Where: Yukon, Canada (60.5° N, 125.8° W: paleocoordinates 5.2° N, 52.8° W)

• coordinate stated in text

When: Silurian (443.8 - 419.2 Ma)

• In summary, the vertebrates indicate either a Late Silurian or anEarlyDevonianage. TheinvertebratesidentifiedbyLenz(p.108) suggestanearlierdating. Themostsignificantofthemforcorrela- tion is the Monograptus dubius from beds overlying the vertebrate horizon. Thisspeciesisalong-livedoneinEurope,rangingfrom the Wenlock (zone 27 of the British section) into the Middle Ludlow

•(zone35or36). Theendofitsknownrangeoverlapsthesuggested vertebrate dating, and so Late Silurian, either Early or Middle Lud-

•low, may be taken tentatively as the probable age of this fauna, as estimated from the vertebrates. If this is correct it will extend

•downward the range of Homalaspidella and the Traquairaspididae, and suggest earlier specializations in certain Cyathaspididae.

Environment/lithology: marine; dolomite

Size class: macrofossils

Primary reference: R. H. Denison. 1963. New Silurian Heterostraci from Southeastern Yukon. Fieldiana Geology 14(7):105-141 [M. Uhen/M. Uhen]more details

Purpose of describing collection: general faunal/floral analysis

PaleoDB collection 185831: authorized by Mark Uhen, entered by Mark Uhen on 19.05.2017

Creative Commons license: CC BY (attribution)