Paleontology in Maryland facts for kids
Paleontology in Maryland is all about finding and studying ancient life in the U.S. state of Maryland. It also includes the work done by scientists from Maryland. The fossils of tiny sea creatures found here are quite similar to those found in nearby Delaware.
For much of the early Paleozoic Era, Maryland was covered by a shallow sea. But sometimes, parts of the state were above water, like during the Ordovician Period and Devonian Period. Ancient sea animals like brachiopods (shellfish) and bryozoans (tiny colonial animals) lived in these waters. On land, plants like horsetails and scale trees grew tall. By the end of the Paleozoic Era, the sea had completely left Maryland.
In the early Mesozoic Era, the supercontinent Pangaea began to break apart. This massive geological event also created huge lakes in Maryland. Dinosaur footprints were left along the shores of these ancient lakes. During the Cretaceous Period, dinosaurs roamed the state.
Later, in the early Cenozoic Era, Maryland was sometimes underwater and sometimes dry land. During the last Ice Age, huge, hairy mastodons lived here.
Long ago, the local Delaware people had stories about a creature called the "Grandfather of the Monsters" and Little People. These myths might have been inspired by the dinosaur footprints they found. By the 1850s, scientists officially started studying Maryland's fossils. One of the first big finds was Astrodon, which was the first sauropod (long-necked dinosaur) ever described from North America.
Maryland also had one of the most important Pleistocene Epoch mammal discoveries in American history. This happened in the early 1900s when Ice Age fossils were found in a Allegany County cave. The Miocene Epoch murex snail called Ecphora gardnerae gardnerae is Maryland's official state fossil. And Astrodon johnstoni is the official state dinosaur of Maryland!
Contents
Ancient Maryland: A Journey Through Time
We haven't found any fossils from the very oldest time, the Precambrian Period, in Maryland. So, the state's fossil record begins with the Paleozoic Era.
Life in the Paleozoic Era
During the Cambrian Period and Ordovician Period, Maryland was covered by a warm, shallow sea. Later in the Ordovician, geological forces lifted the state above sea level. But the seas eventually returned. During the Devonian Period, Maryland was lifted out of the sea again. Then, erosion and sinking land brought it back underwater. One last time, at the end of the Carboniferous Period and beginning of the Permian Period, Maryland was lifted up.
When Maryland was underwater, creatures like brachiopods and bryozoans thrived. When the sea was gone, plants like horsetails and scale trees grew across the state. Maryland was hot and humid during the late Paleozoic. By the end of this era, most of the state was dry land.
Dinosaurs and Ancient Lakes in the Mesozoic Era
During the Mesozoic Era, powerful geological forces were breaking apart the supercontinent Pangaea. These same forces created deep cracks, or rifts, in Maryland. Lakes and rivers formed in these rifts. Plants that grew nearby sometimes became fossils in the mud and sand deposited by these waters.
The first dinosaur footprints in Maryland were found in rocks from the Late Triassic Period. These were laid down north of Emmitsburg in Frederick County. For about 30 million years, from the Late Triassic to the Early Jurassic, a huge lake covered the Culpeper Basin.
Sea levels changed a lot during the Cretaceous Period. Sometimes Maryland was underwater, and sometimes it was dry land. Sea creatures like brachiopods and molluscs lived in the waters. Maryland and Washington, D.C. are the only places east of the Mississippi River where we've found Early Cretaceous Period dinosaur remains. The only known Late Cretaceous Period dinosaur fossils in Maryland were found in the Severn Formation in Prince George's County. Many Late Cretaceous sharks, like Squalicorax, are found there, along with occasional Mosasaur fossils.
Mammals and Megalodon in the Cenozoic Era
During the Tertiary Period of the Cenozoic Era, sea levels also changed a lot. In the Paleocene Epoch, Maryland was home to at least 10 different kinds of tiny crustaceans called ostracods. During the Miocene Epoch, a sea turtle called Bothremys lived in Maryland. It might have eaten snails by crushing their shells.
The famous Chesapeake Group rocks along the coast of Calvert County are known for their many different kinds of ancient marine mammals. Many types of sharks swam over Calvert County, including Otodus megalodon. This was the largest shark that ever lived! Many young megalodon fossils found here suggest it might have been a breeding or nursery area for them. The Chesapeake Group is also where Maryland's state fossil, Ecphora gardnerae, was found. This snail fossil was one of the first fossils described in North America. It's known for being delicate and having a unique color. Scientists recently found that it still holds tiny bits of the original proteins from the living animal!
The Ice Age in Maryland
Giant glaciers never reached Maryland during the last Ice Age. However, they still affected the area. When water was frozen in glaciers, it caused sea levels to drop. Maryland's climate became cold, and it often snowed. Because of this, the plants and animals living here were different. Animals like mastodons, mammoths, and smilodon (saber-toothed cats) lived in Maryland.
During warmer times, the glaciers would melt, and sea levels would rise. Clams, oysters, mussels, and snails lived in these higher waters. Their fossils are found in the eastern part of the state. On land, Ice Age Maryland had many different kinds of mammals.
