Shark Vert Vs Fish Vert

[RyanNREMTP]

How does one tell the difference between a shark vertebrae and a fish vertebrae? I've found six vertebrae so far lately and at first I thought they were fish but since I'm finding a lot of shark teeth I find myself confundled.

[siteseer]

Shark vertebrae tend to be preserved as just the centrum (the hockey puck-like disk) with two openings on top and two on the bottom where the hemal and neural arches were attached. The arches were cartilaginous in life and disintegrate quickly after death. The centrum sometimes survives as a fossil because it is at least partially ossified. Because they aren't solid bone, they are fragile, chipping easily.

In bony fish vertebrae the arches are often still attached at least in part because they are extensions of the vertebrae . Even if they have broken off, you can usually see the nubs of bone where they were attached.

How does one tell the difference between a shark vertebrae and a fish vertebrae? I've found six vertebrae so far lately and at first I thought they were fish but since I'm finding a lot of shark teeth I find myself confundled.

[MarcoSr]

If you post pictures of them, I will try to id them for you. Shoot the pictures of them on their sides (They could roll in this view), not straight down into the concave end surfaces.

Marco Sr.

[RyanNREMTP]

I'll try to post some pictures tonight if the light is still good.

Does anyone have a pdf file on this so I can study and learn this topic?

[MarcoSr]

I'll try to post some pictures tonight if the light is still good.

Does anyone have a pdf file on this so I can study and learn this topic?

I don't know if there is a good PDF, but here are some pictures to illustrate. These specimens are from the Eocene of VA. I'm showing two types of shark vertebra. There are numerous types. The Scyliorhinoid type shark vertebra is pretty easy to distinguish from a fish vertebra as it is pretty smooth with paired deep distinctive foramina which originally contained the bases of cartilaginous processes. You have to look a little closer at the Lamnoid type shark vertebra. For me it is very difficult to tell some ray vertebrae from shark vertebrae.

Shark Vertebrae:

Lamnoid type

Scyliorhinoid type

Fish Vertebrae:

Marco Sr.

Edited July 20, 2014 by MarcoSr

[Ramo]

I just realized that I don't photograph many fish verts. Probably because they are so much more common here in Kansas than shark verts.

The first picture is of a few shark verts I found in association. The second picture (with all the shark teeth) is has a couple fish verts in the condition I usually find them. The last picture is of a cross section of a string of shark verts/ shark vert impressions.

Hope these help.

Ramo

[RyanNREMTP]

Here is an older picture of one of the smaller ones I took awhile back.

[RyanNREMTP]

Best I could do at home.

[MarcoSr]

Unfortunately the condition of the specimens makes an id difficult from the pictures. I might change my id with them in my hand.

However, this specimen looks like shark from this view based on what looks like foramina.

These two look like fish from this view based upon what looks like nubs of the arches and/or the cap/end shape.

Hard to tell on the others.

Marco Sr.

Edited July 21, 2014 by MarcoSr

[BobWill]

Not really so confudling. Actually you should expect to find shark teeth with fish verts for reasons besides them swimming together. As others said the shark verts don't fossilize as well and since sharks make lots more teeth than fish the two should be the most likely to be preserved.

[Harry Pristis]

See shark vertebrae types here:

http://www.thefossilforum.com/index.php?/gallery/image/12117-shark-vertebral-centra/

[RyanNREMTP]

Thank you all.

[MarcoSr]

See shark vertebrae types here:

http://www.thefossilforum.com/index.php?/gallery/image/12117-shark-vertebral-centra/

Unfortunately those are only two types of shark vertebrae. There are others. Plus rays have vertebrae that are very similar. I have not been able to find copies of the Tessman 1966 and the Applegate 1967 papers on the web which should be very useful in the id.

Marco Sr.

[Harry Pristis]

MarcoSr posted:

Unfortunately those are only two types of shark vertebrae. There are others. Plus rays have vertebrae that are very similar. I have not been able to find copies of the Tessman 1966 and the Applegate 1967 papers on the web which should be very useful in the id.

