Obsessed with Cow shark teeth

[Rowboater]

I was on a good run with bottom lateral cow shark teeth in a new spot (seems to have ended lately; thought it would get better in the winter but footprints everywhere).  While most cow shark teeth I had found in the past were rootless and broken, they were easy to identify with the multiple points, and by serrations on the first spike (or so I thought).  I have a fair amount of these serrated first spikes.

Recently I found two "pathological" bottom lateral cow shark teeth (out of less than a dozen I had found there).  I've been looking hard but not finding much lately.  I gathered up most of my previous collected cow shark teeth and looked at the serrations on the big first point.  I was surprised that, while not as obvious as the first two, several had serations on a separate smaller first point, some seemed to have fused large serrations, and many could just be loss of serrations with weathering.

The scan is of most of my bottom lateral cow shark teeth, all from Middlesex county VA, from three hunting spots. In one spot, where most broken and small teeth are from, almost all have serrations on the first spike (most of those in the right four columns).  The ones from the recent spot and similar from other spots (left two columns) are much more variable: some have small spikes rather than serrations on the first spike, some have a small spike with serrations, several have fused serrations, and some are weathered but no obvious serrations on the first spike.  There of course is overlap.  It's unclear if this is just normal variability that varies by hunting site, or if the new site has a different subspecies.   

The new spot has a lot less shark teeth beyond the interesting cow shark bottom laterals (seems I would have found a symphyseal by now?) Mostly just the same I usually find, but less teeth.  A few interesting things, will need IDs and will post soon.

@flyersfan805 has a nice collection for comparison (and I'm sure there are others):

 

 

[Meganeura]

46 minutes ago, Rowboater said:

I was on a good run with bottom lateral cow shark teeth in a new spot (seems to have ended lately; thought it would get better in the winter but footprints everywhere).  While most cow shark teeth I had found in the past were rootless and broken, they were easy to identify with the multiple points, and by serrations on the first spike (or so I thought).  I have a fair amount of these serrated first spikes.

Recently I found two "pathological" bottom lateral cow shark teeth (out of less than a dozen I had found there).  I've been looking hard but not finding much lately.  I gathered up most of my previous collected cow shark teeth and looked at the serrations on the big first point.  I was surprised that, while not as obvious as the first two, several had serations on a separate smaller first point, some seemed to have fused large serrations, and many could just be loss of serrations with weathering.

The scan is of most of my bottom lateral cow shark teeth, all from Middlesex county VA, from three hunting spots. In one spot, where most broken and small teeth are from, almost all have serrations on the first spike (most of those in the right four columns).  The ones from the recent spot and similar from other spots (left two columns) are much more variable: some have small spikes rather than serrations on the first spike, some have a small spike with serrations, several have fused serrations, and some are weathered but no obvious serrations on the first spike.  There of course is overlap.  It's unclear if this is just normal variability that varies by hunting site, or if the new site has a different subspecies.   

The new spot has a lot less shark teeth beyond the interesting cow shark bottom laterals (seems I would have found a symphyseal by now?) Mostly just the same I usually find, but less teeth.  A few interesting things, will need IDs and will post soon.

@flyersfan805 has a nice collection for comparison (and I'm sure there are others):

 

 

[Bjohn170]

Those are some very nice cows! Makes me want to hit the beach!

[Fin Lover]

Don't you ever feel guilty for keeping so many of them to yourself?   

[Family Fun]

Not sure why, but I love the cow shark teeth, maybe because I've never found one.  Those are spectacular, I need to go north I expect, so I can find a nice one.

[Jeffrey P]

Those are extremely cool! Congratulations and thanks for posting. 

[Rowboater]

@Meganeura, @Fin Lover @Bjohn170 @Family Fun@Jeffrey P@cowsharks

 

My scanner was broken for a month, finally got it working again.  I had always IDed cow shark pieces by serrations on the first, bigger point.  Most of my older teeth (including some from more recently at the new spot) have these serrations, sometimes many small, some with bigger, fewer but all continuing along the first spike: 

 

 

The ones with fewer, bigger serrations are often webbed, or weathered:

 

 

The new teeth (and an old piece of tooth at the left of the second scan) have separate points before the major, first, usually serrated point.  A few even have serrations on the small point before the "first" generally largest tooth:

Some are badly weathered, and there is a fair amount of overlap with the other teeth..  I doubt I would have noticed the differences between the new spot and my older teeth if the different types had been mixed up during years of collecting, but seems a striking difference today at the new spot (maybe a third of the teeth lack serrations on the main point and have distinct small points in front of the first point instead.

Whether this reflects a subspecies (from the location distinctions), or age, sexual dimorphism, or different positions of the teeth in the jaw, adaptation to foods, etc will require more collecting and maybe reading about Extant Cowshark dentition. 

[automech]

In your first pic, on the lower right, the three teeth that go from orange to black look really cool.

[PaleoPastels]

How am I just NOW seeing this thread!? 
As a Hexanchiformes lover…. DROOLING over here!   
 

The colors of that orange & grey one in your last pic….   

 

Wonderful finds- congrats on everything!!!!!!! This makes me want to stop what Im doing and visit my mom & stepdad who live on the East coast and scubas & treasure hunts for shark teeth over there. 
 

 

[Parker Brown]

These teeth are absolutely beautiful!

 

I found my fish cow-shark tooth in a creek just west of Orlando recently and its one of my main teeth in my collection now. Hopefully one day I can have some high quality ones like these!!

[hemipristis]

There was one particular spoil pile of Lower Yorktown within the Lee Creek Mine where we routinely found a half dozen to a dozen per trip each amongst our little collecting group of three that we nicknamed it “The Ranch”

[Rowboater]

Update:  found a few more (sadly only a very few more) at the "New Spot" and also found some pieces (I think they're cow shark) with a small point rather than serrations on the first, main point mostly from the "Old Spot" (at least I think that's where they are from.  So less exclusively spot specific.  

 

Still in comparison with typical lower lateral cowshark teeth, with distinct generally small serrations of the first point, there are many teeth that have big chunky serrations on the first point (often webbed together).

 

I am mostly interested in those teeth like the "pathological" teeth (two bottom left) with clear cut small points in front of a non-serrated first point.  Weathering confounds the teeth, but clearly some have points, often with chunky serrations, that could weather into discrete points, like the "pathological teeth."

 

@Meganeura @Bjohn170 @Fin Lover @automech @PaleoPastels @Family Fun @Jeffrey P @Parker Brown @hemipristis @Al Dente @cowsharks @MarcoSr  Just wondering if others have seen this variability and if there are gender differences, size differences, positional differences in lower jaw that might explain the systematic "somewhat" spot-specific differences I'm seeing?  Thanks for your thoughts.