Monola Formation

The Monola Formation is a geologic formation in California. It preserves fossils dating back to the Cambrian period.

Monola Formation
Stratigraphic range: Middle Cambrian PreꞒ Ꞓ O S D C P T J K Pg N [1]
Type	Formation
Overlies	Mule Spring Limestone
Lithology
Primary	Shale
Other	Clay, Mudstone, Limestone, Siltstone
Location
Region	California
Country	United States

Geology

The Monola Formation is primarily composed of siliceous shales, and greyish-black clay shale, and calcareous siltstone. In parts of the siliceous shale, there are occasional layers of lime mudstone and bioclastic limestone.^[2]

Paleobiota

The Monola Limestone contains a small collection of trilobites, like Glosopleura and Alokistocare.^[3]

Color key Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon		Notes Uncertain or tentative taxa are in small text; crossed out taxa are discredited.

Arthropoda

Genus	Species	Notes	Images
Alokistocare[3]	Alokistocare sp.	Ptychoparid trilobite.
Syspacephalus[3]	Syspacephalus sp.	Ptychoparid trilobite.
Paraantagmus[2]	P. latus	Ptychoparid trilobite.
Amecephalus[2]	A. arrojosensis	Ptychoparid trilobite.
Mexicella[2]	M. robusta	Ptychoparid trilobite.
Onchocephalites[2]	O. laevis O. resseri	Ptychoparid trilobite.
Syspacephalus[2]	S. variosus S. granulosus (?)	Ptychoparid trilobite.
Tonopahella[2]	T. goldfieldensis T. walcotii (?)	Ptychoparid trilobite.
Nyella (?)[2]	N. (?) plana	Ptychoparid trilobite.
Glossopleura[3]	Glossopleura sp.	Corynexochid trilobite.
Oryctocephalus[3][2]	Oryctocephalus sp. O. orientalis O. indicus O. nyensis	Corynexochid trilobite.
Microryctocara[2]	M. nevadensis	Corynexochid trilobite.
Bathyuriscus[2]	Bathyuriscus sp.	Corynexochid trilobite, previously reported as Wenkchemnia sulcata and W. spinicollis.
Ogygopsis[3]	Ogygopsis sp.	Dorypygid trilobite.

See also

• Earth sciences portal
• California portal
• Paleontology portal

• List of fossiliferous stratigraphic units in California
• Paleontology in California