Also known as Naibuchi district, Pseudaspidoceras cfr. armatum ammonite zone, South Saghalin

Where: Sakhalin, Russian Federation (47.4° N, 142.8° E: paleocoordinates 55.5° N, 134.1° E)

• coordinate estimated from map

• local area-level geographic resolution

When: Pseudaspidoceras armatum ammonoid zone, Bykov Formation, Early/Lower Turonian to Early/Lower Turonian (93.5 - 89.3 Ma)

• Number III group; Pseudaspidoceras cfr. armatum ammonite zone; Ligerian. From E. YAZYKOVA (Acta Geologica Polonica, Vol. 54 (2004), No. 2, pp. 273-312): "this paper was the first detailed documentation of a Cretaceous ammonite zonation in central and southern Sakhalin. It should be noted, however, that there are numerous problems in that paper with regard to age assignment of the succession and to exposed intervals.For instance, no Albian faunas were recorded and Campanian deposits were misdated as Maastrichtian, Turonian as Coniacian, Santonian as Campanian, Danian as Maastrichtian, etc. Later, MATSUMOTO (1959c) noted that, at first glance, the zones proposed by SHIMIZU appeared to compare well to those then known in Europe, but in fact they often conflicted with data obtained during subsequent field work." PJW: This is now Bykov formation. (It might become Bykov group given how long ranging that formation is.)

• formation-level stratigraphic resolution

Environment/lithology: marine; shale and sandstone

Size class: macrofossils

Preservation: cast

Primary reference: S. Shimizu. 1935. The Upper Cretaceous cephalopods of Japan, Part I. J. Shanghai Sci. Inst.,sec. II 1(11):159-226 [R. Plotnick/R. Plotnick/R. Plotnick]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 64571: authorized by Roy Plotnick, entered by Roy Plotnick on 10.09.2006

Creative Commons license: CC BY (attribution)