Around the middle of the Pleistocene Epoch, Maryland was covered in moist woodlands. At this time, a hole in the limestone of an Allegany County hill became a trap for many animals over a long period. Among the fossils found were animals from very warm, moderate, and very cold climates. This shows how the local wildlife changed as the Earth's climate changed.
Animals from warm southern areas included some bats, peccaries (pig-like animals), and a tapir. A crocodile fossil found in the cave shows that large reptiles also lived in Maryland long ago. Animals from moderate climates included a badger, different kinds of bears, deer, a mastodon, an otter, and a puma-like animal. Animals more typical of northern areas included elk, a fisher (a type of weasel), hares, lemmings, minks, jumping mouses, muskrats, pikas (small mammals), porcupines, long-tailed shrews, red squirrels, and wolverines. Interestingly, very large animals are mostly missing from this fossil site. Few fossils suggest anything bigger than a modern black bear. Also, many common Ice Age animals from other parts of the U.S., like bison, camels, giant ground sloths, grizzly bears, and musk oxen, are not found here.
History of Fossil Discoveries
Scientific Research Begins
In 1859, a state agricultural chemist named Philip T. Tyson found the first dinosaur fossils from the Arundel Formation. He found them in an iron pit near Bladensburg, in Prince George's County. The discovery included two fossil teeth from the Early Cretaceous Period. Around the same time, Tyson also found the first known fossil cycad (palm-like plant) trunks from the Arundel Formation.
Tyson took the dinosaur teeth to a local doctor, Christopher Johnston. Johnston cut thin slices of one tooth to look at it under a microscope. He then wrote a paper about it. Johnston named the teeth Astrodon. In 1865, another scientist, Joseph Leidy, officially named the species Astrodon johnstoni after Christopher Johnston. This was the first time a sauropod species was formally named in North America!
In late 1887, Othniel Charles Marsh, a famous paleontologist, sent John Bell Hatcher to look for dinosaur remains in the Arundel Clay. Hatcher found an iron mine on a farm near Muirkirk. Locals called this mine "Swampoodle." It became the best place on the East Coast to find Early Cretaceous dinosaur fossils in the U.S. Hatcher often dug during the winter, which was very harsh that year. In early 1888, Hatcher continued his difficult winter digs. His hard work helped the area between Maryland and Washington D.C. become known as Dinosaur Alley. Hatcher found hundreds of bones and teeth. However, the fossils were often broken, separated, and from young animals. Later in 1888, Marsh named five new dinosaur species based on what Hatcher found. These included the ankylosaur Priconodon crassus, the sauropods Pleurocoelus altus and Pleurocoelus nanus, and the theropods Allosaurus medius and Coelurus gracilis. At the time, Marsh thought these fossils were from the Late Jurassic Period, but we now know they are from the Early Cretaceous.
In 1894, Arthur Bibbins was hired by the Woman's College of Baltimore (now Goucher College). He taught biology and geology and took care of their museum. Bibbins started collecting fossils from the Arundel Clay that year. He was very good at finding fossil cycad trunks. In the summer of 1894, Bibbins learned that more dinosaur bones had been found locally, both in the same iron mine Marsh had explored and in new places. Bibbins started digging at these sites and quickly gathered a large collection of dinosaur bones. He said the digging was "attended by much difficulty."
The only known dinosaur footprints in Maryland were discovered the next year, in 1895, by James A. Mitchell. He found them in a Frederick County quarry north of Emmitsburg. The prints were preserved in rocks from the Late Triassic Gettysburg Formation. Mitchell not only found them but also drew them.
In the early 1900s, Maryland had one of the most important Ice Age mammal discoveries in American history. In 1912, workers digging a cave for a railroad project near Cumberland in Allegany County accidentally destroyed many fossils. However, scientists soon realized how important the fossils were. Paleontologist J. W. Gidley then worked at the cave between 1912 and 1915.
In 1965, the fossil collection belonging to Goucher College, which Arthur Bibbins had helped collect, was permanently loaned to the National Museum of Natural History at the Smithsonian Institution.
After J. W. Gidley passed away in 1931, his son continued his father's work on the fossils from the Allegany County Cave. In 1938, the younger Gidley published an important report about the fossils. The fossils found there are now kept at the Smithsonian Institution. By the time of the 1938 report, more than 50 different kinds of animals had been identified from the cave. This included many animal groups that would normally live in much warmer or much colder places. Most of the animals were relatively small, and some Ice Age animals common elsewhere in the U.S. were strangely missing.
In 1952, the first known Paleocene Epoch fossil sites in Maryland were found in Prince George's County. By early 1954, ten different species of ostracods had been described from these sites. Later, in 1966, researchers from the Carnegie Museum dug for invertebrate fossils at Scientists' Point on the Chesapeake Bay. More recently, in 1998, Astrodon johnstoni was officially named the state dinosaur of Maryland.
People in Paleontology
- R. S. Lull was born in Annapolis on November 6, 1867.
Natural History Museums
- Maryland Science Center, Baltimore
- Natural History Society of Maryland, Baltimore
- Peale Museum, Baltimore
- Calvert Marine Museum, Solomons
Notable Clubs and Associations
- Maryland Geological Society
- Calvert Marine Museum Fossil Club
