Partial placoderm plate from the Arkona formation

I have never found much in the way of fish remains at Hungry Hollow, Ontario, but once I did find a small fragment from a bony placoderm plate.  Placoderms were early, shark like fish that had external bony armor around their heads. There are a few species known from the middle Devonian aged rocks found at Hungry Hollow (Arkona formation and Widder formation) but this is just a fragment so I doubt I could narrow the species down.

I found this piece near the base of a slope of eroded Arkona formation and could not find any trace of more uphill. You can tell it is bone due to the pale blue color (evidence of the phosphate mineral Vivianite) and the spongy structure within the piece.

Top surface - this is what would have been the outer facing portion of the bone. Note the bumps, perhaps they helped streamline the fish for swimming purposes?

Two side views of the bone showing the spongy nature.

This was the interior side of the bone

I collected this specimen from the Arkona formation which is Devonian in age, Givetian stage.

Carcharias cuspidata teeth from the Belgrade formation

These are the last of the teeth that I have been profiling that came in a bag of mixed shark teeth labelled as "Belgrade Quarry, NC".  The two teeth shown here were a bit easier to ID for me although I still needed to get confirmation from the Fossil Forum.  I recognized these teeth as belonging to a Sand Tiger shark, but the Fossil Forum member "Sixgill Pete" was able to further ID them as Carcharias cuspidata which is very common in the Belgrade formation.

Specimen #1 -

Specimen #2

The Belgrade formation is dated to the early Miocene epoch of the Paleogene period.

Carcharhinus sp. teeth from Bone Valley

Here are three teeth that I found in a bag of mixed teeth labelled "Belgrade Quarry, NC".  I believe they are from a Carcharhinus sp. shark based on comments from member "Sixgill Pete" on the Fossil Forum. That member suggested these teeth were possibly from a Carcharhinus obscurus which is an extant species known as the Dusky Shark. Based on some comments from members of the Fossil Forum, these teeth likely come from "Bone Valley" in Florida (based on color of the fossils, which is not a reliable rule but it is often a good guide) and are middle Miocene to Pliocene in age.

Specimen #1

Specimen #2

Specimen #3

As I mentioned earlier , these teeth came in a bag labelled as "Belgrade Quarry, NC". That quarry exposes sediments from the Eocene to the Miocene.  Carcharhinus obscurus is not generally acceped to have evolved until the late Miocene epoch so it's likely these teeth are from a different quarry

Hemipristis serra teeth from the Belgrade Quarry?

The teeth of the extinct Snaggletooth shark (Hemipristis serra) are fairly easy to ID from the tooth shape alone.  Triangular in shape, usually angled to one side, and with large serrations along the edges, particularly along the edge that was facing towards the back of the jaw.  Below are three teeth, two laterals and a frontal, that came in a bag of mixed teeth marked "Belgrade Quarry, NC".

Specimen #1 - right side lateral tooth

Specimen #2 - left side lateral tooth

Specimen #3 - frontal tooth

As I mentioned earlier , these teeth came in a bag labelled as "Belgrade Quarry, NC". That quarry exposes sediments from the Eocene to the Miocene.  Hemipristis serra is known from that quarry but the color of these teeth seem to indicate a different source. Perhaps the Lee Creek quarry, also in North Carolina, where this species is known to be found in the Yorktown formation (late Miocene-Early Pliocene)?

Carcharocles angustidens teeth from the Belgrade/River Bend formation

In a bag of fossil shark teeth that I purchased I found a number of these triangular shaped teeth. The bag was labelled "Belgrade Quarry" with no other information. I spent a hour or so looking for fossil shark tooth pictures on Google Images that matched what I had and the closest were Carcharocles angustidens. A quick posting to the Fossil Forum website confirmed that these were indeed C. angustidens teeth and that they could be found at the Belgrade quarry.

More web searches ultimately led me to Wikipedia and to the follow logic: These fossils come from the Belgrade quarry in North Carolina. Rocks exposed in that quarry range from the Eocene to the Miocene epochs. C. angustidens existed in the late Oligocene and early Miocene (33-22 mya, Rupelian stage to Aquitanian stage).  That narrows the formations they could have been found in to the River Bend formation (Late Oligocene) and the Belgrade formation (Early Miocene). Both of those formations at one point or another were considered part of the Trent marl which was originally dated to the Eocene epoch. Oh yeah, and C. angustidens was an relative of the Megalodon (no biggie) ^1,2,3.

It's nice to have a little bit more information on these fossils as they are a species I did not have in my collection previously. Three of the specimens below would have been found on the front of the shark's jaw while the last one has a little bit more of a curve in it so likely came from along the side or back of the jaw.

Specimen 1

Specimen 2

Specimen 3

Specimen 4

These teeth were found at the Belgrade Quarry near Maysville, in North Carolina in the Belgrade /River Bend formations.

1. Wikipedia - Carcharocles angustidens article
2. Wikipedia - Belgrade formation article
3. Wikipedia - River Bend formation article

Edestus heinrichi tooth and jaw section from Illinois

Below are pictures of a rare shark tooth and jaw section from a bizarre shark called Edestus heinrichi. It was called the "Scissor tooth" shark because reconstructions of it have long jaws sticking out from the face of the shark with teeth lining them. Envision them like a large pair of pinking shears on the body of a shark where the mouth would be. The jaws of these odd group of fish never shed their teeth and just continued to grow outward. Each tooth was rooted in a chunk of cartilage and would stack on the previous piece of cartilage. In this way the shark had a mouth full of teeth at all times.

Edestus was related to a group of sharks that have modern representatives in the Ratfish (Chimaera) and are better represented by the whorl tooth possessing Helicoprion. Both Edestus and Helicoprion lived during the end of the Carboniferous period (upper Pennsylvanian stage). The fossil below was among many found by coal miners in Illinois. Why was it found in a coal mine when it was shark that lived in water? Edestus lived and died in brackish waters in between growth of the coal swamps. As the coal was removed in the mine these non coal bearing rocks were exposed with some of them being marine in origin.

The specimen I own has just a single tooth in a piece of the jaw. There are some terrific examples of more complete jaw sections on the web like this group of pictures from the Illinois state Museum.  This thread on the Fossil Forum has pictures of some nice specimens in other people's collections.

Ptychodus teeth from Texas

Ptychodus was a genus of shell crushing sharks that lived during the Cretaceous. Like all sharks they are best known from their teeth since much of their skeleton is made from cartilage rather than bone. Since they crushed shells rather than rend flesh their teeth were more flattened like a modern ray or skate. Here is a link, to a page on the Oceans of Kansas website with more information on these sharks and pictures of articulated sets of teeth.

This is a tooth from a Ptychodus whipplei that was found in the Atco formation (Cretaceous, Santonian stage)near Prosper Texas.

This smaller tooth is from a different species called P. anonymous. It came from the Arcadia Park formation (Cretaceous, Turonian stage) near Dallas Texas.

Both of these fossils were among a group that I won on  Fossil Forum site. Thanks to Travis for sending me these shark teeth.