Squalicorax review

[siteseer]

This thread was inspired by Sander's excellent review of his collection of Squalicorax teeth.  I have started getting some of my Squalicorax specimens together and a few have been photographed already to provide additional visual references for collectors.  I will try to show teeth chronologically (Albian teeth first, then Cenomanian...) from early in the evolution of the genus and on to the time of its last representatives.

 

  

I start with the two oldest Squalicorax teeth in my collection - a pair of specimens from the Upper Albian-age Pawpaw Formation, Motorola site, Tarrant County, Texas.  The first tooth is S. pawpawensis (10mm along the mesial edge) and the second is S. priscoserratus (just over 10mm along the mesial edge).

[ClearLake]

I look forward to following this thread and comparing your specimens with the original Squalicorax thread. 

[siteseer]

20 hours ago, ClearLake said:

I look forward to following this thread and comparing your specimens with the original Squalicorax thread. 

 

Well, I hope to see other people post some of their specimens in this thread as it goes along.  Each of us, especially those who have been collecting for years and even decades, has had a chance to pick up samples of fossils from various localities through trades, purchases, and hunts.  I've known collectors who've been very generous and have told me, "Oh, you don't have one of these, well, you can have this one or here take this bag/box full of miscellaneous."  I didn't set out to build a Squalicorax collection but I acquired samples of faunas and odd single specimens when I could so after 30 years of that, I had a Squalicorax collection among my shark teeth and I know many others have as well.  Some collectors like to stick to a general region but sometimes pick up odd teeth from other areas that are related to what they find.   They have a special familiarity with what has been found in the region.  They know what some of the old-timers have found and what a few lucky newbies have come up with.  I hope to hear from other collectors who can tell me a given tooth is typical or atypical (size, condition, color) of what you find at that locality.  Sander has already shown some teeth from localities that have more restricted access than in the past or are now closed to collecting or may even be covered by a parking lot, housing division, or airport.  I hope to learn more too.  I'm already thinking of doing a thread on at least one other genus.

[siteseer]

And now we go to the Cenomanian, a block of geologic time that runs from about 94 to 100 million years ago.  It is considered the first stage of the Late Cretaceous.  This tooth was collected from the Early Cenomanian Del Rio Clay at Waco (the lake site), McLennan County, Texas.  It measures 16mm along the mesial edge.  I think this tooth would be labelled S. curvatus or early falcatus.  There may be room for curvatus in that it has a narrower cusp than is seen in falcatus especially later in time.

 

I was lucky to meet a collector in the 90's who had hunted there many times.  He found lots of teeth and those little pyrite ammonites.

Edited April 27, 2022 by siteseer
additional thought

[siteseer]

Here are three teeth that were collected by a geologist with a special interest in shark teeth in the 1960's from Amon Carter Field, Ft. Worth, Tarrant County, Texas.  From left to right, the teeth measure 20mm, 11mm, just over 11mm, and just over 18mm.  The two larger teeth are essentially complete but show some wear.  The two smaller teeth bear better preserved serrations but one has a damaged distal blade.  I think these teeth would be considered early S. falcatus.

Edited April 26, 2022 by siteseer

[siteseer]

Here are two specimens from the Cenomanian-age Mosby Sandstone - a site southwest of Winnett, Petroleum County, Montana.  From right to left, they are 12mm and 10mm along the mesial edge.  I have some partial specimens in the same apparent size range so the teeth seem to be rather small from that locality.  These two would be considered early S. falcatus specimens.  

[Woopaul5]

Got to dig through my phone for more but I have some I can add.

 

Used to collect the Maastrichtian of Monmouth County, New Jersey while I lived there. 
 

Squalicorax pristodonus 

Cretaceous (Maastrichtian)

Navesink Fm

Monmouth County, Naj

Edited April 29, 2022 by Woopaul5

[Woopaul5]

Creek shot of when I found this.

 

Squalicorax pristodonus (posterior)

Cretaceous (Maastrichtian)

Navesink Fm

Monmouth Co, NJ

 

 

Edited April 29, 2022 by Woopaul5

[Woopaul5]

Fairly certain that they changed the name to lindstromi but it’s still kaupi to me.

 

Sorry for the lack of size reference. On the other side of the world from my collection at the moment.

 

Squalicorax kaupi

Cretaceous (Maastrichtian)

Navesink Fm

Big Brook Preserve, NJ

[siteseer]

Thanks for filling in, Paul.

 

When I look at Sander's thread and as think about what I have, I see that most of his specimens are from European localities and most of mine are from American ones as one might assume given that he lives in Holland and I live in California.  There doesn't seem to be a lot of overlap so after all my examples are posted, it might give the newbie shark tooth collector an idea of what a European and American collector were able find in the last 30 years.

 

Here are three of my European specimens from Cenomanian-age sites.  The tooth on the left is from Saratov, Russia with a mesial edge length of 12mm.  The two teeth on the right are from Ciran, Indre-et-Loire Dept., France with the larger of the two about 12mm.  The smaller, incomplete tooth is about 7mm along its longest dimension.  All three appear to be early S. falcatus teeth.

Edited May 4, 2022 by siteseer

[siteseer]

Here's another Cenomanian-age tooth.  This one is from Lussant, France and measures about 9mm.  I was able to trade for a small sample of various teeth from there about 20 years ago.

Edited May 4, 2022 by siteseer

[fossilsonwheels]

Great teeth, great thread Jess. Squalicorax is one that I somewhat over looked. It’s nice to see some from your collection. 

