Spence Shale

Last updated
Spence Shale
Stratigraphic range: Cambrian, Miaolingian, Wuliuan
~507.5-506  Ma
O
S
D
C
P
T
J
K
Pg
N
Hyolithe Spence Shale 01.png
Hyolitha, Spence Shale
Type Member
Thickness9–120 m (30–394 ft)
Lithology
Primary carbonate mudstones
Other carbonate-rich siliciclastic mudstones and Wackestones
Location
Region Idaho, Utah
Country United States
Type section
Named for Spence Gulch
Named by Charles Doolittle Walcott

The Spence Shale is the middle member of the Langston Formation in southeastern Idaho and northeastern Utah. It is exposed in the Bear River Range, the Wasatch Range and the Wellsville Mountains. It is known for its abundant Cambrian trilobites and the preservation of Burgess Shale-type fossils. [1]

Contents

The type locality is Spence Gulch in southeastern Idaho, near the town of Liberty. It was first described by Charles Doolittle Walcott in 1908. [2]

Stratigraphy

The Spence Shale spans the Albertella and Glossopleura biozones. [3]

Fauna

Generic list of the fauna of the Spence Shale: [4] [5] [6]

Arthropoda

Soft-bodied

Agnostida

Trilobita

Brachiopoda

Mollusca

Lophotrochozoa

Echinodermata

Hemichordata

Priapulida

Lobopodia

Porifera

Problematica

Algae

Cyanobacteria

Trace Fossils

See also

Related Research Articles

<i>Waptia</i> Cambrian arthropod

Waptia fieldensis is an extinct species of arthropod from the Middle Cambrian Burgess Shale Lagerstätte of Canada. It grew to a length of 6.65 cm (3 in) and resembled modern shrimp in both morphology and habit. It had a large bivalved carapace and a segmented body terminating into a pair of tail flaps. It was an active swimmer and likely a predator of soft-bodied prey. It is also one of the oldest animals with direct evidence of brood care. Waptia fieldensis is the only species classified under the genus Waptia. Other specimens of Waptia are known from the Spence Shale in Utah.

<span class="mw-page-title-main">Wheeler Shale</span> Geologic formation in Utah notable for trilobite fossils

The Wheeler Shale is a Cambrian (c. 507 Ma) fossil locality world-famous for prolific agnostid and Elrathia kingii trilobite remains and represents a Konzentrat-Lagerstätte. Varied soft bodied organisms are locally preserved, a fauna and preservation style normally associated with the more famous Burgess Shale. As such, the Wheeler Shale also represents a Konservat-Lagerstätten.

<i>Tuzoia</i> Extinct genus of arthropod

Tuzoia is an extinct genus of large bivalved arthropod known from Early to Middle Cambrian marine environments from what is now North America, Australia, China, Europe and Siberia. The large, domed carapace reached lengths of 180 millimetres (7.1 in), making them amongst the largest known Cambrian arthropods.

Cambrorhytium is an enigmatic fossil genus known from the Latham Shale (California), and the Chengjiang (China) and Burgess Shale lagerstätte. 350 specimens of Cambrorhytium are known from the Greater Phyllopod bed, where they comprise 0.7% of the community.

Trilobites are used as index fossils to subdivide the Cambrian period. Assemblages of trilobites define trilobite zones. The Olenellus-zone has traditionally marked the top of the Lower Cambrian, and is followed by the Eokochaspis zone.

The Poleta Formation is a geological unit known for the exceptional fossil preservation in the Indian Springs Lagerstätte, located in eastern California and Nevada.

<i>Bathyuriscus</i>

Bathyuriscus is an extinct genus of Cambrian trilobite. It was a nektobenthic predatory carnivore. The genus Bathyuriscus is endemic to the shallow seas that surrounded Laurentia. Its major characteristics are a large forward-reaching glabella, pointed pleurae or pleurae with very short spines, and a medium pygidium with well-impressed furrows. Complete specimens have never reached the size of 7 cm predicted by the largest pygidium found. Bathyuriscus is often found with the free cheeks shed, indicating a moulted exoskeleton. An average specimen will in addition have a furrowed glabella, crescent-shaped eyes, be semi-circular in overall body shape, have 7 to 9 thoracic segments, and a length of about 1.5 inches.

<i>Siphusauctum</i>

Siphusauctum is an extinct genus of filter-feeding animals that lived during the Middle Cambrian about 510 million years ago. Attached to the substrate by a holdfast, it had a tulip-shaped body, called the calyx, into which it actively pumped water that entered through pores and filtered out and digested organic contents. It grew to a length of only about 20 cm (7.9 in).

