Gateway to the Paleobiology Database
Bonner quarry, Onyx Marble (Pliocene of the United States)

Where: Arizona (35.1° N, 112.6° W: paleocoordinates 35.3° N, 111.8° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Onyx Marble Formation, Pliocene (5.3 - 2.6 Ma)

• The onyx marble containing these specimens was mined from Bonner Quarry by members of the Southwest Onyx and Marble Company from faulted Middle Permian Supai formations on the side of a high angled fault. E. D. McKee was quoted by Petrunkevitch (1945) as stating: "The fault passes under and therefore, antedates basalt flows a few miles to the west and these are of a period I consider to be of Pliocene age. The age of the deposit is definitely 'post-faulting' which means since the middle of Cenozoic time, but deposition might have been any time from then to the present." Pierce (1951) gave an age of between 12 and 50 million years. Petrunkevitch (1955) dated other fossils found in this formation as "?Pliocene", which for lack of other information, we will follow here.

• group of beds-level stratigraphic resolution

Environment/lithology: cave; lithified travertine

• The nature of the structure of the onyx formation suggests that it was laid down by subterranean waters in fissures. Petrunkevitch (1945) suggested that the animals in the onyx were probably washed into the fissures from epigean habitats and became fossilized. Judging by the frail nature of palpigrades it is difficult to imagine specimens being washed in and remaining in the excellent condition of many of the specimens. It is more probable that these animals lived in close proximity to the area of deposition, which suggests that these palpigrades might have been cavernicoles.

Size class: mesofossils

Collected by Southwest Onyx and Marble Company; reposited in the LACM, YPM

• Repository: San Diego Natural History Museum. Petrunkevitch's specimens came from SDNHM originally but were placed in the YPM collection. Pierce's specimens came from J.W. Fisher, president of the Southwest Onyx and Marble Company, donated to LACM.

Primary reference: A. Petrunkevitch. 1945. Calcitro fisheri, a new fossil arachnid. American Journal of Science 243:320-329 [M. Clapham/M. Clapham] more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 152091: authorized by Matthew Clapham, entered by Matthew Clapham on 07.11.2013

Creative Commons license: CC BY (attribution)