ANCHICF.RATOPS ORNATUS 103 



Anchkeratofs agrees most nearly with Pentaceratofs (PI. V, B) in the character of ornamenta- 

 tion at the rear of the crest, but differs from it in the relatively smaller parietal (enestrae, and in 

 the smaller and differently shaped nasal horn. With its contemporary, ArrhmocerotofS (PI. XII), 

 in the Edmonton formation, there is even less agreement. The wide, flat crests are similar in their 

 relatively small parietal fenestrae, and in the extent of vascular grooving on the under side; but 

 there are no great prominences, epoccipital or otherwise, at the rear of the ArrhmocerotofS crest, 

 which is extremely thin. The brow horns are somewhat alike, but the nasal horn in Arrhinoceratofs 

 is supposed by Parks to be lacking. If so, there was certainly a functional organ formed by the nasal 

 bones that took its place, which in form was not unlike that of Anchkeratofs longirostris. The 

 muzzle of the latter is much longer and slenderer than in Arrhinoceratofs. 



Two species of Anchkeratofs have been described, A. ornatus Brown, and A. longirostris Stern- 

 berg. Unfortunately, the material upon which the first is based lacks the anterior part of the skull, 

 as there is very little preserved in front of the orbits, so that the long rostrum which gives its name 

 to Sternberg's species may have been equally characteristic of the other. The specific contrasts, 

 therefore, must be found in the remainder of the skull. One of the chief distinctions between 

 longirostris and ornatus is the curvature of the brow horns, which can be in part the result of pres- 

 sure deformation, for those of longirostris curve upward, decidedly forward, and then slightly out- 

 ward, while the ornatus horns curve outward and then forward. The horns of the former are also 

 smaller and wider apart at their base, which may be sex or individual variation. The distinctions of 

 crest lie in the parietal fenestrae, which are proportionately much longer in longirostris, and the 

 whole crest is thinner, with relatively smaller prominences. 



The two type specimens were collected in approximately the same place and horizon, while a 

 third partial skull in the Royal Ontario Museum resembles longirostris more than ornatus in the 

 extreme forward curvature of the horns and in the somewhat thinner crest, and in the absence of the 

 large epoccipital at the rear end of the squamosal. But the absence of epoccipitals is never to be 

 taken seriously as diagnostic because they are so readily lost from a skull after death, especially if 

 the individual is young. 



The two species may be held tentatively, pending more perfect material of A. ornatus, which is 

 the type of the genus, and must stand in any event. The variations of ceratopsian skulls due to age, 

 sex, or the individual are such that no two ever seem to agree. 



Anchiceratops ornatus Brown"' 1 



Holotype: No. 5251 A.M.N. H.; an incomplete skull, anterior end, and top of supraorbital horns missing. 



Paratype: No. 5259 A.M.N.H.; brain case and supraorbital horns nearly complete. 



Horizon: Edmonton formation. 



Locality: 7 miles below Tolman Ferry, Red Deer River, Alberta, Canada. 



Collector: American Museum expedition of 1912. 



The generic and specific characters are stated to be as follows: "Skull large. Supraorbital 

 horns rising close together, massive at base and divergent, curving outward, then forward. Crest 

 large, thick and flat with small lateral fontanel les; border ornamented by large epoccipital bones; a 

 pair of short knob-like processes on superior posterior end of crest. Squamosal intermediate in 

 length between Monoclonius and Triceralofs. 



". . . The bone that forms the brain-case as well as that of the crest is unusually thick, with 

 such surfaces as were not deeply embedded in muscle, furrowed by wide vascular grooves. 



"The crest ... is broad, flat and quadrilateral in outline and on the upper surface is composed 

 of three elements . . . ; paired lateral bones [squamosals] suturally distinct and a median element, 

 which is interpreted as the fused postfrontals ('parietals'). 



". . . The squamosal is elongate and terminates just in front of the third epoccipital bone count- 

 ing from the rear, opposite the posterior border of the fontanelle. ... In front its extent cannot be 



51 Brown, B., 1914, A, pp. 5 39-548. 



