Summary of a revision of New York State Ordovician eurypterids: implications for eurypterid palaeoecology, diversity and evolution

ABSTRACTThe record of Ordovician Eurypterida from New York State, USA, is shown to be largely false. Twenty-nine species in 17 genera are here recognised as pseudofossils, reducing by more than 75% the total number of named Ordovician eurypterid taxa. Consequently, 10 families now have their first occurrence either later in the Ordovician or in the Early Silurian. The implications for eurypterid palaeoecology, diversity and evolution are not as straightforward as would be expected from such a drastic taxonomic revision. All Ordovician eurypterids are now known to occur in shallow-water, near-shore shales or fine-grained carbonates. Diversity measures indicate that the end-Ordovician extinction event appears to have had less effect on eurypterids than previously known, and their turnover is level in the Ordovician.

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Age and origin of the Cannon Point syenite, Essex County, New York: southernmost expression of Monteregian Hills magmatism?

Canadian Journal of Earth Sciences ◽

10.1139/cjes-2016-0144 ◽

2017 ◽

Vol 54 (4) ◽

pp. 379-392

Author(s):

David G. Bailey ◽

Marian Lupulescu ◽

Jeffrey Chiarenzelli ◽

Jonathan P. Traylor

Keyword(s):

New York ◽

New York State ◽

Alkali Feldspar ◽

Crustal Material ◽

Lake Champlain ◽

Essex County ◽

York State ◽

Fine Grained ◽

The North ◽

Basement Faults

Two syenite sills intrude the local Paleozoic strata of eastern New York State and are exposed along the western shore of Lake Champlain. The sills are fine-grained, alkali feldspar syenites and quartz syenites, with phenocrysts of sanidine and albite. The two sills are compositionally distinct, with crossing rare earth element profiles and different incompatible element ratios, which eliminates the possibility of a simple petrogenetic relationship. Zircon extracted from the upper sill yields a U–Pb age of 131.1 ± 1.7 Ma, making the sills the youngest known igneous rocks in New York State. This age is similar to that of the earliest intrusions in the Monteregian Hills of Quebec, >100 km to the north. Sr and Nd radiogenic isotope ratios are also similar to those observed in some of the syenitic rocks of the eastern Monteregian Hills. The Cannon Point syenites have compositions typical of A-type, within-plate granitoids. They exhibit unusually high Ta and Nb concentrations, resulting in distinct trace element signatures that are similar to those of the silicic rocks of the Valles Caldera, a large, rift-related magmatic system. We suggest that the Cannon Point syenites were melts derived primarily by anatexis of old, primitive, lower crustal material in response to Mesozoic rifting and to the intrusion of mantle-derived magmas. The sills indicate that the effects of continental rifting were spatially and temporally extensive, resulting in the reactivation of basement faults in the Lake Champlain Valley hundreds of kilometers west of the active rift boundary, and crustal melting >50 Ma after the initiation of rifting.

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First Occurrence of Chain Pickerel (Esox niger) in Ontario: Possible Range Expansion from New York Waters of Eastern Lake Ontario

The Canadian Field-Naturalist ◽

10.22621/cfn.v125i1.1116 ◽

2011 ◽

Vol 125 (1) ◽

pp. 16 ◽

Cited By ~ 1

Author(s):

James A. Hoyle ◽

Colin Lake

Keyword(s):

New York ◽

Range Expansion ◽

New York State ◽

Lake Ontario ◽

York State ◽

Mature Adults ◽

First Occurrence ◽

St Lawrence River

In this paper, we document the first Chain Pickerel (Esox niger) collected in Ontario and the first on the northwestern side of the St. Lawrence River in Canada. The fish was caught by a local commercial fisherman in April 2008. Since 2008, five additional specimens have been caught and are also documented here: three in 2009 and two more through spring 2010. All individuals were mature adults in robust condition. The appearance of Chain Pickerel in the Ontario waters of eastern Lake Ontario and the upper St. Lawrence River may signal an expansion in the range of this species from New York state waters.

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