(Amphilius,

Plesiomorphically in catfish the anterior margin of the prevomer lies relatively far from the anterior margin of the mesethmoid [State 0: e.g. Fig. 3.66]. In specimens of genera Trichomycterus and Hatcheria examined, the prevomer extends anteriorly, with its anterior margin lying at about the same level as the anterior margin of the premaxilla [State 1]. In specimens of Nematogenys examined, the prevomer is extended further anteriorly, its anterior margin lying at about the same level of the anterior margin of the mesethmoid [State 2: e.g. Fig. 3.89]. — CS-0: Anterior margin of prevomer markedly posterior to anterior

margin of mesethmoid (all genera not in other CS) — CS-1: Prevomer with anterior extension, its anterior margin lying at

examined [State 0], in specimens of the six genera of CS-1 analysed, the

frontal exhibits a well-developed, thin, extensive anterodorsomesial projection, which almost separates, or completely separates, the dorsomesial surface of the lateral ethmoid and the dorsolateral surface of the mesethmoid in dorsal view [State 1]. — CS-0: Absence of well-developed, thin, extensive anterodorsomesial

projection of frontal (all genera not in other CS) — CS-1: Presence of well-developed, thin, extensive anterodorsomesial

97. Contact between frontal and pterotic. Plesiomorphically in catfish the frontal does not come into contact with the pterotic (see, e.g., Chardon, 1968; Mo, 1991) [State 0: e.g. Fig. 3.67]. In specimens examined of genera listed in CS-1, the posterolateral margin of the frontal comes into contact with the anteromesial margin of the pterotic in dorsal View [State 1: e.g. Fig. 3.17]. — CS-0: Frontal and pterotic not in contact (all genera not in other CS) — CS-1: Frontal and pterotic in contact in dorsal view (Pimelodus,

98. Dorsomesial process of frontal (ordered multistate character). Contrary to all other catfish examined [State 0: e.g. Fig. 3.24], in Paraplotosus there is a well-developed dorsomesial process of the frontal meeting its counterpart on the midline, thus forming a well-developed V-shaped structure on the dorsal surface of the neurocranium [State 1], which is still more prominent in Plotosus [State 2: e.g. Fig. 3.114]. — CS-0: Frontal not presenting dorsomesial process (all genera not in

other CS) — CS-1: Frontal presenting dorsomesial process (Paraplotosus) — CS-2: Dorsomesial process of frontal more developed than in CS-1

(Plotosus) 99. Dorsal salience of frontal and lateral ethmoid. Contrary to the other

siluriforms examined [State 0: e.g. Fig. 3.67], in the specimens of genera Plotosus and Cnidoglanis analysed, there is a well-developed dorsal salience of the neurocranium, at the level of the posterodorsal region of the lateral ethmoid and the anterodorsal region of the frontal [State 1: e g. Fig. 3.114]. — CS-0: Absence of dorsal salience of frontal and lateral ethmoid (all

genera not in other CS) — CS-1: Presence of dorsal salience of frontal and lateral ethmoid

100. Width of frontal. Plesiomorphically in catfish the frontal is very large and hence dearly visible in both dorsal and ventral views of the neurocranium [State 0: e.g. Fig. 3.66]. However, in specimens of genera Cetopsis and Hemicetopsis examined, this bone is so markedly compressed transversally that it is almost completely confined to the neurocranial dorsomesial crests for attachment of the adductor mandibulae and is not visible in a ventral view of the neurocranium [State 1: e.g. Fig. 3. 46]. — CS-0: Frontal not markedly compressed transversally (all genera

and Vari, 1995). Plesiomorphically catfish lack any large openings other than the anterior and posterior median cranial fontanels [State 0: e.g. Fig. 3.67] but in Helogenes there is a large foramen on the dorsolateral surface of each frontal [State 1]. — CS-0: Frontal without large foramen on dorsolateral surface (all

genera not in other CS) — CS-1: Frontal exhibiting large foramen on dorsolateral surface

fontanel is present and usually well developed (see, e.g., Regan, 1911b) [State 0: e.g. Fig. 3.67]. In the adult specimens examined of genera of CS-1, the anterior fontanel is absent [State 1: e.g. Fig. 3.13]. — CS-O: Anterior fontanel present (all genera not in other CS) — CS-1: Anterior fontanel absent (Zaireichthys, CetopsisLoricaria,

