New Ancient Fish Species Discovered Along Pennsylvania Highway – Drexel News Blog

A bodily reconstruction of a new species of Langlieria Upper Devonian (Frasnian) Irish Valley Member of the Catskill Formation. By Jason P. Downs, PhD.

At the end of the Devonian period (380 to 360 million years ago), the world was a very different place than it is today – the climate, physical location and characteristics of the continents slowly changed with time. Over the past 30 years, paleontologists from the Academy of Natural Sciences at Drexel University have studied Devonian-age rock strata, mostly exposed along highways, and collected large numbers of fossil fish from the present-day Pennsylvania.

During the Devonian Period, Pennsylvania 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, the mountains were being pushed east, and these were eroding, sending mud, silt, and sand into the river systems – where countless aquatic organisms found their final resting place and became fossilized.

In 2016, James J. Smaling of York, Pennsylvania contacted the Academy after discovering large, well-preserved fossil bones in rocks along a severed highway in Center County. Smaling, who often devotes his time and effort to searching for traces of ancient life, was aware of the Devonian age of the fossils and recognized the importance of the bones.

Smaling’s discovery is a new species of lobe-finned fish within the group called Langlieria. The fossil remains he found included high quality cranial material – the roof of the skull, the cheek and the lower jaw; fin material; and body scales. The new species Langlieria smalinginamed 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 in images of his findings, it was clear that this was likely to be an important find with great scientific interest,” said Ted Daeschler, PhD, curator of vertebrate zoology at the ‘Academy, professor at the College of Arts and Sciences. and co-author of the new article. “Jim and his fossil collector friend, the late Jim Forster, delivered approximately 250 pounds of red sandstone in several large chunks to the Academy’s Paleontology Laboratory, beginning the fossil evaluation process, splitting the rocks to reveal fossils We quickly determined that the find belonged to the group called Tristichopteridae, a group of lobe-finned fishes.

Daeschler and his colleague Jason Downs, PhD, an Academy research associate, 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. Tristichopterids fit into the tree of life among a great diversity of lobe-finned fishes that lived in streams and along coasts during the middle and late Devonian period. They were large predatory fish a meter long or more.

“The term ‘lobefin ​​fish’ can be a bit confusing to people,” Downs said. “While tristichopterids are fish-like – meaning they have fins, swim and breathe with gills – they are actually disconnected from the modern concept of fish and are more closely related to vertebrates with limbs, fingers and toes (including human ones).”

“To understand the present we must first understand the past, so the mind must reconstruct Pennsylvania with muddy streams moving east to west in a subtropical environment – truly a very different place than we know” , Daeschler said. “Pennsylvania has some very good rocks formed in stream systems from this period, and that’s what we’re looking for.”

Researchers are not only studying Devonian life in Pennsylvania, but around the world. The goal is to build a more comprehensive perspective on the history of life at a time when life on Earth made great strides in transitioning from aquatic to terrestrial environments.

“This finding helps us build on previous research and facilitate a better understanding of the anatomical and ecological changes that this group of vertebrates have undergone at this point in Earth’s history,” Downs said. “Langlieria smalingi gives us new insight into a unique animal at a pivotal time in vertebrate evolutionary history.

Media interested in speaking with Daeschler or Downs should contact Emily Storz, Senior Information Officer, Media Relations, [email protected] or 215.895.2705


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