A Summer in the Cretaceous

[patelinho7]

Hello everyone,

 

This summer, I’ve begun volunteering at the MNCPPC Dinosaur Park in Laurel, MD. It’s somewhere I’ve known about and visited since I was a kid, and it feels great to be a part of the park now that I’m older. For now, I planned to help out this summer as I go back to college in late August, but I’m really enjoying it so I do hope to return on breaks and after I graduate. This park is an early-Cretaceous oxbow lake deposit and is the best source of early-Cretaceous fossils on the east coast. I’ll let you do your research if you’re interested, I don’t want to go on too long. But in essence, the volunteers at the park help the public when they come on the first and third Saturdays of the month to freely surface collect (their finds are kept with the park and catalogued) to help the scientific process. We have some other duties too, but otherwise, we get to fossil hunt for several hours! It really is a dream-job for me. I’ve had this dream of finding dinosaurs close to home since being a kid, and now I get to actually live that dream. I thought I’d start this thread to show what I find over the course of this summer, and hopefully the years to come of volunteering here. I’ll start small, I’ve only volunteered for two Saturdays at the park so far, so my finds will mostly be indeterminate bone fragments, but eventually I’ll probably dial down the small stuff in the hopes I train my eye more and find better specimens. I’ll also potentially post other finds from nearby Potomac Group exposures, and I’ll give background info on all of the posts. I’m so excited to be able to post about Cretaceous fossils, so bear with me! Feel free to offer opinions and IDs, and feel free to ask me questions about what I’m doing and I’ll do my best to answer them. And if you volunteer at the park and are on the forum, please let me know! 

[patelinho7]

Starting off with my first day of volunteering! It was a decent day, could’ve used a recent rain, but decent specimens were found. The public found bivalve internal casts and  metasequoia pinecones. Us volunteers had similar successes plus some random bone fragments and fish scale bits. The finds of the day included a worn nodosaur tooth (Priconodon), an interesting sort-of carbonized pinecone in the clay, and my first ever find! 
 

 

Fish Scale

Lepidotes sp. 

Arundel Clay Fm., Early Cretaceous (Aptian)

Dinosaur Park, Laurel, MD

 

I apologize for the lack of scale and high-quality photos. At some point I will measure the cataloging-paper I take most of my photos on to get a standardized scale for every find. I take these photos in the field and then deposit my find in the collection bin. I should probably just have a ruler on hand.

 

I found this literally 45 minutes after arriving. The other volunteers said it was larger than the usual scales found here, so it was a decent find and a great first find! Just look at the enamel preservation and the telltale blue color.

Edited June 18, 2023 by patelinho7

[patelinho7]

Here was my only other find that same day:

 

 

Bone Fragment

Arundel Clay Fm., Early Cretaceous (Aptian)

Dinosaur Park, Laurel, MD

This was exciting as it was my very first piece of bone from the park. I guess the scale could technically be bone material but this was bone bone. It was an isolated shard so I’m not really sure where/what it came from. I was excited about possibly finding my very first piece of dinosaur bone, but that would have to wait for another day as this bone could also technically be turtle or crocodilian. 
 

I also learned a valuable lesson! Sometimes it is quite hard to distinguish the difference between bone and lignite/other rock, and mistakes are made. Luckily, we have glue for bigger mistakes. I was drawn to this very small and light piece because of the blueish color, which is that whitish patch you see on the larger of the two pieces. The camera doesn’t pick up the blue well. It’s more of a silvery blue-grey anyway. I thought it could maybe be bone, but it also seemed a little like lignite. So I did my usual lignite test, which was to try and sink my fingernail lightly into the piece and see if I got black powder on my finger. I did so, and the piece broke in half! I should’ve known something so fragile would do that. But then I saw the cross section and could see the bone structure under my loupe. Luckily it was as inconsequential bone fragment. But lesson learned, try other methods before you go breaking stuff. I seem to have a record for breaking fossils in half and then using the cross section to identify them (I did that with my dinosaur track ).

 

Last interesting factoid: much of the bone material at this park has this blue-grey color. So does a lot of vertebrate material across the world, modern or prehistoric. What causes it do this? Well, I happened to bring this up to Dr. Weems, and he explained this. A mineral called Vivianite has the capacity to grow and form around bone as a result of iron presence and post-mortem processes like decay. This is usually colorless and cannot be seen, but upon exposure to sunlight, it turns bluer and bluer. I believe this is the rough explanation, I may be missing/incorrectly remembering details so please correct me if I am wrong. It’s another telltale vertebrate material red flag that you can use to take a closer look. If a rock has blue tinging, look around and see if there’s bone nearby.

[Andúril Flame of the West]

This sounds like a fantastic opportunity for doing what you enjoy while also contributing to science and public outreach! Those are indeed some intriguing pieces that you found there. Hopefully there will be more to come. 
 

