126 



spp. However, acceptance of this as a synapomorphy of its members (P. caspica and the 

 clade of P. hispida and P. sibirica) depends on the resolution of the polytomy in this 

 region. Again, state 9 was independently obtained for Martes and Erignathus. 



97) visibility of posterior opening of carotid canal in ventral view: 0 = not visible; 1 = 

 visible; 9 = carotid canal absent (Wyss 1988a). 



In concert with character #101, Wyss (1988a) viewed this feature as a synapomorphy of 

 the phocines minus Erignathus. Wyss (1988a) tied the apomorphic conditions of both 

 features (state 0 in both) to the characteristic inflated bulla of phocines. However, it is 

 unclear to us why these same conditions would not also occur in most arctoids, which 

 also generally possess inflated bullae (Segall 1943; Repenning 1972; Hunt 1974; see also 

 characters #80-82). Our observations also revealed that the two features (i.e., characters 

 #97 and 101) were not necessarily coincident with one another; thus, they appear 

 separately in this analysis. As well, we were uncertain as to whether the phrase "visibility 

 of the carotid canal" referred to the canal in general, or to the foramen of the canal. Thus, 

 we draw a distinction between these two meanings here, and each appears as a separate 

 character. Visibility of the carotid canal here refers to whether evidence of a carotid canal 

 could be glimpsed in ventral view. Wyss (1988a) implies that the carotid canal is visible 

 in most arctoid carnivores except for the clade mentioned above. 



In most taxa, including virtually all phocines, a carotid canal could be ascertained in ventral 

 view; only Ursus, Martes, Zalophus, and Pusa hispida failed to demonstrate evidence of 

 the canal in ventral view. [As the carotid canal is diagnostic of arctoid carnivores only 

 (Wyss 1988a), the characters dealing with this feature (#97-104) do not apply to Canis.] 

 Unfortunately, the polarity of this character cannot be determined due the occurrence of 

 both states in the basal arctoids, so Wyss's (1988a) assessment of state 0 as the apomorphic 

 trait cannot be verified. 



98) visibility of foramen of posterior opening of carotid canal in ventral view: 0 = not 

 visible; 1 = visible; 9 = carotid canal absent (Wyss 1988a). 



This variation on the previous character probably provides a more definitive test of Wyss's 

 (1988a) original character. Any inflation of the auditory bulla will tend to overhang and 

 thus obscure the foramen of the carotid canal. The previous character merely examined 

 for any evidence of the carotid canal, which could be as little as a small divot in the 

 posteroventral edge of the bulla. 



Unlike the previous character, a polarity assessment is possible here and indicates that 

 state 0 is plesiomorphic among arctoids [in contrast to Wyss (1988a)]. The apomoiphic 

 condition, whereby the foramen is visible in ventral view, is limited in distribution to 

 Enhydra and Hydrurga, although Procyon, Lutra, Odobenus, and Mirounga angustirostris 

 are polymorphic for this character. 



99) direction of posterior opening of carotid canal, I: 0 = distinctly greater than 45° 

 medially (i.e., roughly medially); 1 = roughly 45° medially; 2 = distinctly less than 45° 

 medially (i.e., roughly posteriorly); 9 = absent (King 1972) (Fig. 22). 



The direction of the posterior opening of the carotid canal appears to be related to an 

 interaction between the auditory bulla and both the basioccipital and basisphenoid bones. 

 King (1972) notes that there is a tendency in monachines for the basioccipital and 



