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“Bite-Size Bits of Local, National, and Global History”
“Bite-Size Bits of Local, National, and Global History”
Bladensburg in Prince George's County, Maryland — The American Northeast (Mid-Atlantic)
 

Dinosaur Alley

 
 
Dinosaur Alley Marker image. Click for full size.
By Craig Swain, July 18, 2010
1. Dinosaur Alley Marker
Inscription. Bladensburg lies in the geologic region known as "Dinosaur Alley." It is the area on the East Coast of the United States were the greatest number of dinosaur bones have been found. Dinosaur Alley runs along the Route 1 corridor between Baltimore and Washington. The layers of earth in this area are about 100 million years old and are made primarily of clay and sand, not rock.

One hundred million years ago, during the middle Cretaceous period, the Baltimore-Washington area was a flat plain near the sea, just as it is today. The climate, however, was warmer. The forests of that time consisted of conifers (pine trees and their relatives), cycad-like plants (conifer relatives that look like palms), and tree ferns. There were no grasses, briers, or oaks; flowering plants had not even developed yet. This was the home of the dinosaur.

During colonial times, iron-rich ore beds were dug by hand from surface pits. Occasionally dinosaur bones and other fossils were found, but the fossils' scientific importance was not understood at the time. The first dinosaur bones were said to have come from "iron mines in Bladensburg," but the actual site was nine miles north at Mulrkirk. These first discoveries (reported by Philip Thomas Tyson, state geologist in November 1858) were the bones and teeth of a large dinosaur named Astrodon johnstoni
Dinosaur Alley Map image. Click for full size.
By Craig Swain, July 18, 2010
2. Dinosaur Alley Map
(Brachiosaur). Astrodon means star-tooth. It ws the first sauropod (a dinosaur with a long neck and a long tail) found in North America. In 1998, the Astrodon became Maryland's official state dinosaur.

At present, about a dozen categories of dinosaurs are known to be from Dinosaur Alley. These finds represent almost all the categories of dinosaurs. Nonetheless, it is generally believed by paleontologists that the fossils that have been found represent fewer than half the dinosaur species that lived in the Bladensburg area. There are many more species and skeletons to be found.
 
Location. 38° 56.115′ N, 76° 56.311′ W. Marker is in Bladensburg, Maryland, in Prince George's County. Marker is at the intersection of Annapolis Road (State Highway 450) and 46th Street on Annapolis Road. Touch for map. Marker is in Bladensburg Waterfront Park, .2 miles south of the entrance at this intersection. Marker is in this post office area: Bladensburg MD 20710, United States of America.
 
Other nearby markers. At least 8 other markers are within walking distance of this marker. Duels and the Bladensburg Dueling Grounds (a few steps from this marker); The Incidental Cause of the Star-Spangled Banner (1814) (a few steps from this marker); Encampment of Coxey's Army (1894) (a few steps from this
Dinosaur Alley Marker image. Click for full size.
By Craig Swain, July 18, 2010
3. Dinosaur Alley Marker
marker); Clearing the Way to Washington (a few steps from this marker); Historic Bladensburg Waterfront Park - Port Town History (within shouting distance of this marker); First Unmanned Balloon Ascension (1784) (within shouting distance of this marker); Colonial Ropemaking (within shouting distance of this marker); The Battle of Bladensburg (1814) (within shouting distance of this marker). Touch for a list and map of all markers in Bladensburg.
 
More about this marker. The marker displays a drawing of two young Astrodon johnstoni, a map of "Dinosaur Alley," and a drawing of a tooth of Astrodon johnstoni (actual size 1 3/4 inches in height).
 
Categories. Animals
 
A pair of young Astrodon Johnstoni image. Click for full size.
By Allen C. Browne, March 17, 2013
4. A pair of young Astrodon Johnstoni
Close up of Gregory S. Paul illustration on maker
Tooth of an Astrodon johnstoni <br>(actual size 1 3/4 inches in height). image. Click for full size.
By Allen C. Browne, March 17, 2013
5. Tooth of an Astrodon johnstoni
(actual size 1 3/4 inches in height).
Close up of Gregory S. Paul illustration on maker
 
 
Credits. This page was last revised on June 16, 2016. This page originally submitted on July 18, 2010, by Craig Swain of Leesburg, Virginia. This page has been viewed 2,114 times since then and 48 times this year. Photos:   1, 2, 3. submitted on July 18, 2010, by Craig Swain of Leesburg, Virginia.   4, 5. submitted on August 3, 2013, by Allen C. Browne of Silver Spring, Maryland.
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