Interdisciplinary studies of the Hajny Mammoth site, Dewey County, Oklahoma. Don G. Wyckoff, Brian C. Carter, Peggy Flynn, Larry D. Martin, Branley A. Branson, and James L. Theler, 1992, Oklahoma Archeological Survey, University of Oklahoma, Norman, Studies of Oklahoma's Past No. 17, x + 134 pp., $17.00 (paperbound)
✍ Scribed by D. Gentry Steele
- Publisher
- John Wiley and Sons
- Year
- 1994
- Tongue
- English
- Weight
- 158 KB
- Volume
- 9
- Category
- Article
- ISSN
- 0883-6353
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✦ Synopsis
The Hajny Mammoth site, excavated during the fall and spring of 1985/86, represents the most extensively studied Oklahoma Pleistocene paleontological site since the research conducted at the Domebo locality in the 1960s.
The site first came to light when sand and gravel quarrying operations in 1983 exposed mammoth bones eroding from a high terrace 115 feet above and 1 mile east of the Canadian River, in eastern Dewey County. Following the initial discovery, standard archaeological techniques were followed during the excavation because of the potential association of the mammoth remains with Paleoindians. During the subsequent analysis this proved not to be the case.
Dating of the fossil locality proved to be a difficult task. Carter estimated the Hajny site material to be located in a terrace of Illinoian age, approximately 240,000 years old, This estimate was based upon the assumption that the extensive ash layer found above the Hajny site at 94.5 m is roughly contemporaneous with the 610,000-year-old widespread ash deposits found in the southern plains. The gastropod assemblages from the Hajny site also suggest the site to be of Illinoian age. The vertebrate assemblage from the site is less diagnostic of age, but the one vertebrate positively identified to species, the water rat Neofiber leonardi, has been previously recorded only in Yarmouthian deposits in Kansas.
Radiometric dating of the site has proven equivocal. An uncorrected C14 date of 8960 2 240 B.P. was obtained from mammoth bone; Carbon 14 dates of 21,587 2 2364 B.P. to 34,169 k 2378 B.P. were obtained from aquatic snail shells at the site; and U-2341Th-230 dates of 143,026 f 5500 B.P. and 166,045 k 6500 B.P. were obtained from mammoth molar enamel. Wyckoff, in summarizing the evidence of the antiquity of the site, concluded that the Hajny locality and the fossil remains were of late Illinoian age and that the U-234/Th-230 dates most accurately reflect the age of the site.
During the late Illinoian, the Canadian River at the Hajny locality was down cutting, and the channel, at least 120 m wide, was one-third wider than the Canadian River channel is today. During a stable period within this time, five short-lived spring vents developed in the area of the site. These springs were estimated to be of variable flow and duration, but some developed sizable pools, providing suitable habitat for numerous aquatic snails and serving as a resource for vertebrates in the area.
The vertebrate faunal assemblage recovered from the spring deposits consists of nearly 500 bones and bone fragments. Nearly 70 of these can be attributed to mammoth, and 52 to other taxa. The most completely represented animals at the site were two mammoths. The first specimen exposed during the excavation was identified as the west mammoth and the second as the east mammoth. Based upon the degree of eruption and wear of the molars, Flynn inferred that both individuals were mature animals, the west mammoth minimally 28 African Elephant Years (AEY), and the east mammoth 41-55 AEY. The molars of the two specimens exhibited features suggestive of both Mammuthus imperator and M . columbi. Flynn suggested this condition may reflect that the Hajny mammoths represent an evolutionary intermediate between the two species,