Scott et al.—New diminutive species of Catopsalis from Alberta
crest. The cusps of the lingual row are slightly smaller and lower than those of the middle row but are otherwise similar in overall morphology. The valley between the middle and lingual cusp rows is deep but extremely narrow, being essentially slit-like in occlusal view; the valley between each successive cusp is similarly deep but is significantly wider. i1.—The lower incisor of Catopsalis kakwa n. sp. is repre-
sented by three specimens, of which UALVP 57537 is the least worn and most informative. As in other taeniolabidoids, the i1 of C. kakwa n. sp. is gliriformand robust,with a dorsoventrally deep and somewhat mediolaterally compressed crown; the crown and root gently curve dorsally. The crown of i1 has mildly convex lateral, dorsal, and anterior sides, whereas the medial surface is essentially flat. Enamel covers the entire crown but is thickened as a prominent band on the anterior and lateral surfaces. The band is weakly fluted anteroposteriorly, is sharply delineated both laterally andmedially, and is mostly absent fromthe remainder of the crown, likely a combination of it being generally thinner in areas other than the thickened band, and from the results of diagenetic processes. The enamel band extends dorsally to the level of approximately half the depth of the crown near the tip on the lateral surface, but becomes progressively lower posteriorly, where it continues before ending abruptly just past mid-length of the crown. The enamel on themedial surface also extends dorsally but terminates lower on the crown; as on the lateral surface, the enamel band terminates at an increasingly more ventral position posteriorly before ending at approximately mid-length of the crown. A heavy ridge runs along the posteroventral part of the crown on the medial surface, forming a flattened and slightly raised strip; the ridge and its associated strip weaken posteriorly. The unworn tip is bifid, with medial and lateral cusps; a shallow sulcus extends a short distance ventrally along the anterior surface from the notch between the cusps. The medial cusp is directed dorsally and slightly laterally, and although its tip is damaged in UALVP 57537, the lateral cusp was evidently only slightly smaller than the medial cusp and was similarly directed. A crest originating at the lateral side of the lateral cusp extends posteroventrally, sharply delimiting the lateral border of the thickened enamel band and separating it from the more weakly enamelled posterior surface; the crest weakens posterodorsally. A short, flattened area near the tip of the crown on the medial surface represents the point of contact with the contralateral i1. The tip of the crown in TMP 2009.133.0129 is slightly worn, with the wear facet oriented obliquely dorsolaterally- ventromedially, and this orientation is maintained even in more heavily worn specimens (e.g., UALVP 57540). The root is widely open posteriorly in TMP 2009.133.0129, but the aperture is sig- nificantly narrower in UALVP 57540. p4.—The crown of p4 is anteroposteriorly short relative to
its height, triangular in lateral view, and wedge-shaped in occlusal outline, with the posterior part of the crown sig- nificantly wider than the anterior part. The anterior edge of the crown is nearly vertical and faintly convex in profile, whereas the posterior margin is shallower and weakly concave. The anterior side of the crown lacks a depression or concavity that might suggest the presence of p3 in life; the enamel extends ventrally along the anterior side of the anterior root and might have formed a lobe-like structure (the root is broken ventrally on each of the specimens at hand, so that the full extent of the enamel is unknown). The labial side of the crown is virtually
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flat, with the exception of a slight bulge posteriorly; a small cuspule is often developed on a conspicuous posterolabial shelf in this position in Valenopsalis and other species of Catopsalis (e.g., C. alexanderi, C. fissidens; see Sloan and Van Valen, 1965; Middleton, 1982; Lucas et al., 1997), but neither shelf nor cusp is present on any of the referred p4s. The lingual side of the crown is weakly convex, and the enamel extends less ventrally than on the labial side. Three swollen, cusp-like dorsal serrations occur along the cutting edge of the crown, each separated from one another by sharp notches. The anteriormost serration is broken in UALVP 57541 and heavily worn in both TMP specimens, but the dimensions of the parts that remain suggest that it was slightly smaller than the remaining two serrations. A weak carina extends ventrally from the first serration a short distance along the anterior margin of the crown. The first and second serrations are closely appressed, whereas the third serration is set off farther posteriorly and separated from the second by a deep, ventrally directed sulcus on the labial side of the crown. Although the dorsal serrations are worn on each specimen at hand, the strong convexity of the lingual sides of the serrations and the labially facing wear facets suggest that their apices probably faced slightly labially. Wear occurs pri- marily on the labial side of the dorsal serrations: on TMP 2015. 071.0141, the facets are angled at ~60° from horizontal, whereas on UALVP 57541 they are nearly vertical, and the labial face of the crown shows significant wear; a flat, dorsolingually facing wear facet occurs on the third serration in UALVP 57541. The posterior slope of the crown is steeper than the anterior slope, and the posterior wall is virtually flat. A thick crest extends ventrolabially from the third dorsal serration to the level of the posterolabial bulge where it then curls lingually, enclosing a shallow pit posteriorly and labially. A conspicuous interdental facet is developed along the posterolabial crest; the facet faces posteriorly and dorsally, indicating that the anterior parts of m1 overlapped the posterior parts of p4. The p4 is two-rooted, with the posterior root slightly the thicker in horizontal section, and the anterior root projecting slightly anteriorly. The two roots are partially coalesced dorsally inTMP 2015.071.0141. Neither accessory roots nor an interradicular crest are developed. m1.—The m1 of Catopsalis kakwa n. sp. is known from
four complete specimens. The crown is subrectangular in occlusal view, with a slight constriction occurring approximately mid-length imparting a faintly bilobed appearance to the outline. The anterior and posterior margins are smoothly rounded, and the crown is weakly arched dorsally in lateral view. A flat interdental facet occurs on the anterior side of m1 and faces anteriorly and ventrally. The crown supports two rows of large and somewhat inflated cusps that are parallel throughout their anteroposterior extent, but whose individual cusps are staggered, rather than transversely opposed to those in the opposite row. The cusp formula is 5:4. Each of the m1s at hand is worn to certain degree, and accordingly little can be said of the structure of the cusp apices; it is likely, although not with certainty, that
the two rows of cusps were originally subequal in height. The first cusp of the labial row is relatively short and subconical, whereas the remaining cusps are nearly equal in both size and height. The labial cusps become increasingly subquadrate in horizontal section farther posteriorly on the crown and appear
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