Kildare Limestone cephalopods (Ordovician of Ireland)

Also known as Chair Farm, Chair of Kildare

Where: Leinster, Ireland (53.2° N, 6.9° W: paleocoordinates 45.2° S, 20.2° W)

• coordinate estimated from map

• outcrop-level geographic resolution

When: Kildare Limestone Formation, Rawtheyan (455.8 - 445.6 Ma)

• "The age of the limestone is Rawtheyan (the third of the four stages of the Ashgill Series) and it is regarded as correlating most closely with the reef limestone of Keisley (northern England)"

• formation-level stratigraphic resolution

Environment/lithology: reef, buildup or bioherm; shelly/skeletal, gray, red limestone and lenticular, gray lime mudstone

Size class: macrofossils

Preservation: cast, recrystallized

Reposited in the BGS, BMNH, SM

• "I have examined about 50 specimens housed in the collections of the British Geological Survey (BGS, GSM), the Natural History Museum (BMNH), the Geological Survey of Ireland (GSI), the Sedgwick Museum Cambridge (SM) and the Ulster Museum (Northern Ireland) (UM). The total available is fairly small [...] "

•Unfortunately, it is not stated whether the specimens come from the mudstone lenses or from the reefal limestones proper.

Primary reference: C. H. Holland. 1993. Nautiloid cephalopods of the Kildare Limestone (Ashgill), Ireland. Geological Journal 28(1):37-44 [B. Kröger/T. Liebrecht]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 87631: authorized by Björn Kröger, entered by Torsten Liebrecht on 22.03.2009, edited by Björn Kröger

Creative Commons license: CC BY (attribution)

Taxonomic list

Trilobita
 Odontopleurida - Odontopleuridae
Whittingtonia bispinosa McCoy 1846 trilobite
Cephalopoda
 Tarphycerida - Trocholitidae
Trocholites planorbiformes
GSM 104477, figured by Blake (1882), plate 29, figure 9 and 9a
 Orthocerida - Orthoceratidae
"Orthoceras" gregarium
BMNH C82973; GSI F5362, F01319, F01320, F01322, F01323, F08111; GSM 104436, 104437, 104438, 104439, 104442; SM F13881.
Imbricatoceras ascendens n. sp.
GSM 104449 (type), 104450, 104452, 104453; GSI F01317; Imbricatoceras is not the original genus name; species was erected by Blake (1882)
 Orthocerida - Proteoceratidae
"Geisonocerina elongatocinctum" = Isorthoceras elongatocinctum, Gorbyoceras velatum
"Geisonocerina elongatocinctum" = Isorthoceras elongatocinctum Portlock 1843
GSI F08307; GSM 104445, 104451
Gorbyoceras velatum
GSI F08305, FO8306, GSM 104441, 104454; SM A13879, A13880, A14039