Andrews, S.M. & Westoll, T.S. The postcranial skeleton of Eusthenoptero
foordi Whiteaves. Trans. R.Soc. Edinb. 68: 207-329 (1970a).
Andrews, S.M. & Westoll, T.S. The postcranial skeleton of rhipidistian
fishes excluding Eusthenopteron. Trans. R.Soc. Edinb. 68: 391-489
(1970b).
Daeschler, E. B., Shubin, N. H. & Jenkins Jr., F. A. A Devonian tetrapodlike fish and the evolution of the tetrapod body plan. Nature 440,
757-763 (2006).
Jarvik, E. Remarks on the structure of the snout in Megalichthys and
certain other rhipidistid crossopterygians. Ark. Zool. 18: 305-389
(1966).
Kearney, M. & Clark, J. M. Problems due to missing data in phylogenetic
analyses including fossils: a critical review. J. Vertebr. Paleontol. 23,
263-274 (2003).
Lebedev, O. A. Morphology of a new osteolepidid fish from Russia. Bull.
Mus. natl. Hist. nat., Paris, 4e sér., Section C 17, 287-341 (1995).
Long, J. A. The structure and relationships of a new osteolepiform fish
from the Late Devonian of Victoria, Australia. Alcheringa 9, 1-22
(1985).
Maddison, D. R. & Maddison, W. P. MacClade. Version 4. Sunderland:
Sinauer Associates, Inc (2002).
Sakellariou, A., Sawkins, T.J., Limaye, A. & Senden, T.J. 2. X-ray
Tomography for Mesoscale Physics Applications. Physica A 339, 152158 (2004a)
Sakellariou, A., Senden, T.J., Sawkins, T.J., Knackstedt, M.A., Turner,
M.L., Jones, A.C., Saadatfar, M., Roberts, R.J., Limaye, A., Arns,
C.H., Sheppard, A.P. & Sok, R.M. 2004b. An x-ray tomography
facility for quantitative predictions of mechanical and transport
properties in geological, biological and synthetic systems, in
Development in X-Ray Tomography IV (edited by Ulrich Bonse),
Proceedings of SPIE Vol. 5535, 473-484 (SPIE, Bellingham, WA,
2004b).
Shubin, N. H., Daeschler, E. B. & Jenkins Jr., F. A. The pectoral fin of
Tiktaalik rosae and the origin of the tetrapod limb. Nature 440, 764771 (2006).
Swofford, D. L. PAUP*. Phylogenetic Analysis Using Parsimony (*and
Other Methods). Version 4. Sunderland: Sinauer Associates, Inc.
(2002).
Characters
Characters used in previous analyses:
D = taken from Daeschler et al 2006, which are all characters listed below except for
new characters (N) which are: 2,4,33,43, 48 67,69,82, 92, 94, 102 and 103. We
include a short rationale of how all new characters were polarised.
1.
Cosmine:: (D26)
0.
present
1.
absent
2.
Lacrimal bone and posterior naris: (N)
0.
lacrimal always participates in posterior border to posterior naris
1.
lacrimal does not usually participate in narial opening
As Psarolepis, Youngolepis, and basal actinopterygians (Mimia) have the
posterior naris bounded by the anterior of the lacrimal bone, we code this as
the plesiomorphic state. Coding for Gogonasus is 0/1 as in one specimen the
lacrimal does participate in the narial border (MV P221807).
3.
Dermal intracranial joint:: (D50)
0.
present
1.
absent
4.
Hyomandibula orientation: (N)
0.
posteroventral, distally terminating near jaw joint
1.
almost horizontal orientation, opercular process high up dorsally
2.
very short, laterally directed
The plesiomorphic state is seen in the long, posteroventrally directed
hyomandulae of basal actinopterygians, and in Onychodus.
5.
Parasymphysial plate: : (D1)
0.
long, not sutured to coronoid, denticulate or with tooth row
1.
short, sutured to coronoid, denticulated
2.
compressed, unsutured, carrying tooth whorl
6.
Mesial parasymphysial foramen:: (D67)
0.
absent
1.
present
7.
Anterior end of prearticular:: (D2)
0.
not forked
1.
forked
8.
Prearticular and angular:: (D3)
0.
separated by ventral exposure of Meckelian bone
1.
in contact
9.
Mesial lamina of splenial:: (D62)
0.
absent
1.
present
10.
Prearticular:: (D4)
0.
rear part with conspicuous horizontal ledge
1.
rear part flat
11.
