Trilobite Cookies

Even Easier Trilobite Cookies

by Stephen Greb, Kentucky Geological Survey

You’ll need:

1 bag of oval-shaped or circular cookies. Cookies that do not already have icing work best. Several types of cookies can be used, if you want to show variety.
1 cup of M & M’s ® (mini-size works well), Skittles ® or other small, round candies for eyes
Several tubes of icing for decorating. Large tubes and small, detail tubes can both be used.
Plastic knifes for spreading icing
Paper or plastic plates to make the cookies on
Paper towels for clean up

Preparation time: 15-30 minutes, depending on how many cookies you make


1. Place undecorated cookies on a plate or paper towel.

2. Decorate cookies using tube icing. Try to divide the cookies into three parts. You can spread icing on the top third and bottom third to model the head (cephalon) and tail (pygidium) of the trilobite. You can also divide the cookie into three parts along the long axis and spread icing on both sides, leaving the middle strip bare. This models the three longitudinal lobes of the trilobite. You can use small tube icing to make segments across the cookie, or bumps, or spines. Use your imagination.

3. Finish by placing two candy eyes on the head. You can use a dab of icing as “glue” to help hold the candy eyes down. If the eyes don’t stick, it’s okay; some trilobites lacked eyes and were blind.

4. Eat and enjoy!

Trilobite Photos

A fossil trilobite seen from above

A trilobite seen from above. Photo by Martin Mueller.

A fossil trilobite seen from below

A trilobite seen from below. Photo by Martin Mueller.

Two high-resolution photos of a trilobite fossil, including a rare view of a trilobite seen from below. Our President Martin Mueller took these photos at the Houston Museum of Natural Sciences.

Mastodon Bones Found in Michigan Backyard

10,000-14,000 year old mastodon bones found in Michigan

Photo: Rod Sanford/Lansing State Journal

Reblogged from ESCONI (Earth Science Club of Northern Illinois): When we say we enjoy finding fossils in our own backyard, we are usually speaking metaphorically. Eric Witcke means it literally. He and neighbor Daniel LaPoint were excavating a backyard pond at his home in Bellevue Township, Michigan, when they unearthed a paleontological treasure. They called in the some experts from the University of Michigan’s Museum of Paleontology and were told the 42 odd bones belonged to a 37 year old male Mastodon. The Mastodon lived between 10,000 and 14,000 years ago.

Daniel Fisher, the director of the U of M museum, has made two trips to confirm and examine the Bellevue Township find.

He said there have been a total of about 330 confirmed mastodon bone discoveries in Michigan — but just two in the last year. Most of the bones have been found in the southern half of the lower peninsula. Sometimes people find just a tooth or tusk.

LaPoint and Witzke’s collection includes several rib bones, leg, shoulder and hip bones, the base of a tusk and pieces of the animal’s vertebrae.

Fisher has spent several hours looking through what they found and believes the mastodon was a 37-year-old male.

“Preliminary examination indicates that the animal may have been butchered by humans,” said Fisher. Bones show what look like tool marks, in places.

The bones are between 10,000 and 14,000 years old. Fisher said once they’ve been donated to the museum the exact age will likely be narrowed to within 200 or 300 years.

The full story is here.

Petrified Palm

You’ve heard of petrified wood, but have you heard of petrified palm? It’s made from trees of the extinct genus Palmoxylon, which were very similar to palm trees. The process is the same: when the palms died, sometimes they would be covered by water or dirt before they rotted. Then, as groundwater flowed across the ground it carried dissolved silica which would fill the xylem and phloem inside the palm. The result is solid silica in the same shape as the plant. They usually turn out much smoother and more uniform than other types of petrified wood, and petrified palm can be cut, polished, and used as a semiprecious gemstone. It’s mostly found in the Catahoula Formation, Texas, and Louisiana (where it’s the state fossil).

A group of four honey-yellow cabochons shaped like a circle, oval, triangle, and square. They have brown dots and stripes in different patterns, similar to the other petrified palmwood.

Amy O’Connell’s Petrified Palmwood sold at

As you can see, petrified palm’s distinctive round spots make great cabochons.

Turritella Agate

A dark brown, almost black square of rock, cut flat, completely covered with images of tan, tubular shells pointing in various directions.

Photo by Stephanie Reed

Turritella agate is a fossiliferous agate that contains lots of snails who died, sank to the bottom of a lake, and became silicified. When it was first named, people thought the fossils were marine snails from the Turritella genus. The shells are actually from the freshwater snail Elimia tenera, but the Turritella name was too popular already and it stuck. They are found in the Green River Formation in southwestern Wyoming, northeastern Utah, and northwestern Colorado, because that’s where the snails used to live (they are extinct). This specimen is from the personal collection of Show-Me Rockhounds member David Reed.  Fun fact: Elimia tenera snails became fossilized in materials other than agate, such as limestone, so there is also turritella limestone. It’s not quite as pretty in my opinion because the light background doesn’t contrast with the shells like agate does.


A fossil of a shell in light brown limestone. It's a little larger than an American penny.

Photo by John Charlton, Kansas Geological Survey.

Pictured here are some Pennsylvanian bivalves in limestone, collected near Bonner Springs, Kansas. (By Pennsylvanian, we mean the Pennsylvanian Period 323 – 290 million years ago.) But what is a bivalve? Bivalves have hard shells with two parts called valves and are usually bilaterally symmetrical, which means that their left and right sides look the same.  Bivalves belong to the Kingdom Animalia, Phylum Mollusca, Class Bivalvia, and include clams, oysters, scallops, and mussels. Bivalve fossils date back all the way to the Cambrian Period, 510 million years ago.

If you want to find one, Kansas is a pretty good place to start looking.  Kansas has a lot of limestone and shale which is chock full of fossilized clams and oysters.  You might find a little one like in the photo above, or you could find an inoceramid clam, some of which were up to 6 feet in diameter.  Inoceramid clams are extinct, but they used to live on the ocean floor around western Kansas during the Cretaceous Period about 145 to 65 million years ago (yes, the Midwest used to be underwater). This one is about a foot long and you can see that the back is covered in oysters

Volviceramus grandis a big clam fossil seen from the front

Mike Everhart, Oceans of Kansas

Volviceramus grandis a big clam fossil seen from the back with a bunch of fossil oysters attached to it

Mike Everhart, Oceans of Kansas

Sources: Geo Kansas: Oceans of Kansas

Fossilized Leaves for the First Day of Fall

Happy first day of fall!  Or happy first day of autumn, if you prefer.  To celebrate, here are some great fossil leaves from