A Tick From a Prehistoric Arizona Coprolite (Galley Proofs)

ABSTRACT : Ticks have never been reported in archaeological analyses.Here, we present the discovery of a tick from a coprolite excavatedfrom Antelope Cave in extreme northwest Arizona. Dietary analysisindicates that the coprolite has a human origin. This archaeologicaloccupation is associated with the Ancestral Pueblo culture (Anasazi).This discovery supports previous hypotheses that ticks were a potentialsource of disease and that ectoparasites were eaten by ancient people.Nearly 1,000 coprolites from the desert west of the United Stateshave been analyzed for parasite remains (Reinhard, 1990, 1992). Al-though arthropod parasites are rare, they are occasionally found in cop-rolites. The discovery of lice in human coprolites led Fry (1977) toconclude that arthropods were consumed to control infestation. In 2005,we commenced the dietary and parasitological analysis of coprolitesfrom Antelope Cave in the northwestern corner of Arizona. At this site,we discovered a tick from a coprolite. This discovery has health, be-havioral, and ecological implications for the Puebloan people that onceoccupied the cave.Antelope Cave is a large limestone cavern sunk into the gently rollingterrain of the Uinkaret Plateau some 40 km southeast of St. George,Utah. Prehistoric Native Americans occupied it, probably intermittently,for at least 3,000 yr (2028 B.C. to A.D. 1100). The most intense hab-itation of the cave is attributed to Ancestral Puebloan peoples (Anasazi)who lived there 1,300 to 1,000 yr ago. Antelope Cave lies within theVirgin River Branch of prehistoric western Anasazi territory, and thegreat majority of artifacts (for example, woven fiber sandals, plaitedbasketry, Virgin series pottery) in the cave reflects Puebloan (Kayenta)affiliation. There is scant evidence of Fremont cultural influence fromthe north in Utah. Cultural debris left in the cave by its prehistoricinhabitants forms a 1.52-m-thick layer and contains mostly perishableartifacts, including wooden arrow shafts, basketry, string, netting, san-dals, needles and thread, etc., as well as painted pottery and variouslithic tools. The Pueblo people used the cave for shelter, and in thesurrounding area, they grew corn and beans, gathered wild plant foods,and hunted game, mostly rabbits.Professional archaeologists have conducted excavations in the cave,off and on, since 1954 (Janetski and Hall, 1983; Janetski and Wilde,1989). The most extensive excavations were undertaken by the Uni-versity of California–Los Angeles (UCLA) in 1959–1960 (Johnson andPendergast, 1960). The coprolite specimen discussed here was recov-ered by UCLA and came from 1,000-yr-old Pueblo deposits at the rearof the cave. The date is based on cross-dated Anasazi artifacts pendingC14 assay.In 1959, archaeologists from UCLA excavated five 2 2 m pits intothe midden deposit of Antelope Cave. The excavation units were des-ignated AC59-1 through AC59-5. The coprolite of concern here wasrecovered from the 60–76-cm level below the surface in pit AC59-2.Along with the coprolite, this level yielded a wide variety of culturaldebris, including fragments of Pueblo pointed-toe sandals, sandal ties,a net bag, fiber cordage, feather cordage, and pottery. No features, suchas fire hearths, storage pits, latrines, etc., were exposed in this or anyother level.Eight Antelope Cave coprolites have been analyzed to date. Five areconsistent with humans and 3 are consistent with canids, probably dogs.Laboratory sample 2 is the focus of this report. Its field context is AC1516, pit AC 59-2, 60–76 cm below surface. After contextual infor-mation was recorded, the coprolite was cleaned of extraneous dirt, pho-tographed, and weighed. Its weight, 2.67 g was then recorded. Obser-vations relative to biological origin were made. The coprolite was thenrehydrated in 0.5% trisodium phosphate for 48 hr. It was placed in a300-ml beaker, and rehydration solution was added until the coprolitewas completely immersed. Parafilm was used to cover the beaker toprevent potential modern airborne pollen contamination. Observationswere made after 24 hr of rehydration. Rehydration fluid color is some-times useful in verifying human origin (Reinhard and Bryant, 1992).Human coprolites tend to turn the rehydration solution dark brown orblack, although this is not always the case. In addition, the rehydratingcoprolite was examined for a mucilage coat, which sometimes formson dog coprolites after rehydration (Reinhard et al., 1988).After 48 hr of rehydration, 3