Number of coronoids:: (D5)
0.
more than three
1.
three
12.
Meckelian exposure in precoronoid fossa:: (D65)
0.
present
1.
absent
13.
Coronoid proportions:: (D6)
0.
posterior coronoid same length as middle coronoid, or shorter
1.
posterior coronoid significantly longer than middle coronoid
14.
Accessory tooth row on dentary:: (D64)
0.
present
1.
absent
15.
Dentary fang pair:: (D8)
0.
absent
1.
present
16.
Number of fang pairs on posterior coronoid:: (D9)
0.
one
1.
two
2.
none
17.
Suture between anterior coronoid and splenial:: (D63)
0.
absent
1.
present
18.
Coronoid fangs mesial to marginal tooth row:: (D71)
0.
yes
1.
no
19.
Palatal fangs mesial to marginal tooth row:: (D72)
0.
yes
1.
no
20.
Coronoid fangs larger than marginal teeth:: (D70)
0.
yes
1.
no
21.
Tooth infolding:: (D10)
0.
none
1.
generalized polyplocodont
2.
labyrinthodont
3.
dendrodont
22.
Number of fang pairs on ectopterygoid:: (D12)
0.
one
1.
two
2.
none
23.
Proportions of entopterygoid:: (D13)
0.
anterior end level with processus ascendens
1.
anterior end anterior to processus ascendens
24.
Entopterygoids meeting in midline:: (D14)
0.
no
1.
yes
25.
Posterior process of vomer:: (D15)
0.
absent
1.
short
2.
long
26.
Vomers, anteromedial process:: (D16)
0.
absent, vomers widely separated
1.
present
2.
absent, vomers in close contact
27.
Relationship of vomer to parasphenoid:: (D18)
0.
no contact, or simple abutment
1.
overlap or sutured with vomer
28.
Internasal pits:: (D19)
0.
undifferentiated
1.
deep pear - shaped pits
In Daeschler et al. (2006) they use 3 states but as our taxa do not exhibit any
differentiation between absent or very small spiracular slit, we have combined
these as the basal state (0). State 1 only refers to the 2 outgroup taxa here.
29.
Posterior end of parasphenoid:: (D20)
0.
denticulate field extends into spiracular groove
1.
denticulate field does not extend into spiracular groove
30.
Choana:: (D22)
0.
absent
1.
present
31.
Width of ethmoid relative to length from snout tip to posterior margin of
parietals:: (D24)
0.
more than 80%
1.
70% - 80%
2.
50% - 70%
3.
less than 40%
32.
Endoskeletal intracranial joint:: (D51)
0.
absent
1.
present
33.
Basipterygoid process: (N)
0.
small knob-like process
1.
developed as a broad platform
The plesiomorphic state is seen in basal actinopterygians and Onychodus.
34.
Basicranial fenestra:: (D52)
0.
1.
absent
present
35.
Extent of crista parotica:: (D28)
0.
does not reach posterior margin of tabular
1.
reaches posterior margin of tabular
36.
Pineal foramen:: (D27)
0.
present
1.
absent
37.
Proportions of postparietal shield:: (D31)
0.
wide posteriorly
1.
narrow posteriorly
2.
fused as part of skull table
We have coded the wide postparietal shield as plesiomorphic based on
porolepiforms, and Psarolepis, and add one extra state (2) here to reflect the
derived condition in tetrapods. State 0, ‘wide’ equates to being more than
twice as broad posteriorly than anteriorly (e.g. Glyptolepis). State 1, narrow
posteriorly is where the anterior margins of the shield are more then 50% of
the posterior margin.
38.
Postparietals narrow to a point posteriorly:: (D32)
0.
no
1.
yes
39.
Posterior margin of tabulars:: (D33)
0.
anterior to posterior margin of postparietals
1.
level with posterior margin of postparietals
40.
Median postrostral:: (D34)
0.
absent (postrostral mosaic)
1.
present
2.
absent (nasals meet in midline)
41.
Number of nasals:: (D35)
0.
many
1.
one or two
42.
Frontals:: (D36)
0.
absent
1.
present
43.
Shape of spiracular chamber: (N)
0.
Very large, steeply inclined anteriorly
1.
Acutely inclined anteriorly
2.
Horizontal
The difference between state 0 (Eusthenopteron, Onychodus) and condition
seen in both Gogonasus and Medoevia (1) is whether the angle of the inner
entopterygoid ridge denoting the lateral boundary of the spiracular chamber is
steeply inclined (>45deg.) or closer to the horizontal (acute angle).
