Massacre Rocks
Basic information
Sample name: Massacre Rocks

Sample aka: IMNH 85002

Reference: H. G. McDonald. 1998. The Massacre Rocks local fauna from the Pleistocene of southeastern Idaho. Idaho Museum of Natural History Occasional Paper 36:156-172 [ER 4183]
Geography
Country: United States

State: Idaho


County: Power


Coordinate: 42.68° N, -112.97° W
Coordinate basis: stated in text

Scale: quarry

Time interval: Late Pleistocene

Zone: Rancholabrean

Max Ma: 0.126

Min Ma: 0.072

Age basis: OSL

Geography comments: "Sec. 32 T8S, R30E" at an elevation of "approximately 1311.5 m"
thought to be Rancholabrean and roughly equivalent in age to the Late Pleistocene American Falls fauna, providing an upper age limit of 0.126 Ma
underlies the Cedar Butte Basalt, "which is potassium-argon dated to 72,000 ± 14,000 years B.P."

Environment
Lithology: conglomerate

Taphonomic context: fluvial deposit

Habitat comments: a "paleochannel" represented by "unconsolidated... bedded gravel deposits... secondary features such as subaqueous dunes were exposed in the back wall of the trench" and "water depth was about 1 m"

Methods
Life forms: carnivores,ungulates,other large mammals

Sampling methods: quarry

Sample size: 141 specimens

Years: 1985

Days: 3

Museum: Idaho Museum of Natural History

Sampling comments: "found during construction of Interstate 86" and a "test trench" was excavated "from 28 February to 2 March, 1985"
fragments of "shell" were also found

Metadata
Sample number: 4647

Contributor: John Alroy

Enterer: John Alroy

Created: 2025-01-09 05:04:10

Modified: 2025-01-09 05:04:10

Abundance distribution
11 species
4 singletons
total count 141
geometric series index: 22.7
Fisher's α: 2.790
geometric series k: 0.6539
Hurlbert's PIE: 0.6839
Shannon's H: 1.4914
Good's u: 0.9719
Each square represents a species. Square sizes are proportional to counts.
Register
Megalonyx jeffersonii2
Paramylodon harlani2
plus 2 Xenartha indet.
Canis latrans112 kg carnivore-insectivore
Smilodon fatalis1
Mammuthus sp.1
cf.
Mammut cf. americanum1
plus 9 Proboscidea indet.
Equus sp.23
Camelops hesternus70
Odocoileus sp.2
Bison latifrons25
Bison cf. antiquus13
plus 7 Bison sp.