USNM 438c. Searcy Spring (Silurian of the United States)

Where: Arkansas (35.8° N, 91.6° W: paleocoordinates 27.5° S, 58.4° W)

• coordinate based on political unit

• local area-level geographic resolution

When: St. Clair Limestone Formation, Wenlock (433.4 - 427.4 Ma)

• formation-level stratigraphic resolution

Environment/lithology: deep subtidal ramp; shelly/skeletal, gray grainstone and gray lime mudstone

• SEP environmental call based on scanty given info. and ref (see 26022)
• "consists predominantly of grey to pink or red pelmatozoan biosparite and grey biomicrite and at certain horizons contains abundant trilobites, brachiopods, mollusks, and ostracodes"

Size class: macrofossils

Reposited in the USNM

Primary reference: D. J. Holloway. 2021. Middle Silurian trilobites from Arkansas and Oklahoma, USA. Orders Lichida and Odontopleurida. Palaeontographica Abteilung A 319(1-6):57-131 [P. Wagner/P. Wagner]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 229058: authorized by Pete Wagner, entered by Pete Wagner on 04.02.2023

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names
Trilobita
 Corynexochida - Styginidae
Liolalax clairensis, Liolalax "sp. A", Scutelluidae "pygidium indet. 2", ? Ciliscutellum "sp.", Kosovopeltis "sp. 1", ? Kosovopeltis "sp. 2", ? Octobronteus incertus, ? Octobronteus ormistoni, Illaenoides elongata
Liolalax "sp. A" Holloway and Lane 1999 trilobite
Scutelluidae "pygidium indet. 2" Richter and Richter 1955 trilobite
? Ciliscutellum "sp." Lin 1987 trilobite
Kosovopeltis "sp. 1" Snajdr 1958 trilobite
? Kosovopeltis "sp. 2" Snajdr 1958 trilobite
Illaenoides elongata Thomas 1929 trilobite
 Corynexochida - Illaenidae
Bumastus cf. danielsi, Bumastus barriensis
Bumastus barriensis Murchison 1839 trilobite
 Odontopleurida - Odontopleuridae
Ceratocephala depauperata, Miraspis "sp. A", ? Kettneraspis arkansana, Dalaspis obsoleta, ? Diacanthaspis (Diacanthaspis) tricosa, Selenopeltoides nodulatus
Ceratocephala depauperata Van Ingen 1901 trilobite
Miraspis "sp. A" Richter and Richter 1917 trilobite
? Kettneraspis arkansana Van Ingen 1901 trilobite
Dalaspis obsoleta Van Ingen 1901 trilobite
Selenopeltoides nodulatus Van Ingen 1901 trilobite
 Lichida - Lichidae
Dicranopeltis kallaion, Dicranopeltis eretes, Dicranopeltis arkansana, Arctinurus clairensis, Trochurus (Trochurus) depauperatus, Trochurus (Atyzela) searcyensis
Dicranopeltis eretes Holloway 2021 trilobite
Dicranopeltis arkansana Van Ingen 1901 trilobite
Arctinurus clairensis Thomas 1929 trilobite
 Phacopida - Dalmanitidae
"Dalmanites howelli" = Dalmanites, "Dalmanites ptyktorion" = Dalmanites, "Dalmanites "sp. 1"" = Dalmanites, "Dalmanites "sp. 3"" = Dalmanites, "Ommokris bassleri" = Dalmanites, Delops collatus
"Dalmanites howelli" = Dalmanites trilobite
"Dalmanites ptyktorion" = Dalmanites trilobite
"Dalmanites "sp. 1"" = Dalmanites Barrande 1852 trilobite
"Dalmanites "sp. 3"" = Dalmanites Barrande 1852 trilobite
"Ommokris bassleri" = Dalmanites trilobite
Delops collatus trilobite
 Phacopida - Phacopidae
Ananaspis sp., Eophacops fontana
Ananaspis sp. Campbell 1967 trilobite
 Phacopida - Cheiruridae
Deiphon longifrons, Sphaerexochus glaber
Sphaerexochus glaber Holloway 1980 trilobite
 Phacopida - Encrinuridae
Staurocephalus lagena, Staurocephalus aff. lagena, Staurocephalus oarion, Balizoma sp., Encrinurus egani
Balizoma sp. Holloway 1980 trilobite
Encrinurus egani trilobite
 Phacopida - Calymenidae
"Sthenarocalymene scutula" = Gravicalymene scutula, Diacalymene altirostris
"Sthenarocalymene scutula" = Gravicalymene scutula Holloway 1980 trilobite
 Proetida - Brachymetopidae
Radnoria sp.
Radnoria sp. Wasmann 1894 trilobite
 Proetida - Aulacopleuridae
Harpidella spinulocervix
 Proetida - Proetidae
Cornuproetus kyphora, Pseudogerastos vaningeni
Cornuproetus kyphora Holloway 1980 trilobite
Pseudogerastos vaningeni Foerste 1923 trilobite
 Proetida - Tropidocoryphidae
Decoroproetus "sp. 1", Decoroproetus corycoeus, Dipharangus xeo
Decoroproetus "sp. 1" Pribyl 1946 trilobite
Decoroproetus corycoeus Conrad 1842 trilobite
Dipharangus xeo trilobite