Trilobites, biostratigraphy, and lithostratigraphy of the Crepicephalus and Aphelaspis zones, lower Deadwood Formation (Marjuman and Steptoean stages, Upper Cambrian), Black Hills, South Dakota

2000 ◽  
Vol 74 (2) ◽  
pp. 199-223 ◽  
Author(s):  
James H. Stitt ◽  
Patrick J. Perfetta

Trilobites assigned to 25 genera and 39 species are reported from the Crepicephalus Zone (Marjuman Stage) and Aphelaspis Zone (Steptoean Stage) in the lower part of the Deadwood Formation in the Black Hills of South Dakota. Six taxa are left in open nomenclature, and one new species, Glaphyraspis newtoni, is described.Analysis of the lithologies for this interval from the best exposed measured sections on a southeast-northwest transect reveal a nearshore, shallow subtidal, siliciclastic dominated environment to the southeast, succeeded offshore by a shallow subtidal to lowest intertidal carbonate shoal environment, and then a transitional shaly limestone interval into a more shaly distal intrashelf basin to the northwest.Specimens of species of Coosia, Crepicephalus, Tricrepicephalus, Kingstonia, Pseudagnostina, and Coosina comprise more than 75 percent of the fauna of the Crepicephalus Zone. Coosina ariston, Crepicephalus snowyensis, Tricrepicephalus tripunctatus, Arcuolimbus convexus, and some species of Blountia had a strong preference for the shallow-water siliciclastic facies present in the southeastern sections closest to the paleoshoreline. Crepicephalus rectus, Tricrepicephalus coria, Agnostogonus, cf. A. incognitus and the genera Coosella and Uncaspis preferred the farther offshore, deeper-water, shaly intershelf basin located in the northern Black Hills. Trilobites from the Crepicephalus Zone are used to correlate the lower part of the Deadwood Formation with coeval strata elsewhere in North America.

1998 ◽  
Vol 72 (6) ◽  
pp. 1030-1046 ◽  
Author(s):  
James H. Stitt

Trilobites assigned to 14 genera and 14 species are reported from basal part of the Deadwood Formation in the Black Hills of South Dakota. Six additional taxa are left in open nomenclature. One new species, Cedarina dakotaensis, is described. These trilobites are assigned to a new zone, the Cedarina dakotaensis Zone, named after the most abundant trilobite species.Species of Cedarina and Modocia are the most abundant in the Cedarina dakotaensis Zone, accompanied by less common specimens of species of Arapahoia, Menomonia, Hardyoides, Welleraspis, Kormagnostus, and Kingstonia. Cedarina dakotaensis and Modocia centralis are the most abundant species in the nearshore sandstone lithofacies, whereas Arapahoia spatulata is the predominate taxon in the offshore limestone lithofacies.The fauna of the Cedarina dakotaensis Zone (which lacks species of Cedaria) occupies the biostratigraphic interval of the traditional Cedaria Zone of the Marjuman Stage. Trilobites from the Cedarina dakotaensis Zone can be used to correlate the basal part of the Deadwood with coeval strata elsewhere in North America.


1997 ◽  
Vol 71 (1) ◽  
pp. 86-102 ◽  
Author(s):  
James H. Stitt ◽  
Wendy Metcalf Straatmann

Trilobites assigned to 29 genera and 39 species are reported from the Deadwood Formation in the Black Hills of South Dakota. Two new species, Prosaukia lochmani and Arcifimbria pahasapaensis, are described. Brachiopods are reported from the Taenicephalus Zone.A biostratigraphic zonation is established for the upper part of the Deadwood Formation. The Taenicephalus Zone in the lower part of the study interval is succeeded upsection by the Ellipsocephaloides Zone, both of which are assigned to the Franconian Stage. These two zones are overlain in turn by the Illaenurus and Saukia Zones of the Trempealeauan Stage. These zones are used to correlate this part of the Deadwood with coeval strata in Montana and Wyoming, central Texas, Oklahoma, and Alberta, Canada. The lowstand of sea level that occurred in the Great Basin at the time of the deposition of the Saukiella junia Subzone of the Saukia Zone probably extended eastward into the Black Hills, resulting in the absence of this fauna in the Black Hills.


