Late Ordovician Epoch
Ordovician period
Sandbian Age
(Early-Middle Caradoc)

Sandbian (Early-Middle Caradoc)

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

Paleozoic Era
   Cambrian Period
   Ordovician Period
      Early Ordovician Epoch
     Middle Ordovician Epoch
         Dapingian Age
         Darriwilian Age
      Late Ordovician Epoch
         Sandbian Age 
         Katian Age
         Hirnantian Age
   Silurian Period
   Devonian Period
   Carboniferous Period
   Permian Period


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 The traditional division of the Late Ordovician into the Caradoc and Ashgill has been replaced by a three-part division.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)


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



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

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unless otherwise indicated, content by M. Alan Kazlev 1998-2002
page uploaded 8 June 2002
last modified ATW080323
checked ATW050511
(original page uploaded on Kheper site 27 May 1998)
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