A Pliocene fauna from Western Nebraska / by W.D. Matthew and Harold J. Cook.

  • Matthew, William Diller, 1871-1930.
Date:
1909
Catalogue details

Licence: In copyright

Credit: A Pliocene fauna from Western Nebraska / by W.D. Matthew and Harold J. Cook. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    1009.] as in JE. haydeni. Three separate upper camassials agree in size with M. scuvus or the mutation above described, but are not regarded as determinable specifically. Comparative Measurements (type specimens). 90 3 '3 1 ! 3 SO ■§ «0 g to c SJ £ 1 s: a % eo SQ 8g Lower dentition, p3-m3 69.7 97. 77.5 97. 67. P4, anteroposterior diameter . . . 20.1 14.3 22 15.8 “ transverse “ ... 10. 8. 10. M, anteroposterior “ ... 27.5 36. 28. 36. 27. “ transverse “ ... 10.2 16. 11. 15.2 11. M,, anteroposterior “ ... 18. 12. 15. 10.4 “ transverse 9. 10. 7.8 Depth of jaw beneath p .... 25. 27. “ “ “ “ m, 29.5 44.3 35. 48. 29. Thickness of jaw beneath m, . 14.8 20. 1 17. 12.8 1 Tephrocyon hippophagus sp. now This species is represented by eight lower jaws and part of an upper jaw, and probably bv various skeletal parts. The type, No. 13836, is figured. The species is about as large as a coyote, but the jaw is much more robust and deeper anteriorly, and the teeth more massive. It approaches .Elurodon in these respects, and agrees with Cam's comprCssus (Cope) and other Mio- cene species. More complete material will very probably show that these later Tertiary dogs are all generieally distinct from Canis, and that many of them are referable to Tephrocyon. In comparison with .Elurodon, the premolars are less reduced, more compressed and trenchant, the accessory cusps more prominent and com- pressed. P4 does not have the peculiar backward pitch characteristic of .Elurodon, and probably correlated with the development of the parastyle on p1. The species is considerably smaller than .E. seems; it is larger than Canis (“ .Elurodon ”) compressus (Cope), the jaw longer and much deeper, the second and third molars smaller. The jaw is shorter and deeper than in any modem species of Canis, the dingo, C. lupus and the jackals coming nearest in this respect; the accessory cusps of the premolars are larger and the paraconid of m2 is well developed. We are unable to make comparisons with the Pleistocene South American species which would probably show nearer affinities.