Maryland's Hidden Gem: Dinosaur Park

Dinosaur Park in Laurel, MD, is a tiny, 7.5-acre tract of county parkland surrounded by a business park in bustling, suburban Maryland. Nevertheless, it is the most prolific dinosaur and plant site east of the Mississippi.

The first fossils there were found in the 18^th century by slaves in the siderite (bog iron ore) mine that was there at the time. It wasn’t until 1858 that the bones turning up in the mine were identified as dinosaur remains. The bones found that year were from what would have been, if they a had done all the paperwork, the second dinosaur identified in the US, Astrodon johnstoni, which is now Maryland’s State Dinosaur[1] . Since then dinosaurs, turtles, small mammals, crocodilians, gastropods, clams, and tons of fossil plant material have been found there, all of it now at the Smithsonian.

The site is part of the Arundel Formation, dating to the Lower Cretaceous, 115 mya, when the place was an oxbow lake. Tributaries were strong enough to wash dino bones into the lake. The fossils there are disarticulated wash-out. Whole skeletons are not generally found or expected here.

The exposed hillside consists of a mix of fine grey soil, siderite bog iron and lignite (coalified fossil wood the consistency of charcoal). The lignite and siderite form a thin, dense gravel layer. The challenge for visitors and paleontology volunteers alike is to find the pale blue bones and shiny teeth in the cacophony of black and orange. Collection is done almost exclusively by surface scanning. If something large turns up by way of erosion, then they cordon it off and dig it out. Anything other than the wood is documented with the finder’s name and sent to the Smithsonian. Visitors may keep one palm-sized piece of fossil wood if they like.

My husband and I met a friend and her two daughters there today. It was cold, but sunny. There were harsh shadows on the ground, which are supposed to make it easier to pick out shiny teeth. I find the contrast too harsh to see details. The park is open from noon to 4 every other Saturday. We got there close to 1 and spent a couple hours there, despite the chill in the air.

I didn’t expect to find any exciting fauna. That’s usually our daughter’s job, and she was at work. I was engrossed in the lignite and the siderite plant impressions, hoping maybe to find a seed cone or two for their collection. Apparently, a handful in a day is not unusual there.  I had no luck on either score.

I did find a nice plant impression in the siderite. Looks like tree bark. I asked if that could be the one I took home. The volunteer looked at me sternly and asked, "Do you now what it is?"

"Tree bark impression in siderite, but I don't know from which tree."

“What do you do for a living?”

“Artist.”

“What do you do that will prove to me that this will be used for educational or scientific purposes?”

I told him about my fossil blog and the homeschool paleontology series I just ran at my local library. He was convinced. Now I have it at home, but I may offer it to the Delaware Museum of Natural History, where I volunteer.

Each of the girls also found something nice, albeit smaller, to bring home. Unsurprisingly, most of the other kids were disappointed because they didn’t find dinosaur teeth. There was a list at the registration table of maybe a dozen interesting things found today. As far as I know, no one found anything interesting while we were there. Some days go like that, but I was not disappointed. It was a good afternoon to see someplace new.