Big Brook Fossil Hunting Guide: Cretaceous Shark Teeth and Fossils in New Jersey
Plan a fossil hunting trip to Big Brook Park in Monmouth County, New Jersey. This guide covers Late Cretaceous shark teeth and other fossils, Boundary Road parking, current park collecting rules, geology, field tips, equipment, and a detailed fossil identification guide.
Key Takeaway: Big Brook is one of New Jersey's best-known fossil hunting areas. The stream concentrates Late Cretaceous fossils eroded from older marine sediments, especially shark teeth. Mosasaur, sawfish, ray, fish, belemnite, ammonite, and rare dinosaur fossils can also turn up. Fossil collecting access is now from the Boundary Road parking lot, and current Monmouth County Park System rules should be checked before every trip.
Quick Facts for Big Brook Fossil Hunters
Location: Big Brook Park, Monmouth County, New Jersey.
Fossil Access: Use the Boundary Road parking lot for fossil collecting access.
Age: Late Cretaceous, with many classic finds around 70 million years old.
Rock Units: The brook exposes Upper Cretaceous units including the Wenonah, Mount Laurel, and Navesink formations. Fossils weather out and become concentrated in modern stream gravels.
Best Known For: Fossil shark teeth, plus mosasaurs, sawfish and rays, bony fish, belemnites, ammonites, and rare dinosaur remains.
Best Finds for Beginners
Small shark teeth are the classic Big Brook find. Patiently searching gravel/pebble areas is often more productive than moving quickly.
How Fossils Collect
Fossils erode from Cretaceous sediments and are reworked by the brook. Heavier teeth, bone fragments, pebbles, and shell material can collect together in gravel. Search areas where gravel/pebbles accumulate.
About Big Brook Fossil Hunting in New Jersey
Big Brook has been a favorite New Jersey fossil hunting destination for generations because fossils are continuously exposed by stream erosion. Instead of digging into a rock quarry or cliff, collectors search loose gravel in and along the brook for fossils that have weathered out of Late Cretaceous marine sediments.
The best-known finds are shark teeth, especially teeth from extinct Cretaceous sharks. The same deposits also preserve rays, sawfish, bony fish, marine reptiles, shellfish, belemnites, ammonites, and other animals that lived in or near the ancient Atlantic coastal sea. Terrestrial fossils are much rarer, but dinosaur teeth and bone fragments occasionally reached the marine environment and were buried with the sea life.
Why Are Cretaceous Fossils Found at Big Brook?
New Jersey Was Along a Cretaceous Sea
During the Late Cretaceous, sea level was much higher than today and much of the New Jersey Coastal Plain was underwater or close to the coast. Marine sediments accumulated offshore and preserved sharks, rays, bony fish, marine reptiles, mollusks, and other organisms. Remains of dinosaurs and other land animals occasionally reached the sea from nearby land.
The Fossils Come From Several Rock Units
Big Brook exposes a Late Cretaceous sequence that includes the Wenonah, Mount Laurel, and Navesink formations. The stream cuts through these sediments and moves fossils into modern gravel deposits. Because the fossils have been reworked by flowing water, a fossil found loose in the brook is not always easy to assign to one exact formation.
Research on Big Brook shows that many vertebrate fossils in the stream gravels are likely sourced from the Mount Laurel Formation, although fossils from the Navesink and other nearby units also occur. This is one reason a simple statement that every Big Brook fossil comes from the Navesink Formation can be misleading.
Why Dinosaur Fossils Are Rare
Most of the sediments were deposited in marine settings, so sea animals dominate the fossil record. Dinosaur remains had to be transported from land into the marine environment before burial. That makes hadrosaur teeth and other dinosaur material exciting but uncommon finds compared with shark teeth and marine invertebrates.
Fossils You Can Find at Big Brook
Big Brook is famous for variety. A normal trip may produce small shark teeth and pieces of marine invertebrates, while more unusual finds include mosasaur teeth, sawfish rostral teeth, ray teeth, fish vertebrae, ammonite fragments, and occasional reptile or dinosaur material.
Shark Teeth
The most familiar finds include extinct goblin sharks, crow sharks, mackerel-type sharks, and tiny angel shark teeth. Tooth shape, serrations, cusplets, and enamel texture help with identification.
Mosasaurs
Mosasaur teeth and isolated bones are much less common than shark teeth. These large marine reptiles were important predators in Late Cretaceous seas.
