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Western New York Fossil Hunting


Fossil Identification

Fossil Identification Western New York

Hamilton Group: Fossil Identification Page

Devonian Reef Fossils

Click on the type of fossil or scroll down to browse:



Trilobites are probably what most people are after when they fossil hunt in Western NY. There is a trilobite bed exposed in the Hamilton Group. It requires a slight bit of digging at the Pen Dixie Site, but it's worth it as pristine specimens can be found.

Trilobites that can be found in this area include: Eldredgeops (Phacops) rana, Greenops sp., Dechenella (Basidechenella) rowi, and Trimerus (Dipleura) Dekayi.

Eldredgops milleri (Formerly known as Phacops rana)

Why do some people not call these Phacops anymore?

In a nutshell, it all started with a paper by Struve in 1990. He observed some slight differences between Phacops species in Europe/North America and Morocco, particularly in the eyes and lenses. He found enough differences that he erected a new genus, Eldredgeops, for Phacops rana of North America and Europe.

This isn't the first time Phacops has been broken up into different genera. The slight differences in the eyes is also why we have the genera "Paciphacops" and "Kainops" for Phacops looking trilobites.

Reference: (Struve, W. 1990. [Palaozoologie III (1986-1990)]. Courier Forschungsinstitut Senckenberg 127: 251-279)

Eldredgeops/Phacops is by far the most abundant trilobite in the Devonian of Western New York. It is very easy to identify, as it has the famous "Frog Eyes" and large glabella (nose like thing). Besides for these two features, it is a rather plain looking trilobite.

Click on the image to go to the Trilobite Fossils page for many more examples.

This is an example of an Eldredgeops (Phacops) Trilobite from Western NY - Click on the image to see many more fossil specimens from Western New York.

Formation: Wanakah Shale, Ludlowville Formation, Hamilton Group
Age: Middle Devonian ~370 - 400 m.y
Location: Western New York

Greenops Trilobites

Greenops barberi , Greenops grabaui
(Formerly Greenops boothi)

Greenops trilobites are small, usually no more than 1.5 inches in length. They have spines coming from the cephalon and an ornamented pygidium (tail) fringe.
G. barberi has shorter, more triangular fringes, while G. grabaui has longer fringes.

Click on the image to go to the Trilobite Fossils page for many more examples.

This is an example of an Greenops Trilobite from Western NY - Click on the image to see many more fossil specimens from Western New York.

Formation: Wanakah Shale, Ludlowville Formation, Hamilton Group
Age: Middle Devonian ~370 - 400 m.y
Location: Western New York

Spiriferid Brachiopods

Brachiopods are similar to mollusks, like clams, however, they are not closely related. Unlike most present day mollusks, the two shells of a brachiopod were different sizes.

Brachiopods were the dominant form of life in the seas in most of the Paleozoic, including the Devonian. Therefore, they are a very common fossil of the Devonian coral reefs in Western New York. Dozens upon dozens of species and genera can be found in the fossilized Devonian coral reefs.

Many genera and species Spiriferid Brachippods occur in the Devonian of Western New York.

Specimens shown below include:
Mucrospirifer Mucronatus, Mediopirifer Audaculus, and Spinocyrtia Granulose.

Mucrospirifer mucronatus (Conrad)

M. Mucronatus is a small to medium sized brachiopod fossil. It is very beautiful in that the hinge line is straight and very long, ending in a spine-like point. The term Mucronate means to end abruptly in a point.
Unfortunately, the mucronate ends are often broken off.

They are very wide, usually 3 or 4 times wider than the height. They have radial striations, and often numerous growth lines are visible.

If you can find one still in the matrix, the long mucronate spines can still be preserved.

Formation: Wanakah Shale, Ludlowville Formation, Hamilton Group
Age: Middle Devonian ~370 - 400 m.y
Location: Western New York
Size: The larger one is 2 1/8" (54mm)

Fossil Mucrospirifer mucronatus brachiopod

This fossil Mucrospirifer mucronatus brachiopod s inflated, but a little squished. The size is 1 7/8" (48 mm).

Mediopirifer Audaculus (Spirifer Audaculus)

These fossil brachiopods are more robust looking than M. mucronatus. Also the hinge line is not as straight as in M. mucronatus, and they are less elliptical, in that their width and height are not in as extreme proportions as M. mucronatus. They have more of a semi-circle shape.

This specimen is inflated, but again, a little squished. They are a more convex than M. mucronatus. It is 1.5" (38 mm) in size.