And, your evidence is . . . ?

Here's a ray vertebra:

[Al Dente]

Here's a ray vertebra:

I'll post some pictures of my ray vertebral centrums tomorrow. Ray centrums look just like shark centrums. Harry- I think your vertebra is from a bony fish.

[Harry Pristis]

Al Dente posted:

I'll post some pictures of my ray vertebral centrums tomorrow. Ray centrums look just like shark centrums. Harry- I think your vertebra is from a bony fish.

I am always eager to learn, Al. I must tell you, though, that I am fairly confident about the FSMuseum identification of my vert. There are distinctions between ray and shark centra.

Skate and ray vertebrae are uncommon fossils . . . or, perhaps better said, they are uncommonly identified as skate and ray fossils. I'm looking forward to seeing your images.

[MarcoSr]

And, your evidence is . . . ?

Dr. Bruce Welton shows other types like Cetorhinus and Squatina, in "Collector's Guide to Fossil Sharks and Rays from the Cretaceous of Texas", 1993. Kent in "Fossil Sharks of the Chesapeake Bay Region", 1994 states "Numerous distinctive types of centra are found in sharks (Applegate, 1967), but only two types, lamnoid and scyliorhinoid (Tessman, 1966) are commonly found in the Chesapeake Bay area." But my main evidence is the hundreds of well preserved centra that I have in my collection, which are of a different type than lamnoid and scyliorhinoid, from Cretaceous to Pleistocene from sites all over the world. I just don't have a good reference to identify them and haven't been able to find copies of either the Tessman or Applegate paper on the web.

Marco Sr.

[Harry Pristis]

MarcoSr posted

Dr. Bruce Welton shows other types like Cetorhinus and Squatina, in "Collector's Guide to Fossil Sharks and Rays from the Cretaceous of Texas", 1993. Kent in "Fossil Sharks of the Chesapeake Bay Region", 1994 states "Numerous distinctive types of centra are found in sharks (Applegate, 1967), but only two types, lamnoid and scyliorhinoid (Tessman, 1966) are commonly found in the Chesapeake Bay area." But my main evidence is the hundreds of well preserved centra that I have in my collection, which are of a different type than lamnoid and scyliorhinoid, from Cretaceous to Pleistocene from sites all over the world. I just don't have a good reference to identify them and haven't been able to find copies of either the Tessman or Applegate paper on the web.

I looked at Welton and Kent again before I responded to you. I am reluctant to call these remarks 'evidence.' They're hints. I've already mentioned (in my Gallery image) what Norm Tessman had to say.

Maybe someone has a copy of the referenced 1967 Applegate paper. That would contribute substantially to our understanding, 'cause so far we have 'lamnoid,' 'scyliorhinoid,' and 'other.'

BTW, among your hundreds of well-preserved centra, do you have some skate or ray centra?

[MarcoSr]

BTW, among your hundreds of well-preserved centra, do you have some skate or ray centra?

I have a good number of different types of centra that are either shark or ray/skate. I have different books with grainy pictures of fossil centra like Pristis and Dasyatis which really don't help much with an id. I have been trying to find a comprehensive reference that shows extant ray/skate centra like Pristis, Raja, Dasyatis, Rhinobatos, Rhynchobatus, Rhinoptera, Myliobatis, Aetobatus etc.which would really help with fossil ray/skate centra id. If anyone is aware of a good ray/skate centra reference please let me know. I'm looking forward to the pictures that Eric will post of some of his ray centra. I'll probably have those types in my collection. My son found a partially associated Miocene ray a while back with teeth and centra but the specimen is still in a plaster jacket. I definitely want to look at both the teeth and centra when he preps that out.

Marco Sr.

[RyanNREMTP]

I have bookmarked the DPS site for "Collector's Guide to Fossil Sharks and Rays from the Cretaceous of Texas". Hopefully I'll get to buy it soon. That is the cheapest place for it.

