Vulpes sp.

TEDFORD R. H., WANG X. & TAYLOR B. E., 2009, Phylogenetic Systematics Of The North American Fossil Caninae (Carnivora: Canidae), Bulletin of the American Museum of Natural History 2009 (325), pp. 1-218 : 56-58

Vulpes sp. cf. V. velox (Say), 1823 Figure 7, 23E–H; appendix 3

Vulpes fulvus?: Brown, 1908: 182 .

Vulpes , near V. velox: Dalquest, 1978: 287 .

Material: Beck Ranch Local Fauna, Ogallala Group (early Blancan fide Dalquest, 1978), MSU 9477, right M1; MSU 9473, broken M1; and MSU 8662, M1.

Irvington site 2, UCMP locality V3604, late Irvingtonian, Alameda County, California: UCMP 81733*, fragment of right ramus, c–m1, m2 broken, m3 alveolus; UCMP 81734*, fragment of left ramus m1–m2; UCMP 81735*, talonid left m1; UCMP 81736*, right m1.

Fairmead Landfill site, UCMP locality V93128 , late Irvingtonian, Upper Unit C of Turlock Lake Formation, Madera County, California ( Dundas et al., 1996): UCMP 170181*, 18 questionably associated teeth, including M1, P4, and other upper premolars and canines*; UCMP 170180*, associated right ramus and right maxillary in matrix block.

Angus Quarry, UNSM locality No-101, late Irvingtonian, unnamed deposits resting on Ogallala Formation, Nuckolls County, southeastern Nebraska: UNSM 33612, right ramus with c–p1 alveoli, p2, p3 alveolus, p4– m2, m3 alveolus.

Albert Ahrens site, UNDM locality No- 104, late Irvingtonian, from pond deposit within Loveland Loess, incised into Lava Creek B Tephra (0.61 Ma), Nuckolls County, southeastern Nebraska: UNSM 2000-91, unworn right m1, unworn left P4, left M1, and right M2 representing different individuals.

‘‘Sheridan beds’’ (late Irvingtonian), Hay Springs area, Sheridan County, Nebraska: F:AM 25516, right P4; F:AM 25516Z, left partial ramus with c–p1 alveoli, p4–m1 (fig. 23G–H); and UNSM 26163, right partial ramus with p3–m2, m3 alveolus (fig. 23E–F) from Gordon Quarry 1.

Conrad Fissure (late Irvingtonian), Newton County, Arkansas: AMNH 11764, right p4 and left M1 ( Brown, 1908: 182).

Distribution: Early Blancan of Texas; late Irvingtonian of California, Nebraska, and Arkansas.

Remarks: The Beck Ranch M1 ( MSU 9477) is water-worn, but its major features can be discerned including the larger size of the paracone relative to the metacone, the narrow labial cingulum, and the development of the posterior lingual cingulum, all of which agree with Vulpes . The Beck Ranch M1 (anteroposterior diameter, 7.3 mm, transverse diameter, 9.2 mm) is within the range of the V. velox sample we have used for comparison (appendix 3).

The two late Irvingtonian rami from Nebraska differ between themselves to a somewhat greater degree than the small sample of Vulpes velox used for comparison. UNSM 26163 is a small fox with the length of m1 within the size range of Vulpes velox . In both specimens the hypoconid and entoconid are joined by cristids, as in most living foxes. There is an entoconulid between the metaconid and entoconid in both rami. The second lower molar is small relative to the size of m1 and also comparable to that of Vulpes velox , but the metaconid is markedly larger than the protoconid, and the talonid is equal to the trigonid in length. The p3 and p4 are smaller and less robust than in the other Hay Springs jaw (F:AM 25516Z) or in Vulpes velox . A P4 (F: AM 23516) agrees in both size and weakness of the protocone with Vulpes velox and is unlike the larger P4 of Vulpes vulpes or V. lagopus , which have proportionally larger and more anteriorly situated protocones. In size and morphology F:AM 25516Z and 25516 are very similar to Vulpes velox . The Conard Fissure teeth are both appropriate in size and morphology for V. velox . Brown (1908: 182) referred to them as ‘‘ Vulpes fulvus ?’’ but noted their smaller size. The measurements show that these teeth are robust but lie, for the most part, within the range of V. velox .

The material from the late Irvingtonian of California closely resembles that described from contemporary deposits in Nebraska. Although the southwestern part of North America is inhabited today by the smaller kit fox ( V. macrotis ), the medial Pleistocene remains seem to pertain to a larger animal that in size and morphology agree more completely with the midcontinent swift fox ( V. velox ). By the late Rancholabrean the kit fox was established in the California central valley ( Schultz, 1938) and is recorded in the Mohave Desert region to the east ( Jefferson, 1991), where it continues to exist. The most useful materials are the jaw fragments from the Irvingtonian site. The teeth are similar to those of V. velox and the Hay Springs material figured here in that the m1 talonids have entoconulids that close the talonid basin lingually. The entoconid and hypoconid are united by cristae, leaving a hypoconulid behind the transverse crest. The m2 has a large metaconid that is higher then the protoconid.

Small foxes of this size are known from Pliocene and early Pleistocene strata in Eurasia (Europe: V. alopecoides and V. praeglacialis , see Bonifay, 1971, and Rabe- der, 1976; China: V. chikushanensis , see Teilhard de Chardin, 1940; and V. baihaiensis Qiu and Tedford, 1990 ). The early to medial Pleistocene Vulpes praeglacialis ( Kormos, 1932) resembles the Irvingtonian Vulpes sp. cf. V. velox , especially in the morphology of the m1 talonid in the presence of cristae connecting the entoconid and hypoconid, presence of an entoconulid, and in the size of the m2 relative to m1 with its welldeveloped anterolabial cingulum and large metaconid. Kormos (1932), Bonifay (1971), and Benes (1972) regarded V. praeglacialis as the precursor of V. lagopus despite the paucity of evidence of specific morphological resemblance. Rabeder (1976), on the other hand, relegated V. praeglacialis to a lineage leading from V. alopecoides through V. praeglacialis to V. angustidens Thenius, 1954 , to V. vulpes , and regarded V. lagopus as a morphologically independent lineage phyletically isolated from other foxes. Vulpes praecorsac from the medial Pleistocene of eastern Europe further differs in the lower dentition in lacking a transverse crest on m1, showing reduction of the m1–m2 metaconids, and in having larger premolars, features that could ally it with the living red fox as well as the corsac foxes.

These North American specimens are brought together on the basis of size and overall similarity rather than evidence of specific morphological relationships. A considerable gap in age separates the early Blancan Beck Ranch upper molars from the array of materials of late Irvingtonian age. Assiduous searching of available collections on our part has failed to establish a continuity of record for Vulpes species between the early Pliocene and medial Pleistocene, just as Kurten and Anderson (1980: 174) had concluded. It thus seems possible that the array of Pleistocene and living Vulpes species of North America may all derive from the fox fauna of Eurasia rather than involve forms of proximal New World origin.