During the late part of the Devonian Period (380-to-360 million years old ago), the world was a very different place than today – the climate, physical location and features of the continents have slowly changed with time. Over the past 30 years, paleontologists from the Academy of Natural Sciences of Drexel University have studied Devonian-age rock strata, mostly exposed along highway roadcuts, and collected large numbers of fossil fish across what is now Pennsylvania.
Pennsylvania during the Devonian Period was part of a larger landmass that spanned the equator and included parts of North America, Europe and Greenland. While Pennsylvania was south of the equator, mountains were being pushed up to the east, and those were eroding away, sending mud, silt and sand into stream systems – where countless aquatic organisms found their final resting place and became fossilized.
In 2016, James J. Smaling, of York, Pennsylvania, reached out to the Academy after he discovered some large, well-preserved fossil bones in rocks along a highway road cut in Centre County. Smaling, who often dedicates his time and effort to the search for traces of ancient life, was aware of the Devonian age of the fossils and recognized the bones as significant.
Smaling’s find is a new species of lobe-finned fish within the group called Langlieria. The fossil remains he found included high-quality cranial material — the skull roof, cheek and lower jaw; fin material; and body scales. The new species Langlieria smalingi, named in honor of its discoverer, was recently described, and published in the Proceedings of the Academy of Natural Sciences of Philadelphia.
“As soon as Jim Smaling sent images of his finds, it was clear that this was likely an important discovery with great scientific interest,” said Ted Daeschler, PhD, curator of vertebrate zoology at the Academy, professor in the College of Arts and Sciences and co-author of the new paper. “Jim and his fossil-collecting buddy, the late Jim Forster, delivered about 250 pounds of red sandstone in several large blocks to the Academy’s paleontology lab, beginning the process of assessing the fossils, splitting the rocks to reveal additional fossils, and the detailed work of fossil preparation and preservation. We quickly determined that the find belonged to the group called tristichopterids, a group of lobe-finned fish.”
Daeschler and colleague Jason Downs, PhD, a research associate at the Academy, associate professor at Delaware Valley University and co-author of the description of the new species, have collaborated for more than 20 years on many important fossil discoveries, including several species of tristichopterids from Pennsylvania. The tristichopterids fit into the tree of life among a great diversity of lobe-finned fish that lived in streams and along coastlines in the middle and late part of the Devonian Period. They were large, predatory fish, a meter or more in length.
“The term ‘lobed-finned fish’ can be a bit confusing to people,” Downs said. “While tristichopterids have a fish-like look – meaning they have fins, swim, and breathe with gills – they’re actually disconnected from the modern concept of a fish and are more closely related to vertebrates with limbs, fingers, and toes (including humans).”
“To understand the present, we have to first understand the past, so the mind needs to reconstruct Pennsylvania with muddy streams washing from east to west in a subtropical environment – really a very different place than we are familiar with,” said Daeschler. “Pennsylvania has really good rocks formed in the stream systems from that time period, and that’s what we are after.”
The researchers are looking not only at Devonian life from Pennsylvania, but from across the globe. The goal is to build a more complete perspective of the history of life during a time period when life on Earth made big advances in the transition from aquatic to terrestrial environments.
“This find is helping us build on past research and facilitate a better understanding of the anatomical and ecological changes experienced by this group of vertebrates at this point in Earth history,” said Downs. “Langlieria smalingi gives us a new glimpse at a unique animal at a pivotal time in the evolutionary history of vertebrates.”
News media interested in speaking with Daeschler or Downs should contact Emily Storz, senior news manager, media relations, firstname.lastname@example.org or 215.895.2705