What is Amber?

Amber is fossilized tree sap or resin. Nearly all amber comes from coniferous trees. The resin comes mainly from damage to the bark of the tree. For instance, when a live pine branch is broken, sap runs out of the wound. This yellowish resin hardens to protect the tree and prevent further damage.

The resin also has antiseptic properties to help heal the tree. The resin is also very sticky and will trap insects and other debris such as seeds and leaves that may encounter it. In some cases, air will become trapped as the sap flows, creating bubbles. On rare occasions, water is trapped in the bubbles creating enhydros, liquid water inside the air bubbles. Paleontologists can study these air bubbles and water to see what the ancient environment was like.

The resin also may have flowed several times creating layers trapping various insects on different layers. When an abundance of resin flows, it may even drip and fall to the forest floor trapping dirt, leaves, seeds and other organic material.

Ancient Amber

As ancient trees died and fell to the ground or individual pieces dried and fell to the forest floor, resin-covered trees were washed into streams and rivers and were buried in sedimentary deposits.

Amber dates from around one million years ago to around 300 million years ago, so there is a wide variety of organic matter that has been trapped. Trapped organic matter is called an inclusion.

Where is Amber Stone Found?

Amber can be found in some parts of the world in great abundance. When found, it can have many shapes including irregular nodules, blobs, large thin sheets and even a drop-like shape.

The Baltic region produces most of the commercially available amber. Areas around Russia, Lithuania and Poland are major sources of amber.

The area of what is now the Baltic Sea was dry land millions of years ago. The area was populated with animals, plants and conifer trees. Later, when large amounts of ice melted, the sea level rose and began washing amber and other fossils onto the beaches.

Today, fishermen with their drag nets are hauling in Ice Age bones and other fossils as they fish.

So much amber has been found that many European palaces are adorned with amber lamps, furniture, picture frames, artworks, sculptures and jewelry. Entire rooms have even been filled with amber.

Amber Properties

Amber has a Mohs hardness of 2 to 2.5.

It is an organic substance and it does retain its chemical composition for some time. As it hardens the resin molecules link with others to form larger molecules in a process called polymerization. This slow process can take several tens of thousands to millions of years.

After it polymerizes, the amber becomes less soluble in various organic solvents. This means that it will not become sticky when in contact with toluene, acetone, alcohol or other solvents. Copal or what some call “young amber” will get softer and sticky when in contact with organic solvents. Copal is sometimes desired for jewelry making as real amber is far too brittle and tends to shatter.

Young amber is not considered true amber and comes mostly from Columbia and Madagascar. True amber for lapidary uses comes from the Baltic and the Dominican Republic. Amber can be polished and often it will reveal treasures inside that can tell us about prehistoric times.

This story about amber stone previously appeared in Rock & Gem magazine. Click here to subscribe. Story by Joseph “PaleoJoe” Kchodl.

The post Amber Stone: Nature’s Insect Death Trap first appeared on Rock & Gem Magazine.

Shark Teeth Fossilization

Fossilized shark teeth are one of the few easily recognizable parts of a shark that fossilizes. The internal skeleton of sharks is cartilage and disappears soon after burial in sediments. The main exceptions are the teeth and dermal ossicles, which are the tiny hard sandpaper-like protrusions on shark skin. The central vertebrate can also become calcified and is occasionally fossilized. Cartilage does not mineralize like bones and breaks down much quicker than the hard parts of a shark. Teeth are the most common shark fossil, but sometimes the fossilized dermal ossicles and pieces of vertebrate are found in the same sediments. The dermal ossicles are tiny and are not as easy to identify as the shark teeth.

Permineralization

Shark teeth become fossils through permineralization. Permineralization can happen with other organisms including crab fossils on Florida beaches. This results when minerals dissolved in water fill the open spaces of an organism or organic tissue, and eventually, only the minerals remain. When a shark loses a tooth or a shark dies, the teeth and the shark sink to the bottom and may be covered by sediments. Teeth or sharks that are not buried, such as those that settle on a rocky bottom or in fast-moving water, will disintegrate. The buried sediment provides an anaerobic, or oxygen-deficient, environment and this preserves the tooth or other hard parts of the shark.

Over time the sediment accumulates and the pressure from the sediments pushes water with dissolved minerals into the tooth. Eventually, the minerals crystallize, and the tooth is nearly entirely replaced by silica and other elements including phosphorous, iron and calcium. The buried sediments are later subjected to tectonic forces and eroded, which exposes the sediments with the shark teeth and other fossils. This mineralization requires lots of time. Fossil shark teeth generally range in age from 75 million to 10 thousand years, and the best way to determine the age of a shark tooth is to know the age of the geologic formation that hosted the fossil. The permineralization process also turns the fossil shark teeth black or dark gray, which makes them much easier to spot in sands along the beach.

The Fossil-Rich Aquia Formation

Shark teeth and other fossils at the Purse area are found in the Aquia Formation. The Aquia Formation is composed of clayey, silty, glauconitic sands and has some areas that are rich in invertebrate fossils. The Aquia Formation was deposited during the Paleocene Epoch, which was approximately 59 to 55.5 million years ago. The Aquia Formation is much older than the sediments at Calvert Cliffs on the eastern Maryland shore along the Chesapeake, which is another shark tooth collecting region in Maryland. The Calvert Cliff fossils are within the Chesapeake Group, and were deposited during Miocene Epoch, which was 23 to 5 million years ago. The fossils along the Calvert Cliffs are much younger than those of the Purse area.

In southwestern Maryland, the Aquia Formation is best exposed in cliffs along the Potomac and along streams that have cut into the formation. The cliffs along the Potomac are unstable and are constantly eroded. This exposes more sections with shark teeth and other Paleocene fossils.

