'Skehanos' Enters the Scientific Lexicon

'Skehanos' Enters the Scientific Lexicon

By Mark Sullivan
Staff Writer

As longtime director he helped put the Weston Observatory on the seismometers of earthquake-trackers the world over. He said the first Mass on the volcanic island Surtsey soon after it rose from the North Atlantic.

Rev. James Skehan, SJ, is now the namesake of a genus of trilobite that existed 500 million years ago. Photo by Justin Knight
Now, Rev. James Skehan, SJ, professor emeritus in the Geology and Geophysics Department, has had a half-billion-year-old genus of trilobite named in his honor, in a fossil bouquet to his lifetime contribution to the earth sciences.

Mount Holyoke College paleontologist Mark A. S. McMenamin coined the name Skehanos for a genus of the undersea invertebrate from 500 million years ago whose fossilized remains have been found in Hayward's Quarry in Quincy, Mass.

"The genus is named for James W. Skehan, to honor his contributions to New England geology," McMenamin writes in the journal Northeastern Geology and Environmental Sciences in a December article establishing the genus.

The trilobite, an extinct marine arthropod vaguely resembling a horseshoe crab, inhabited the primordial seas that covered New England during the Cambrian period 500 million years ago. Skehanos is of "particular evolutionary importance because these trilobites are apparently ancestral to most...later trilobites," writes McMenamin.

Much of Fr. Skehan's published research during the past 40 years has been devoted to the history of the Avalon terrane, the geological micro-continent stretching from Long Island to Belgium upon which Boston lies. The Avalon terrane drifted over time, joining the North American land mass in a continental collision 400 million years ago.

Studying the fossils of Skehanos and cousins left behind in the undersea mud that formed New England's rock ribs adds to knowledge of the geologic record of North America.

The Skehanos trilobite found in Quincy also has been found in South Carolina, in the Asbill Pond formation near Batesburg, McMenamin reports. This discovery indicates that, on the basis of trilobite occurrences, the Carolina terrane should be considered part of the Avalonian group of terranes.

The distinction is the latest for scientist priest Fr. Skehan, whose interest in rocks, born in the stony potato fields of his native Aroostook County in Maine, has taken him around the world in a quest to map multi-million year changes in the Earth's face.

At Weston Observatory, which he directed from 1973-93, a portrait of Fr. Skehan was unveiled this month to mark his 80th birthday. The fossil came as a most unexpected and welcome present.

"I cannot imagine a more significant gift and accolade than having the Avalonian trilobite genus Skehanos named for me by a fellow geologist who has established that Skehanos may have evolutionary linkages to even older Precambrian ancestral Australian species, and also may serve as a key to possible worldwide discovery of additional Avalonian terranes," Fr. Skehan said.


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