Paleoecology Lab: Description of Assemblages
James R. Ebert, SUNY Oneonta
Assemblage 1: Lower Devonian (Lochkovian) reef assemblage from Mosquito Point Reef, Coeymans Formation,
Helderberg Group of central New York State
Assemblage comprises 4 slabs that bear in situ colonies
of Stromatoporoids, favositid tabulate corals and
fragments of rugose corals in a coarse, gravelly matrix of
crinoid debris.
Assemblage 2: Upper Silurian (Přídolí) intertidal flat assemblage from the Thacher Member of the Manlius
Formation, Helderberg Group of central New York State.
Assemblage 2 comprises 3 slabs with a high abundance, but
low diversity fauna. Tentaculitids dominate the assemblage
with rare fragments of branching bryozoans and rare valves
of Howellella vanuxemi, a small spriferid brachiopod
Assemblage 3: Lower Devonian (Lochkovian) shallow shelf assemblage from the Old Stone Fort Member (informal)
of the Becraft Formation, Helderberg Group of central New York State. This unit was previously known as the upper
“tongue” of the Kalkberg Formation.
Assemblage 3 comprises 5 slabs with a high
abundance and high diversity fauna, some of
which are in situ. This fauna is representative of
the most diverse fauna in the Helderberg Group.
The slabs display abundant brachiopods belonging
to at least 6 species, bryozoans, sponges,
trilobites, rugose corals, crinoid debris, and rare
tabulate corals, cephalopods, gastropods and
bivalves. Published descriptions from this unit
report over 300 species with a minimum of 65
different species of brachiopods.
Assemblage 4: Mixed deeper siliciclastic shelf assemblage from the Middle Devonian (Givetian) and Upper Devonian
(Frasnian) of New York State. This assemblage is a composite from at least two different formations.
Assemblage 4 comprises 3 slabs, two of which are
silty shale and one of which is a siltstone. All fossils
are preserved as molds and casts. Small bivalves
predominate with fewer pieces of crinoids stem,
brachiopods, tentaculitids and one cephalopod.