Spinocyrtia Granulose (Spirifer Granulosus)

This is a very large spiriferid brachiopod fossil. It looks like a large, more robust, version of M. audaculus. It is very rounded, and the hinge line is not straight, but is slightly concave. It's called spinocyrtia because of fine spines (almost like tiny hairs) that cover the brachiopod. These spines are only preserved on exceptional specimens.

This specimen is a little squished, as the top shell is partially slid into the bottom one. The larger one is 2 3/8"" (60mm)

Non-Spiriferid Brachiopod Fossils

This simply refers to the brachiopods that do not have the spiriferid shape.

Fossil specimens below include: Athyris Spiriferoides , Rhipidomella sp. , Pseudoatrypa Devoniana. , Spinatrypa Spinosa. , Stropheodonta Demissa. , Pseudoatrypa Devoniana. , and Longispina mucronatus.

Athyris Spiriferoides

These brachiopods are very easy to identify. They have a robust appearance, have very round outline, and both valves are convex, the ventral larger than the dorsal. The valves also have thick growth rings, or lamellae on them.

The above specimens show the circular like shape. The lower left spefimen shows a side view with the hinge line facing forward. It shows the very convex shape of both the ventral and dorsal valve.

Rhipidomella sp.

These fossil brachiopods are very circular and flat, looking like little silver dollars. The valves are both slightly convex, and are covered by little radail lines, or striations. There are a few species of them, most species are difficult to tell apart.

Rhipidomella penelope

This is the largest Rhipodomella brachiopod. usually they are over an inch in width. The hinge line appears more straight than the other Rhipodomella species.

Devonian fossil brachiopods from New York; Rhipidomella Penelope (Hall)

Rhipidomella ?vanuxemi

This specimen is probably R. vanuxemi. It is more tear-dropped shaped (the length and width are more equal) than R. penelope, and slightly smaller.

Pseudoatrypa devoniana

These robust looking brachiopods are easy to identify. The shape speaks for itself. The pedical valve is nearly flat, while the brachial valve is extremely convex. They are also covered in prominent plications, or radial lines.

Spinatrypa Spinosa (Atrypa Spinosa)

Spinatrypa spinosa is called Atrypa Spinosa in old publications. The name has been revised a while back. This somewhat smaller brachiopod is relatively common in the Moscow shale of the Hamilton group. The two valves are similarly convex; the pedical valve is only slightly less convex. It also has very course plications, or radial lines running down the valves.

Stropheodonta demissa

This is a medium sized brachiopod fossil. It has an easily identifiable shape, looking like a half-circle. The pedical valve is very convex, while the brachial valve is concave. It also has strong radial striations running the length of both shells.

There is a very similar looking brachiopod called Megastrophia concava. However, it is much larger in size.

Longispina mucronatus

These are small brachiopod fossils. I often find them pyritized, like the two below. There is also another image of one on the Phacops page. It is next to an enrolled phacops.

Pyritized Devonian fossil shell brachiopod from New York; longispina mucronatus

Gastropods (Snails)

Gastropod fossils appear to be much less common than brachiopods and corals, but they are present.
Currently, there is one gastropod specimen below: Naticonema lineata

Naticonema lineata

This is a small fossil gastropod. Growth lines are visible.

Devonian fossil gastropod from New York; naticonema lineata


Fossil corals are abundant in the Devonian. Many are solitary "Horn" Corals.

Pleurodictyum americanum

These Tabulate corals are easy to identify, as they have a honeycomb pattern, and look like little golf balls cut in half.
All Tabulate corals are now extinct.

One intersting thing to note about these Pleurodictyum corals, is most look like they have a little "pie slice" cut out of the bottom of them. This can be seen in the image below.
This "pie slice" is actually the mold of a gastropod, Palaeozygopleura Hamiltoniae. It appears this tabulate coral prefered to use these gastropod shells to colonize on.

This shows differnt views of the tabulate coral. The coral on the left is water worn.

These are two pleurodictyum tabulate corals growing on other objects. The one in matrix is growing on something underneath it that is pyritized. It also has allot of quartzite on it, so I can't prep it out to see what it is. The other one is a tiny one growing on a Mucrospirifer Mucronatus.

Horn Corals - Solitary Roguse Corals

Fossil Horn corals are a type of Roguse Coral. They do not live in colonies, so they are referred to as solitary.
All Roguse corals are now extinct.
There are quite a few species and genera of roguse corals to be found, however, I have always been uncomfortable at identifying them.
Common ones found in the Devonian of Western New York include Heliophyllum Halli and Stereolasma Rectum.