1995 ◽  
Vol 69 (6) ◽  
pp. 1183-1185 ◽  
Author(s):  
James H. Stitt ◽  
Wendy L. Metcalf

During preparation of a manuscript on new collections of Upper Cambrian trilobites from the Threadgill Creek section in central Texas (Longacre, 1970, text-fig. 6), a new trilobite species Ptychopleurites spinosa was discovered that can be used to recognize a revised base to the Saukia Zone (Trempealeauan Stage) in central Texas. This species is represented in central Texas by numerous, well-preserved cranidia and librigenae, but no pygidia have been recovered. Recently Ptychopleurites spinosa was also identified in a collection of trilobites of the partly correlative Illaenurus Zone (= lower part of Saukia Zone) from the type section of the Deadwood Formation in the Black Hills of South Dakota. This work is part of a paper that will describe the latest Franconian and Trempealeauan trilobites from the Deadwood Formation, using collections made by Dr. Christina Lochman-Balk. Ptychopleurites spinosa is represented in the Black Hills by incompletely preserved cranidia and well-preserved librigenae. Because it is not known which of these two papers will be published first, it was decided to establish Ptychopleurites spinosa as a new species with one of the better Texas cranidia as the holotype and the Black Hills material as part of the suite of paratypes.


Zootaxa ◽  
2020 ◽  
Vol 4834 (1) ◽  
pp. 96-106
Author(s):  
TOMOYUKI KOMAI

A new species of the pagurid hermit crab genus Turleania McLaughlin, 1997, T. rubriguttatus, is described on the basis of two specimens, including one male and one female, from shallow subtidal waters in Kochi Prefecture, Japan. The new species appears close to T. albatrossae (McLaughlin & Haig, 1996), known from the Philippines, but the proximally unarmed dorsal surface of the right chela palm and the lack of a dorsomesial row of spines on the left cheliped carpus easily distinguish T. rubriguttatus n. sp. from T. albatrossae. Examination of the type material of T. similis Komai, 1999 and T. spinimanus Komai, 1999, and supplemental material from Japan, confirms that the two taxa are synonymous with T. senticosa (McLaughlin & Haig, 1996), as was suggested by previous authors. Re-examination clarified that in T. senticosa the maxilliped 3 has no developed arthrobranchs, and this led the author to assess the status of T. sinensis Han, Sha & An, 2016, which is also synonymised with T. senticosa. 


2012 ◽  
Vol 149 (6) ◽  
pp. 964-988 ◽  
Author(s):  
ALAN W. OWEN ◽  
DAVID L. BRUTON

AbstractThe trilobite fauna of the upper Ordovician (middle Katian) Pyle Mountain Argillite comprises a mixture of abundant mesopelagic cyclopygids and other pelagic taxa and a benthic fauna dominated by trilobites lacking eyes. Such faunas were widespread in deep water environments around Gondwana and terranes derived from that continent throughout Ordovician time but this is the only known record of such a fauna from North America and thus from Laurentia. It probably reflects a major sea level rise (the ‘Linearis drowning events’) as does the development of coeval cyclopygid-dominated deep water trilobite faunas in terranes that were marginal to Laurentia and are now preserved in Ireland and Scotland. The Pyle Mountain Argillite trilobite fauna occurs with a deep water Foliomena brachiopod fauna and comprises 22 species. Pelagic trilobites (mostly cyclopygids) constitute 36% of the preserved sclerites, and 45% of the fauna is the remains of trilobites lacking eyes, including one new species, Dindymene whittingtoni sp. nov. Three species of cyclopygid are present, belonging in Cyclopyge, Symphysops and Microparia (Heterocyclopyge). Cyclopygids are widely thought to have been stratified in the water column in life and thus their taxonomic diversity reflects the relative depths of the sea-beds on which their remains accumulated. A tabulation of middle and upper Katian cyclopygid-bearing faunas from several palaeoplates and terranes arranged on the basis of increasing numbers of cyclopygid genera allows an assessment of the relative depth ranges of the associated benthic taxa. The Pyle Mountain Argillite fauna lies towards the deeper end of this depth spectrum.


