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