Sandbian (Early-Middle Caradoc)

The Sandbian Age of the Late Ordovician Epoch: 461 to 456 million years ago

The Ordovician has been quite significantly revised in recent years. The traditional division of the Late Ordovician into the Caradoc and Ashgill has been replaced by a three-part division. The first of these is the Sandbian, which is more or less equivalent to the Early Caradoc and most of the Middle Caradoc. The Katian includes the Late Caradoc and all of the Ashgill prior to the start of serious global cooling. The Hirnantian, formerly a stage of the Ashgill, is now the final age of the Ordovician.  ATW080323.

Marine Invertebrates

Phylum Cnidaria

Class Anthozoa

Rugose Corals

Lambeophyllum profundum (Conrad)
specimen about 2.5 cm long and in diameter
Blackriveran age (Harnagian)
New York
(reference: Moore, Lalicker & Fischer, Invertebrate Fossils, p.114)

Trilobites

Calyptaulax callicephalus
dalmanitid trilobite - family Pterygometopidae
Black River and Trenton Groups
(= Harnagian to Longvillina)
eastern and northeast Canada, and New York state

Phylum Brachiopoda

Order Orthida
Family Dalmanellidae

Paucicrura rogata (Sardeson)
shell about 7mm long and wide
Trenton Group
North America
more on Paucicrura
(at the Union College Geology Department site)

Order Strophomenida
Family Sowerbyellidae

Sowerbyella sericea (Sowerby)
Sandbian
England
shell about 1 cm wide
more on Swerbyella
(at the Union College Geology Department site)

Links

Mohawk Valley Fossils - a very informative site, put together by the Union College Geology Department. Detailed surveys of occurrences of fossils of creatures that lived during Late Sandbian to Early Katian times (probably Longvillian and Actonian).

Ordovician Trentonian fauna from the Galena and Maquoketa of West DePere and Green Bay Wisconsin