Shark Fossils Found at the Calvert Cliffs of Maryland

Fossils here include:

Shark Teeth, Shark Vertebrae, Megalodons

(The smallest divisions in the ruler are 1/8")

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Shark Teeth Sharks are related to Skates and Rays, as they are all in the Chondrichthyes Class. Fish in this class have a skeleton made of cartilage instead of true bone. What this means for the fossil collector is bones from these animals seldom fossilize. Occasionally a vertebra may be found, however mostly the hard shark teeth and ray crushing plates are found.

Alopias cf. latidens (Leriche, 1909) (Thresher Shark) Identification based on Kent (1994, pp.71-73). These teeth are uncommon in this area. Thresher sharks can get up to 11 feet in length, however almost half of its length is in its long tail. Modern Thresher sharks (A. vulpinus) are pelagic (open ocean sharks), and nocturnal. They usually eat small fish and squid. These fossil Thresher sharks probably had a similar behavior to their modern counterparts.

This is a slightly worn lateral tooth. Formation: Calvert, Plum Point member Age: Early - Middle Miocene ~ 18-15 m.y. Location: Plum pt, Calvert Co., MD Size: ~9/16" (13mm)

These are a few smaller ones. Formation: Calvert Age: Middle Miocene ~ 18-15 m.y. Location: First two are from Randle Cliff, the other one is from near Breezy Pt., Calvert Co., MD Size: Largest one (anterior) has a 1/2" slant height (12mm)

Carcharinus (Whaler Sharks) The Whaler Sharks are a large group of sharks, with over 57 extant species. They are found virtually all over the globe. They feed on a variety of prey, from bony fish, other sharks and rays, and squid Whaler Sharks were also very common in the Miocene seas. Teeth from the Whaler Shark genus are among the most common teeth found at many places in the Chesapeake group. It can be difficult to distinguish between many of these species based on their fossil teeth alone. This genus of shark still populates the Chesapeake bay today. The bay even acts as one of the most important nursery grounds on the east coast for the sandbar shark, Carcharhinus plumbeus.

Carcharhinus brachyurus (Gunther, 1870) aka egertoni (Agassiz, 1843) (Bronze Whaler or Copper Shark) Identification based on Kent (1994) & Purdy et al (2001). I use to call these teeth C. egertoni, but I guess that name is synonymous with C. brachyurus. Whatever they are, here is their info: This species of shark is still extant today. The lowers are easily confused with lemon shark teeth (Negioprion sp.), however, C. brachyurus lowers have tiny serrations at the top of their teeth, whereas lemon sharks do not.

The first set are labial views, the second are lingual views. Formation: Calvert, Plum Point member Age: Early - Middle Miocene ~ 18-15 m.y. Location: Randle Cliff, Calvert Co., MD Size: Uppers are about 5/8" (16mm), lowers are a bit smaller"

Carcharhinus priscus (Agassiz, 1843) (Gray Shark) Identification based on Kent (1994, pp.80-82). This genus of tooth is the most common found at many places along the Calvert Cliffs.

The top row show the lingual views, the bottom row show labial views. C. Priscus teeth have finely serrated enameloid shoulders and crown. Uppers and lowers are very difficult to distinguish, here they are shown in no particular order. Formation: Calvert, Plum Point member Age: Early - Middle Miocene ~ 18-15 m.y. Location: Randle Cliff, Calvert Co., MD Size: ~3/8" (10mm)

Carcharias sp. (Sand Tiger Shark) Identification based on Kent (1994, pp.39-43). Some Sand Tiger species can reach lengths of about 10 feet. Their fang like teeth are ideal for grasping fish. Their diet consists mostly of fish and sometimes crustaceans.

Carcharias teeth are very common at the cliffs, but they are usually too worn or too small to determine the species. They are probably a mix of C. acutissima, and reticulata. Formation: Calvert, Plum Point member Age: Early - Middle Miocene ~ 18-15 m.y. Location: Randle Cliff, Calvert Co., MD Size:

Carcharias cuspidata (Agassiz, 1843b) (Sand Tiger Shark) Identification based on Kent (1994, pp.80-82).

