Cephalopod
Cephalopods are a class of marine mollusks that include some of the most fascinating creatures to have ever lived, both extinct and living. Today, they’re represented by squid, octopuses, and cuttlefish, but in the ancient seas of Northwest Pennsylvania and Northeast Ohio, their ancestors ruled the water.
Fossil cephalopods, especially orthocones (straight-shelled nautiloid cephalopods), are common in Paleozoic rock layers throughout the region. These animals had long, chambered shells and used a siphuncle, a tube running through each chamber, to regulate buoyancy. Their fossils are often straight or gently curved and display beautiful internal chamber patterns when cut or polished.
Cephalopods were fast-moving, intelligent predators, using tentacles and jet propulsion to hunt trilobites, smaller mollusks, and other marine organisms. Their fossilized remains offer a glimpse into a time when invertebrates dominated the seas.
Whether coiled like an ammonite or straight like an orthocone, cephalopod fossils are striking and iconic finds, offering both scientific value and aesthetic appeal.
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Photos of Cephalopod
From trip: Lake Erie in August
