Antediluvian Beasts of the East : Scapanorhynchus texanus

It’s evening, and a number of pycnodont fish called Anomaeodus phaseolus swim above a coral reef in the cold, murky coastal waters of the newly formed Atlantic Ocean. They gracefully zip through the salty water, feasting on any morsel of edible material they can find. But there are bigger, stranger fish in this sea.

Behind a cluster of corals, a silent predator patrols the water, scanning for any signs of movement. Enter Scapanorhynchus texanus. The shark darts from the coral, and snares one of the Anomaeodus in its jaws. For the fish, death is certain , and for the shark, it’s just another successful hunt.

Scapanorhychus was a prehistoric goblin shark, and an extremely successful one at that. The largest species, S. texanus, was a common sight in the Atlantic Ocean during the Late Cretaceous. Fossil teeth and other possible remains of this shark species are found along Eastern US Seaboard, being found within the states of New Jersey (Phillips et. al., 2001) and North Carolina (Case, 1979). The teeth of S. texanus are the largest among all Scapanorhynchus species. When we scale S. texanus by comparing known S. texanus remains with those of the modern goblin shark, we find that S. texanus was around 11 feet in length.

Scapanorhynchus texanus teeth collected Ramanessin Brook, NJ.  Photo by the author, 2015.

Scapanorhynchus texanus teeth collected Ramanessin Brook, NJ. Photo by the author, 2015.

The fossilized anterior teeth of this shark have an elongated main cusp with bilateral roots, perfect for snagging slippery prey. The lateral teeth of the shark are more triangular in shape then the anterior teeth, and are far broader. 

The fossilized remains of this Mitsukurinid shark are  found in coastal deposits (Phillips et. al., 2001), suggesting that this animal occupied the niche of a coastal predator. This is a far different niche from modern goblin sharks, who prefer the ocean depths as their hunting ground. Well-preserved body fossils of some species of Scapanorhynchus show that this shark species also possessed the long, pointed snout and long tail of modern goblin sharks.

Scapanorhynchus texanus lateral tooth. Photo by the author, 2015.

Scapanorhynchus texanus lateral tooth collected at Ramanessin Brook, NJ. Photo by the author, 2015.

The teeth shown above came from “Scaps” which called the coastal plain of New Jersey home. This coastline was home to a variety of other large predators, including mosasaurs such as Halisaurus platyspondylus (Wright, 1988).

The teeth of other sharks which Scapanorhynchus texanus coexisted with at Ramanessin Brook. Photo by the author, 2015.

The teeth of other sharks which Scapanorhynchus texanus coexisted with at Ramanessin Brook. From left to right: Paranomotodon angustidens, Squalicorax kaupi, Archaeolamna kopingensis kopingensis. Photo by the author, 2015.

Teeth from other Scapanorhynchus species are also found in the Middle East (Retzler et. al., 2013), showing that this shark was present on both sizes of the Atlantic Ocean.

Scapanorhynchus texanus and an marine turtle by the author. Colored pencils and Copic markers on paper, 2015.

Scapanorhynchus texanus and an marine turtle by the author. Colored pencils and Copic markers on paper, 2015.

S. texanus was thriving during the Campanian and Maastrichtian stages of the Cretaceous, but this shark’s success was short-lived. Many species of Scapanorhynchus, as indicated by the fossil record, greatly declined in number following the KT extinction. However, this shark wasn’t at the end of its line. The modern goblin shark, Mitsukurina owstoni, is a surviving member of Scapanorhynchus’s lineage and continues to haunt the depths of the ocean today.

 References 

1. Phillips D., Rose E., Pedersen J. 2001. Big Brook Upper Cretaceous Geology and Paleontology. 127 W 83rd Street, New York, NY: The New York Paleontological Society.

2. Case, G. R. . 1979.”Cretaceous selachians from the Peedee Formation (Late Maestrichtian) of Duplin County, North Carolina.” Brimleyana (2): 77-89 [J. Kriwet/W. Glaeser/M. Carrano]

3. Wright KR. 1988. “A new specimen of Halisaurus platyspondylus (Squamata: Mosasauridae) from the Navesink Formation (Maastrichtian) of New Jersey.” Journal of Vertebrate Paleontology 8 (Supplement 3): 29A-30A.

4. Retzler A., Wilson M.A., Avni Y. .2013. “Chondrichthyans from the Menuha Formation (Late Cretaceous: Santonian–Early Campanian) of the Makhtesh Ramon region, southern Israel”. Cretaceous Research 40: 81–89.

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