Rhombopora leptoclada-Hebetoechia? kuzmini Comm., Early Lochkovian, Cent. Taimyr (Devonian of Russian Federation)

Where: Russian Federation (73.8° N, 91.0° E: paleocoordinates 18.6° N, 4.9° W)

• coordinate estimated from map

• outcrop-level geographic resolution

When: Lochkovian (419.2 - 410.8 Ma)

• Lower Uryun subhorizon

Environment/lithology: marine; black, argillaceous limestone

• "The 500 m thick section is built up predominantly of argillaceous carbonate deposits. The base contains gypsum, argillaceous dolomites, siltstones (Belyi Kamen subhorizon, Ust' Taryeya horizon, the equivalent of the Lower Lochkovian) grading up section into rhythmically interbedded carbonate and argillaceous rocks (the Uryun and Tolbat subhorizons of the Ust' Tareya horizon; Daksan, Yunkhoda, Taribigai subhorizons, the Zlobin horizon; the Trigonirhynchia postventricos and Favosites regularissimus zones, equivalents of the Lochkovian-Zlichovian), there are also variegated siltstones, marls, dolomites (the Wijdeaspis arctica zone, the end of the Lower Devonian. The section shows a cyclic development...(carbonate beds with basal argillaceous units) while the general trend was regressive-transgressive-regressive...absence of channel facies...There are a number of communities showing a trend in the development of environments from gypsiferous lagoons to open marine basins, beginning basally with A and extending upwards into F, namely: A. Fish-Phyllopod; B. Lingula-Phyllopod; C. Pelecypod-Phyllopod; D. Eurypterid-Pelecypod; E. Howellella-Tiverina; F. Rhombopora-Hebetoechia...hypersaline at bottom to normal marine at top." "...belonging to the shallow water, nearshore region, in a quiet to weakly turbulent zone, possibly in the inner zone of the mouth of a lagoon's seaward mouth. The overall nature of the fauna indicates a BA 2 assignment."
• See geology. "Dark, almost black, argillaceous detrital limestones..."

Primary reference: S. V. Cherkesova. 1999. Lower Early Devonian communities of Taimyr. In A. J. Boucot and J. D. Lawson (eds.), Paleocommunities--a case study from the Silurian and Lower Devonian 458-461 [M. Foote/M. Foote/M. Foote]more details

Purpose of describing collection: paleoecologic analysis

PaleoDB collection 26673: authorized by Michael Foote, entered by Michael Foote on 23.10.2002

Creative Commons license: CC BY (attribution)

Taxonomic list

 Palaeocopida -
 Leperditicopida -
Herrmannina sp. Kegel 1933 ostracod
 Athyridida - Athyrididae
 Spiriferinida - Cyrtinidae
Cyrtina sp. Davidson 1858
 Spiriferida - Delthyrididae
 Rhynchonellida - Hebetoechiidae
 Rhynchonellida - Innaechiidae
"? Hebetoechia kuzmini" = Dubovikovia kuzmini
"? Hebetoechia kuzmini" = Dubovikovia kuzmini Cherkesova 1968
"Pelecypoda indet." = Bivalvia
"Pelecypoda indet." = Bivalvia Linnaeus 1758 clam
Gastropoda indet. Cuvier 1797 snail
 Cystoporida - Fistuliporidae
 Rhabdomesida - Rhomboporidae
  - Thelodontidae
Nostolepis sp. Pander 1856
Crinoidea indet. Miller 1821 Sea lily
 Chaetetida - Tiverinidae
 Favositida - Favositidae
Favositidae indet. Dana 1846 tabulate coral
 Favositida - Pachyporidae