<i>Thoracocare</i>

Thoracocare is a minute to very small trilobite, that lived during part of the Middle Cambrian in what are today the states of Idaho, Nevada and Utah. It is the only trilobite known with just two thorax segments outside most members of the Agnostida order. It can be distinguished from Agnostida by the very wide subquadrate glabella, parallel-side or widening forward in the largest specimen, with the full front side touching the border. Two species are known, one, T. idahoensis, only from pygidia.

The Lead Bell Shale is a geologic formation in Idaho. It preserves fossils dating back to the Cambrian period.

<span class="mw-page-title-main">Langston Formation</span>

The Langston Formation is a geologic formation in Idaho and Utah. It preserves fossils dating back to the Cambrian period. The formation is composed of bluish-gray limestone, weathering to a buff color, often with rounded edges.

The Rennie Shale is a geologic formation in Idaho. It preserves fossils dating back to the Cambrian period.

<span class="mw-page-title-main">Weeks Formation</span> Geologic formation in Utah, United States

The Weeks Formation is a geologic formation in Utah. It preserves fossils dating back to the Cambrian period and more specifically the Guzhangian stage. Its upper part has yielded a diverse fauna dominated by trilobites and brachiopods, but also comprising various soft-bodied organisms, such as Falcatamacaris. As such, it is regarded as a Konservat-Lagerstätte.

The Dunderberg Shale is a geologic formation in Nevada and Utah.

The Verulam Formation is a geologic formation and Lagerstätte in Ontario, Canada. It preserves fossils dating back to the Katian stage of the Ordovician period, or Shermanian to Chatfieldian in the regional stratigraphy.

The Rockslide Formation is a geologic formation in Northwest Territories. It preserves fossils dating back to the Drumian.

The Mount Whyte Formation is a stratigraphic unit that is present on the western edge of the Western Canada Sedimentary Basin in the southern Canadian Rockies and the adjacent southwestern Alberta plains. It was deposited during Middle Cambrian time and consists of shale interbedded with other siliciclastic rock types and limestones. It was named for Mount Whyte in Banff National Park by Charles Doolittle Walcott, the discoverer of the Burgess shale fossils, and it includes several genera of fossil trilobites.

The Whiteaves Formation is a geologic formation in British Columbia. It preserves fossils dating back to the Jurassic period.

<i>Collinsovermis</i> Extinct genus of worms

Collinsovermis is a genus of extinct panarthropod belonging to the group Lobopodia and known from the middle Cambrian Burgess Shale in British Columbia, Canada. It is monotypic having only one species, Collinsovermis monstruosus. After its initial discovery in 1983, Desmond H. Collins popularised it as a unique animal and was subsequently dubbed "Collins' monster" for its unusual super armoured body. The formal scientific description and name were given in 2020.

<i>Acinocricus</i> Extinct genus of worms

Acinocricus is a genus of extinct worm belonging to the group Lobopodia and known from the middle Cambrian Spence Shale of Utah, United States. As a monotypic genus, it has one species Acinocricus stichus. The only lobopodian discovered from the Spence Shale, it was described by Simon Conway Morris and Richard A. Robison in 1988. Owing to the original fragmentary fossils discovered since 1982, it was initially classified as an alga, but later realised to be an animal belonging to Cambrian fauna.

References

  1. Kimmig, J., Strotz, L.C., Kimmig, S.R., Egenhoff, S.O., Lieberman, B.S. 2019. The Spence Shale Lagerstätte: an important window into Cambrian biodiversity. Journal of the Geological Society of London, 176, 609–619.
  2. Walcott, C.D. 1908. Cambrian Geology and Palaeontology. Smithsonian Museum, Miscellaneous Collections, 53.
  3. Kimmig, J., Strotz, L.C., Kimmig, S.R., Egenhoff, S.O., Lieberman, B.S. 2019. The Spence Shale Lagerstätte: an important window into Cambrian biodiversity. Journal of the Geological Society of London, 176, 609–619.
  4. Kimmig, J., Strotz, L.C., Kimmig, S.R., Egenhoff, S.O., Lieberman, B.S. 2019. The Spence Shale Lagerstätte: an important window into Cambrian biodiversity. Journal of the Geological Society of London, 176, 609–619.
  5. Wen, R., Babcock, L.E., Peng, J., Robison, R.A. 2019. New edrioasteroid (Echinodermata) from the Spence Shale (Cambrian), Idaho, USA: further evidence of attachment in the early evolutionary history of edrioasteroids. Bulletin of Geosciences, 94, 115–124.
  6. Hammersburg, S.R., Hasiotis, S.T., Robison, R.R. 2018. Ichnotaxonomy of the Cambrian Spence Shale Member of the Langston Formation, Wellsville Mountains, Northern Utah, USA. Paleontological Contributions, 20, 1–66.