C. cuspidata is one of the more robust Carcharias teeth found at the cliffs. Formation: Calvert, Plum Point member Age: Early - Middle Miocene ~ 18-15 m.y. Location: Randle Cliff, Calvert Co., MD Size: 1 1/8" slant height (39mm)

Megatooth Sharks (C. megalodons and C. subauriculatus) The Megatooths have moved to their own page. Click here to get to them

The Megs have moved, click here to get to the Calvert meg page Formation: Calvert, Plum Point member Age: Early - Middle Miocene ~ 18-15 m.y. Location: Plum Pt., Calvert Co., MD Size: 2.75" (70mm) slant height

Galeocerdo aduncus (Agassiz, 1843) (Tiger Shark) Identification based on Kent (1994) & Purdy et al (2001). This species lived from the Oligocene into the Miocene and probably evolved into the extant G. cuvier. However, Purdy et al (2001) believe G. aduncus is not available as a scientific name. However, until a new name is assigned, I will continue to refer to it as G. aduncus. This extinct species is also smaller than the extant (living) Tiger shark (G. cuvier).

Right two are lingual views . Notice the coarse serrations on the enameloid shoulders. Uppers and lowers are very difficult to tell apart, these are arranged in no particular order. Formation: Calvert, Plum Point member Age: Early - Middle Miocene ~ 18-15 m.y. Location: Randle Cliff, Calvert Co., MD Size: usually ~ 1/2-3/4" (13-19mm)

Galeocerdo contortus (Gibbs, 1849) (Tiger Shark) Identification based on Kent (1994) & Purdy et al (2001). This species of Tiger Shark is very common along the U.S. East Coast deposits, but rarely found along the U.S. West Coast deposits. This species Lived from the upper Oligocene and became extinct in the Miocene. There are a few big differences between these and G. aduncus. First, the crowns are twisted, looking pathological, as shown in the profile view. Also, the enameloid shoulder has very fine serrations, unlike the coarse serrations of G. aduncus. This slender tooth form probably means the contortus fed on bony fish, while the aduncus and extant cuvier species fed on a wider variety of prey. This extinct species is also smaller than the extant (living) Tiger shark (G. cuvier).

The small upper teeth in the center are parasymphyseals. The lower right-most tooth is a posterior. The rightmost upper and lower teeth are lingual views. The roots on lower contortus teeth are more robust than the roots on uppers. However, laterals and anterio-laterals are very difficult to tell apart. Formation: Calvert, Plum Point member Age: Early - Middle Miocene ~ 18-15 m.y. Location: Randle Cliff, Calvert Co., MD Size: ~ 5/8 to 7/8" (16 - 22mm)

Hemipristis serra (Agassiz, 1843) (Snaggeltooth Shark) Identification based on Kent (1994) & Purdy et al (2001). This species lived from the late Oligocene into the early Pleistocene. They are commonly called Snaggeltooth Sharks due to the large serrations on their teeth. Species of Hemipristis are extant today, however, they are only found in tropical waters, and are much smaller than the fossil species. The fossil species are also found worldwide.

The center lower is a lingual view, the rest are labial views. The lowers rolled part way onto their sides, making profile views. As you can see, uppers and lowers are very different. To further demonstrate this difference, here is a modern Hemipristis jaw. Formation: Calvert & Choptank Age: Miocene ~ 18-15 m.y. Location: From various places, Calvert Co., MD Size: Largest is 1 1/2" (38mm)

These are all lingual views. This is to show the size and shape variation in the Hemi's. The smaller ones are abundant. Larger ones are slightly more difficult to find. Formation: Calvert & Choptank Age: Miocene ~ 18-15 m.y. Location: From various places, Calvert Co., MD Size: Largest is 1 3/8" (35mm)

Here is a neat pathological hemi. It has a curved blade and a double tip. difficult to find. Formation: Calvert or Choptank Age: Miocene ~ 18-15 m.y. Location: Chesapeake Bay area Size: ~1" (25 mm) Date: November 2006 TRIP

Isurus (Rafinesque, 1810) (Mako Sharks) Identification based on Kent (1994) & Purdy et al (2001). Mako sharks can grow up to 12 feet in length. Some fossil Makos probably were slightly larger than this. Makos are generally pelagic, or open ocean sharks. Modern Makos eat a variety of prey, including other sharks, fish (including tuna and swordfish), and squid. Some fossil Makos evolved into the present day Shortfin, and Longfin Mako sharks. Others may have evolved into the modern Great White shark. The "Makos" that evolved into the Great Whites should be assigned into the genus Cosmopolitodus to distinguish them from other Makos (Isurus sp.). However, Purdy et al (2001) believes Isurus could not have evolved into the Carcharodon genera. Among his evidence is a reference to Mitochondrial DNA sequences that estimate the Carcharodon origins in the Paleocene or early Eocene, which is much to early if Isurus evolved into Carcharodon.