[State 0: e.g. Fig. 3.67], specimens examined of genera listed in CS-1 present an additional median cranial fontanel, for a total of three median cranial fontanels [State 1]. — CS-0: Absence of additional median cranial fontanel (all genera not

from de Pinna, 1996). As mentioned above, plesiomorphically catfish lack any large openings other than the anterior and posterior median cranial fontanels [State 0: e.g. Fig. 3.67], but peculiarly in Gagata there is a welldeveloped foramen between the dorsal surfaces of the frontal, sphenotic and parieto-supraocdpital on each side of the head [State 1]. — CS-0: Absence of well-developed foramen between sphenotic, frontal

and parieto-supraocdpital (all genera not in other CS) — CS-1: Presence of well-developed foramen between sphenotic, frontal

105. Contact between lateral ethmoid and pterosphenoid. Contrary to the plesiomorphic situation found in other catfish, in which the anterodorsal margin of the pterosphenoid and posterodorsal margin of the lateral ethmoid lie relatively far from each other [State 0: e.g. Fig. 3.63], in Cetopsis and Hemicetopsis the anterodorsal surface of the pterosphenoid is markedly expanded anteriorly and the posterodorsal surface of the lateral ethmoid is markedly expanded posteriorly, with these bones being almost in contact, or inclusively in contact [State 1: e.g. Fig. 3.46]. — CS-0: Anterodorsal margin of pterosphenoid and posterodorsal

margin of lateral ethmoid relatively far from each other (all genera not in other CS)

— CS-1: Anterodorsal margin of pterosphenoid and posterodorsal margin of lateral ethmoid near to each other, or inclusively in contact (Cetopsis, Hemicetopsis)

106. Anteroventrolateral process of pterosphenoid. The plesiom orphic configuration for the siluriforms is seemingly that present in other ostariophysans and in the vast majority of the siluriforms, in which the pterosphenoid lacks a well-developed anteroventrolateral process for articulation with the hyomandibulo-metapterygoid (see, e.g., Diogo et al., 2001a) [State 0: e.g. Fig. 3.89]. However, such a process is present in the specimens examined of genus Diplomystes and genus Trichomycterus [State 1: e.g. Fig. 3.63]. — CS-0: Absence of anteroventrolateral process of pterosphenoid (all

genera not in other CS) — CS-1: Presence of anteroventrolateral process of pterosphenoid

and contrary to all other catfish examined [State 0: e.g. Fig. 3.46], the pterosphenoid exhibits a prominent, anterolaterally pointed, lateral process [State 1]. — CS-0: Absence of lateral process of pterosphenoid (all genera not in

posterior portion of the parasphenoid is markedly large [State 0: e.g. Fig. 3.66], in the plotosids examined the posterior portion of this bone is notably compressed transversally [State 1]. — CS-0: Posterior portion of parasphenoid not com pressed

transversally (all genera not in other CS)

— CS-1: Posterior portion of parasphenoid markedly compressed transversally (Plotosus, Paraplotosus, Cnidoglanis, NeosiluruS

109. Anterodorsolateral salience of sphenotic (ordered multistate character). The plesiomorphic condition for catfish is seemingly that found in Diplomystes and the vast majority of siluriforms, as well as of ostariophysans, in which the sphenotic lacks major well-developed processes or saliences [State 0: e.g. Fig. 3.67]. However, in catfish of CS-1 there is a welldeveloped, large anterodorsolateral salience of the sphenotic [State 1: e.g. Fig. 3.89], which is particularly pronounced in catfish of CS-2 [State 2]. — CS-0: Absence of well-developed anterodorsolateral salience of

sphenotic (all genera not in other CS) — CS-1: Presence of well-developed anterodorsolateral salience of

— CS-2: A nterodorsolateral salience of sphenotic even more pronounced than in CS-1 (Malapterurus, Auchenoglanis

110. Lateral bifurcation of anterodorsolateral salience of sphenotic. Contrary to other catfish [State 0: e.g. Fig. 3.89], in Austroglanis there is a marked bifurcation of the anterodorsolateral salience of the sphenotic (see above) [State 1: e.g. Fig. 3.33]. — CS-0: Absence of marked bifurcation of anterodorsolateral salience

— CS-1: Presence of marked bifurcation of anterodorsolateral salience of sphenotic (AustroglaniS

— Inapplicable: Since there is no well-developed anterodorsolateral salience of sphenotic (all genera not in other CS)