[sander]

This is looking good already!

I must say that I do also have more Squalicorax teeth from the USA, but because I still have to find out their age I have not yet posted them. I suspect a mix up in location names. I can therefore only post those after I have figured the locations out (need to contact the guy who found them again).

Keep up the posts,

Kind regards,

Sander

[siteseer]

Thank you Kurt and Sander. 

 

Sander, I would not have started this project without your excellent thread.  It is quite the inspiration.

 

We've seen that Cenomanian Squalicorax teeth tend to be small compared to later forms though Sander showed a tooth that was unusually large for the time.  Here is a tooth that is almost as large as the one he showed.  It measures 22mm along the mesial edge.  It's from the Bluebonnet Formation, Bell County, TX.  Because I've had teeth with similar preservation from the same formation from the Temple area, that may be where this one is from as well.  it still has some matrix attached but I cleaned off enough it to get a good measurement.

 

 

Edited May 7, 2022 by siteseer
additional thought

[siteseer]

I found two more large teeth from the Amon Carter Field site (large for the site and the age) and am glad I did before moving on to the Turonian.  I wondered if the higher-crowned tooth could be S. baharijensis.  It's just over 20mm along the mesial edge; the other tooth is at 20mm.  I think that's a S. falcatus lateral.

Edited May 15, 2022 by siteseer

[siteseer]

Here's a tooth from Marble, Itasca County, Minnesota out of the Coleraine Formation which has not been pinned down to an age but seems to bridge the Cenomanan and Turonian so it's a good tooth for that transition in this thread..  It appears to belong to S. falcatus.

[siteseer]

Here's a group for Texas collectors.  These teeth were collected from a North Austin site, Travis County, TX.  I think it was a temporary construction site that exposed the South Bosque Shale (Early Turonian), Eagle Ford Group.  The largest tooth is just over 12 mm along the mesial edge.

Edited May 17, 2022 by siteseer
added size

[siteseer]

More Turonian-age teeth from Texas...I don't remember from whom I received these teeth but the info reads:

 

Eagle Ford Shale - Britton Member

1 mile east of FM 1382 and Eagle Ford Drive, Dallas, TX

 

I have read that the Britton Member of the Eagle Ford Formation has been upgraded to being a formation and the Eagle Ford is now considered a group.  The Britton was told to me to be Turonian-age but I have seen it charted as Cenomanian.  Most recently, I've seen it as Cenomanian-Early Turonian.  It might have been better for me to have checked it yesterday before posting the South Bosque Shale teeth but I could just as well wait years for Texas geology (or the geology of any area) to be reinterpreted and questioned and reinterpreted again but I would never get the photos of these teeth on the forum that way.

 

The largest tooth is just over 12mm along the mesial edge, and just to clarify, when I say "mesial edge," that's the measurement from crown tip to root end - the longest dimension of the tooth.

 

 

[Rock Hound]

I hope that my humble submission for this thread, might be of some value.  These are the 4 best examples, out of the 10 Crow Shark Teeth I currently own.  All 10 are this same type and position of tooth.  Some face Left, and some face Right.  Otherwise all 10 are the same.  All were found in a single location on the Tombigbee River, in the late 1970s to early 1980s.  They were extracted from an exposed layer within a high river bank.  Shoveling and sifting yielded Goblin Shark Teeth, Crow Shark Teeth, and occasional other bits and pieces from the same layer.  Almost all fossils found, were very black in appearance.

 

[Al Dente]

9 hours ago, Rock Hound said:

All 10 are this same type and position of tooth. 

You have 2 different species of Squalicorax in this photo. The two on the left are Squalicorax yangaensis and the two on the right are Squalicorax kaupi, but some people call these S. lindstromi.

 

 

[Rock Hound]

7 hours ago, Al Dente said:

You have 2 different species of Squalicorax in this photo. The two on the left are Squalicorax yangaensis and the two on the right are Squalicorax kaupi, but some people call these S. lindstromi.

 

 

Thank you.  I now see the subtle difference in the teeth.  At first glance, I took them for being the same.

[siteseer]

3 hours ago, Rock Hound said:

Thank you.  I now see the subtle difference in the teeth.  At first glance, I took them for being the same.

 

Thanks for showing your Tombigbee River teeth.  I have a sample from there and a couple of other sites in Mississippi as well.  I will be getting to those.

[siteseer]

Here's a tooth collected near Pueblo, Colorado.  I was told it was from the Carlile Shale.  I looks like a specimen of S. falcatus and measures 18mm along the mesial edge.

[siteseer]

Here are two teeth from the Carlile Shale, Edgemont, Fall River County, South Dakota.  The tooth in the matrix piece measures 15mm along the mesial edge.  The isolated tooth measures 20mm.  This is more of what people think of as Squalicorax falcatus - teeth averaging a little larger than what is generally seen during the Cenomanian.

 

The matrix piece is actually one of the first fossils I bought back when Natural Wonders and Nature Company stores were just opening in 1987.  My whole fossil collection fit in a cigar box at the time.  You used to see teeth from Edgemont at shows but the BLM annexed the land so you couldn't collect there anymore by the early 2000's.

Edited May 20, 2022 by siteseer

[siteseer]

Here's another South Dakota tooth.  It's from a quarry in/near Big Stone City, Grant County, SD.  It's just under 16mm along the mesial edge.