A Glimpse Into a Middle Devonian Ecosystem: Penn Dixie Fossil Beds,
Erie County, New York
Carly Leventhal, Dr. Tamra Schiappa, Geography, Geology, and the Environment Department, cnl1004@sru.edu
Introduction
Penn Dixie Fossil Quarry and Nature Reserve is an
educational center located in Erie County, NY. It provides an
opportunity for individuals to explore the geology and
paleontology of Western New York. The diverse fossil
assemblage preserved in the rocks provide researchers with a
unique opportunity to learn about life in the past. The purpose
of this research was to reconstruct the Middle Devonian (393382 million years ago) paleoenvironment using fossils and
rocks collected from this locality.

Stratigraphy
• Middle Devonian
Hamilton group
• Age: 377 to 384
million years old
• Formations: The
Marcellus,
Skaneateles,
Ludlowville, and
Moscow.
• Exposed units:
West River Shale,
Genundewa
Limestone, North
Evans Limestone,
Windom Shale,
Tichenor Limestone,
and Wanakah Shale
of the Moscow
Figure 1: Stratigraphic units present at
Formation (Figure 1). the Penn Dixie Site (Bastedo, 1999).

Paleontology and Paleoecology
• Fossils collected include Brachiopods, Corals,
Trilobites, Echinoderms, Bryozoans, Cephalopods,
Gastropods, Bivalves and Conodonts.
• Shown below are some of the fossil species that were
studied.

Stereolasma rectum
Taxonomy:
Phylum: Cnidaria
Class: Anthoza
Family:
Stereolasmatidae

Amplexiphyllum
hamiltonae
Taxonomy:
Phylum: Cnidaria
Class: Anthoza
Family:
Stereolasmatidae

Rhipidomella sp.
Taxonomy:
Phylum: Brachiopoda
Class: Rhynchonellata
Family: Rhipidomellidae

• Fossils collected from the Windom Shale.
• The Windom Shale is a soft, fissile, medium-grey shale with
interbedded fossiliferous units.
• Thin calcareous beds contain abundant fossils near the
base of the unit and a few feet from the top.
• These fossiliferous sections are separated by barren, grey
shales containing no fossils (Brett, 1974).

Figure 2: Ecological patterns
within Hamilton Group (Modified
from Bonuso et al., 2002.)

Pseudoatrypa
devonica
Taxonomy:
Phylum: Brachiopoda
Class: Rhynchonellata
Family: Atrypidae

Phacops rana (thorax)
Taxonomy:
Phylum: Arthropoda
Class: Trilobita
Family: Phacopidae

• Diverse community; > 8
species.
• Brachiopods/ corals abundant.
• Suspension feeding organisms
dominant --Brachiopods,
Corals, and Echinoderms
(Figure 2).
• Scavengers - Trilobites,not as
abundant.
• Characteristics of life and death
assemblages.
• Trilobites and Brachiopods are
disarticulated
• Scattered skeletal parts
from bioturbation
of scavengers, or energy that
moved the fragments.

Paleoenvironment Reconstruction
• Penn Dixie Quarry sediments
and fossil faunas
indicate deposition on a
shallow marine shelf within
a Middle Devonian epeiric
sea (Figure 4).
• During this time, NY close to
equator; seas were tropical.
• Sediments deposited
westward formed Catskill
Delta (Figure 3).
• Low energy, warm,
Figure 3: Characteristics of “Catskill Delta”
clear, shallow marine enviro depositional systems (Strokes)
nment in the photic zone.
• Light grey Windom
Shale associated
with aerobic
zone. Species in faunal
assemblage needed higher
amounts of oxygen to survive
(Stokes).
• Brachiopods and Corals are
dominant sessile filter
feeders. Trilobites are
scavengers. Echinoderms
are rare sessile filter
feeders.

Figure 4: Paleogeographic map of North
America during the Middle Devonian; Fossil
locality marked by star (Modified from Blakey)

References
Bastedo, J.C., 1999, Penn Dixie Paleontological and Outdoor Education Center: Visit to a Classic Geological and Outdoor
Education Center. N.Y. State Geological Association 71 Annual Meeting Guidebook, Fredonia, N.Y., p. A1-A18.
Blakey, Ron. “Paleogeography and Geologic Evolution of North America”, Global Plate Tectonics and paleogeography.
Northern Arizona University.
Bonuso, N., Newton, C.R., Brower, J.C., Ivany, L.C., 2002, Does coordinated stasis yield taxonomic and ecologic stability: Middle
Devonian Hamilton Group of central New York. Geological Society of America. Geology, Vol. 30; no. 12; p. 1055-1058.
Brett, C.E., 1974, Biostratigraphy and Paleoecology of the Windom Shale Member (Moscow Formation) in Erie County, NY:
New York State Geological Association, 46th Annual Meeting Guidebook, p. G1-G15.
Brett, C.E., 1986, Dynamic Stratigraphy and Depositional Environments of the Hamilton Group (Middle Devonian) in New York
State, Part 1. Cultural Education Center, Albany, New York. p. 166.
Brett, C.E., 1986, Dynamic Stratigraphy and Depositional Environments of the Hamilton Group (Middle Devonian) in New York
State, Part 2. Cultural Education Center, Albany, New York. p. 166.
Maletz, J., 2008, Middle to Upper Devonian Stratigraphy and Faunas of Erie County, Western New York: Field Trip NE GSA, p.
1-14.
Stokes, J.P, Zambito, J.J., Using Marine Fossils to Unlock the Middle Devonian Paleoenvironments of Western New York:
Middle Devonian Fossils for Teachers, p. 414-434.

Acknowledgements
I would like to thank Dr. Schiappa and the GGE Department for
providing me with the knowledge, tools, facilities, and assistance in
being able to do this research.