Scaphiocoelia Zone trilobites, Gamoneda Fmn., Tarija region (Devonian of Bolivia)

Where: Tarija, Bolivia (21.5° S, 64.0° W: paleocoordinates 67.2° S, 98.7° W)

• coordinate based on political unit

• local area-level geographic resolution

When: Gamoneda Formation, Emsian (407.6 - 393.3 Ma)

• Scaphiocoelia Zone well recognized. Emsian age follows Isaacson (ref. 9680).

• member-level stratigraphic resolution

Environment/lithology: marine; micaceous, gray siltstone and burrowed, micaceous, gray sandstone

• Isaacson (ref. 9681) interprets as deeper than Belen and Icla, so this would make it subtidal, BA 2-3.
• From Isaacson (ref. 9681):"...begins with 100 m of siltstone...gray...mica...mudstone interbeds...240 m of sandstone follows, with a minor mudstone unit towards the top...Sst is fine- to med.-gr....gray...mica...planar cross-stratification...mudstone unit...[more sandstone and siltstone...Zoophycos..."

Primary reference: N. Eldredge and L. Branisa. 1980. Calmoniid trilobites of the Lower Devonian Scaphiocoelia Zone of Bolivia, with remarks on related species. Bulletin of the American Museum of Natural History 165(2):181-289 [M. Foote/M. Foote/M. Foote]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 36137: authorized by Michael Foote, entered by Michael Foote on 14.01.2004

Creative Commons license: CC BY (attribution)

Taxonomic list

• Emphasis is on calmoniids, which make up the majority of Scaphiocoelia Zone trilobites, but other forms are treated as well.
 Phacopida - Acastidae
? Acastoides gamonedensis n. sp. trilobite
 Phacopida - Dalmanitidae
cf. Francovichia sp. Branisa 1960 trilobite
 Phacopida - Calmoniidae
Calmoniidae indet. Delo 1935 trilobite
sp. indet. B
Kozlowskiaspis (Romanops) australis n. subgen. n. sp. trilobite
Bainella (Belenops) insolita n. subgen. trilobite
Deltacephalaspis (Deltacephalaspis) comis n. gen. n. subgen. n. sp. trilobite
Deltacephalaspis (Deltacephalaspis) retrospina n. gen. n. subgen. n. sp. trilobite
Deltacephalaspis (Prestalia) tumida n. gen. n. subgen. n. sp. trilobite
Schizostylus (Curuyella) granulata n. subgen. n. sp. trilobite
Phacopina convexa n. sp. trilobite
 Phacopida - Homalonotidae
"Burmeisteria" sp. Salter 1865 trilobite
"Burmeisteria s.l."
 Xiphosurida -
Eurypterida indet. Burmeister 1843 eurypterid