Haragan Formation, Oklahoma

last revised 12 October 2014 by S.M. Gon III

Locality: Near Clarita, Coal County, south central Oklahoma, USA

Stratigraphy: Haragan Formation and related Bois D'Arc & Frisco Formations)
Age: Early Devonian (Lochkovian), ca 417 mya

The Black Cat Mountain trilobite quarry site in Coal County, Oklahoma

The Paleozoic is well-represented in Oklahoma, and the state boasts some of the most spectacular trilobites in the US. These come from Lower Devonian formations in Coal County, Oklahoma, located in the south-central region of the state. The two primary Devonian formations are the Haragan and Bois d' Arc, with soft pale limestone that yields beautiful caramel-colored trilobites resembling those from the Saint Petersburg region of Russia. Over 30 different Devonian trilobite species in about a dozen genera have been described.

The Devonian trilobites of Oklahoma are in many way similar to the trilobite assemblage found in the Atlas Mountains of Morocco, due to proximal paleogeography. While on continents separated by thousands of miles today, during Devonian times, present-day Morocco was part of the northwestern continental shelf of Gondwana, and present-day Oklahoma was part of the Southern continental shelf of Euramerica. These locations were adjacent and at very similar latitudes and likely bore nearly identical marine environments. The comparable species likely share common ancestry and occupy the same or closely related genera.


Oklahoma during the Devonian	Oklahoma today

Among the most common trilobites from the Haragan are Kainops invius, as well as Paciphacops campbelli, and Huntoniatonia spp.. Very rare, but distinctive Haragan taxa include Ceratonurus sp., Dicranurus hamatus elegantus, Lobopyge consanguinea, and Breviscutellum sp. The preservation of exoskeleton at Haragan is typically strikingly excellent, with a rich caramel brown exoskeleton contrasting against very light matrix, as in the examples below:

	photo by Stephen Marley		photo by Stephen Marley
Kettneraspis williamsi (Whittington 1956) ORDER LICHIDA Family Odontopleuridae	Ceratonurus sp (Campbell 1977) ORDER LICHIDA Family Odontopleuridae	Dicranurus hamatus elegantus (Campbell 1977) ORDER LICHIDA Family Odontopleuridae	Acanthopyge (Lobopyge) consanguinea (Clarke 1894) ORDER LICHIDA Family Lichidae
photo by Stephen Marley		photo by Stephen Marley	photo by Stephen Marley
Reedops deckeri Delo 1935 ORDER PHACOPIDA Family Phacopidae	Huntoniatonia oklahomae (Richardson 1949) ORDER PHACOPIDA Family Dalmanitidae	Cyphaspis carrolli Adrain & Kloc 1997 ORDER PROETIDA Family Aulacopleuridae	Breviscutellum sp. (Campbell 1977) ORDER CORYNEXOCHIDA Family Styginidae

As is often the case in Devonian sites, the major constituent orders are Phacopida, Corynexochida (Styginidae), Proetida, and Lichida. The Oklahoma trilobite fauna is particularly rich in Phacopida, with numerous described species of Huntoniatonia, as well as multiple species and genera of phacopoids such as Kainops spp., Paciphacops spp., Viaphacops, and Reedops. Here is a complete list of Haragan trilobite species in three formations, with taxa in comon between two of more formations shown in red.