44.
Extratemporal:: (D37)
0.
present
1.
absent
45.
Contact between the extratemporal and supratemporal:: (D38)
0.
absent
1.
present
46.
Posterodorsal process of maxilla:: (D41)
0.
present, deep throughout its length
1.
wedge shaped, deep posteriorly
2.
weak or absent
In Daeschler et al. (2006) they use 2 character states here but we have
expanded this to three states and made the plesiomorphic condition to include
onychodontids which have a uniformly broad posterodorsal process on the
maxilla, as in basal actinopterygians.
47.
Jugal - quadratojugal contact:: (D42)
0.
absent
1.
present
48.
Radius and ulna facets: (N)
0.
in same transverse plane
1.
stepped, in different planes
The stepped articulatory facets on Eusthenopteron are assumed present in
Megalichthys as Andrews & Westoll (1970a) claim the humerus is essentially
similar to that of Eusthenopteron. As the condition seen in Onychodus and in
the larval lungfish Neoceratodus is to have ulna and radial facets at the same
levels, we regard the stepped condition as derived.
49.
Position of orbits:: (D45)
0.
lateral and widely spaced
1.
dorsal and close together
50.
Extrascapular overlap:: (D48)
0.
no strong overlap
1.
lateral overlap median
2.
median overlaps lateral
51.
Anterior margin of median extrascapular:: (D49)
0.
broad, extensive contact
1.
point or very short contact
We regard the primitive state as seen in basal osteichthyans as having a broad
median extrascapular contact with postparietal shield (onychodonts,
porolepiforms, dipnoans bone A).
52.
Dermal ornament: (D69)
0.
even
1.
separate "starburst" on each bone
53.
Intertemporal bones:: (D75)
0.
present
1.
absent
54.
Spiracular notch:: (D87)
0.
absent-very small
1.
narrow groove
2.
wide notch
‘Wide’ notch here refs to the expanded size of the opening as in Gogonasus,
Panderichthys and Tiktaalik.
55.
Proportion of skull roof (measured as length from tip of snout to
posterior margin of postparietals) lying anterior to middle of orbits::
(D75)
0.
0 - <50%
1.
1 - 50%
2.
>50%
56.
Relative size of prefrontal and postfrontal:: (D76)
0.
similar
1.
prefrontal much bigger
57.
Postfrontals extend anterior of orbits:: (D86)
0.
yes
1.
no
58.
Extrascapular bones:: (D77)
0.
present
1.
absent
59.
Jugal extends anterior to middle of orbit:: (D78)
0.
no
1.
yes
60.
Lacrimal excluded from orbit:: (D79)
0.
no
1.
yes
61.
Short ventral process on entepicondyle: (N)
0.
absent
1.
present
As this process is absent on most tetrapodomorphan humeri, we consider it a
derived feature. This process is here shown clearly on Fig 2a for Gogonasus
and seen on Tiktaalik in Shubin et al., 2006, Fig 2a.
62.
Opercular:: (D111)
0.
present
1.
absent
63.
Submandibulars and Gulars:: (D80)
0.
present
1.
absent
64.
Preopercular:: (D88)
0.
large, broad
1.
large, bar-like
2.
small
65.
Large median gular:: (D81)
0.
absent
1.
present
66.
Sublingual rod: (N)
0.
absent
1.
present
The plesiomorphic state is taken to be the absence of a sublingual rod as it is
not found in any actinopterygians, or in porolepiforms.
67.
Clavicle ascending process: (N)
0
Clavicle has rod-like ascending process
1.
Clavicle lacks rod-like ascending process
The ascending process here defined as an extended narrow process, not just a
process or corner of the posterolateral corner of the clavicle. In basal
osteichthyans like Mimia and Onychodus there is well-developed ascending
process, but in forms like Gogonasus the anterolateral corner of the clavicle
ends with an acute point, but is not drawn out into a rod-like process.
68.
Interclavicle:: (D83)
0.
small, unornamented
1.
large, ornamented
69.
Supracleithrum and postemporal: (N)
0.
enlarged, bigger than scales
1.
small, scale-like bones
2.
lost from shoulder girdle
We here code the plesiomorphic state as seen in basal actinopterygians (e.g.