111. Ventromesial projection of sphenotic. Contrary to all other catfish examined [State 0: e.g. Fig. 3.66], in specimens of Callichthys analysed the sphenotic exhibits a well-developed, thin ventromesial projection that extends mesially to contact a similar well-developed, thin ventrolateral projection of the prootic [State 1]. — CS-0: Absence of well-developed ventromesial projection of

sphenotic (all genera not in other CS) — CS-1: Presence of well-developed ventromesial projection of

siluriforms the sphenotic lacks major well-developed processes or saliences [State 0: e.g. Fig. 3.67], but in the four genera of CS-1 this bone exhibits a prominent, anteriorly directed anterodorsal process [State 1: Fig. 3.46]. — CS-0: Absence of prominent anterodorsal process of sphenotic (all

genera not in other CS)

— CS-1: Presence of prominent anterodorsal process of sphenotic (Cetopsis, Hemicetopsis, Helogenes, Ageneiosus)

113. Fusion between sphenotic, prootic and pterosphenoid (character inspired from de Pinna, 1992). Contrary to other catfish examined [State 0: e.g. Fig. 3.67], in the specimens of genera Trichomycterus and Hatcheria examined the sphenotic, prootic and pterosphenoid are seemingly fused into a single element [State 1]. — CS-0: Sphenotic, prootic and pterosphenoid not fused (all genera

not in other CS) — CS-1: Sphenotic, prootic and pterosphenoid seemingly fused into a

e.g., Chardon, 1968; Mo, 1991; de Pinna, 1993; Oliveira et al, 2001). Contrary to the plesiomorphic siluriform condition present in other catfish examined, in which the utriculus is not a particularly conspicuous element and is confined within the central area of the prootic [State 0: e.g. Fig. 3.66], in genera of CS-1 [State 1], and especially in genera of CS-2 [State 2], the utricular otolith is a greatly enlarged element profoundly inflating the ventral surface of the neurocranium. — CS-0: Utricular otolith not markedly developed (all genera not in

other CS) — CS-1: Utricular otolith markedly developed, profoundly inflating

— CS-2: Utricular otolith more developed than in CS-1, profoundly inflating ventral surfaces of prootic and pterotic, and also the exoccipital (Arius, Genidens)

115. Fossa between ventromesial surface of pterotic and ventrolateral surface of exoccipital (ordered multistate character). Contrary to all other catfish examined [State 0: e.g. Fig. 3.66], in Bagarius and Gagata a large, somewhat deep fossa occurs on the neurocranial floor between the ventromesial surface of the pterotic and the ventrolateral surface of the exoccipital [State 1], which is still more enlarged and deeper in Glyptostemon and Glyptothorax [State 2: e.g. Fig. 3.122]. — CS-0: Absence of large fossa between ventral surfaces of pterotic

and exoccipital (all genera not in other CS) — CS-1: Presence of large, somewhat deep fossa between ventral

116. Posterior process of exoccipital. Contrary to all other catfish examined [State 0: e.g. Fig. 3.66], in specimens of genera of CS-1 analysed, the exoccipital

exhibits a prominent, thin posterior process, which comes into contact posteriorly with the anterior surface of the fourth parapophysis [State 1]. — CS-0: Absence of prominent posterior process of exocdpital (all

1968). Contrary to all other catfish examined [State 0: e.g. Fig. 3.66], in specimens of the five genera of CS-1 analysed, the exoccipital and basioccipital are seemingly fused into a single element [State 1]. — CS-0: Exocdpital and basiocdpital not fused (all genera not in other

CS) — CS-1: Exoccipital and basioccipital fused in a single element

Pinna, 1993; Lundberg, 1993). Contrary to other catfish examined, in which the epioccipital situates essentially on the posterior wall of the cranium and does not constitute a significant part of the cranial roof [State 0: e.g. Fig. 3.67], in siluriforms of CS-2 the epiocdpital constitutes a significant part of the dorsal surface of the cranial roof [State 1: e.g. Fig. 3.74]. — CS-0: Epioccipital not constituting significant part of cranial roof

(all genera not in other CS) — CS-1: Epioccipital constituting significant part of cranial roof