Purse Area Beaches

The Purse area is remote but the roads to get to the site are all paved. The area is reached by taking State Route 224, also known as Riverside Road, which bisects the Nanjemoy WMA. The trailhead parking area is clearly marked with a sign that says it is part of the Nanjemoy WMA. While parking at the trailhead is limited, it is possible to park on the sides of the road south of the park. Parking is limited in these areas, and collectors may have to walk up to one-quarter of a mile to get to the trailhead on busy days.

The trail from the parking area to the beach is flat and well-defined, and collectors will not get lost if they continue to walk westward to the beach. Since the area is relatively remote, there are no nearby restrooms or places to eat. Visitors should bring lunch and plenty of drinking water. It is important to come prepared, as anyone that leaves will quickly lose their parking space and miss out on time spent on the beach.

Purse Beach Advantages

The Purse area beach is narrow, and it is tough to find a good space to sit for lunch or relax when not collecting if the beach is crowded. It becomes much narrower during high tide. Like most beaches, it gets the most use on weekends, but people can show up during the work week.

Purse Beach has another big advantage for fossil collectors and other visitors. The beach faces west, so it has sun until it gets dark. This is a big contrast to the beaches at the Calvert Cliffs on the eastern side of Maryland, which face to the east. The sun quickly goes below the cliffs by late afternoon, and the collecting sites in eastern Maryland become cold and much darker, which makes it more difficult to find shark teeth.

Finding Shark Teeth

Shark teeth, as well as fossil dental plates of rays, are found directly on the surface of the sand and gravel along the beach and along the water line. Some collectors use a small shovel or trowel to dig into the beach gravel and then use a screen to examine the sand and gravel for shark teeth. A metal colander or similar screen can be used for screening, but it is important to have the holes sized correctly. If the holes are too big, some of the smaller teeth will pass through the holes, and if they are too small, they will not screen the sand. Generally, holes should be at least one-quarter inch in diameter. Some collectors also make their own screens with wire screen and wood from their local hardware store.

Walking along the beach and scanning the water line for shark teeth and other fossils is productive for many collectors. Low tide is best for collecting, and it is easy to find the tide tables online. The beach is continuously washing and reworking the sand, and shark teeth and other fossils can be easily spotted on the surface. Shark teeth and ray plates are black and are easy to see in the brown sand and gravel. The sharply pointed shape of a black shark tooth also stands out against the sand and gravel. The ray dental plates have a rectangular shape and are also black.

Tiny Teeth

Many of the shark teeth and ray plates along Purse Beach are tiny and sometimes less than one-quarter inch. Larger teeth are found with the smaller teeth, so any area with teeth may also reveal larger teeth. The largest teeth range up to about one inch long. The teeth at Purse are generally pointy and curved, in contrast to some of the large triangle-shaped teeth found at other shark teeth localities. Many of the teeth found in the Purse area are extremely narrow with sharp points, and these are reportedly from Scapanorhynchus, which is an extinct genus of shark that is like the living goblin shark.

Walking on the beach is safest with shoes. There is potential for broken glass, but the biggest threats to bare feet are small pieces of sharp pointed driftwood. The beach near the trail that leads from the road is generally open and easy to hike. If carrying a phone or camera it is better to stay on land, as some of the water is more than waist deep, and there is always the potential to slip or trip in the water.

Turritella Fossils – A Bonus

Small cliffs are present north of the trail where it reaches the beach. Fossils are abundant in the rocks exposed in this area, and many of these are turritella, which are tightly coiled sea snails that are shaped like a narrow cone. Most of the fossils are weathered and crumble when touched, but some of their casts are intact. Some of the interiors of the turritella are preserved by fine mud that has filled their interior spaces. The mud solidified and remained intact long after the original shells had eroded. These casts are like a negative of the original animal’s shell.

Turritella is a genus of medium-sized sea snails. They have coiled shells that resemble an elongated cone. The name comes from the Latin “turritus” which means turreted or towered. The Latin diminutive suffix “-ella” means small. Turritella fossils are worldwide and range in age from the Cretaceous to recent periods. Turritella agate is a beautiful specimen and lapidary material.

Where to Find Turritella Fossils

South of the trail along the beach is a small point on the Potomac River. This is just south of a swampy area that drains into the river. The cliffs become steeper south of the swampy area and many trees have fallen and block the beach path. Sections of the cliffs have collapsed and are on shore. This area is difficult to access and will require climbing over fallen trees and wading into the water.

This area has huge outcrops of the Aquia Formation, and in some sections, the entire rock is made of fossils. The fossils are easy to see as they are generally white against the brown-to-black background of the sandy shale matrix. The outcrops have turritella and bivalve fossils, and many of them are solid and are found as loose pieces next to the outcrops and the large boulders. The large blocks that have fallen from the cliffs are often loaded with fossils, and the matrix material is relatively soft. Digging in the cliffs is illegal, as this leads to increased erosion and is dangerous in areas with overhangs. Many of these fossils are turritella casts, and large rocks with distinct turritella casts are found in this area. While shark teeth are certainly present along the beach near the cliffs, the shoreline is so rocky that it is difficult to find teeth in this area.

Getting to Purse and GPS Coordinates

Purse is reached by taking State Route 224, which roughly follows the Potomac River shoreline in southwestern Charles County. State Route 224 is also known as Riverside Road. The parking area is marked with a sign that says “Nanjemoy Wildlife Management Area.”

The following are key GPS coordinates obtained from Google Earth:

• Parking area at trailhead: 38°25’56.33”N, 77°15’6.28”W

• Beach area at end of trail: 38°25’54.69”N, 77°15’23.34”W

• Southern outcrops with turritella fossils: 38°25’24.81”N, 77°15’40.00”W

The Purse area is accessible throughout the year, depending on the weather. Snow and ice are potential issues during the winter, and thunderstorms are a safety hazard, especially during periods of unsettled weather in the spring and summer. Families and advanced collectors will find that the Purse area offers the opportunity to collect both shark teeth and turritella fossils.

