SW ridge of Llandegley Rocks, Powys, Wales (Ordovician of the United Kingdom)

Where: United Kingdom (52.2° N, 3.3° W: paleocoordinates 58.7° S, 18.6° W)

• coordinate estimated from map

• hand sample-level geographic resolution

When: Didymograptus artus / Didymograptus murchisoni graptolite zone, Builth Volcanic Formation, Llanvirn (468.0 - 458.4 Ma)

• Didymograptus artus/Didymograptus murchisoni biozonal boundary, Llanvirn

• formation-level stratigraphic resolution

Environment/lithology: coastal; lithified, coarse-grained, volcaniclastic sandstone and lithified, bentonitic ash

• The local stratigraphic section represents the evolution of two volcanic cones...Coarse volcanogenic sandstones representing erosion of the Bulith edifice...suggestive of shore-face conditions, with high environmental gradients, and adjacent emergence on the flanks of the Builth Volcanic cone.
• Coarse volcanogenic sandstones representing erosion of the Builth edifice...The lithology is coarse volcanogenic standstone, with abundant to dominant shardic/pumiceous material, euhedral and angular grains, and sponge spicules. All beds are pervasively silicified, although very rare calcareous nodules occur in the lower part of the sequence; siliceous nodules are abundant. Occasional thin bentonites occur throughout. Irregular rippled bedding is locally obvious, including apparent interference morphologies, while non-orthogonal bidirectional alignment of sponge spicules supports a combined wave-current flow regime. Pyritised filamentous overgrowth of bioclasts is preserved within a calcite nodule, suggesting cyanobacterial/algal growth within the photic zone.

Size classes: macrofossils, mesofossils, microfossils

Preservation: mold/impression

Primary reference: J. P. Botting. 2003. Llanvirn (Middle Ordovician) echinoderms from Llandegley Rocks, Central Wales. Palaeontology 46(4):685-708 [S. Cole/S. Cole]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 191644: authorized by Selina Cole, entered by Selina Cole on 06.02.2018

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names
Asteroidea
 Euaxosida - Mesopalaeasteridae
? Mesopalaeaster sp.
? Mesopalaeaster sp. Schuchert 1914 sea star
 Hadrosida - Hudsonasteridae
"Protopalaeaster cf. simplex" = Hudsonaster
"Protopalaeaster cf. simplex" = Hudsonaster sea star
 Hadrosida - Promopalaeasteridae
Promopalaeasteridae "sp. A"
Promopalaeasteridae "sp. A" Schuchert 1915 sea star
 Rhombifera - Echinosphaeritidae
"Echinosphaerites (Echinosphaerites) cf. granulatus" = Echinosphaerites granulatus
"Echinosphaerites (Echinosphaerites) cf. granulatus" = Echinosphaerites granulatus Botting 2003
Crinoidea
  -
Crinoidea "sp. A", Crinoidea "sp. B"
Crinoidea "sp. A" Miller 1821 Sea lily
Crinoidea "sp. B" Miller 1821 Sea lily
 Diplobathrida - Rhodocrinitidae
Cefnocrinus samgilmouri n. gen. n. sp.
Cefnocrinus samgilmouri n. gen. n. sp. Botting 2003 Sea lily
 Myelodactylida - Iocrinidae
Caleidocrinus cf. turgidulus, Iocrinus cf. whitteryi, Iocrinus llandegleyi n. sp.
Caleidocrinus cf. turgidulus Ramsbottom 1961 Sea lily
Iocrinus cf. whitteryi Ramsbottom 1961 Sea lily
Iocrinus llandegleyi n. sp. Botting 2003 Sea lily