Mark's Locality
Basic information
Sample name: Mark's Locality
Sample aka: CM locality 3613; Twelvemile Gulch; WMU locality 110
Reference: R. L. Anemone and W. Dirks. 2009. An anachronistic Clarkforkian mammal fauna from the Paleocene Fort Union Formation (Great Divide Basin, Wyoming, USA). Geologica Acta 7(1-2):113-124 [ER 4114]
Geography
Country: United States
State: Wyoming
County: Sweetwater
Coordinate: 42° 50' 44" N, 109° 36' 9" W
Latlng basis: stated in text
Scale: outcrop
Formation: Fort Union
Time interval: Late Palaeocene
Zone: Clarkforkian
Max Ma: 56.85
Min Ma: 56.0
Age basis: paleomag
Geography comments: coordinate is of a measured section at CM locality 3613
from the uppermost Fort Union Formation, and assigned to zone Cf-2 as redefined by the authors
Cf-2 is entirely within the early part of C24r and is show in Fig. 21 to span approximately 56.85 to 56 Ma based on stratigraphic data for Polecat Bench
from the uppermost Fort Union Formation, and assigned to zone Cf-2 as redefined by the authors
Cf-2 is entirely within the early part of C24r and is show in Fig. 21 to span approximately 56.85 to 56 Ma based on stratigraphic data for Polecat Bench
Environment
Lithology: siltstone
Taphonomic context: overbank deposit
Habitat comments: there are two fossiliferous layers in the locality, the lower "a weakly laminated greenish siltstone" with "plant material" and the upper "A series of interbedded siltstones and sandy siltstones" with "thin sandstone lenses"
apart from some cross-bedded fluvial sandstones in the section, it is implied to be mostly "paludal"
said to be mudstones instead by Anemone and Dirks (2009)
"mostly isolated teeth, a number of disarticulated postcrania, and a few jaws"
apart from some cross-bedded fluvial sandstones in the section, it is implied to be mostly "paludal"
said to be mudstones instead by Anemone and Dirks (2009)
"mostly isolated teeth, a number of disarticulated postcrania, and a few jaws"
Methods
Life forms: carnivores, primates, rodents, ungulates, other small mammals
Sampling methods: screenwash, surface
Sample size: 126 specimens
Years: 1994
Museum: Carnegie Museum of Natural History
Net or trap nights: 0
Basal area status: not applicable
Sampling comments: originally described by Anemone and Dirks (2009, ER 4114), who present a considerably different faunal list
the material was at Western Michigan University according to Anemone and Dirks (2009) but in the Carnegie Museum according to Anemone et al. (2024)
"first located and identified in 1994... The locality has been surface collected during five different field seasons and screen washed. Wet screen washing (with .3 cm screen) of the upper fossil-bearing unit in the field resulted in the retrieval of approximately 20 kg of fossil-bearing matrix" but the weight of the original sediment is not indicated (Anemone and Dirks 2009)
a single Phenacodus tooth was found at CM 3612, plus non-mammalian vertebrates; this specimen is included in Table 1 but discounted in the entered list
non-mammalian vertebrates are presumably present but not discussed
the material was at Western Michigan University according to Anemone and Dirks (2009) but in the Carnegie Museum according to Anemone et al. (2024)
"first located and identified in 1994... The locality has been surface collected during five different field seasons and screen washed. Wet screen washing (with .3 cm screen) of the upper fossil-bearing unit in the field resulted in the retrieval of approximately 20 kg of fossil-bearing matrix" but the weight of the original sediment is not indicated (Anemone and Dirks 2009)
a single Phenacodus tooth was found at CM 3612, plus non-mammalian vertebrates; this specimen is included in Table 1 but discounted in the entered list
non-mammalian vertebrates are presumably present but not discussed
Metadata
Sample no: 4545
Contributor no: John Alroy
Enterer: John Alroy
Modifier no: John Alroy
Created: 2024-12-03 08:42:23
Modified: 2025-12-14 12:28:33
Abundance distribution
Each square represents a species. Square sizes are proportional to counts. Values are logged.
Statistics
22 species
10 singletons
total count 126
geometric series index: 54.6
Fisher's α: 7.711
geometric series k: 0.8399
Hurlbert's PIE: 0.8373
Shannon's H: 2.2798
Good's u: 0.9211
Register
| †Ectypodus tardus | 1 | |
| Prochetodon sp. | 2 | |
| †Peradectes protinnominatus | 2 | |
| Adunator sp. | 3 | |
| †Plagioctenodon goliath | 2 | |
| †Plagioctenodon cf. dawsonae | 1 | |
| Palaeosinopa sp. | 1 | |
| †Labidolemur kayi | 1 | |
| †Carpolestes nigridens (plesiadapiform) | 7 | |
| †Plesiadapis cookei (plesiadapiform) | 20 | |
| †Plesiadapis dubius (plesiadapiform) | 21 | |
| †Phenacolemur cavatus (plesiadapiform) | 6 | |
| type | ||
| †Arctodontomys simplicidens (plesiadapiform) | 1 | |
| Arctodontomys sp. | 1 | |
| †Acritoparamys atwateri | 2 | |
| Dissacus sp. | 1 | |
| †Uintacyon rudis | 1 | |
| †Didymictis proteus (viverravid) | 1 | |
| Thryptacodon sp. | 4 | |
| †Phenacodus intermedius | 1 | |
| †Ectocion osbornianus | 8 | |
| †Apheliscus nitidus | 39 | |