Mimia) in which these bones are relatively larger than regular scales, and may
have different shapes from that of the scales. The condition of having small
scale like bones in these positions is identified for Tiktaalik and is also seen in
Gogonasus.
70.
Anocleithrum:: (D54)
0.
exposed
1.
subdermal
71.
Orientation of cleithrum:: (D105)
0.
vertically oriented: tilted less than 10 degrees caudally
1.
angulated: tilted over 10 degrees caudally
72.
Cleithrum ornamentation: (D106)
0.
present
1.
absent
73.
Contact margin for clavicle on cleithrum:: (D53)
0.
straight or faintly convex
1.
strongly concave
74.
Attachment of scapulocorocoid to cleithrum:: (D108)
0.
tripodal, via three processes
1.
via a single dorsal process of scapulocorocoid that lies flush against
internal surface of cleithrum
2.
complete fusion between surfaces of the scapula and cleithrum
75.
Glenoid position:: (D104)
0.
elevated from plane formed by clavicles
1.
offset ventrally to lie at same level as clavicular plane
76.
Glenoid orientation:: (D110)
0.
posterior and/or ventral orientation
1.
lateral component to glenoid orientation
77.
Coracoid plate:: (D103)
0.
absent
1.
present and extends ventromedially
78.
Subscapular fossa: : (D109)
0.
absent
1.
present
79.
Body of humerus:: (D56)
0.
cylindrical
1.
flattened rectangular
80.
Caput humeri:: (D112)
0.
rounded to hemispherical shaped
1.
subrectangular, much wider than high
2.
elongate (bifid or strap - shaped)
In Daeschler et al. (2006) only 2 states are defined (0, ball-like or1, straplike). After closer examination of the humeri of a number of
tetrapodomorphs, we have added an extra state to accommodate the
condition seen in Gogonasus where it is neither ball-shaped nor strap-like,
but extensively wide and of uniform width.
81.
Radial facet:: (D98)
0.
faces distally
1.
has some ventrally directed component
82.
Entepicondyle size: (N)
0.
entepicondyle narrow relative to humerus shaft length
1.
entepicondyle as broad as or broader than humerus is long
Based on plesiomorphic archipterygial fin patterns (e.g. dipnoans,
porolepiforms) we assume that primary mesomere (A1) lacks a welldeveloped entepicondyle, so the extensive developments of such a feature are
here considered to be derived within tetrapodomorphs. We measure the
entepicondylar process as being the ventrally-orientated flange coming off the
humeral shaft, measured from the ventral humeral shaft edge to its widest
extent relative to maximum humeral shaft length. Thus in Gogonasus, as
shown in Fig.1a, the entepicondyle is clearly much shorter in its width than
the humerus is long.
83.
Anterior termination of ventral ridge:: (D96)
0.
adjacent to the caput humeri
1.
offset distally toward the proximodistal mid - region of anterior margin
of humerus
84.
Ectepicondylar process:: (D100)
0.
terminates proximal to epipodial facets
1.
extends distal to epipodial facets
85.
Area proximal to radial facet:: (D102)
0.
short, cylindrical leading edge, with no muscle scars
1.
enlarged, sharp leading edge, with areas for muscle attachment
86.
Articulations for more than two radials on the ulnare:: (D90)
0.
several radials articulate with ulnare
1.
articulates mainly with one large A4 element and/or other much
smaller radials
87.
Postaxial process on ulnare:: (D91)
0.
present
1.
absent
88.
Ventral ridge orientation:: (D97)
0.
diagonal to long axis of the humerus
1.
perpendicular to long axis of humerus
89.
Radials:: (D57)
0.
jointed
1.
unjointed
90.
Radius shape: (D94)
0.
narrow, tapered or even breadth throughout
1.
broad (almost as wide as long) or flared distally
We clarify our definition of this character as expressed by Daeschler et al.
(2006) by stating that the plesiomorphic radius must have been rod-like, not
broad or expanded, as it is in the small radials in dipnoans and porolepiform
pectoral fins.
91.
Radial length:: (D101)
0.
longer than humerus
1.
shorter than humerus
92.
Termination of radius: (N)
0.
radius and intermedium terminate at different levels
1.
radius and intermedium terminate at same level
93.
Transverse joint at the level of the ulnare, intermedium and radius::
(D89)
0.
absent
1.
present
94.
Intermedium shape: (N)
0.
narrow, tapered
1.
broad or flared
Using the same rationale as for Ch.91, the plesiomorphic state must be having
a simple, rod –like intermedium.
95.