Isurus desori (Sismonda, 1849) (Shortfin Mako Shark) Identification based on Kent (1994) & Purdy et al (2001). This species lived from the late Oligocene into the Pliocene, and probably evolved into the extant I. oxyrhinchus the Shortfin Mako.

This beauty (a lower anterior) is as big as my lee creek mako finds! Left is the lingual view, right is the profile view. Formation: Calvert, Plum Point member Age: Early - Middle Miocene ~ 18-15 m.y. Location: Willows, Calvert Co., MD Size: 2" (51mm) Date: Spring 2002

These are two smaller shortfin makos. Formation: Calvert, Plum Point member Age: Early - Middle Miocene ~ 18-15 m.y. Location: Left is from Brownies Beach , right is from Plum pt., Calvert Co., MD Size: right has a 1 1/2" slant (38mm) Date: Right was found in summer 2002

These are a couple smaller teeth. The left two are labial views, the right two are lingual views. Formation: Choptank & Calvert Age: Early - Middle Miocene ~ 18-15 m.y. Location: Various places, Calvert Co., MD Size: Largest is 1 1/4" (31mm) slant height

Isurus retroflexus (Agassiz, 1843) (Longfin Mako Shark) Identification based on Kent (1994). This species lived in the Miocene, and probably evolved into the extant I. paucus, the Longfin Mako.

This jet-black tooth is a rarer mako species found at the cliffs. The first view is the lingual view, the second is the labial view. In the labial view, there is a deep groove separating the platform from the rest of the tooth, this can be seen as the dark line running across the root. Formation: Calvert, Plum Point member Age: Early - Middle Miocene ~ 18-15 m.y. Location: Randle Cliffs, Calvert Co., MD Size: ~

Isurus hastalis (Agassiz, 1843) (exctinct Giant Mako Shark) Identification based on Kent (1994) & Purdy et al (2001). This was one of the larger Mako sharks. Some teeth can get to be over 3", which make for a very large shark (over 20 feet in length). It lived from the Oligocene into the Pliocene. This is the species whose predecessors are thought by some to have evolved into the extant Great White (Carcharodon carcharias). If this is the case, it should be called Cosmopolitodus hastalis. However, Purdy et al (2001) provides evidence against this, including Mitochondrial DNA sequences that estimate the Carcharodon origins in the Paleocene or early Eocene, which is much to early if Isurus evolved into Carcharodon. Also, ther appear to be two forms of this shark, or two species, I hastalis and I xiphodon. The xiphodons have a broader blade than the hastalis. I make no distinction here between species. Check the Lee Creek page to see examples of both species.

Here is a pristine mako. Found in a fresh fall, it never made it to the water to get worn. Click on the pic to see the trip it was found on. Formation: Calvert, Plum Point member Age: Early - Middle Miocene ~ 18-15 m.y. Location: Calvert Cliffs, Calvert Co., MD Size: ~ 1 11/16" (43mm) slant Date: July 2006 TRIP

This is nice lower mako tooth. Click on the pic to see the trip it was found on. Formation: Calvert or Choptank Age: Early - Middle Miocene ~ 18-15 m.y. Location: Chesapeake Bay area Size: ~ 2 1/16" (52mm) slant Date: June 2007 TRIP

This is a beautiful 2" lower mako tooth. Click on the pic to see the trip it was found on. Formation: Calvert or Choptank Age: Early - Middle Miocene ~ 18-15 m.y. Location: Chesapeake Bay area Size: ~ 2" (51mm) slant Date: November 2006 TRIP