Crinoids are commonly called Sea Lillys. They were much more diverse and common in the paleozoic, but still exist today. However, most crinoids today are free swimming, and do not have a stem that anchors them onto the sea floor, like in fossil specimens. There are some deep sea crinoids that still have the stalk, which look like the fossil ones.

Crinoids are very beautiful when preserved well. Unfortunately, in this area, it is difficult to find well preserved fossil specimens.

Crinoid stem and part of Calyx

This specimen has a large portion of the stem preserved. However, it appears the Calyx (head) had started to deteriorate before fossillization.

Crinoid coiled holdfasts

Some types of crinoids have "roots" that wrap around an object in order to anchor them in place. They sometimes look like little ropes wound in a circle.

This interesting fossil looks like a bunch of ropes wound together. It is from the bottom of a crinoid. It is part of a holdfast, or anchor. It was probably coiled around an object to help anchor the animal.

Crinoid encrusting holdfasts

Unlike the coiled holdfasts of some crinoids, other crinoids have an encrusting holdfast. It's kind of like a root that grows around an object, which holds the crinoid in place.

These are fragments of encrusting holdfasts.

This is another section of an encrusting holdfast from a fossil crinoid.

Crinoid stem sections

These fossils are stem fragments from Crinoids. The stems are composed of numerous disks, or columnals. The Columnals come in many disk-like shapes, depending on the species.

The lower stem fragment in the image has bryazoans encrusting it.

The fossil crinoid stem sections are the most common parts of crinoids found while fossil collecting.


Cephalopods are part of the mollusk class. Cephalopods include squid, cuttlefish, octopus, and the nautilus.

Cephaolopods were much more abundant in the Paleozoic. There were many forms of Nautiloids, including odd straight-shelled forms. There were also the well known Ammonites and Belemnites that do not exist today.

Straight-Shelled Nautiloids

Although there are only 2 genus of Nautiloids alive today, they were much more diverse in the past. Many forms had a straight shell instead of a coiled shell. Nothing comparable lives today.

Spyroceras sp. - Straight-Shelled Nautiloid

Fossils of Straight-Shelled Nautiloids are very fragile, and as a result, are often found fragmented. This is a piece of one.

This is an impression, or cast, of a striaght-shelled nautiloid. The actual fossil probably eroded away at some point. The impression is painted in with artists fixative to make it contrast more from the surrounding rock.

Straight-Shelled Nautiloid

This appears to be some sort of poorly preserved straight


Bryozoa are tiny filter feeding colonial organisms. They are sometimes referred to as Moss Animals. They are commonly found encrusting other fossils.

Hederella sp.

This is a an interesting image of Hederella sp. growing all over a piece of horn coral (Stereolasma rectum).

Recommended Books for Western New York Fossils:

Field Guide to the Devonian Fossils of New York
by Karl A. Wilson, 2014

There hasn't been a decent book on the fossils of Western New York available to the nonn professional until this book came out. This is a MUST for anyone fossil hunting in Western New York. It is an updated guide to all the Devonian taxa of New York... Simply amazing! It's a nice replacement for the out of print and outdated "Devonian Paleontology of New York" that I've used so much.

Geology And Paleontology Of Eighteen Mile Creek And The Lake Shore Sections Of Erie County, New York (1898)
by Amadeus William Grabau, 1898 (2010 reprint)

This is a famous publication by Grabau himself. Serious Devonian fossil hunter needs this! Grabau laid the framework for Devonian fossils! This book is a nice history piece chalk full of pictures and descriptions for fossil identification.
The prices often fluxuate, but you can usually get a copy from $30 - $40.

Dynamic Stratigraphy and Depositional Environments of the Hamilton Group (Middle Devonian) in New York State, Part II
Editors: Ed Landing and carlton E. Brett. (1991)

This New York State Museum Bulletin (#469) is a collection of research papers about the Middle Devonian of New York.

I recommend this book if you want a deep understanding of the the paleoenviroments of the Devonian of New York. The papers include how the sediments were deposited, faunal lists, reconstructions of paleoenvironments, stratigraphy, and more. Being research papers, it's a bit more technical than the other books, but it gives a great overview of the Devonian of western New York.

Devonian Biostratigraphy of New York

International Union of Geological Sciences
Subcommission on Devonian Stratigraphy, (Part 1 and Part 2)
Editors: Willian A. Oliver, Jr. and Gilber Klapper
July 1981, Washington D.C.

This is an incredibly informative book, however it is somewhat difficult to find. Your best bet is a University Library.

Recommended Link:

New York Paleontology
Although a bit old, this is still arguably the best New York Paleontology website out there!

Trilobites for Sale:

Trilobites from Fossilera

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