Dead Horse
Basic information
Sample name: Dead Horse

Reference: E. P. Gustafson. 1986. Preliminary biostratigraphy of the White River Group (Oligocene, Chadron and Brule formations) in the vicinity of Chadron, Nebraska. Transactions of the Nebraska Academy of Sciences 14:7-19 [ER 4137]
Geography
Country: United States

State: Nebraska


County: Dawes


Coordinate: 42.83° N, -103.07° W
Coordinate basis: estimated from map

Scale: local area

Formation: Chadron

Time interval: Early Oligocene

Zone: Brule

Section: Chadron

Unit number: 2

Unit order: below to above

Max Ma: 33.726

Min Ma: 33.214

Age basis: paleomag

Geography comments: coordinate based on a point west of the town of Chadron (see Fig. 1)
apparently, from seven localities in the area's sections 2, 3, and 4 (see Fig. 1)
from a stratigraphic interval in the Orella Member near the base of chron C13n (age assignment based on the boundaries of C13n according to Ogg 2020)
the text misidentifies the normal zone in Fig. 3 as chron C11n instead of C13n
"Most of the fossils occur within the 30 ft (9.2 m) of sediment immediately above the PWL, and most lie below a thin Blue Ash which Skinner has used as a marker"

Environment
Lithology: siltstone

Habitat comments: "a series of very highly fossiliferous pink and green siltstones with pink predominating, characterized by the exceptionally high abundance of large tortoises and oreodonts and known in field notes as the Turtle Level. Skulls of mammals at this level commonly are associated with partial postcranial skeleton"

Methods
Life forms: carnivores,rodents,ungulates,other small mammals

Sample size: 305 specimens

Museum: Chadron State College

Sampling comments: "This paper is the result of three years of field work" (years not stated)
previous collections not enumerated here were made by the University of Nebraska State Museum and the AMNH
"The fossil fauna is dominated by tortoises and oreodonts"

Metadata
Sample number: 4591

Contributor: John Alroy

Enterer: John Alroy

Created: 2024-12-09 11:30:37

Modified: 2024-12-09 11:30:37

Abundance distribution
21 species
4 singletons
total count 305
geometric series index: 33.0
Fisher's α: 5.116
geometric series k: 0.8037
Hurlbert's PIE: 0.8509
Shannon's H: 2.2351
Good's u: 0.9869
Each square represents a species. Square sizes are proportional to counts.
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