Beachcombing a 96 Million Year Old Shore

[Mikrogeophagus]

Piggybacking off of the fantastic trip report @Jared C wrote about our Eocene excursion, I thought I'd go ahead and publish an account of the solo expedition I embarked on several days prior. Some of you who are familiar with my past endeavors in the fossil rich creeks and constructions of North Texas may know that dinosaur material has been a huge goal of mine for a while now. The Woodbine offers a shot at fulfilling such a dream, though dinosaurs are still very difficult to come by. Luckily, the uniqueness of its environment means that a day without a dino is by no means an unsuccessful one as a plethora of other strange and wonderful things can be found in their stead. After an early start, I set out with a sizeable list of new sites in the Upper Woodbine. There were some mild successes to start, but to keep things concise I will only speak of the final and most productive spot.

 

By now it was midafternoon and the winds were howling at full force. After floating about, examining various chunks of oyster hash, I at last reached a stopping point. Before me was a massive boulder, the size of a car, with a fantastically complex arrangement of debris cemented to one face. From afar it was just a greyish mess, but up close I could pick apart the various oyster shells, driftwood, Thalassanoides, etc. This mixture of debris and later considerations led me to believe that I was gazing upon an ancient storm deposit.

 

Oyster shell hash

 

Up until this point, I had been unsuccessful in finding any sign of vertebrates. I laid myself upon the slanted body of the boulder and got my face as close as possible to its heavily ornamented surface. Like a visual puzzle of sorts, it was very inviting to look at. Intuition told me that there had to have been something of worth hidden within the noise.

 

Phosphate and carbonized wood

 

It took a bit of time, but sure enough I eventually found a tiny pebble of phosphate lost in between the fissure to some branching burrow. The familiar sheen immediately reminded me of the jet black teeth I had once pulled out of the basal Atco conglomerate. With a little more wind in my sails, I continued perusing until I was met with something much more substantial.

 

First phosphatic Cretodus semiplicatus of the day

 

I had found a beautiful Cretodus semiplicatus. To those whom the Woodbine is foreign, such a find may seem pretty lucky as Cretodus is usually a rarity in most places. However, the marginal marine deposition of the group means that coastal predators are represented in very high numbers, so much so that C. semiplicatus is often the most common taxon of large shark to be found. Contrast this with the deeper waters of the slightly younger Bouldin Flags Fm in Central TX, where the same species occurs in much smaller numbers (though admittedly the individual sizes of the teeth are often considerably bigger). Anyways, I got to busting it out which proved difficult. The high density of durable oyster shells halted my progress greatly. Somehow I managed to extract the tooth as a clean chip without it poofing away into a million fine particles.

 

From there, I began finding a large quantity of phosphatic bone material. Most were reptilian in nature and either obviously belonged to turtle or likely belonged to a croc. Sadly, the resilient nature of the matrix and fragility of the bones made a clean extraction more or less impossible... for me at least.

 

Croc vert likely Terminonaris cf. robusta

 

T

Turtle elements

 

Random ammonite fragment

 

As my walking continued I began finding some occurrences of sandier depositions that were much easier to dig through and even richer with phosphate. What surprised me most, however, was their appearance.

 

C. semiplicatus in situ

 

In my eyes, those pictures above look as though they could have been taken along the shores of any sandy beach saturated with seashells. The soft sand was so loosely packed, the slightest pressure could disturb the granules and send them drifting away. As I scanned, I couldn't help but imagine the tropical storm or hurricane that must have taken place here 96 million years ago in order to create this flash-frozen formation. The wind suddenly felt of an ocean breeze, and the cloudy backdrop like a Mesozoic sky in recovery from absolute chaos; Alone, I wandered the shore.

 

A couple of croc teeth. Likely Terminonaris cf. robusta

 

To round off the day, I found some beautiful, though damaged, croc teeth. Like the critters asleep in this dune, it seemed I had lost track of time, so I made my way home.