Now that you volunteer there I may just have to pay the park a visit. I recall going there once quite a while ago when I knew next to nothing about fossils. It was fun to meet Dr. Kranz - is he there on most digging days? - and to find some pieces of lignite. The only piece of interest I found was something that I once thought was a tree or skin impression but which I now believe to be a fragment of an ironstone concretion. 

 

It has been a long time so my memory may not serve me right, but I recall that one of the volunteers came across something that they identified as a mammal tooth that day. 
 

Again, this is great news and a wonderful opportunity to help science. I look forward to hearing about your future finds! 

[digit]

2 hours ago, patelinho7 said:

Just look at the enamel preservation and the telltale blue color.

I know what you mean. I had the privilege of hunting out on a private ranch in eastern Wyoming and came up with a nice little group of these. The bluishness seem to fade to a chocolate brown over time. Gar scales (lepisosteidae) are pretty common finds in Florida but it's pretty cool to find ones going all the way back to the Cretaceous.

 

 

Cheers.

 

-Ken

 

 

 

[patelinho7]

1 hour ago, Andúril Flame of the West said:

 is he there on most digging days? 

Dr. Kranz unfortunately does not come to the open houses or park activities. I imagine he’s winding down his activities since 5 hours of back and knee damaging work in the hot sun is not ideal! I believe he’s still holding his summer camps so he is still active in general. Yes, I think it’s worth another visit! It’s not the most yielding fossil hunting but it’s fascinating to be so close to an active paleontological site.

 

32 minutes ago, digit said:

I know what you mean. I had the privilege of hunting out on a private ranch in eastern Wyoming and came up with a nice little group of these. The bluishness seem to fade to a chocolate brown over time. Gar scales (lepisosteidae) are pretty common finds in Florida but it's pretty cool to find ones going all the way back to the Cretaceous.

 
Wow, what nice scales! Those are the common ones I saw on the internet when I searched for similar scales. They look very different from the Cretaceous ones at the park, but I suppose it’s probably because they’re from a totally different period? The preservation is so nice. In any case, gar scales are quite unique and cool with their enameled scales 

[EMP]

Cool stuff, I look forward to seeing what you find!

[patelinho7]

(Thanks for all the replies! I’ve been busy and a little behind on updating this thread)
 

My previous two posts with pictures were from the first Saturday I volunteered, June 3, so this post is for this past Saturday, June 17.

 

This day was incredibly slow. There were thunderstorms in the forecast last week, so we were all excited. Down in VA, it poured cats and dogs on Friday. But upon returning to the park, I found that Laurel got zero rain and totally avoided the storm cells. The conditions were awful, most of the park was this powdery-gray, sandy mess. Not ideal hunting conditions for anyone. The only place to look was the gravel that already had been there for many weeks since we haven’t gotten rain for a while.

 

Not much was found at all. The public found next to nothing. All I heard was that one kid found an impression of a metasequoia cone, not even the cone itself. Even us volunteers had rough hunting. The main find of the day was a sizable crocodile osteoderm found right after we all arrived on a spoil pile, and then a few small bone fragments for the rest of the day.

 

I found one small bone fragment. For a beginner hunter at this park, finding anything at all, especially a bone fragment in these conditions, was great! It was a very porous piece of bone that almost looked too well preserved to be a fossil. But indeed it was. And better yet, the other volunteers told me that based on the find’s location and its very distinct appearance, it most probably belongs to a dinosaur bone found a while ago. This was great news for me! I finally fulfilled a childhood dream of mine, finding dinosaur bone. And so close to home! The distance from home is very important to me as well! It makes it more special. Here it is:

 

 

 

Bone Fragment

Arundel Clay Fm., Early Cretaceous (Aptian)

Dinosaur Park, Laurel, MD
 

This one also has a tinge of light blue that doesn’t show up on camera well. That’s how I found it. It’s always so hard to believe that you’ll be able to distinguish between bone and lignite that both have blueish-grayish tinge, but once you really get an eye for the different types of pebbles, bone really is clear as day. Especially this one, since the bone structure was so exposed.

 

I also found a piece of siderite with peculiar holes that reminded me of a cone, but it turned out to be a likely internal bivalve cast. Not at all what I expected! It was also very hard to make out so I didn’t take any photos.

 

Not a bad day in the end! Conditions were poor, but I found my first dino material!! And I hope it’s only the beginning…

 

The next day I will post is Tuesday, June 20. We did a scheduled dig with the Girl Scouts. At the time I’m finishing up this report, it has already happened. So stay tuned for that post!

[digit]

Sounds like you are putting in time so sooner or later interesting finds will come.

 

 

Cheers.

 

-Ken

[NickG]

Dino Park is an absolute gem. 

[patelinho7]

I had plans to properly update this thread over the course of the last few visits I made over the summer, but I lost the draft I made and forgot to re-write it .

 

In essence, I found some turtle shell, numerous more bone fragments, and my first tooth that we still aren’t sure what it is from (it is my profile picture, if you would like to see a better photo let me know).

 

but moving on, I finally came home for my fall break and was just in time to make a trip to the park for a dig day. Public is welcome to register for private digs, but we are booked until summer of 2024. It was beautiful weather and a great day to spend with our guests as well as each other. The recent rains also made the ground softer to work in.

