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J.A. Long, G.C. Young 
Figure 5 Porlalodus bradshawae gen. et sp. nov. A, WAM 94.2.8., labial view, X 4 . B, WAM 94.2.10., lingual view, X 4 
(both from Portal Mountain, type locality). C, WAM 94.2.12., lingual aspect, slightly flattened to show basal 
view also, X 2, from "Gorgon's Head", Cook Mountains. D, E, Holotype WAM 92.3.60. X 4, D, labial view, 
E, left lateral view (Portal Mountain, type locality). F, WAM 92.3.65, labial view, from Fault Bluff, "fish 
hotel" B horizon. A-C are latex casts whitened with ammonium chloride, D-F are actual specimens 
(whitened). 
well-defined ridges or transverse groove. Single 
large nutritive foramen and rostrocaudal groove 
on ventral surface. 
Remarks 
Young (1982: 835) oriented these teeth with the 
expanded side of the base assumed for the 
purpose of description to correspond to the lingual 
torus of other forms'. However the curvature of 
the cusps (which should point into the mouth) 
indicates that this basal projection must be an 
extension of the labial, not the lingual surface, and 
in this respect Portalodus gen. nov. differs from 
Xenacanthns, and all other forms with diplodont 
teeth, in lacking a lingual torus, and instead having 
the opposite surface of the base developed as a 
labial projection. The only other shark tooth type 
known with this configuration is the genus 
Omalodus erected by Ginter and Ivanov (1992; 
earlier named as Phoebodus bryanti by Wells 1944), 
but this form is much smaller, and differs in having 
three principal cusps with smaller cusplets in 
between them. 
Holotype 
WAM 92.3.60 (Figures 5D, E; 6A), a large tooth 
from Portal Mountain, section 200 m west of 
section PI, collected by J. Long. 
Other Material 
Approximately 32 teeth. Portal Mountain (teeth): 
CPC 21214-227, 31614, AMF 54329-331, 555735, 