TRILOBITA OF DEVONIAN OKLAHOMA

Haragan Formation	Bois d'Arc Formation (Fittstown & Cravatt Members)	Frisco Formation
Order Phacopida Suborder Phacopina Superfamily Dalmanitoidea Family Dalmanitidae Huntoniatonia (H.) huntonensis (Ulrich & Delo 1940) Huntoniatonia (H.) lingulifer (Ulrich & Delo 1940) Huntoniatonia (H.) oklahomae (Richardson 1949) Huntoniatonia (H.) purduei purduei (Dunbar 1919) Huntoniatonia (H.) "new form" Campbell 1977 Odontochile? taffi (Ulrich & Delo 1940) Superfamily Phacopoidea Family Phacopidae Kainops raymondi (Delo 1935) Paciphacops (P.) campbelli Reedops deckeri Delo 1935	Order Phacopida Suborder Cheirurina Family Cheiruridae Cheirurus? sp. Campbell 1977 Suborder Phacopina Superfamily Dalmanitoidea Family Dalmanitidae Huntoniatonia (H.) huntonensis (Ulrich & Delo 1940) Huntoniatonia (H.) lingulifer (Ulrich & Delo 1940) Huntoniatonia (H.) purduei fittstownensis Huntoniatonia (H.) purduei purduei (Dunbar 1919) Huntoniatonia (Prosocephalus) xylabion Campbell 1977 Phalangocephalus rutabulum Campbell 1977 Zlichovaspis syncrama (Campbell 1977) Superfamily Phacopoidea Family Phacopidae Kainops invius Campbell 1977 Kainops raymondi (Delo 1935) Paciphacops (P.) birdsongensis (Delo 1940) Viaphacops bombifrons (Hall 1961)	Order Phacopida Suborder Phacopina Superfamily Dalmanitoidea Family Dalmanitidae Odontochile ceraunus Campbell 1977 Superfamily Phacopoidea Family Phacopidae Paciphacops (P.) sp. Campbell 1977 Viaphacops bombifrons (Hall 1961) Viaphacops n.sp. Campbell 1977
Order Corynexochida Suborder Illaenina Family Styginidae Breviscutellum sp. Campbell 1977	Order Corynexochida Suborder Illaenina Family Styginidae Breviscutellum sp. Campbell 1977
Order Proetida Superfamily Aulacopleuroidea Family Brachymetopidae Cordania falcata Whittington 1960 Family Aulacopleuridae Cyphaspis carrolli Adrain & Kloc 1997 Maurotarion axitiosum (Campbell 1977) Superfamily Proetoidea Family Proetidae Dechenellid sp. Campbell 1977	Order Proetida Superfamily Aulacopleuroidea Family Brachymetopidae Cordania wessmani Adrain & Kloc 1997 Family Aulacopleuridae Maurotarion axitiosum Campbell 1977 Otarion sp.A, Campbell 1977 Superfamily Proetoidea Family Proetidae Coniproetus sp. Campbell 1977 Dechenellid? Campbell 1977	Order Proetida Superfamily Aulacopleuroidea Family Aulacopleuridae Otarion? sp.A Campbell 1977 Superfamily Proetoidea Family Proetidae Proetus? sp. Campbell 1977
Order Lichida Superfamily Lichoidea Family Lichidae Acanthopyge (Lobopyge) consanguinea ["Bug-X"] Oinochoe bigsbyi (Hall 1861) Oinochoe coccymelum (Campbell 1977) Terataspis? sp. Superfamily Odontopleuroidea Family Odontopleuridae Ceratonurus sp. Campbell 1977 Dicranurus hamatus (Hall) elegantus Campbell 1977 Kettneraspis williamsi (Whittington 1956) Laethoprusia grafhami Adrain et al 2008	Order Lichida Superfamily Lichoidea Family Lichidae Superfamily Odontopleuroidea Family Odontopleuridae Dicranurus hamatus (Hall) elegantus Campbell 1977 Kettneraspis williamsi? (Whittington 1956)	Order Lichida Superfamily Lichoidea Family Lichidae Terataspis? sp. Campbell 1977

NOTES: The determination of the lichid "Bug-X" as Acanthopyge (Lobopyge) consanguinea was made recently by Dr. Bruce Lieberman, Associate Professor of Geology, University of Kansas. Acanthopyge (L.) consanguinea (Clarke 1894) was originally described from a partial specimen (pygidium and genal spines) from New York, and redescribed in Whittington 1956. The description for Laethoprusia grafhami can be found in:Adrain, J.M., B.D.E. Chatterton, and G.J. Kloc, 2008. Systematics of the Koneprusiine trilobites, with new taxa from the Silurian and Devonian of Laurentia. Journal of Paleontology 82(4):657–675. The species was described from a single, remarkable complete specimen.

Some Haragan references:

Campbell, K.S.W. (1977) Trilobites of the Haragan, Bois d’Arc and Frisco Formations (Early Devonian), Arbuckle Mountains region, Oklahoma. Bull. Okla. Geol. Surv. 123:i-iv, 1-227

Ramsköld, L. and Werdelin, L. (1991) The Phylogeny and Evolution of some Phacopid Trilobites. Cladistics 7:29-74 .

Black Cat Mountain Trilobites website (under construction) by Robert "Bob" Carroll and George Winters.

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