308-Million-Year-Old Arachnid Fossil Challenges Classification

Douglassarachne acanthopoda, discovered in Illinois, exhibits unique spiny legs unlike any known arachnid group.

The fossil was found in the Mazon Creek locality, a significant site for late Carboniferous period fossils.
Douglassarachne acanthopoda's body length is about 1.5 centimeters with notably robust and spiny legs.
Researchers are unable to place it in any known arachnid order due to its unique features.
The fossil provides insight into the experimental body plans of arachnids 300 million years ago.
The specimen was donated to the Field Museum of Natural History by the Douglass family.