119. Presence of prominent, roundish posterodorsal process of epioccipital. Contrary to all other catfish examined [State 0: e.g. Fig. 3.67], in Cranoglanis there is a prominent, stout, roundish posterodorsal process of the epioccipital, from which originate a goodly part of the fibres of the protractor of the mullerian process [State 1: e.g. Fig. 3.58]. — CS-0: Absence of prominent, stout, roundish posterodorsal process

of epioccipital (all genera not in other CS) — CS-1: Presence of prominent, stout, roundish posterodorsal process

inspired from Mo, 1991). Contrary to all other catfish examined [State 0: e.g. Fig. 3.63], in the four bagrid genera analysed and in Malapterurus there is a well-developed posterodorsal projection of the pterotic which, together with the anterodorsolateral margin of the post-temporosupracleithrum, delimits a well-developed, laterally opened, 'fossa posttemporalis' (see terminology of Mo, 1991) [State 1: e.g. Fig. 3.42]. — CS-0: Absence of well-developed posterodorsolateral projection of

pterotic delimiting well-developed, laterally opened, 'fossa posttemporalis' (all genera not in other CS)

— CS-1: Presence of well-developed posterodorsolateral projection of pterotic delimiting well-developed, laterally opened, 'fossa posttemporalis' (Bagrus, Bagrichthys, Hemibagrus, Rita, Malapterurus)

121. Foramen between pterotic and parieto-supraoccipital. As noted above, plesiomorphically catfish lack any large openings other than the anterior and posterior median cranial fontanels [State 0: e.g. Fig. 3.67]. Uniquely in Paramphilius a small foramen lies between the dorsal surfaces of the pterotic and parieto-supraoccipital on each side of the head [State 1]. — CS-0: Absence of small foramen between pterotic and parieto-

supraoccipital (all genera not in other CS) — CS-1: Presence of small foramen between pterotic and parieto-

Lundberg, 1982). Contrary to all other catfish examined [State 0: e.g. Fig. 3.66], in Ictalurus and Amiurus a prominent, ventrolateral process of the pterotic occurs, which receives the 'subpterotic process' (see terminology of Lundberg, 1982) of the post-temporo-supracleithrum [State 1]. — CS-0: Absence of prominent ventrolateral process of pterotic (all

genera not in other CS) — CS-1: Presence of prominent ventrolateral process of pterotic

inspired from de Pinna, 1996). As noted above, plesiomorphically catfish lack any large openings or fossas other than the anterior and posterior median cranial fontanels [State 0: e.g. Fig. 3.67]. In siluriforms of CS-1, a well-defined, deep 'supratemporal fossa' (see terminology of de Pinna, 1996) lies between the dorsomesial surface of the pterotic and the dorsolateral surface of the parieto-supraoccipital on each side of the head [State 1: e.g. Fig. 3.74]. In the two genera of CS-2 a complete foramen occurs between the dorsomesial surface of the pterotic and the dorsolateral surface of the parieto-supraoccipital on each side of the head [State 2]. — CS-0: Absence of supratemporal fossa (all genera not in other CS) — CS-1: Presence of supratemporal fossa between dorsal surfaces of

124. Parietal as separate ossification on cranial roof (character inspired from Lundberg, 1975b). As emphasised by Lundberg (1975b), contrary to the plesiomorphic condition found in all other catfish examined, in which the parietal and the supraoccipital are likely fused into a single element [State 0: e.g. Fig. 3.67], in both young and adult Helogenes the parietal

seems to be present as a separate element on the dorsal surface of the cranial roof [State 1], — CS-0: Parietal not a separate element on the cranial roof (all genera

not in other CS) — CS-1: Parietal seemingly a separate element on the cranial roof

extrascapular and pterotic (ordered multistate character). As noted above, plesiomorphically catfish lack any well-developed openings or fossas other than the anterior and posterior median cranial fontanels [State 0: e.g. Fig. 3.67]. In catfish of CS-1 a well-developed, deep fossa occurs between the dorsomesial limb of the posttemporo-supracleithrum, extrascapular and pterotic [State 1: e.g. Fig. 3.33], which is remarkably developed in specimens of Arius and Genidens examined [State 2: e.g. Fig. 3.20]. — CS-0: Absence of well-developed, deep fossa between dorsomesial

limb of posttemporo-supracleithrum, extrascapular and pterotic (all genera not in other CS)

— CS-2: Fossa betw een dorsom esial limb of posttem porosupracleithrum, extrascapular and pterotic remarkably developed (Arius, Genidens)