 

It was a quiet day find-wise, but my patience was rewarded with a massive dose of “leaver’s luck”, I believe it’s called? We were wrapping up and I went to my bag to drink some water, and as I bent down to sit, I noticed a clear-as-day, bright-white carina sticking up at me! And this time I actually remembered to take in-situ photos!

 

 

 

 

 

 

 

 

Crocodile tooth

Arundel Clay Fm., Early Cretaceous (Aptian)

Dinosaur Park, Laurel, MD

 

I don’t know what species it is, so anyone is welcome to speculate and/or provide ID if you recognize it. My second tooth, two-in-a-row (across DP visits), and a very nice one! Quite happy with my luck.

 

Also, enjoy our wonderful Deinonychus sculpture: 

 

 

 

 

p.s. As I was in the area with some time to spare, I visited one of my old Patuxent Fm. stomping grounds in search of dino tracks and brought a couple “maybe”s home as well as a possible coprolite? I have no experience with coprolites so that will likely be an ID post after I do some research on it.

 

[patelinho7]

Since my last post, I have visited Dino Park twice, once for a scheduled dig program and once (this past weekend) for a standard public program. Interestingly, the one benefit of being away for college meant that when I was finally home for small breaks and weekends, usually all I could get up to Dino Park for were the dig programs. I’m excited to say that I’ve gained so much experience and exposure already in excavation techniques and other field work methods (like mapping, cataloguing, etc.). I also found my first decent chunk of bone via excavation! While I was a beginner, I was tasked with bringing overburdens down to the bone layer to practice digging, limit possible damage due to inexperience, and also still make a dent in the dig progress. Now, I’m able to dig in the bone layer! Very fun. This was the culmination of several dig programs I volunteered in, and this day was around Thanksgiving.

 

Fast forward to now, it’s the end of the year and we’ve had a very successful year at Dinosaur Park. I’m finally on winter break, which means 90% of my mental space and energy is devoted to paleo . It was the last public program of the year, so we had planned a volunteer potluck! Everyone came early and brought tons of goodies and we had a great time. I brought chai blondies I’ve baked for the first time, but I also brought brownies. The blondies were just ok, so it’s a good thing I had brownies for backup. After a while, we transitioned to manning our positions for the day (public day starts at 12 pm, we got there around 10 am). It was a quiet day, the volunteers had a lot of freedom to do whatever they pleased. It’s mid December, usually hordes of visitors don’t come out. However, it was definitely good weather (high of 54 deg F and sunny) and winter is my favorite hunting season. We’ve got a bunch of newer young volunteers (high schoolers I imagine) who are incredibly passionate about paleontology and sat together for much of the day gushing about dinosaurs and other topics in paleontology. It was really nice to see, this field really does have hope for the future. I’m a bit quiet and keep to myself so I didn’t participate all that much unfortunately, but also, I spend much of the time hunting so I was never quite stationary enough to engage. 
 

Now, the fossils! It was my most productive day thus far. I totaled 4 decent finds, including 3 somewhat diagnostic finds. The first 3 finds were within 45 minutes of starting. My eye gets better every time I come and I’m seeing the results. My learning curve/success rate is getting ridiculously lucky, every successive visit I find something better and better. I’m starting to see a pattern, though, as I improve, I have tremendous success within the first hour, and then quickly lose steam and focus, and sometimes get a dose of leavers luck to cap off the day with a find. I’ll have to figure out how to increase my endurance and find fossils throughout the whole session. 
 

I had just complained about the winter low sun angle making it difficult to see colors (I search for colors here rather than shapes or textures), so I began looking in the shade of a particularly large bolder. I noticed a small light-colored speck and picked it up, amazed to see that it looked like the very tip of a tooth. I hollered to some of my fellow volunteers to take a look and they were astonished to see that it was in fact a whole tooth, about 4-5mm wide. We weren’t totally sure what it belonged to, so we called over our park paleontologist, JP, who identified it as a crocodyliform. It is a rather uncommon find, as most croc teeth are totally different here. People were quite excited about this find as it was both such a small tooth to spot as well as a rare tooth. If anyone has any suggestions on what species it could belong to, I’m all ears! I’d like to learn more about whatever type of crocodilians could produce such a tooth.

 

Crocodyliform tooth

Arundel Clay Fm., Early Cretaceous (Aptian)

Dinosaur Park, Laurel, MD

 

 

After that, I found turtle shell, a bone fragment, and rounded off with a tooth fragment to end the day. It’s quite a small piece, so I’m not really sure what it belongs to. It looks like it could be a section of one of the carinae of a larger tooth. It doesn’t look like a herbivorous dinosaur, not rounded enough to be croc I’d think, and I don’t see any theropod-esque serrations. Again, open to suggestions!

 

 

Indet. tooth

Arundel Clay Fm., Early Cretaceous (Aptian)

Dinosaur Park, Laurel, MD