1973 ◽  
Vol 51 (1) ◽  
pp. 43-49 ◽  
Author(s):  
Orson K. Miller Jr. ◽  
Gary A. Laursen ◽  
Barbara M. Murray

Eight species of agarics in the Basidiomycetes from arctic and alpine tundra in Alaska and adjacent Canada are included. Four taxa are reported from North America for the first time including one new species. One taxon is reported for the first time from arctic tundra in North America. New ecological information, host ranges, and fruiting periods are presented for all taxa. Camera lucida drawings are included for five taxa.


1995 ◽  
Vol 69 (1) ◽  
pp. 110-122 ◽  
Author(s):  
M. J. Orchard

Exceptionally well preserved Lower Triassic conodonts from Oman include an array ofNeospathodusspecies, many of which are new. Those from the upper Lower Triassic, or Spathian, are described in conjunction with a restudy of conodont type material from Chios, Greece, and an assessment of contemporary collections from Pakistan and western North America. The taxonomic scope of three key species from Chios,Neospathodus homeri, N. triangularis, andN. gondolelloides, is revised. Seven new species are described from Oman:N. abruptus, N. brevissimus, N. brochus, N. crassatus, N. curtatus, N. pusillus, andN. symmetricus;and one new species,N. clinatus, is described from Pakistan. The alliedIcriospathodus collinsoniis also described from Oman. The occurrence and range ofNeospathodusspecies are presented in the context of the ammonoid succession in the Spathian of North America. BothN. homeriandN. triangularis, as revised, have shorter ranges and are more age diagnostic than previously thought.Neospathodus gondolelloidesis a distinct taxon, and not synonymous withChiosella timorensis.Five informal faunal divisions are identified based onNeospathodusand allied species. In ascending stratigraphic order, these are typified byIcriospathodus collinsoni, Neospathodus homeri, N. triangularis, N. symmetricus, andN. gondolelloides.Oman collections represent three of these faunas, which occur also in theColumbitesthroughProhungarites/Subcolumbitesammonoid beds of western U.S.A.


2013 ◽  
Vol 87 (5) ◽  
pp. 804-817 ◽  
Author(s):  
Stephen R. Westrop ◽  
Jonathan M. Adrain

The first records of the upper Cambrian agnostoid generaKormagnostella, E. Romanenko,inRomanenko and Romanenko, 1967, andBiciragnostusF. Ergaliev,inEraliev and Ergaliev, 2001, in Laurentian North America are from a narrow stratigraphic interval in the Steptoean–Sunwaptan boundary interval (Furongian, Jiangshanian) of Nevada and Utah. In Nevada, both genera occur in a condensed bioclastic lag below a major flooding surface, andKormagnostellaalso appears in a transgressive interval in Utah. Immigration of these genera is associated with sea level rise, and also with faunal turnover.Biciragnostusis confined to the latestElviniaZone, immediately below the onset of a trilobite and agnostoid extinction event at the base of theIrvingella majorZone (basal Sunwaptan).Kormagnostellais present in the latestElviniaZone, and has its highest occurrence in theI. majorZone. Stratigraphic data from the Karatau-Naryn Terrane, Kazakhstan indicate that both genera disappear near the local extinction ofIrvingella, suggesting that faunal turnover in that region may have been broadly correlative with the more profound extinction in Laurentia. New species areKormagnostella advena,K. insolitaandBiciragnostus viator.


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