The coastal seas surrounding Appalachia left behind some of the best preserved fossil specimens in all of the East Coast. One state in particular is famous for its Cretaceous Marine fossils: New Jersey. Every year, private collectors and museum paleontologists alike flock to New Jersey to uncover ancient bones left behind by creatures which lived around 70 million years ago. One of the most famous site is Ramanessin Brook, where not only Cretaceous marine fossils but also Pleistocene fossils can be found.
Commonly, fossils from the Navesink and Wenonah/ Mt. Laurel Formations are found in the brook, providing a glimpse into the ancient past of New Jersey. Fossils dating from the Pleistocene Ice Age are also found in the brook, giving this site a bit of variation in its fossil contents. Ramanessin Brook is known for one thing in particular: shark teeth. Exquisitely preserved shark teeth are a dime-a-dozen when it comes to this place. Although seemingly nothing compared to localities in the west, sites like Ramanessin brook offer us a lot of information on the ancient sea life of the Western Atlantic Ocean.
Invertebrate fossils are also found in the sediments of the brook. Partial ammonite shells, belemnite guards, and even giant oyster shells are pretty common at the brook. Here are a selection of invertebrate fossils:
Vertebrate body fossils are even more common then those of invertebrates at Ramanessin Brook. By far the most common are shark teeth. During this trip, shark teeth from at least 5 different species of shark were collected. Common teeth include those of Archaeolamna kopingensis kopingensis , Squalicorax kaupi, and Scapanorhynchus texanus. What’s especially interesting is that S. texanus, unlike its modern relative, lived in coastal waters. S. texanus is also the largest known species of Scapanorhynchus.
Porbeagle sharks are represented by a couple genera, namely Archaeolamna kopingensis kopingensis and Cretodus borodini. These were both mid-sized sharks, with A. kopingensis kopingensis reaching 10 feet in length and C. borodini peaking at 7 feet from snout to tail.
The largest sharks in these waters were Squalicorax pristodontus. Only one tooth of this shark was found during my trip. These guys could reach up to 20 feet in length. Even these sharks, however, weren’t the largest predators in the sea, with large mosasaurs like Mosasaurus and Prognathodon also calling the west Atlantic home (Gallagher, 2005).
The ecosystem the Navesink and Mt. Laurel/ Wenonah Formations represent is a coastal sea. As evidenced by the shark teeth above, there was a high diversity of sharks in the Western Atlantic during the Late Campanian/ Early Maastrichtian.
These fossils are also a tricky task to identify in some circumstances. Not much has been published recently on Eastern US deposits (one of the reasons I started the series Antediluvian Beasts) , and so to accurately identify these fossils, we must look at the old literature (I’m taking literature by Joseph Leidy) and the new(ish). I will have much more to say about this site in the future, but for now I wanted to give a brief introduction. For a little more on the animals of Ramanessin Brook, refer to these past articles:
1.Gallagher, W. B. . 2005. “Recent mosasaur discoveries from New Jersey and Delaware, USA: stratigraphy, taphonomy and implications for mosasaur extinction.” Netherlands Journal of Geosciences 84(3):241-245