This story about fossil shark teeth previously appeared in Rock & Gem magazine. Click here to subscribe. Story & Photos by Robert Beard.

The post Fossil Shark Teeth at Purse Beach first appeared on Rock & Gem Magazine.

Where to Find Fossil Fish – Dig Sites

Two sites outside the small town of Kemmerer, Wyoming, offer pay-to-dig. Just make an appointment or register, show up and they will take great care of you, showing you how to fish… with a hammer and chisel.

One site is the Warfield Quarry, also known online as Fossil Safari, and the other is the American Quarry.

While visiting the pay-to-dig sites in Kemmerer, it is a must to travel a short distance away to the Fossil Butte National Monument. Sorry no collecting here, but the museum boasts a tremendous variety of animals and plants from the Green River Formation. Cut unobtrusively into the hillside, the visitor center is filled with wonderous fossils, a great compilation of the ecosystem 50 million years ago.

The Green River Formation

Pay-to-dig sites are part of the Green River Formation where there are hundreds, no, thousands of fish trapped in rock that was once a series of fairly shallow lakes. Streams and rivers drained the surrounding mountains enabling the formation of this special fossil location.

The Green River Formation is known as a lagerstatte, which loosely translated from German means “storage place.” The area butts up against the limestone of the Wasatch, Unita, Wind River and other mountain ranges. It is an area where fabulous and spectacularly preserved fossils including plants and animals represent a snapshot of life living within that ecosystem.

When & How was this Site Made?

The Eocene period, about 53 to 48 million years ago, was a transition from a warm and moist environment to one that was hotter and drier. This is evidenced by some of the fossil finds in the area. Palm fronds, crocodile and sycamore leaf remains point to a warm moist environment and deciduous tree leaves point to a drier climate. The mountains were partially made up of limestone. During heavy rains, water would run down into the streams and rivers bringing with it sand, mud and silt sediments filled with dissolved minerals such as calcium oxides, inorganic elements and calcium components.

This would wash into the lakes fouling the water, making it turbid and in some cases changing the pH levels. At times the change in the chemical composition of the water was detrimental to the life forms in it.

Fish would die along with many of the other creatures and become buried in the silty sediments. Paleontologists can tell by looking at the various layers, which were deposited during times of drought and which were deposited in times of flood. It is also possible by studying the cross-section of the quarry where the best location is to find fossil fish.

The spectacular fossilization and completeness of the fossil fish is because they were buried quickly. Even the bottomfeeding scavengers were not quick enough or did not survive to disarticulate the bodies of the dead fish. The sediments filtered down to the bottom of the lake and covered the creatures with thin layers. It is within these layers that spectacular fish specimens may be found.

Where to Find Fossil Fish – Digging

In specific horizons, one of which is called the split fish layer, a finely laminated limestone is present that entombed many fish. This is easy to split and if the rock contains a fossil, it splits so that you can easily see it in both a positive fish fossil and also a negative impression. The fish are beautifully preserved with bones, gill covers, ribs and even scales intact. In some cases, a bit of matrix, the limestone that clings to the fish skeleton, is still present. It is quite easy to remove. In many instances, all that is needed is a dental pick, or a pin vise to gently remove excess rock matrix. You must be very careful not to go too deep into the limestone so it’s best to attack it at an acute angle.

This limestone is so fine-grained that many plants and insects that fell into the water or were washed in from rivers and streams are also seen in spectacular detail.

In some areas birds, reptiles, turtles and even crocodiles may be found all preserved in exquisite detail.

This story about where to find fossil fish previously appeared in Rock & Gem magazine. Click here to subscribe! Story and photos by Joseph “PaleoJoe” Kchodl.

The post Where to Find Fossil Fish first appeared on Rock & Gem Magazine.

Beautiful Petoskey Stones

Walking along the northern Lower Peninsula shorelines of Lake Huron and Lake Michigan, it is easy to see this fossil’s natural attraction on people. Looking into the water, one can sometimes see this coral, rounded by relentless waves, worn smooth showing its beautiful internal structure. It is easy to see that rockhounds, jewelry makers and almost everyone would be taken by this attractive fossil.

Once removed from the water, however, it quickly dries and loses its bright polished shine. To achieve that permanent shine, it is necessary to polish the rock by grinding and sanding it and finishing it with a polishing compound to bring out the beautiful luster of the stone.

What Corals Make Petoskey Stones?

Petoskey stones are fossilized corals. There are at least nine species of Hexagonaria, but the only true Petoskey Stone is the H. percarinata. These corals are marine organisms that are made up of many, sometimes thousands of hard calcium carbonate exoskeletons called corallites. Each corallite contains a polyp – an individual multi-cellular animal.

There are two major types of corals – solitary corals growing by themselves, and colonial corals, growing in a tight community of genetically identical polyps. The polyp is the actual living individual creature that inhabits each corallite. As the coral grows, it extends the calcium carbonate exoskeleton and seals off part of the base.

Symbiotic Relationships

Corals live in a symbiotic relationship with a variety of marine algae. Although corals have stinging tentacles and are able to capture food such as zooplankton, the algae provide the energy corals need to survive.

Food is captured by tentacles and brought down to the center where the mouth and stomach are located. The algae use a process called photosynthesis to provide additional energy to the coral polyp. In turn, the hard calcium carbonate exoskeleton of the coral and stinging tentacles provide protection for the algae.

The coral polyp produces waste products that the algae needs for its survival. Because sunlight is needed for the algae’s photosynthesis processes and sunlight only penetrates the ocean to a certain depth, corals normally grow in shallow waters from 30 to 150 feet.

Hexagonaria Coral

Hexagonaria coral is a colonial marine animal that lived in warm shallow salt-water tropical seas. Prehistoric Michigan was once such an environment. During the Devonian Period some 419 -358 million years ago, Michigan was located much closer to the equator.

