Thumbnails of Types of Cretaceous Fossils
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Dinosaurs
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Dinosaur remains that floated offshore during the cretaceous are sometimes found with the marine fossils. They are
scarce finds. The most common dinosaur material found are Hadrosaur teeth. They are very small and are often very worn.
Some examples of Dinosaur material are shown below.
Hadrosaur Teeth
Duck Billed Dinosaur
These are Hadrosaur teeth, the more common Dinosaur find in the brooks of New Jersey. All dinosaure material is scarce.
Mosasaur
Great Marine Reptile
The Mosasaur was a great marine reptile that thrived during the Cretaceous. It was a top predator of the seas. The most common species of Mosasaur found in Monmouth County is M. conodon, a medium sized Mosasaur.
To learn all about these Great Marine Reptiles of the Cretaceous, go to the
Mosasaur Gallery
.
Identification:Mosasaur teeth superficially look like crocodile teeth. However, mosasaur teeth have a distinct cutting edge (seen in the top center view).
The cutting edge is the easiest way to distinguish mosasaur teeth from crocodile teeth.
Mosasaur conodon tooth. This tooth is chipped up, but most of the enamel is in great condition. Another few days in the brook, and it probably would have split apart.
Sharks
Shark teeth are by far the most common cretaceous fossils found in the Big Brook area. A careful searching the gravel bars will produce at least a few teeth.
To learn all about Sharks, go to the
Shark Gallery
.
Archaeolamna kopingensis (Davis 1890)
Extinct Mackerel Shark
Cretolamna appendiculata (Agassiz 1843) Extinct Mackerel Shark
Cretolamna appendiculata looks like a small Cretaceous version of the
Paleocene and Eocene Otodus obliquus. It is thought by many that Otodus obliquus evolved
from Cretolamna appendiculata sometime in the late cretaceous.
This species became extinct sometime in the Paleocene, while the genus became
extinct in the Eocene.
Scapanorhynchus texanus (Romer 1852)
Extinct Goblin Shark
Having a flat snout that protrudes from the head, Goblin sharks look odd. This species
became extinct near the end of the Cretaceous, while the genus lasted into the Eocene.
A different genus of goblin shark still lives today, the deepwater Mitsukurina genus, although
it is rarely seen.
Goblin teeth are probably the most common cretaceous teeth found in the Big Brook area of NJ.
They can also reach sizes of over 2".
To learn more about Goblin Sharks, and to see pictures of the actual sharks, go to the Goblin Shark Page.
Identification: A defining characteristics of goblin anterior teeth are their striations on the lingual side of the tooth that continue onto the root (in unworn specimens).
The above tooth is a an example of a lateral tooth.
Notice how different the lateral teeth are compared to anterior teeth. Lateral teeth are significantly wider and flatter, they often have a cusplet or two,
and the striations have all but vanished.
This tooth is 1.12" (28 mm).
Squalicorax
Extinct Crow Sharks
This well known group of extinct sharks have distinctive teeth. The genus was only present in the Cretaceous. Out of the numerous species of squalicorax, two are represented from the Cretaceous of New
Squalicorax kaupi (Agassiz, 1843)
Extinct Crow Shark
Identification: This species is smaller than S. pristodontus, and has a distinct notch on the distil shoulder of their crowns.
Squalicorax pristodontus (Agassiz, 1843)
Extinct Crow Shark
Identification: This species have larger teeth than S. kaupi, and does not have a distinct notch on the distil shoulder of their crowns.
Squatina hassei (Leriche 1929)
Extinct Angel Shark
Squantina hassei is the Cretaceous species of the Angel shark.
Like all species of Angel Shark, the teeth are tiny. They are often less than 1/4" (6 mm).
Squatina Vertebra
Angel Shark Vertebra
This is a vertebra from a squantina shark. Angel shark vertebra, for some reason, always seem to have either the cartilage or the prismatic cartilage marks all over them (those are the little hexagon dots all over the vert in the image). This vertebra has been donated to the American Museum of Natural History and is specimen number: "AMNH FF 22425"
Skate and Ray Fossils
Ray fossils are often found in the New Jersey area. The most interesting ray fossils found are from Sawfish.
Ischyrhiza mira (Leidy)
Sawfish
Sawfish rostral teeth (the teeth that stick out of the sawfishes' snout) can be found on occasion at Big Brook.
These are three teeth that were found within a couple inches of each other on a gravel bar.
Brachyrhizodus wichitaensis (Roemer)
Myliobatoid Ray
Isolated teeth from this ray are fairly common at the site. This image shows 3 views of a tooth that attached to the side of the ray plate.
Bony Fish Fossils
Fish fossils are fairly common. Usually the fossils found are pieces of fish vertebra
Anomaeodus sp.
Pychodontid fish
Pycnodontid fish have a crushing mouth plate. The teeth, when not found isolated, look like rows of paving stones. Isolated teeth are round on one side, and hollow on the other side. The image a below shows both sides of the teeth.
Pychodontid fish have a battery of flat crushing teeth that enabled them to feed on crustaceans and mollusks.
Pychodontid crushing teeth can easily be confused with some of the worn gravel in the area. However, the bottoms of the crushing teeth are hollowed out.
The round looking teeth are often overlooked due to the fact that they look like small pebbles.
Hadrodus sp.
Hadrodus fish have a crushing teeth, similar to Pycnodontid, however the crushing teeth are very small and circular. They also have gill teeth the make rows toward the back of thier mouths. The image below shows examples of these gill teeth.
Enchodus petrosus (Cope)
Saber-Tooth Salmon
You've heard of Saber-Tooth Lions of the Pliocene, but have you ever heard of a Saber-Tooth
Salmon from the Cretaceous?
These large monster salmon are a predecessor to modern salmon. However, they had large saber-like
teeth that could reach over 3" long. Enchodus became extinct in the Paleocene, which is good...
I would hate to go fishing and catch one of those!
Fish Vertebra
Fish vertebra can be common in the sediments. They are usually smaller than this example.
Invertebrate Fossils
Invertebrate fossils are commonly found. These include Belemnites and other types of Cephalopods.
Belemnitella americana
Straight Shelled Cephalopod
A Belemnite is a type of extinct cephalopod. It looked kind of like a squid. The amber colored belemnite fossils found here are the internal shells of these squid like animals.
Belemnites are scarce if collecting at Ramanessin Brook and some other areas. However, at certain spots along Big Brook, they can be found in number.
Ammonite Fragments
Ammonite fragments are a somewhat common find. They are easy to identify due to the suture patterns.
Whole ammonites are very difficult to find.
Protocallianassa mortoni (Pilsbry, 1901)
Ghost Shimp Burrows - Trace Fossils
Some layers in the Navensink trench are chalk full of fossilized borrows from invertebrates.
The long tube like structures are fossilized invertebrate borrows. They are probably from Ghost shrimp. Their borrows filled in with iron rich sediments.

DINOSAURS
MOSASAURS
SHARKS
SKATES / RAYS
BONY FISH
INVERTEBRATES

