Mt Watt [Stairway Sandstone] (Ordovician of Australia)

Where: Northern Territory, Australia (25.5° S, 134.0° E: paleocoordinates 15.6° N, 170.4° E)

• coordinate based on nearby landmark

• local area-level geographic resolution

When: Stairway Sandstone Formation, Arenig (478.6 - 466.0 Ma)

• STRATIGRAPHIC RELATIONS: From the Stairway Sandstone, which overlies the Horn Valley Siltstone (late Early Ordovician), and is gradationally overlain by the Stokes Siltstone (Late Ordovician). AGE: late

•Arenigian to early Llanvirnian, on the basis of conodont biostratigraphy. STRATIGRAPHIC POSITION: Fossils collected from scree.

• formation-level stratigraphic resolution

Environment/lithology: marine; lithified lithology not reported

• SPECIFIC LITHOLOGY: LITHIFICATION:

Size class: macrofossils

Collection methods: surface (in situ),

• COLLECTOR: Not specified, but multiple collectors. REPOSITORY: Bureau of Mineral Resources, Canberra.

Primary reference: A. Ritchie and J. Gilbert-Tomlinson. 1977. First Ordovician vertebrates from the Southern Hemisphere. Alcheringa 1:351-368 [A. Hendy/A. Hendy]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 90382: authorized by Austin Hendy, entered by Austin Hendy on 18.07.2009

Creative Commons license: CC BY (attribution)

Taxonomic list

• COVERAGE: Limited to taxonomic groups described in manuscript and characteristic forms mentioned in text. NOMENCLATURE: Authoritative publication, with relatively modern nomenclature and species-resolution identifications.
Bivalvia
 Protobranchia - Ctenodontidae
"Isoarca crassatellaeformis" = Alococoncha crassatellaeformis
"Isoarca crassatellaeformis" = Alococoncha crassatellaeformis Tate 1896 clam
 Protobranchia -
"Isoarca orbicularis" = Johnmartinia orbicularis
"Isoarca orbicularis" = Johnmartinia orbicularis Tate 1896 clam
Pteraspidomorphi
 Arandaspidida - Arandaspididae
Porophoraspis crenulata n. sp. Ritchie and Gilbert-Tomlinson 1977
Arandaspis prionotolepis n. sp. Ritchie and Gilbert-Tomlinson 1977
 Ichnofossils -
Cruziana cf. furcifera d'Orbigny 1842