Much of Michigan’s bedrock is made up of huge limestone beds that underlie the surface soil. These large tracts of limestone bedrock are the remains of ancient coral reefs that filled the sea that once covered what is now Michigan. Ancient coral seas were full of a variety of creatures that included but were not limited to, corals -both solitary and colonial.

Each corallite of the Hexagonaria is made of a sometimes five but usually six-sided compartment which adjoined the others in the colony and created the elaborate six-sided hexagon. The radiating lines one sees in the Petoskey Stone are the septa and theca. The septa are the lines of division between each corallite and the theca are the internal radiating lines. These patterns of hexagon shapes and radiating lines are what will gives the Petoskey Stone its uniqueness among rocks.

Finding Petoskey Stones

The Hexagonaria are found across Michigan along lakeshores and rivers in the sediments commonly called the Traverse group. They are rounded fragments of the coral Hexagonaria. Some of these coral reefs still lie beneath the ground and some under the water of Little Traverse Bay.

Because of the wave and abrasive action of the sand, these stones are rounded and washed up on the beach. The action of ice moving also brings these stones into shallow water. The best time to hunt for Petoskey stones is in the spring as soon as the ice melts. But beware, it is a cold time to search! I have seen locals donning dry suits and walking in waist-deep water as ice floats by and picking up the stones before they even reach the shore.

How Did Petoskey Stones Get Their Name?

The name Petoskey is said to come from an old Odawa Indian legend. It is said that a French fur trader, Antoine Carre, came to Michigan traveling extensively in the area now known as Petoskey where he met and married an Odawa princess. In time, he was adopted by the local Odawa tribe and eventually was made their chief.

It is further told that in the spring of 1787 traveling with his wife on his way from near present-day Chicago, he camped near what is now Kalamazoo. During the night, his wife gave birth to a son. Legend says that as the morning sun rose, the sun’s rays fell upon the infant’s face, and his father pronounced his name shall be Petosegay. The translation of the Odawa Petosegay means sunbeam or rising sun or rays of dawn.

Petosegay became a fur trader like his father and also became quite wealthy. He owned much land in the Petoskey area, and a community was settled on the shores of Little Traverse Bay. The present location of the city of Petoskey stands as a tribute to Petosegay. Because these rounded and water-tumbled fossils were found in great abundance on the shores of Little Traverse Bay, they became known as Petoskey stones.

Becoming a State Stone

The Petoskey stone was made the state stone of Michigan by legislative action. Then-Governor George Romney signed House Bill 2297 in 1965. This legislation elevated this fossil to the prestigious position it now holds around the world. For visitors to the Great Lakes, a Petoskey stone find is often a must-do!

This story about Petoskey stones appeared in the September 2021 issue of Rock & Gem magazine. Click here to subscribe! Story by Joseph “Paleo Joe” Kchodl.  

The post Petoskey Stones: Where & How to Find Them first appeared on Rock & Gem Magazine.

The story of “ghost crabs” is unique. Crabs are so rare as fossils that they are a prized find. Crabs and other crustaceans have a hard carapace or external shell. This exoskeleton is thin and fragile and falls apart immediately upon death. These discarded shells break into small pieces when washed up on the beach or are broken apart in the tides and currents. But in the case of the ghost crabs, they are found essentially complete. Locals along the line from Eau Gallie Causeway to Pineda, Florida, call these fossils stoned crabs, beach crabs and coquina crabs.

What is Coquina?

Coquina is a sedimentary rock formed almost entirely of ground-up fragments of shells from mollusks and other invertebrates and cemented with grains of sand.

The rich history of Florida’s geography is replete with the advancing and receding of coastline along with fluctuating sea levels. As these shorelines moved, animals died and were buried. Florida also boasts coquina deposits inland that can also be found full of fossils. Florida can be a fossil hunter’s dream!

How Did Whole Fossils Form?

Because of the shape of these crab fossils with their claws folded in front of them as in life, it is believed that these crabs died in their burrows perhaps to escape a winter chill or a quick fall in temperature. When they died in their burrows there was no disarticulation, they remained virtually intact. They then mineralized along with the sand and shell rubble that surrounded them.

The crabs fossilized by the same process that created those ancient coquina rock formations on land in East Central Florida. These coquina deposits are approximately 110,000 years old. Due to offshore dredging, fossils get washed up on the shores of Florida’s beaches. Normally anything washing up on a beach is pulverized rapidly by the incessant waves or abraded by the beach sand. Such is the fate of the ghost crabs of Brevard County – if not found quickly enough.

The crabs are generally covered with a thick layer of heavily cemented sandy matrix. If the crab has been in the surf for quite some time, it can be highly abraded, worn and even slightly polished. Some of the voids between the claws and legs can be infilled with calcium grains, calcite crystals and cemented sand.

Florida’s Coastline

Along Florida’s coast, the barrier island and sand dune system is believed to have formed within the last 7000 years. It is also believed that the crabs could have accumulated over the last 100,000 years. The sandy beaches are smooth and clear of debris during most of the year and it is particularly after hurricanes and strong storms that these crabs wash up on shore and can be easily found. They are rare but usually widely scattered along the beaches.

These crabs are believed to come from two sources of offshore coquina rock deposits to the east which appear to be the ancient shoreline before the retreat of the last Pleistocene Ice Age some 10,000 years ago.

It’s also believed that during the construction of Port Canaveral 70 years ago that dredging activities dislodged much of the Anastasia formation releasing some of these fossils from their long slumber.

Beachcombing is fun and now beachcombers can also be fossil hunters looking for that elusive megalodon tooth…or maybe even a ghost crab.

This story about Florida beach crab fossils previously appeared in Rock & Gem magazine. Click here to subscribe. Story by Joseph J. “PaleoJoe” Kchodl.

The post How to Find Florida Beach Crab Fossils first appeared on Rock & Gem Magazine.

In 2022, Massachusetts became the latest state to announce an official dinosaur. Podokesaurus holyokensis, or ‘fleetfooted lizard,” was discovered in 1910 in western Massachusetts by Mount Holyoke College professor Mignon Talbot, also making her the very first woman in America to find, discover, name and describe a dinosaur!