126. Presence of fossa between dorsomesial limb of posttemporo-supracleithrum and parieto-supraoccipital. Plesiomorphically catfish lack any well-developed openings or fossas other than the anterior and posterior median cranial fontanels (see above) [State 0: e.g. Fig. 3.67]. In siluriforms of CS-1, however, there is a well-developed, deep fossa between the anteromesial

surface of the dorsomesial limb of posttemporo-supracleifhrum, parietosupraoccipital and, eventually, epioccipital [State 1: e.g. Fig. 3.25]. — CS-0: Absence of well-developed, deep fossa between posttemporo-

supracleithrum, parieto-supraoccipital and, eventually, epioccipital (all genera not in other CS)

— CS-1: Presence of well-developed, deep fossa between posttemporosupracleithrum, parieto-supraoccipital and, eventually, epioccipital (Erethistes, Hara, Bunocephalus, Aspredo, Xyliphius, Chaca)

127. Size of basioccipital. Contrary to the catfish examined [State 0: e.g. Fig. 3.66], in Andersonia the basioccipital is a peculiarly developed structure even larger than the broad prootic [State 1] (see Diogo, 2003b). — CS-0: Basioccipital not peculiarly developed (all genera not in other

CS) — CS-1: Peculiarly developed basioccipital larger than broad prootic

[State 0: e.g. Fig. 3.89], in specimens of Arius and Genidens analysed a well-developed ventral process of the basioccipital occurs, which comes into contact with a similar ventral process of the first vertebra, forming a prominent, V-shaped ventral salience on the posterior surface of the neurocranial floor [State 1]. — CS-0: Absence of well-developed ventral process of basioccipital

(all genera not in other CS) — CS-1: Presence of well-developed ventral process of basioccipital

de Pinna and Vari, 1995). Contrary to all other catfish examined [State 0: e.g. Fig. 3.67], Helogenes exhibits a markedly anteroposteriorly compressed parieto-supraoccipital [State 1]. — CS-0: Parieto-supraoccipital not m arkedly com pressed

anteroposteriorly (all genera not in other CS) — CS-1: Parieto-supraoccipital markedly compressed anteroposteriorly

catfish examined [State 0: e.g. Fig. 3.67], in the two genera of CS-1 a well-developed lateral projection of the parieto-supraoccipital occurs that is markedly extended laterally, thus surrounding a significant part of the posterior margin of the pterotic and which, together with the main body and the posterior process of the parieto-supraoccipital, forms a somewhat T-shaped parieto-supraoccipital in dorsal view [State 1: e.g. Fig. 3.46]. — CS-0: Absence of well-developed lateral projection of parieto-

supraoccipital (all genera not in other CS) — CS-1: Presence of well-developed lateral projection of parieto-

131. Posterior margin of parieto-supraoccipital (unordered multistate character) (character inspired from Chardon, 1968). Plesiomorphically catfish present a well-developed posterior process of the parieto-supraoccipital [State 0: e.g. Fig. 3.67] but in specimens of genera of CS-1 examined, this process is particularly conspicuous [State 1: e.g. Fig. 3.77]. A different configuration is found in those catfish of CS-2, in which the parietosupraoccipital is markedly truncated posteriorly [State 2: e.g. Fig. 3.25]. — CS-0: Well-developed posterior process of parieto-supraoccipital (all

genera not in other CS) — CS-1: Particularly conspicuous posterior process of parieto-

132. Lateral laminae of parieto-supraoccipital (ordered multistate character) (character inspired from He et al., 1999). Plesiomorphically in catfish the parietosupraocdpital lacks major lateral laminae [State 0: e.g. Fig. 3.67]. Uniquely in Andersonia, Belonoglanis and Trachyglanis the parieto-supraocdpital exhibits a well-developed, broad, dorsolateral laminar extension which, however, is considerably less developed in Andersonia and Trachyglanis [State 1: e.g. Fig. 3.12] than in Belonoglanis [State 2]. — CS-0: Absence of lateral laminae of parieto-supraocdpital (all genera

not in other CS) — CS-1: Presence of well-developed lateral laminae of parieto-

extrascapular, dorsomesial surface of pterotic and dorsolateral surface of parietosupraoccipital. As noted above, plesiomorphically catfish lack any welldeveloped openings other than the anterior and posterior median cranial fontanels [State 0: e.g. Fig. 3.67], but in Pangasius and Helicophagus a well-developed foramen lies between the anterodorsal surface of the extrascapular dorsomesial surface of the pterotic and dorsolateral surface of the parieto-supraocdpital [State 1: e.g. Fig. 3.96]. — CS-0: Absence of foramen between extrascapular, pterotic and

paxieto-supraoccipital (all genera not in other CS) — CS-1: Presence of well-developed foramen between extrascapular,