22 
Clayton E. Ray, Elaine Anderson, S. David Webb 
N 
X 
OR 
Eira barbara 
43 
1.34 
1.23-1.53 
Grisonella cuja 
10 
1.73 
1.55-1.88 
Galictis vittata 
14 
1.85 
1.73-1.98 
Trigonictis macrodon 
ANSP 11626, holotype 
1.67 
USNM 306507, North Carolina 
1.99 
KUVP 4604, holotype of 
T. kansasensis (from 
Hibbard 1941a:346) 
1.85 
UW 41527, Washington (from 
Gustafson 1978, table 14) 
1.85 
Hagerman sample in USNM 
5 
1.81 
1.73-1.86 
T. cookii 
Hagerman sample (from Bjork 
1970, table 8) 
3 
1.94 
1.81-2.03 
UF/FSM 27509 
1.89 
Thus Trigonictis clearly is similar to 
Grisonella and Galictis in relative 
length of Mj-, and unlike Eira, which 
has a reduced 
Mj-. However, as 
noted above, in all features other than 
relative 
size, M 
j- of Trigonictis is 
more similar to that of Eira than to that of Grisonella or Galictis. The 
overall profile of the mandible of Trigonictis macrodon as seen in labial 
aspect in the specimen from Florida (Fig. 4B) is much more like that in 
Eira than in Galictis, in that the ventral border is straight, not convex 
ventrally, and the coronoid process is broad and blunt, not tapering and 
pointed. On the other hand the ventral border is curved and the coronoid 
pointed in the Florida specimen tentatively referred to T. cookii (Fig. 7B). 
and the shape of the coronoid is reversed in specimens assigned to the two 
species from Idaho (Shotwell 1970, Fig. 37J,N). Similarly, we have not 
been able to identify consistent characters in the shape and extent of the 
masseteric fossa. The “narrower muzzle” of Galera macrodon, as com- 
pared to the tayra, noted by Cope, does seem to be reflected in Trigonictis 
in its narrower symphyseal region with more crowded incisive alveoli, as 
preserved in UF/FSM 18912. In summary, Trigonictis be about 
as similar to (and as different from) the tayra, as to (and from) the grison. 
The tendency of American authors to refer to Trigonictis as a grison, an 
extinct grison, a grison ancestor, or as grison-like is not justifiable, and is 
in fact misleading, as a case equally strong and probably equally errone- 
ous can be made for the tayra. We are not able to follow Bjork’s 
(1970:28) suggestion that T. cookii might be ancestral to Galictis vittata 
(and Sminthosinis bowleri to Grisonella cuja), especially as there are 
coeval fossil galictines in Eurasia much more like the modern Galictis. 