Not every state has an official dinosaur. For instance, Montana has a dinosaur trail, but not a state dino. Find out who made the cut and why.

Arizona

Sonorasaurus thompsoni (2018)

This “Sonora lizard” was named after geology student Richard Thompson. He didn’t rely on trace fossils to identify his find, instead, he found a nearly complete skeleton weathering out on a rock wall in an unexplored region of the Sonoran Desert in southern Arizona in 1994. This brachiosaurus was almost named “Chihuahuahsaurus” but paleontologist Ronald Paul Ratkevich with the Arizona-Sonora Desert Museum thought that made this dino sound like a tiny dog. Lol!

Arkansas

Arkansaurus fridayi (2017)

In 1972, circling vultures led Locksburg, Arkansas, service station owner Joe B. Friday to some odd bones poking out of a gravel ditch after local roadwork. He dug them up – three claws, four phalanges and three metatarsals – to display in his station. While on display, they caught the attention of paleontologist, Dr. James H. Quinn who determined them related to Ornithomimus and presented them at the 1973 Geological Society of America Meeting. Before Quinn could formally name his six- to 15-foot tall omnivore (plant and meat eater), he died while fossil prospecting in Nevada. The bill to name Arkansaurus fridayi as the State dinosaur was proposed by high school student Mason Cypress Oury.

California

Augustynolophus morrisi (2017)

California is known for the La Brea Tar Pits and the dinosaur fossil finds there. This dinosaur, combines the names of the Augustyn family (friends of the Los Angeles County Museum) and paleontologist William Morris, with dino relative, Saurolophus. Discovered in the Moreno Formation, the only known specimens of this herbivorous hadrosaur have been found in California, making it the perfect official state dinosaur.

Colorado

Stegosaurus (1982)

Since 1982, Stegosaurus “covered lizard” has technically been the official state fossil, not dinosaur, of Colorado. The first (1876) stegosaurus fossils were found in Colorado and the Denver Museum of Nature & Science even displays a skeleton unearthed by a local teacher and Canon City High School students. The brain in the head of this 10-ton giant was the size of a walnut, but research suggests a second, larger brain was in its… hindquarters!

Connecticut

Dilophosaurus wetherilli (2017)

This “two-crested lizard,” was among the earliest large predatory dinosaurs, thanks to its serrated teeth. It is the largest known North American land animal of its time. Today, it enjoys top billing among Jurassic Park characters, where a smaller (!) version was given the fictional ability to spit venom and expand its neck frill. It was designated the state dinosaur of Connecticut based on tracks found there.

Delaware

Dryptosaurus aquilunguis (2022)

This “tearing lizard” lived over 60 million years ago. It was a two-ton carnivorous dino that dominated the latter-Cretaceous period. Named by Othniel C. Marsh in 1877, Dryptosaurus is among the first theropods known to science.

Maryland

Astrodon johnstoni (1998)

This dino’s scientific name, Astrodon, means “star tooth.” Found in 1859 by John D. Latchford in his open iron ore pit near Prince George’s County, this planteating sauropod is the second dino species ever identified in the United States. In 1998, it was named after Baltimore Dental College professor Christopher Johnston, who sectioned the first Astrodon johnstoni tooth and discovered the star pattern inside.

Missouri

Hypsibema missouriensis (2004)

Originally called Neosaurus missouriensis, then Parrosaurus missouriensis, one thing is sure: Missouri loves its 10-foot tall, three-ton, duck-billed, plant-eating state dinosaur. The first bones – 13 vertebrae of a tail – were found in 1942 while digging a family cistern near Glen Allen. It marked the first and only dino remains found in Missouri. When House Bill 1209 went into effect in 2004, Missouri became the sixth state to have an official dinosaur and in 2008, a full-size H. missouriensis went on display at the Bollinger County Museum of Natural History.

New Jersey

Hadrosaurus foulkii (1991)

This duckbilled dinosaur was found by John Hopkins in 1858 while digging in a Haddonfield marl pit. More than 75 million years old, it became the first dinosaur species identified in North America from more than teeth. Thanks to write-in campaigns by Mrs. Berry and her fourth-grade class at Strawbridge Elementary School in Haddon Townships, Hadrosaurus was named state dinosaur in 1991.

Oklahoma

Acrocanthosaurus atokensis (2006)

This “high-spined lizard” lived across North America during the Early Cretaceous period. Fossil remains of the spiny predator have ranged from Maryland to Wyoming. At roughly 40 feet in length and weighing in at about four tons, Acrocanthosaurus was the largest theropod in its ecosystem. Its name comes from the Greek words for “thorn” and “lizard,” and Atoka County in Oklahoma, where the first fossils were found. The largest and most complete skeleton, nicknamed ‘Fran,’ was recovered from the Antlers Formation of Oklahoma and now resides in the North Carolina Museum of Natural Sciences.

Texas

Sauroposeidon proteles (2009)

When the first fossil remains of this “lizard earthquake god” and last known North American sauropod were found in 1994, they were so old and unusual in size that they were misidentified as petrified wood! Further analysis has since ranked it among the longest (110 feet), heaviest (60 tons), and tallest (55 feet) of all known dinosaurs. The reference to earthquakes comes from the notion that its weight was so great it must have made the ground shake as it walked.

Utah

Utahraptor ostrommaysorum (2018)

Its name means “Utah’s predator,” and this Early Cretaceous period carnivore, was roughly the size of a modern grizzly bear. The first fossils were found in 1975 near Moab but didn’t gain attention until 1991, when a large foot claw was uncovered in Gaston Quarry in Grand County. Originally to be named after film director Steven Spielberg, ostrommaysi was chosen instead, in honor of paleontologist John Ostrom, and Chris Mays, founder of robotics effects company Dinamation International.