Dorsal and anal fins:: (D58)
0.
present
1.
absent
96.
Caudal fin:: (D59)
0.
heterocercal
1.
diphycercal
97.
Scale morphology:: (D61)
0.
rhomboid with internal ridge
1.
round without median boss
2.
rounded, with median boss
3.
elongated, oval- round
We have added extra states here to differentiate between rounded scales with a
median boss (derived and restricted distribution) and tetrapod scales that are
elongated and oval-shaped.
98.
Basal scutes:: (D60)
0.
absent
1.
present
99.
Lepidotrichia:: (D92)
0.
present and jointed in region that overlaps endochondral elements
1.
present and unjointed in region that overlaps endochondral elements
2.
absent
100.
Imbricate ribs:: (D113)
0.
absent
1.
present
101.
Expanded ribs:: (D114)
0.
absent
1.
present
102.
Shape of mesomere A4: (N)
0.
narrow or tapered
1.
short, relatively broad
This feature is only known for a few tetrapodomorphans so polarity is
difficult to establish. We have based it on the observation that Tiktaalik
probably has a derived condition, so the plesiomorphic condition is might be
seen in Eusthenopteron.
103.
Shape of mesomere A5: (N)
0.
narrow and or tapered
1.
broadens posteriorly
This character is polarised as for Ch. 105.
Character Matrix
12345
Onychodus
Glyptolepis
Barameda
Marsdenichthys
Eusthenopteron
Medoevia
Megalichthys
Gogonasus
Panderichthys
Tiktaalik
Acanthostega
Ichthyostega
Onychodus
Glyptolepis
Barameda
Marsdenichthys
Eusthenopteron
Medoevia
Megalichthys
Gogonasus
Panderichthys
Tiktaalik
Acanthostega
Ichthyostega
Onychodus
Glyptolepis
Barameda
Marsdenichthys
Eusthenopteron
Medoevia
Megalichthys
Gogonasus
Panderichthys
Tiktaalik
Acanthostega
Ichthyostega
1 11111
67890 12345
11112
67890
22222
12345
22223 33333
67890 12345
33334
67890
44444
12345
10002
10000
110?1
110?1
1100?
01011
010?1
00/1011
11121
11121
10121
10121
00000
00000
000?0
?????
00000
00000
00000
00000
00101
00?0?
11111
11111
00000
10000
10?01
???00
10100
10000
10000
10000
10101
10101
01111
01111
20000
00000
10000
???00
10000
00000
00000
00000
20000
200?0
21111
21111
01000
30000
11000
???0?
11102
10100
10?00
10100
20?02
20102
22111
22111
001?0
00100
0?0?1
100?1
11011
11011
11011
11011
11011
110?1
10011
10011
010??
0111?
011??
11???
31111
11111
11111
11111
31110
3????
2010?
2010?
11001
10000
01101
01011
01011
0101?
11011
01101
01012
01012
02012
02012
10001
00000
10?01
10?00
0001?0100
10?00
10100
0121?121112111?1-
44445
67890
55555
12345
55556
67890
66666
12345
66667
67890
77777
12345
77778
67890
88888
12345
88889
67890
00000
20-02
2?000
10?01
10101
10?01
10101
10001
2?011
210121?121?1-
00000
00?00
00000
00010
00010
0/10010
00010
10020
00020
-0122
-1122
-1121
--000
?0000
00000
00000
00000
00000
00000
00000
00000
11110/1
11111
11111
00000
00000
00000
?0010
00010
00010
00010
10010
?0011
11021
11120
?112-
?0?01
00000
?00?1
?1?00
10000
1?000
?1?00
11010
11010
11?10
0012?
?012?
00100
00000
00000
000??
00100
00000
00000
00000
10111
10111
11?21
01?20
00011 00?0? ??-0?
00000 ?-??? -??000000 01000 0101?
????? ????? ???0?
00000 01000 00001
00001 01000 ??00?
00000 01000 00000
00011 1000/10 10000
11112 00001 ??000
11112 10101 11010
11112 00111 ----0
11112 10111 ----1
99999
12345
99990
67890
111
000
123
????0
?-0-0
0001?
????0
00010
????0
0??00
01000
11001
11101
1-- 11
11- -1
11000
01000
?1010
?210?
12100
?010?
00100
00100
10010
?001?
13020
1?021
0??
0??
000
???
000
???
?0?
011
1??
111
0-1--
Supplementary Information Figure S1: