Stephen Groff has spent nearly his entire relationship with the Calvert Marine Museum working his way up — from junior docent, to volunteer, to Fossil Club president — and this month, the museum named him its new assistant curator of paleontology.
Groff steps into the role with a scientific résumé that includes both being honored by a fossil species and naming one himself. In April 2019, Groff and fellow fossil enthusiast Marcus Jones discovered the bony braincase of a fossil cobia embedded in a block of sediment that had fallen from Calvert Cliffs — the first cobia skull ever recovered in the fossil record. Groff has described the discovery’s slow reveal: he returned to the site the next day with CMM Paleontology Collections Manager John Nance to properly collect the specimen, and it was only then that the pair realized what they had was a full skull. CMM Curator of Paleontology Dr. Stephen Godfrey and Italian fossil-fish specialist Dr. Giorgio Carnevale later determined the find represented an entirely new species, naming it Rachycentron stremphaencus — a name blending “Stephen” and “Marcus” — in a paper published in the Journal of Paleontology.
More recently, Groff turned discoverer into namer himself. This July, he served as lead author on a paper in the Journal of Crustacean Biology describing Pinnotheres prochowniki, a newly identified species of fossil pea crab found at Calvert Cliffs and dating back roughly 10 million years. The species honors the late Bill Prochownik, a longtime CMM paleontology volunteer nicknamed “Robo-Bill” within the local fossil-hunting community for his relentless work excavating specimens from the cliffs. Prochownik died unexpectedly in 2023 at age 40 and was posthumously named the museum’s Volunteer of the Year that year. Groff co-authored the paper with Victor J. Perez, Carrie E. Schweitzer, John R. Nance, and Cory C. Deltrove.
That combination — being the subject of a scientific naming and, later, doing the naming himself — reflects the arc of a program built almost entirely on dedicated amateurs and volunteers. CMM’s paleontology collection now holds roughly 200,000 specimens drawn from Calvert Cliffs, a site that has yielded significant fossil finds for more than a century. The museum’s paleontology program leans heavily on volunteers to locate, excavate, and prepare specimens pulled from the cliffline as it erodes — the same work Groff has done in nearly every role the department offers, now including its newest one.
“Groff brings a wealth of experience and passion for the preservation of the rich fossil resources preserved here in Calvert County along Calvert Cliffs and within the state of Maryland,” the museum said in announcing the appointment, adding that he is “excited to continue the tradition of the museum to make new discoveries and share those as widely as possible.”