Wyoming

Triceratops horridus (1994)

Named for its “three-horned face,” this frilled herbivore was among the last non-avian dinosaurs to disappear during the Cretaceous-Paleogene Extinction 66 million years ago. The first fossils of this dino superstar, who has appeared in films and on postage stamps, were misidentified as belonging to a very large and unusual bison. Six years before becoming Wyoming’s State Dinosaur, it was named the State Fossil of South Dakota.

This list of state dinosaurs article previously appeared in Rock & Gem magazine. Click here to subscribe! Story by L.A Sokolowski.

The post List of State Dinosaurs first appeared on Rock & Gem Magazine.

Located right in the middle of downtown L.A., among the freeways and skyscrapers, the La Brea Tar Pits is an active paleontological research site where scientists dig for dinosaurs. The site is formed around a group of tar pits, where natural asphalt has been seeping up through the ground for tens of thousands of years. Over millennia, Ice Age animals became trapped in the sticky asphalt, which then preserved their bones as fossils. Trace fossils don’t come into play as much here as the actual bones themselves.

Finding the La Brea Tar Pits

The Tar Pits were first observed by European explorers in 1769, but were known to the Native peoples of Southern California for generations. The presence of fossils in the bubbling asphalt was not discovered until 1901 by a Union Oil geologist. When the significance of the pits was realized after years of fruitful excavation of fossils, the property’s owner, George Allan Hancock, donated the land to the County of Los Angeles so it could be preserved. Excavation of the pits continued on and off through the early 20th century, and in 1977, the George C. Page Museum, which housed many of the pit fossils, was opened to the public. To date, millions of fossils are on display at the museum, which is now called the Page Museum and Tar Pits. Visitors can watch paleontologists work in the lab and get an up-close look at the research being performed.

Deadly Tar

The reason behind the rich trove of Pleistocene fossils found at the La Brea Tar Pits lies in the unusual geology of the site. A large reservoir of petroleum called the Salt Lake Oil Field is located beneath the surface of the land; the result of marine plankton deposited in an ocean basin during the Miocene Epoch of five to 25 million years ago. During that time, the tectonic plates in the Southern California region changed to strike-slip faults, and crustal plates rotated. This stretched the Los Angeles region and formed a deep structural basis. Large amounts of marine sediments were deposited and were six feet deep in sections. Later, nearby mountains uplifted, and rivers flowing down brought large amounts of sand and gravel with them.

During the last 50,000 years, this petroleum—actually a low-grade crude oil and not tar, despite the site’s name, trapped and preserved the remains of animals and plants that lived in the area, which were then buried by sediment. The preservative properties of asphalt have maintained the integrity of bones that would have perished in other environments.

Tar Pit Discoveries

Discoveries from the La Brea Tar Pits have revealed a huge variety of animals that became stuck in the asphalt when it was covered over by water, dust or leaves. Mistaking the pits for a pond or solid ground, animals stepped onto it and became trapped. Carnivores were drawn to the trapped animals and became stuck themselves. Insects and birds became caught in the sticky substance as well, and over thousands of years, millions of creatures had fallen victim to the pits.

These circumstances, which played out long before Los Angeles existed as a city, have made the La Brea Tar Pits one of the most significant paleontological sites in North America.

“Our site has literally millions of specimens,” says Emily Lindsey, Ph.D., Associate Curator, and Excavation Site Director. “In some cases, we have thousands of individuals represented. This allows scientists to ask questions about species biology, behavior, and evolution that are almost never possible to study in the fossil record.”

A Unique Site

The Tar Pits are also unique because they have provided a variety of fossils that are rarely found together, including plants and animals, big fossils and small fossils, with more than 500 species in total, making it one of the only fossil sites in the world where something approximating an entire ecosystem is represented, according to Dr. Lindsey.

In addition, she points out that the period that La Brea Tar Pits covers is incredibly important for understanding the place we are in today.

“Over the last approximately 50,000 years, glaciers advanced and receded; the Ice Age ended; humans arrived for the first time in North America; and nearly three-quarters of all large mammals on Earth went extinct,” she says. “Studying how all these different processes interacted can give us valuable information for addressing today’s challenges of climate change, human impacts on ecosystems, and extinctions.”

Many Species of the La Brea Tar Pits

The sheer variety of animal fossils that have been uncovered in the pits is unprecedented and spans from herbivores like wooly mammoths and ground sloths to predators such as dire wolves and saber-toothed cats. Birds like eagles and vultures and insects such as beetles and flies have been found, along with freshwater invertebrates such as mollusks and anthropoids, that may have found their way into the pits because of streams flowing into the area.

The large animal most often discovered in the pits is the dire wolf (Aenocyon dirus), with nearly 4,000 individual wolves having been excavated from the pits. The Tar Pits boast the largest number of dire wolf fossils ever found, and more than 400 of their skulls are on display at the Page Museum. Dire wolves were larger than modern wolves, and preyed on western horses (Equus occidentalis), ancient bison (Bison antiquus), ancient ground sloths (Xenarthra), and camels (Camelops), all species found in the La Brea fossil record. Dire wolves were likely lured into the pits by the herbivore species they preyed on that had become trapped in the asphalt.

Other Common Finds

The second most common large animal found in the Tar Pits is the saber-toothed cat (Smilodon fatalis). The Page Museum houses the largest collection of sabertoothed cat fossils in the world, with 2,000 individual animals discovered in the pits. This well-known ancient predator could weigh as much as 600 pounds and possessed two dagger-liked front teeth designed for killing. Saber-toothed cats preyed frequently on two of the herbivore species commonly found in the La Brea Tar Pits: bison and camels. This likely explains why so many of these predators were found in the pits.

In addition to western horses, ancient bison, ground sloths, and camels, other herbivores fell victim to the sticky asphalt, leaving their bones behind. Wooly mammoths, mastodons, elephants, and tapirs have all been found at the site, along with modern species like coyotes, raccoons, and rabbits.