This thread has gone in a different direction than I thought it would have gone. I don't mean in a bad way. If anything it has shown why I really like this site out of all the forums I visit. Even when two people disagree on something they remain civil about it. I don't see that in most places on the internet.

[Coco]

Hi,

Maybe someone has a copy of the referenced 1967 Applegate paper. That would contribute substantially to our understanding, 'cause so far we have 'lamnoid,' 'scyliorhinoid,' and 'other.'

I had a look on my PDF bibliography and I don't have them...

Coco

[Al Dente]

Here are some of my batoid vertebral centrums. The first is a fossil. It is a centrum from Pristis lathami. I've been told many times that these are from sawfish but I was sceptical until I saw a photo of an associated rostrum with a string of these centrums. This one is from the Eocene Castle Hayne Formation.

Here are some modern ray centrums. These are from a Dasyatis sabina that I caught in the Pamlico River in 2009. The centrums are about 5 mm. in diameter. These centrums remind me very much of shark centrums.

And here are some modern skate centrums. I caught several Clearnose skate (Raja eglanteria) on the Outer Banks of North Carolina. The centrums have prismatic cartilage attached to them. This prismatic cartilage is very delicate and I would guess it would quickly get worn off of most centrums before they fossilized. The round centrums are about 5 mm in diameter.

This web site also has a photo of some skate centrums:http://www.marinebiodiversity.ca/skatesandrays/internal%20anatomy.htm

[RyanNREMTP]

Now that's pretty cool there.

[MarcoSr]

Here are some of my batoid vertebral centrums. The first is a fossil. It is a centrum from Pristis lathami. I've been told many times that these are from sawfish but I was sceptical until I saw a photo of an associated rostrum with a string of these centrums. This one is from the Eocene Castle Hayne Formation.

pristisvert2.jpg pristisvert1.jpg

Here are some modern ray centrums. These are from a Dasyatis sabina that I caught in the Pamlico River in 2009. The centrums are about 5 mm. in diameter. These centrums remind me very much of shark centrums.

dasyatisverts.jpg

And here are some modern skate centrums. I caught several Clearnose skate (Raja eglanteria) on the Outer Banks of North Carolina. The centrums have prismatic cartilage attached to them. This prismatic cartilage is very delicate and I would guess it would quickly get worn off of most centrums before they fossilized. The round centrums are about 5 mm in diameter.

rajaverts.jpg clearnose skate.jpg

This web site also has a photo of some skate centrums:http://www.marinebiodiversity.ca/skatesandrays/internal%20anatomy.htm

Eric

Thank you for posting these specimens. Your extant specimens especially show how much an individual ray/skate centrum can resemble those of certain shark types.

I am glad you confirmed the id of the Pristis lathami with an associated centra string. I have seen grainy pictures of individual fossil centrum identified as Pristis lathami in several publications before which compare very well to your specimen. But I was also doubtful of this id. I have that type of centrum from the Eocene of VA from a fauna where I also found Pristis lathami rostral teeth, so now I'm more confident with a Pristis id for them.

I have never found a centrum with cartilage still attached. That would be a very rare find for an individual specimen.

The pictures of the extant Dasyatis and Raja specimens are very helpful. You would think that there would be publications showing extant ray/skate centra but I really haven't found any. I can only find papers on individual species mostly with pictures of strings of centra or individual centrum shot from the ends so you get almost no fine detail for an id. I have seen pictures of supposed individual Dasyatis fossil centrum which don't match your extant specimens at all. So now I am extremely skeptical of the id for those fossil centrum. I definitely feel unless you use associated fossil ray/skate specimens as a guide for individual fossil centrum id an id is suspect. The next best thing is to use extant species to get a good understanding of morphology and try to apply that to fossil species id.

Marco Sr.

[RyanNREMTP]

Sharks have remained relatively unchanged for severral millions of years, do we know how much if any rays have changed? Their body appears to be more specialized so I'm wondering how they have evolved overr the eons.