We know less about Early Pennsylvanian ecosystems, but they played a key role in the evolution of insects, arachnids, tetrapods, and seed plants.
While much of the fossil record focuses on swampy coal-rich sites, a new discovery in Massachusetts offers a different look.
Researchers have found a rich fossil site in the Wamsutta Formation of eastern North America. This site, preserved in clastic deposits, gives us a unique view of life during this important time, helping fill in the gaps about early ecosystems and the organisms that lived in them.
A Window into Ancient Terrestrial Ecosystems
The Lantern North (LN) fossil site, dating to around 320–318 million years ago, is located in the Wamsutta Formation in eastern North America. The site is a significant paleontological location in Massachusetts, USA and was discovered by geologists in 2019.
This site predates most well-known fossil sites from the Coal Age, preserving not only body fossils but also footprints, burrows, and other trace fossils that reveal animal behaviors and interactions.
Evidence of some of the earliest insect behaviors—like egg-laying and plant galling—has also been found here, pushing these behaviors back in the fossil record by millions of years.
Unlike the swampy coal-forming environments common to other fossil sites of this period, the Wamsutta Formation captures a seasonally wet, forested alluvial fan environment near the ancient equator, offering a fresh perspective on early terrestrial ecosystems.
This site reveals 131 vertebrate, invertebrate, and plant fossils, including 83 plant types and early evidence of insect egg-laying. One example is the discovery of a full-body impression of a whip scorpion species, Inmontibusichnus charleshenryturneri.
The researchers explain that fossils like this are “extremely rare,” and this one is thought to be “the first record of its kind that can be unquestionably attributed to a whip scorpion tracemaker,” according to the study.
Careful Collection & Analysis of Early Lantern North Life
Fossils at the LN site in southeastern Massachusetts, USA, have been collected since 2007. Potential fossil-bearing rocks, like fine sandstones and shale, were uncovered and carefully examined.
The researchers removed the fossils using hand tools, mapped in the rock layers, and recorded with GPS coordinates for precise location tracking. Wider exposures around the site were studied to understand the surrounding rock layers, connecting them back to the fossil-rich areas.
In the lab, fossils were photographed with specialized cameras and lenses, and small features were examined with a microscope, with images sharpened through focus-stacking for detailed analysis.
Where to Find the Specimens
Most fossils referenced in the study are housed at Harvard University’s Museum of Comparative Zoology (MCZ), with a few invertebrate fossils held in the University of Kansas Natural History Museum’s Fossil Insect Collection.
These findings offer a glimpse into ancient terrestrial ecosystems and evolutionary relationships among early land organisms.
As lead author Richard Knecht, a student at the Griffin Graduate School of Arts and Sciences in the Department of Organismic and Evolutionary Biology, explained, “This site gives us an unprecedented look at a terrestrial ecosystem from a crucial time in the evolution of life on land. We’re seeing evidence of complex plant-insect interactions and some of the earliest appearances of major animal groups that went on to dominate terrestrial habitats.” (ref)
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Nancy Maffia
Nancy received a bachelor’s in biology from Elmira College and a master’s degree in horticulture and communications from the University of Kentucky. Worked in plant taxonomy at the University of Florida and the L. H. Bailey Hortorium at Cornell University, and wrote and edited gardening books at Rodale Press in Emmaus, PA. Her interests are plant identification, gardening, hiking, and reading.