Providing Information

Although large animals found at the La Brea Tar Pits get the most attention, a variety of other tinier fossils excavated from the pits is providing a wealth of information to paleontologists studying the behavior of ancient species, as well as the process of extinction.

“Fossils from La Brea Tar Pits have given unprecedented insight on what the world looked like during the Pleistocene or Ice Age,” says Dr. Lindsey. “Thanks to this treasure trove of fossils, scientists have concluded that saber-toothed cats hunted in groups; that bison migrated in and out of the Los Angeles area; and that trees were starved for carbon during the height of the Ice Age.”

But according to Dr. Lindsey, the most powerful findings of the Tar Pits are likely yet to come.

“A renewed focus on smaller fossils— such as leaves, seeds, insects, rodents, lizards, and birds—has the power to tell us a lot about how climate change and human activities intersected to turn the lush megafauna savannah of the Ice Age into the Southern California landscape we know today.”

This story about the La Brea tar pits previously appeared in Rock & Gem magazine. Click here to subscribe. Story by Audrey Pavia.

The post Exploring the La Brea Tar Pits first appeared on Rock & Gem Magazine.

What Are Ichnofossils?

Unlike when digging for dinosaur bones, Ichnofossils are categorized by their appearance and the implied behavior of the organic nature of their creators. They can be a helpful supplement to discovering more about dinosaurs, including their habits and habitats, and even determining a list of state dinosaurs.

Fossils themselves provide actual evidence through petrified or permineralized remains of shells, bones, leaves, teeth, or other direct evidence of prehistoric life. Ichnofossils are impressions, evidence in the sediment showing some activity by a creature or plant.

Ichnofossils also include feeding marks and coprolites — dino poo for lack of a better word. By slicing into coprolites, paleontologists can sometimes deduce whether the animal was an herbivore or carnivore. If plant material or seeds are found it was a plant eater. If shards of bone are found it was a meat eater. At times it is difficult to determine what specific creature left the evidence. There is also a newer study of urolites caused by the evacuation of liquid waste into softer sediments. Yes, paleontologists see evidence of that sometimes too.

As far as plants are concerned, ichnofossils can be the impressions of leaves though all the leaf material is completely gone. This can also include marks left in sediment showing a leaf or leaves as they blew across the ground. It also includes cavities in the rock where roots grew and decayed.

How Ichnofossils Formed

It’s easy to understand how plants and animals formed fossils, but it’s a little harder to grasp ichnofossil formation. The formation of ichnofossils requires certain conditions.

First, the sediment must be muddy soft soil or other substrates that can take an impression. The impressions then must dry quickly or be filled with softer sediment for them to be preserved. As the surrounding ground dries and hardens, the tracks are infilled with these softer sediments. The tracks begin to form ichnofossils. Eventually, the sediments turn to stone. Because of erosion, or digging by paleontologists, the tracks are exposed and the softer sediments are removed to reveal the ichnofossil track or trace.

What Ichnofossils Tell Us

Trace fossils can tell us more about the fossil animal than just its bones. In some cases they can tell us if they interacted with other creatures, they could show us confrontations and battles, herding behaviors and so much more.

Animal track ichnofossils can tell paleontologists whether the animals walked in herds or were solitary loners. They can also tell us how fast these animals moved. A mathematical formula has been developed that measures the distance between strides and the estimated length of the leg bones.

Fossil tracks can reveal whether a creature was four-legged or two-legged and if it dragged its tail while it walked. In nearly all cases of dinosaur trackways, no tail swish marks were left in the sediment meaning they did not drag their tails.

Paleontologists can generally also determine the type of creature by looking at the bone structures of the foot bones and the impression of the track in sediment.

Insects and other creatures also left evidence of their passing. Marine trilobites and crabs as well as terrestrial centipedes and millipedes left their footprints in soft sediment. Worms as they dug through sediments left cavities much like worms do today showing us that creatures then did the same as creatures today.

One can only imagine the excitement of paleontologists finding and describing trace fossils. Scientific knowledge and research coupled with imagination allow us to recreate what life was like during prehistoric times. Ichnofossils are an important piece of the puzzle.

This story about trace fossils previously appeared in Rock & Gem magazine. Click here to subscribe. Story by Joseph “PaleoJoe” Kchodl.

The post What are Trace Fossils? first appeared on Rock & Gem Magazine.

More than 20 years ago, geology and earth sciences teacher Steve Scott arrived in Venice, Florida with his family for a vacation. One day, while he was combing the beach, Scott talked to a couple of locals who told him that the fossil beds under the water were teeming with the remains not only of sharks but of other animals who roamed the earth and water there millions of years ago. It didn’t take long before he was off the shore and into the water.

“I’ve been collecting minerals and rocks my entire life, so when I learned about the underwater fossil beds, I became a certified diver,” he says.

His first dive was a game-changer. “I found a jaw from a giant sloth, and about 15 yards away I found a 5 1/2-inch Megalodon tooth,” he recalls. “That sloth jaw was a wonderful find. I’ve never forgotten that dive. I was hooked.”

Located on Florida’s Gulf Coast, Venice, Florida, was initially settled as long ago as 8200 BCE by Paleo-Indians who hunted the animals whose remains are contained in fossil beds beneath the water.

Thanks to those offshore fossil beds, Venice has long been a mecca for divers who come from all over the U.S. and around the world. They search not only for shark’s teeth but for fossilized remains of everything from the large extinct elephant-like Mastodon to prehistoric giraffe.

At the same time, the waters off the Venice shore were a favorite birthing and resting spot for Megalodon or “Big Tooth” sharks that cruised the area sometime between 23 to 3.5 million years ago.

“This was a shark nursery,” explains Capt. Mike Konesnik, the owner of Aquanutz Charters who has hosted and supervised fossil dives in Venice for the better part of 10 years. “The females would drop pups, rest and feed before they returned to sea and headed north to the Carolinas.”