This is a nice 2" upper mako that I found in a clay block. Click on the pic to see the trip it was found on. Formation: Calvert Age: Early - Middle Miocene ~ 18-15 m.y. Location: Chesapeake Bay Area, VA Size: ~ 2" (51mm) slant Date: August 2007 TRIP

This is a nice 2" lower mako that Amy found in a clay block. Click on the pic to see the trip it was found on. Formation: Calvert Age: Early - Middle Miocene ~ 18-15 m.y. Location: Calvert Cliffs, Calvert Co., MD Size: ~ 2" (51mm) slant Date: November 2006 TRIP

This is a nice 2" lower mako that Amy found in a clay block. Click on the pic to see the trip it was found on. Formation: Calvert Age: Early - Middle Miocene ~ 18-15 m.y. Location: Chesapeake Bay area Size: ~ 1 3/4" (44mm) slant Date: November 2006 TRIP

Upper and lower anterio-lateral teeth. The first view is the lingual view, the second is the labial view. Formation: Calvert, Plum Point member Age: Early - Middle Miocene ~ 18-15 m.y. Location: Plum Pt., Calvert Co., MD Size: both are ~ 1 5/8" (41mm)

This is an interesting yellow/orange mako. The left is the labial view, the right is the lingual view. Formation: Calvert, Plum Point member Age: Early - Middle Miocene ~ 18-15 m.y. Location: Randle Cliffs, Calvert Co., MD Size: ~ 1 5/8" (40mm) slant Date: Spring 2002

This is a nice robust slightly worn mako. The left is the labial view, the right is the lingual view. We found this one while snorkeling. View a pic of it when it was found Formation: Choptank Age: Middle Miocene ~ 18-15 m.y. Location: Found Snorkeling. Calvert Co., MD Size: ~ 1 13/16" (45mm) slant Date: Summer 2002

Here is a nice orange colored mako from Brownies Beach. Click on the pic to see the trip it was found on. Formation: Calvert, Plum Pt. member Age: Early - Middle Miocene ~ 18-15 m.y. Location: Randle Cliffs, Calvert Co., MD Size: ~ 1 7/8" (47 mm) slant Date: July 2003 TRIP

Isurus sp. (Mako Shark)

These are some smaller mako teeth. Most of them appear to be I desori. Notice some juvenile makos have cusps. Formation: Calvert & Choptank Age: Middle Miocene ~ 18-12 m.y. Location: Various Places, Calvert Co., MD Size: Largest is 1 1/8 (29mm) slant height

Negaprion eurybathrodono (Blake, 1862) (Lemon Shark) Identification based on Kent (1994). This species of lemon shark only lived in the Miocene.

These teeth are very common in the Calvert Formation. Lowers can be easily confused with Carcharhinus sp. lowers, however they have smooth to very week serrated enameloid shoulders, where Carcharhinus sp. have serrated enameloid shoulders. Formation: Calvert, Plum Point member Age: Early - Middle Miocene ~ 18-15 m.y. Location: Randle Cliffs, Calvert Co., MD Size:

Here are some slightly larger N eurybathrodono Formation: Calvert, Plum Point member Age: Early - Middle Miocene ~ 18-15 m.y. Location: Near Scientists CLiffs, Calvert Co., MD Size: ~ 1" (25mm)

Notorhynchus cepedianus (Peron, 1807) aka primigenius (Agassiz, 1843) (Sevengill Cow Shark) Identification based on Kent (1994) & Purdy et al (2001). Purdy et al (2001) believe these teeth are identical to the extant N. cepedianus, and therefore N. primigenius is just synonymous to N. cepedianus. Cow sharks are very primitive sharks, and look almost as weird as their teeth. Cow sharks lack the many dorsal fins on their backs that most sharks have. Instead, they only have a single dorsal fin toward their tail. They are also very wide and bulky. This species is extant today, but rare. They are active in shallow waters and are very aggressive. They can get up to 10 feet in length. Their diet consists of mainly other sharks, rays, bony fish, and seals.

