Figure 1
Hyena fossils from Old Crow, Yukon Territory, Canada. Chasmaporthetes cf. C. ossifragus, CMN 24958, right p3: A. lingual stereopair views, B. labial stereopair views, C. occlusal stereopair views. CMN 38053, left m1: D. labial stereopair views, E. lingual stereopair views, F. occlusal stereopair views.
Table 1
Measurements of Chasmaporthetes specimens from the Old Crown Basin, Yukon Territory. Abbreviations: mac, mesial accessory cusp; dac, distal accessory cusp; L, length; H, height; HSB, Hunter-Schreger Bands; b, bottom 1/3 of crown; m, middle 1/3 of crown; t, top 1/3 of crown; u, undulating HSB layers; a, acute undulating HSB layers.
| Specimen No. | CMN 24958 | CMN 38053 |
|---|---|---|
| Element | Rp3 | Lm1 |
| Length (mm) | 19.11 | 29.08 |
| Width (anterior, mm) | 9.94 | 13.12 |
| Width (posterior, mm) | 11.58 | 8.24 (partial) |
| L, mac (mm) | 4.97 | – |
| L. main cusp (mm) | 10.38 | – |
| Height, main cusp (mm) | 13.34 | – |
| L, dac (mm) | 4.92 | – |
| L. trigonid (mm) | – | 22.25 |
| L, talonid (mm) | – | 6.41 |
| H, paraconid (mm) | – | 13.4 |
| H, protoconid (mm) | – | 15.55 |
| HSB (b, m, t) | u, a, ? | u, a, a |
Figure 2
Chasmaporthetes measurements and distributions. A. p3 length versus width. B. m1 length versus width. C. relative m1 width and trigonid blade length in Chasmaporthetes. Wm1, m1 width; ltrm1, m1 trigonid length; lm1, m1 length. Symbols: triangle, Africa specimens; diamond, Asia specimens; square, Europe; blue circle, North America; black circle, Old Crow Basin specimens. D. Fossil localities containing Chasmaporthetes. New material described in this study from Old Crow Basin (Locality 11A) is marked with a star. Dashed arrows indicate likely dispersal route evidenced by new fossils. Locality information for other fossil occurrences taken from Tseng et al. (2013). Regions with more than one fossil locality are indicated with a quantity after the locality marker. Globe image by Connormah (CC BY-SA 3.0). E. Stratigraphic occurrence of Chasmaporthetes and other large carnivorans discussed in the text. Age ranges are taken from Wang et al., (1999), Tedford et al., (2009), Tseng et al., (2013) and Paleobiology Database via Fossilworks (http://fossilworks.org). Silhouettes are modified from Phylopic (Arctodus and Canis lupus: T. Heath [public domain]; Canis dirus: Zimices [CC BY-NC 3.0]; Canis armbrusteri image based on C. lupus by S. Traver [public domain]), modified from artwork by M. Antón, or generated for this study.