When we think of prehistoric times, we often think of cavemen. Our hunter-gatherer ancestors foraging through dense forests, hunting wild game with nothing but handmade bows and arrows. If we look back even further, we think of dinosaurs roaming the Earth throughout the Triassic, Jurassic, and Cretaceous Periods. But what if we go back even further than the dinosaurs? Way back to the Paleozoic Era, and more specifically, the Devonian Period? This is where Alpena continues to hold on to the secrets of 400 million years ago.
The Devonian Period was the 4th period of the Paleozoic Era, which was roughly 416-358 million years ago! We call this period the “Age of the Fishes”, because of the intense diversity of marine life during this time. A time before the supercontinent of Pangaea was formed. A time when the oceans covered 85% of this strange Devonian world.
Most of the fish during this time period were cartilaginous; ancestors to the shark species we know of today. Since cartilage does not fossilize, the fossils you may find at Rockport will typically be from “filter feeding” creatures that existed during the middle Devonian Period. However, remnants of the most notorious fish species from the Devonian era have been found in Michigan before. This carnivorous placoderm fish came to be during the late Devonian Period, and is named Dunkleosteus (pronounced DUNKLE-OSTEUS). This creature adorned bony armor on the head and frontal region of the body, as well as bony structures, (much like teeth, but not true teeth), that were used to shear their prey. Paleontologists can only speculate what the torso and tail of this fish looked like, however it is believed that the Dunkleosteus grew as long as 33 ft.!
The chances of finding a Dunkleosteus in the quarry of Rockport are rare, but this king of the Devonian sea deserves an honorable mention. A depiction of this fish is shown above in the mural outside of Besser Museum for Northeast Michigan, painted by the talented Judy Dawley.
So what can you be sure to find amongst these rocks from millions of years ago at Rockport State Recreation Area?
- Bryozoans– Aquatic invertebrate, filter feeders.
- Corals– The Devonian Period was also a time of great reefs, covering most of the world’s oceans.
- Crinoids– Echinoderms, also filter feeders.
- Brachiopods– Lophotrochozoan animals with hard shells known as “valves” on the upper and lower surfaces.
Before you begin your amateur paleontology adventure, don’t forget to pack the essentials!
- A bucket- visitors are permitted to take up to 25 lbs. of fossils per person, per year.
- Sturdy shoes for walking/hiking.
- The Rockport Adventure Guide– Because Rockport is full of more than one kind of adventure!
- Swim gear- April is too chilly for a swim, but if you are taking a Rockport adventure this summer, you won’t be able to resist a dip in the crystal clear waters of Lake Huron.
- A camera- or a fully charged phone for smartphone photography. You will want to capture all the beautiful sights!
- Snacks and water
- Bug Spray
- Sunglasses and sunscreen
Show us pictures of your finds and tag @sanctuary_of_the_great_lakes on Instagram, or Alpena: Sanctuary of the Great Lakes on Facebook.
Find out more about the Devonian Period by clicking the link here to National Geographic