Union seam (Carboniferous of the United Kingdom)

Where: England, United Kingdom (53.7° N, 2.2° W: paleocoordinates 0.3° N, 7.6° E)

• coordinate estimated from map

• local area-level geographic resolution

When: Westphalian A (318.1 - 314.6 Ma)

• "the Union seam splits into the Upper Foot or Bullion seam above and the Lower Main or Gannister seam below" (Galtier 1997)

• bed-level stratigraphic resolution

Environment/lithology: coal and coal ball

Preservation: permineralized

Collection methods: surface (in situ), chemical, peel or thin section,

• "Each coal ball was sectioned and etched, and cellulose acetate peels were prepared and examined under the microscope in the field...from about two thousand coal balls, less than 400, containing diverse plant assemblages, were selected and sent to the laboratory in Montpellier. However, the peels from all coal balls examined were kept, including those from rejected coal balls that contained mainly lycopod bark. They represent a random sample of Lancashire coal balls, much more significant than any collection from museums, where biased selection always exists." (Galtier 1997)

Primary reference: J. Galtier. 1997. Coal-ball floras of the Namurian-Westphalian of Europe. Review of Palaeobotany and Palynology 95:51-72 [H. Sims/J. Cassara/J. Cassara]more details

Purpose of describing collection: paleoecologic analysis

PaleoDB collection 37369: authorized by Hallie Sims, entered by Jason Cassara on 14.03.2004

Creative Commons license: CC BY (attribution)

Taxonomic list

• One coal ball out of about 2000 contained bone fragments and a goniatite. These are not included in this list. "The large number of endemic species is regarded as misleading and may be merely related to a 'splitter' taxonomic approach. This may apply to...the four species of Lepidophylloides from the Union..." (Galtier 1997). These four species are L. equilaterale, L. latifolium, L. sewardii and L. thomasii.
Rhabdoxylon dichotomum
  -
Psalixochlaena cylindrica
  -
Psalixochlaena cylindrica Williamson 1878
 Coenopteridales -
unclassified
  -
Stipitopteris
  -
Stipitopteris sp. Grand'Eury 1877
Polypodiopsida
 Equisetales - Equisetidae
Pachytesta
  -
Pinopsida
 Cordaitanthales -
 Cordaitanthales - Cordaitanthaceae
Mitrospermum compressum Williamson 1910
 Coniferales -
Conostoma
  -
Lycopodiopsida
 Isoetales -
Paralycopodites brevifolius clubmoss
questionable occurrence
Cladoxylopsida
 Zygopteridae - Zygopteridae
Equisetopsida
 Sphenophyllales -
Calamitopsida
 Calamitales -
Anachoropteris
  -
Bothrodendron
  -
Medullosa
  -
Medullosa pusilla
questionable occurrence
Sphenopteridae
  - Sphenopteridae
Mesostrobus scottii
  -
Mesostrobus scottii Watson 1909
Miadesmia membranacea
  -
Miadesmia membranacea Bertrand 1895
Lepidocarpon
  -
Myeloxylon
  -
Myeloxylon sp. Brongniart 1849
Sigillariaceae
  - Sigillariaceae
 Lepidodendrales - Lepidodendraceae
Lepidocarpaceae
  - Lepidocarpaceae
Lagenostoma
  -
Lagenostoma ovoides
  -
Lagenostoma ovoides Williamson 1876
Lyginorachis
  -
Heterangium
  -
Microspermopteris
  -
Physostoma
  -
Physostoma elegans
  -
Physostoma elegans Williamson 1876
 Cordaitales -
Amyelon radicans Williamson 1874
Stigmaria
  -
Stigmaria ficoides
  -
Stigmaria ficoides Sternberg 1822
Medullosa anglica
  -
"Medullosa anglica" = Pecopteromedullosa anglica
"Medullosa anglica" = Pecopteromedullosa anglica Scott 1899