 

~~~~~~~~~~~~~~

 

I have a bit of micro matrix to go through, but as of now, these are the species of vertebrates found:

 

Cretodus semiplicatus

 

Cenocarcharias tenuiplicatus

 

Meristodonoides rajkovichi

 

Pseudohypolophus mcnultyi

 

Some nice pycnodont teeth were found

 

Mostly Haimirichia amonensis, but I will take a closer look later

 

Terminonaris cf. robusta

 

I really thought I saw a dino tooth sticking out of the sand when I first spotted this. Actually it is an inarticulate brachiopod ( @Tidgy's Dad enjoy!) called Lingula subspatula.

 

Thanks for reading!

Edited March 20 by Mikrogeophagus

[Tidgy's Dad]

Lovely organo-phosphatic shell!

Thanks for alerting me.

The matrix looks a nightmare but you found some unusual and beautiful teeth.

[ThePhysicist]

Even sans dinos, this would be a good day in my book! Great finds and glad you bagged up some matrix for later. For dinos you might try looking a bit farther West? Your ideal deposits are likely channels further inland.

[Jared C]

Not only are you a skilled hunter, but an excellent wordsmith. I really enjoyed this report, and would drop dead if I found a C. semiplicatus tooth. Awesome work

[Praefectus]

Nice finds!

[Ludwigia]

4 hours ago, Mikrogeophagus said:

Thanks for reading!

 

And thanks for the great report. You sure did find a nice honey hole...or should I say honey block It's also interesting for me to compare your cretaceous shark tooth finds with mine from the Miocene.

[JohnJ]

Well done, Tyler!  I really enjoyed your report.  

[Fossildude19]

Great report and finds. Thanks for sharing them with us.

 

[jpc]

Looks like a grand day in the field.  Thanks for sharing.  Croc vert... cool.  

 

[digit]

Thanks for the vicarious fossil hunt--really enjoyed it!

 

 

Cheers.

 

-Ken

[Andúril Flame of the West]

Wonderful finds and I must second @Jared C‘s comment on your report style! Beautiful thorough writing and some amazing pictures to go with it. Interesting that the phosphatic shark teeth and bones are in such good condition. I have come across some in my local Cretaceous deposits and, unfortunately, they are extremely weathered .

 

Looking forward to future trip reports! 

[Mikrogeophagus]

18 hours ago, ThePhysicist said:

For dinos you might try looking a bit farther West? Your ideal deposits are likely channels further inland

Sounds like a good idea. I think I definitely aimed a little too high in the stratigraphy. One site I went to even dipped into the basal Eagle Ford, Tarrant Formation. Got some neat teeth, but obviously once again not the intended goal for the day. Once summer rolls around I'll have a new list of target sites!

 

14 hours ago, Ludwigia said:

It's also interesting for me to compare your cretaceous shark tooth finds with mine from the Miocene.

The sites and teeth certainly look similar! Those goblin sharks seem to be exact matches with the Cretaceous ones of TX too. Some things never change I guess!

[Ludwigia]

7 hours ago, Mikrogeophagus said:

Some things never change I guess!

 

It seems that when nature finds a useful form, it repeats it over the ages, irregardless of which kingdom they belong to.

[Notidanodon]

Wow what a haul, wish there were Cretaceous deposits like that near me!

[Brad84]

Great finds! Thanks for the post. I have a lot of shark teeth but I am horrible at figuring out the names. The Woodbine is fun to hunt and can be either a blessing or a curse! I have been lucky in my endeavors and have plenty of Protohadro stuff . Keep looking and you will find them! The dinosaur teeth are usually in lag deposits so look for lenses of the gravel when out. Here’s some of the teeth I have in my collection. Good luck!

 

[Mikrogeophagus]

@Brad84 Thanks for the tip and I gotta say that's a nice collection! I had no idea that much Woodbine dino material existed let alone in a single collection That's some good motivation!

 

If you want shark IDs, I'm writing up a huge guide which will include most of the Woodbine species from the Rush Creek Member. This post was from the Arlington Member and had its own unique species which I am now contemplating adding onto the guide.

 

 

[Brad84]

7 minutes ago, Mikrogeophagus said:

@Brad84 Thanks for the tip and I gotta say that's a nice collection! I had no idea that much Woodbine dino material existed let alone in a single collection That's some good motivation!

 

If you want shark IDs, I'm writing up a huge guide which will include most of the Woodbine species from the Rush Creek Member. This post was from the Arlington Member and had its own unique species which I am now contemplating adding onto the guide.

 

I worked the Arlington Archosaur site from the beginning and have found many sites now. It’s interesting the way the environment changes from each area. I can’t wait to see what you come up with!

[Atoothsatooth42]

Fantastic post! Some of the coolest finds I’ve seen in a while. Makes me want to try my hand at an Eocene or Cretaceous site for some Dino fossils.