Devonian Microfossils

For my senior thesis at Skidmore College, I investigated the occurrence of a yet-to-be-described microfossil from a group of organisms known as dacryoconarids. Together with my advisor Richard Lindemann, we published a paper describing the species, naming it Nowakia halihanensis.

Dacryoconarids , an enigmatic order of Paleozoic zooplankers prevalent from the early Devonian-to the Frasnian-Famennian boundary (~420-375 million years ago),  are  understudied, but have great potential to serve as biostratigraphic markers for minor and major biotic events in the Devonian system. They are ubiquitous and evolve rapidly.

The holotype (type specimen) of Nowakia halihanensis

The Devonian is an extremely dynamic period of Earth history, which records the rise of terrestrial plants and numerous extinction events associated with global black shales. Understanding the temporal relationship between these events requires clear stratigraphic markers.

Our research demonstrated that Nowakia halihanensisis is associated with a specific biotic turnover recorded in a single bed (named the Halihan Hill Bed). It therefore has great potential to serve as a marker for a very specific extinction event. Identifying this species elsewhere would allow for a very precise correlation between different outcrops and locations.

There is much work that needs to be done. There are countless other species of dacryconarids that remain undescribed. These species could help to elucidate more of the many mysteries of the Devonian period.

Fossils loaded onto stubs to be photographed in a scanning electron microscope.

Papers and Abstracts:

Lindemann RL and KASPRAK AH. 2008. Nowakia halihanensis N. SP. from the Halihan Hill Bed, Oatka Creek Formation (middle Devonian) of New York. Northeastern Geology and Environmental Science, Vol. 30. no. 4. p 334-347

KASPRAK AH . Nowakia (dacryoconarida) in the Halihan Hill Bed (Oatka Creek Formation) of New York. Program with Abstracts: Northeastern Section Meeting, Geological Society of America. March 27-30th, 2008. *

* This presentation was awarded “best undergraduate poster” at the 2008 Northeastern Geological Society of America conference.


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