PROBOSCIDEA ILLIGER, 1811

Maguire, Kaitlin Clare & Schmitz, Joshua X. Samuels and Mark D., 2022, The fauna and chronostratigraphy of the middle Miocene Mascall type area, John Day Basin, Oregon, USA, PaleoBios 35, pp. 1-51 : 37

PROBOSCIDEA ILLIGER, 1811

PRODOSCIDEA INDET.

Referred specimens —From:JDNM-266:fragmentary tooth material, JODA 2475, JODA 3754, JODA 3756, JODA 12898, JODA 15328, JODA 15346, JODA 15795; partial molar, JODA 7192. From JDNM-71D: fragmentary tooth material, JODA 15554. From UCMP V 4834: fragmentary tooth material, JODA 15628.

Occurrence —JDNM-266, JDNM-71D, UCMP V 4834.

Description —JODA 7192 is the anterior portion of a molar with one full loph and half of the second loph. It is smaller than the m3 of JODA 1321, which is assigned to Mammut sp. in the Rattlesnake Formation. JODA 7192 has a medial sulcus and lacks central conules. Approximate transverse width of the first loph is 44.39 mm and approximate width of second loph is 53.06 mm.

Remarks —Fragmentary material of proboscideans has been collected from the lower and middle units of the Mascall Formation. Specimens collected from JDNM- 266 were float material and may have weathered from the upper Mascall units above JDNM-266. The medial sulcus and lack of central conules in JODA 7192 suggest that it may be attributable to Zygolophodon Vacek, 1877 . Zygolophodon is one of the taxa Tedford et al. (2004) lists as characterizing early Barstovian faunas; however, it is also present in the Hemingfordian age Massacre Lake fauna in Nevada ( Lambert and Shoshani 1998). Zygolophodon has also been recovered from the early Barstovian Sucker Creek and Skull Springs faunas of Oregon, and the Virgin Valley and High Rock Canyon faunas of Nevada ( Tedford et al. 2004). Earlier work on the Mascall deposits has reported the presence of Gomphotherium Burmeister, 1837 in the formation (e.g., Fremd et al. 1994, Prothero et al. 2006), but this study cannot find evidence for this genus in the type Mascall area.