Notice the small cusps on mesial edge of the lateral, whereas Hexanchus (Sixgill Cow Shark) laterals have fine serrations. Notorynchus teeth are MUCH more common than Hexanchus teeth. Click on the pic to see the trip this was found on. Formation: Choptank, Zone 17? Age: Middle Miocene ~ 15 m.y. Location: Near Willows and Randle Cliffs, Calvert Co., MD Size: This nice specimen is approximately 1" (25mm) Date: June 2006 TRIP

Usually these teeth are found with the roots mostly missing (as in the pic below). Formation: Calvert, Plum Point member Age: Early - Middle Miocene ~ 18-15 m.y. Location: Near Willows and Randle Cliffs, Calvert Co., MD Size: Big broken lateral is about 1" (25mm)

Notorhynchus teeth are commonly found broken, such as the teeth in this pic. Formation: Calvert Age: Early - Middle Miocene ~ 18-15 m.y. Location: various places, Calvert Co., MD Size:

Rhizoprionodon fischeuri (Joleaud, 1912d) (Sharpnose Shark) Identification based on Kent (1994) This is a small shark, roughly 5 feet long, with a long snout (hence the name). This species is very rare in the Calvert formation. This may be partly due to their tiny size. There is a large sexual dimorphism in lower teeth, as the male and female lowers look very different from one another.

These two teeth are male lowers. They may be associated teeth, since they were found in a large chunk of Zone 10 almost touching each other. These teeth are very small, with one pronounced enameloid shoulder, and two large lingual protuberances surrounding the nutrient groove. They also have no serrations on the crown or enameloid shoulders. Formation: Calvert, Plum Point member, Zone 10 Age: Middle Miocene ~ 16-15 m.y. Location: Randle Cliffs, Calvert Co., MD Size: roughly 1/4" (5mm)

Sphyrna laevissimus (Cope, 1867) (Hammerhead Shark) Identification based on Kent (1994). Hammer Head Sharks can get up to 11 feet in length. They feed on a variety of prey, including other sharks, bony fish, and crustaceans. This species lived only in the Miocene A species of Hammerhead, the Common Hammerhead (Sphyrna zygaena), still populates the Chesapeake bay today, and is one of the largest sharks in the bay.

Upper left tooth is a labial view, all others are lingual views. These are much less common than grey shark teeth, and, if you're not careful, they can easily be confused with them. However, notice the deep notch in the roots, also there are no serrations present on the teeth. Formation: Calvert, Plum Point member Age: Early - Middle Miocene ~ 18-15 m.y. Location: Large one is from Willows, all others from Randle Cliffs, Calvert Co., MD Size: usually between 1/2-3/4" (13-19mm)

Squatina subserrata "lerichei" (Munster, 1846) (Angel Shark) Identification based on Kent (1994) & Purdy et al (2001). Angel sharks are very flat, looking more like a Ray than a Shark. Some species can reach lengths up to 6 feet. Angel sharks bury themselves on the Ocean bottom, and wait for prey to swim by. They feed on fish, mollusks, crustaceans. Their mouths house numerous tiny teeth for grasping. Because Squantina teeth are very small, they are difficult to find. All of my teeth were found by screening. This fossil species lived from the late Oligocene to the Miocene.

These teeth are tiny and hard to spot, but are very easy to identify when found. Formation: Calvert, Plum Point member Age: Early - Middle Miocene ~ 18-15 m.y. Location: Randle Cliffs, Calvert Co., MD Size: ~ 1/4" (6.4mm)

Shark Vertebrae

Shark Vertebral centra Identification based on Kent (1994). Although sharks are made of Cartilage, their vertebra sometimes fossilizes. Shark vertebrae pieces are fairly common.

Stress cracks running to the center of shark vertebrae are very common, and are caused from the heat and pressure on the vertebrae during the fossilization process. Formation: Calvert, Plum Point member Age: Early - Middle Miocene ~ 18-15 m.y. Location: Randle Cliffs, Calvert Co., MD Size: largest one is ~1 1/16" (28mm)

Shark vertebrae these sizes are decent finds at the cliffs. The dark circles on the larger one are barnacle marks. The larger one was found by snorkeling. Formation: The small one is Calvert, Plum Point member. The larger one is from the Choptank formation. Age: Early - Middle Miocene ~ 18-15 m.y. Location: Smaller one is from Willows, Calvert Co., MD , Larger one is from snorkeling Size: ~1 1/2" & 1 3/4" (38 & 44mm) Date: Spring 2002

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