Sawfish and Rays
Sawfish rostral teeth and ray crushing teeth occur in the brook gravels and can look very different from ordinary shark teeth.
Bony Fish
Fish vertebrae, crushing teeth, and teeth from predatory fishes such as Enchodus can be found among the stream gravel.
Invertebrates
Belemnites, ammonite fragments, oysters, brachiopods, and trace fossils help show that the area was once a marine environment.
Rare Land Fossils
Hadrosaur teeth and other dinosaur material occasionally occur, but terrestrial fossils are far less common than marine fossils.
Big Brook Fossil Identification Guide
Once you get home, use the dedicated Big Brook identification page to compare your finds with photographed examples. It covers sharks, mosasaurs, dinosaurs, skates and rays, bony fish, belemnites, ammonites, and other Cretaceous fossils found in the New Jersey brooks.
Big Brook Fossil Hunting Parking and Access
Use the Boundary Road Parking Lot for Fossil Collecting
The Monmouth County Park System currently directs fossil collectors to access Big Brook from the Boundary Road parking lot. The parking area is listed on Google Maps as Big Brook Park Boundary Road Parking, 103 Boundary Rd, Colts Neck, NJ 07722. The older Hillsdale Road parking is permamently closed.
Google Map: Big Brook Park Boundary Road Parking
Big Brook Park also has a main entrance on Route 520, but the Boundary Road parking lot is closer to the actual brook for fossil collecting.
Before You Drive: Access rules and park conditions can change. Check the official Big Brook Park page before your trip, especially after storms or during seasonal closures.
Current Big Brook Fossil Collecting Rules
Big Brook is a public park, and the collecting rules are designed to protect the stream while still allowing visitors to enjoy fossil hunting. The summary below reflects the current Monmouth County Park System supplemental rules. Always check the official rules before visiting because regulations can change.
Park Hours
Collect fossils only during posted park hours.
Parking
Fossil collecting access is from the Boundary Road lot. The older access site on Hillsdale road is closed.
No Bank Digging
Excavating or digging into the stream bank is prohibited.
Hand Tools Only
Small hand tools such as trowels and shovels may be no greater than 14 inches in total length. Mechanical digging, drilling, or sifting equipment is prohibited.
Stream Bed Limit
Do not disturb the stream bed deeper than 6 inches.
Daily Take Limit
Small paleontological items taken from the park must fit within about a 12-ounce can or a sandwich-size zip-top bag per person, per day.
Groups
No permit or fee is required for individuals or groups of 10 or fewer. Larger groups must register for a Naturalist-led program.
Children
Children under 14 must be accompanied by a parent or guardian who remains in visual contact.
Protect the Brook
Do not damage vegetation or wildlife, divert the stream, or dam its natural flow.
Official Rules: Review the Monmouth County Park System Supplemental Rules Governing Fossil Collecting at Big Brook Park before your visit.
How to Find Fossils at Big Brook
Big Brook fossil hunting is mostly a matter of slowing down and learning what to look for. Shark teeth and bone fragments can blend into the dark gravel, so careful searching usually works better than rushing through a large stretch of stream.
1. Start With Gravel
Look for gravel bars and pockets of pebbles, this is generally where the fossils accumulate
2. Search Slowly
Scan a small patch of gravel carefully. Fossil teeth are the same color as the pebbles and blend right in.
3. Check Both Sides
Turn over unusual pieces. A fossil may be recognizable on one side, but eroded and unrecognizable on the other.
4. Iron Concretions
The formations have layers of iron concretions, which come in all shapes and sizes. These are often confused for fossils.
5. Use Only Legal Tools
Stay within the current hand-tool and stream-bed limits, and never dig into the banks.
6. Recheck After Rain
Rain and freeze-thaw can expose new material, but wait until water levels have returned to safe conditions.
7. Identify Later
Keep notes and compare unusual finds with the Big Brook identification guide once you can examine them closely.
Stream Safety
Do not fossil hunt during flooding or rapidly rising water. Stream conditions can change quickly after rain. The park also warns that streams may contain sharp objects, so sturdy footwear is important.
Recommended Fossil Hunting Equipment
Waterproof Boots
Sturdy waterproof boots or wading shoes with tough soles protect your feet if you step on broken glass.
Small Hand Tool
If you bring a trowel or shovel, keep the total tool length within the current 14-inch park limit.
Small Fossil Container
Use a sandwich-size zip-top bag or similarly small container so you stay aware of the current take-home volume limit.