The young sharks remained in the nursery until they instinctively knew their bodies were strong enough to ward off predators in the open ocean, he says. Meanwhile, the evidence of their diet was left behind.

“They (the females) may have been feeding on whales and the babies may have been feeding on whales because we’ve found (whale) ribs,” Konesnik says.

As a result, the amount of still undiscovered shark teeth is seemingly endless. “What’s amazing is that we keep finding things,” says Scott, who now has 325 dives under his belt. “This shows you how big and thick those fossil beds are – there are more sharks there than there are people on earth.”

What’s attractive to divers is that most of those finds are made in just 30-feet of water. “It’s an easy dive,” Konesnik explains. “If you’re a fossil hunter you have a tendency to push the limit, and it’s much safer to push the limit in 30-feet of water than in 100-feet.”

That makes a difference even to an experienced diver, according to Ethan Schuth.

A fossil hunter since childhood, Schuth does most of his exploring for evidence of dinosaurs on land. In 2016, when some friends from the Dallas Paleo Society raved about their Florida dive, Schuth decided to find out why.

So he became a certified diver, headed to Venice and booked a trip on Konesnik’s charter. “I had never hunted for fossils in the water before, and it’s totally different,” Schuth points out. “On land, you can see, in the water, it’s darker and the environment is constantly changing – it’s a brand new dive every day – you can be in the water and find nothing, but the next day another diver may have brushed the site with a fin and opened up an entire area that you overlooked.”

That was the case during the first dive on his first day in Venice.

“I found a couple of little shark teeth – maybe two inches, but the last dive on the last day gave me the big tooth I was looking for,” Schuth recalls. “It’s as though it was meant to be. I was hooked.”

These days, Schuth spends 10 days every year fossil hunting off Venice’s beaches.

Meanwhile, the pursuit is growing, according to Konesnik. Every year a new crop of divers arrives in Venice to explore the waters there. Most are men, some veteran divers in their 80s, some as young as 12 years old making their first dives.

Meanwhile, underwater fossil searching is catching on with women, too, he says.

In any case, Konesnik requires that only certified divers who have made a minimum of 15 dives may sign on for one of his charters. Safety is one reason for that, but it’s not the only one. Inexperienced divers are most likely to focus on the mechanics of their dive and not on the reason they are in the water in the first place.

“They have to have some experience because if you are concentrating on the dive, you are not concentrating on the hunt,” Konesnik says. “Finding the shark’s teeth is not the reward, the hunt is.”

Even so, many divers are on the hunt for large finds – no matter what their condition, says Scott.

“Most of the fossils divers find are weathered and battered from being in the water for millions of years, and people are always looking for that 5 ½-inch tooth,” Scott says.

“But there are a million possibilities.”

These days, Scott, now retired, owns a condo on the beach and spends at least two months every year diving for fossils off Venice Beach. Whatever he finds, all the dives are good ones.

“I remember during November and December in 2021 the dives were especially memorable because the water was crystal clear,” Scott recalls. “But really it’s a treasure hunt – every time you find something, you make a memory – every day is a day you’ll remember.”

This story about shark teeth previously appeared in Rock & Gem magazine. Click here to subscribe. Story by Pat Raia.

The post Diving for Shark Teeth first appeared on Rock & Gem Magazine.

What are Mercenaria Clams?

Unlike fossil fish, the Mercenaria permagna is a marine bivalve – an aquatic mollusk with two similar halves hinged together and containing the soft parts of the creature within the calcium carbonate shell. Other popular marine fossils include trilobite fossils, fossil ammonites and agatized coral. Various Mercenaria species, also called Venus clams, are still alive in the oceans today and are edible. You may see them on the menu as quahog, cherrystone and littleneck clams. The valves usually have bilateral symmetry, which means only that the two haves are nearly equal in size and shape.

How Mercenaria Clams Fossilized

During the Pleistocene Epoch, 78,000 to 1.8 million years ago, these animals thrived in the warm saltwater tropical seas that periodically transgressed Florida. A transgression is the inundation of a landmass with water, be it salt or fresh, that remains for an extended period.

Throughout history, sea levels would occasionally rise and fall. Sometimes this was because of the sea rising, and sometimes it was because of the land sinking through geological forces such as plate tectonics.

Regardless, the clams lived and died in this space because they were trapped beneath the waves and sand or tossed up onto the beach. Being a hard substance, the calcium carbonate shells would generally survive decay while the soft tissues decayed, creating a void. Over time, calcium-rich water would permeate the shells and deposit calcite within the void, creating beautiful amber-colored rhombohedral crystals.

These amber-colored crystals are sometimes called honey amber. The impurities determine the color of the crystals during formation.

Coquina Matrix

Calcite is one of the most common and abundant minerals on earth. It has a Moh’s hardness of three, and a soft Coquina matrix generally surrounds the clams.

During the era in question, when the sea level dropped significantly, acidic rainwater dissolved some of the shells and beach sand that had accumulated and cemented them together to form Coquina. This Coquina is composed of many shell fragments and other dissolved or partially dissolved calcium carbonate structures. As sea levels again rose, successive sediment layers covered the area.

Where to Find Mercenaria Clams

These natural history wonders came from the once-closed Rucks Pit Crystal Mine located in Fort Drum, Florida. They have a pay-to-dig site where people can pick through the spoils piles; however, the most prized complete specimens are hardly ever found. Geologically, they generally were found within specific zones just above the Tamiami Formation within the Lower Nashua Unit. Diggers are most likely to find pieces of clams, whelks, and other shell material along with small and large calcite crystals, but it’s worth a try!

This story about fossil hunting in Florida for Mercenaria clams appeared in Rock & Gem magazine. Click here to subscribe. Story by Joseph “PaleoJoe” Kchodl.

The post Fossil Hunting in Florida for Mercenaria Clams first appeared on Rock & Gem Magazine.