Water and Sun Protection
Bring drinking water, sunscreen, and a hat during warm weather.
Tick and Mosquito Repellent
Wooded stream corridors have ticks and mosquitoes, especially during warmer months.
Recommended Equipment for Big Brook
SE 13 1/4 Inch Stackable Classifier Gold Prospecting Pan - Stainless Steel Mesh Sifting Pan
This is a 13.25-Inch diameter and 3.5-Inch deep sifter. It's lightweight and the 1/4" screen is ideal for shark tooth sifting at the brooks. There is also a 1/8" screen version for the really small stuff, but I recommend the 1/4" version.
iunio Camping Shovel,Shovel Folding, Portable, Collapsible Spade (Basic E-Tool)
This is a small protable folding shovel to go with a small sifter. The blade is 6 inch regulation length, so it's good to go for in the brooks. Just remember to get the smaller one, as the others have blades that are too long for the regulations.
Recommended Books for New Jersey Fossils and Paleontology:
When Dinosaurs Roamed New Jersey
William Gallagher, 1997
Explore New Jersey's geological journey from Cambrian seas to the Pleistocene Ice Age in 'When Dinosaurs Roamed.' Gallagher unveils fossil hunters' tales, ecological insights,
and scientific controversies, offering a concise and captivating glimpse into the state's prehistoric wonders. Although it was written in 1997, it is still the best book on NJ paleontology out there!
101 American Fossil Sites You've Gotta See
Albert B Dickas, 2018
This is a great updated fossil sites book with at least one fossil site in each state. Each site is broken into 2 pages. One has detailed information, such as directions, GPS coordinates, formation information, etc...
The other is dedicated to images of the site and the fossils found there. It also gives information on fossil 'viewing' sites such as dinosaur trackways, museums, and active excavations.
Plus, my fossil photos are peppered throughout this book, including the Big Brook site!
References and Current Access Information
Monmouth County Park System. Big Brook Park. Current park information, fossil collecting access, and Boundary Road parking guidance. Big Brook Park official page.
Monmouth County Park System. Supplemental Rules Governing the Hunting and Collecting of Fossils at Big Brook Park. Current fossil collecting rules.
Brownstein, C. D. (2019). New records of theropods from the latest Cretaceous of New Jersey and the Maastrichtian Appalachian fauna. Royal Society Open Science 6:191206. Open-access article.
Brown, J. O., and Morano, J. Common Cretaceous fossils of Big Brook and Ramanessin Creek, in Geological Association of New Jersey materials on Monmouth County geology and paleontology. GANJ guidebook.
Big Brook Fossil Hunting FAQs
Where do I park to hunt fossils at Big Brook?
Use the Boundary Road parking lot. The Monmouth County Park System currently lists Boundary Road as the fossil collecting access, and Google Maps lists the parking area as Big Brook Park Boundary Road Parking at 103 Boundary Rd, Colts Neck, NJ 07722.
What fossils can you find at Big Brook, New Jersey?
Shark teeth are the best-known finds. You can also find sawfish and ray fossils, fish teeth and vertebrae, belemnites, ammonite fragments, mosasaur material, and rare dinosaur fossils.
How old are the fossils at Big Brook?
Most classic Big Brook fossils are Late Cretaceous and roughly around 70 million years old. Several Upper Cretaceous formations are exposed in the brook area.
Do I need a permit to collect fossils?
No permit or fee is required for individuals or groups of 10 or fewer under current park rules. Larger groups must register for a Naturalist-led program.
Can I dig into the stream banks?
No. Digging or excavation into the stream banks is prohibited.
What tools can I use?
Small hand tools such as trowels and shovels may be no greater than 14 inches in total length. Mechanical digging, drilling, or sifting equipment is prohibited, and stream-bed disturbance may be no deeper than 6 inches.
How many fossils can I keep?
The current rule uses a volume limit. Small paleontological items removed in one day must fit within about a 12-ounce can or a sandwich-size zip-top bag per person.
When is the best time to hunt fossils?
Fresh gravel can appear after rain and freeze-thaw, but never enter the brook during flooding or unsafe high water. Wait until conditions return to normal.
Is Big Brook good for children?
Yes, but stream conditions require close supervision. Children under 14 must be accompanied by a parent or guardian who remains in visual contact.
How do I identify a fossil I found?
Use this webpages Big Brook Fossil Identification Guide. It includes photographs and identification notes for the most common fossil groups.
