Ages of Rock

Artwork © Ray Troll 2015  See Ray’s work at http://www.trollart.com

Ages of Rock

Hover over the fossils for information about each one.

Whorl Toothed Shark

Helicoprion is a shark from the Permian age (270 million years old) found today in the phosphate quarries of southeast Idaho. Although Helicoprion is known globally, the Phosphoria deposits in Idaho preserve the largest, most abundant and pristine specimens of the fossil, which include the lower jaw cartilage, teeth and rare impressions of skin.

Further Exploration

3D Fossil by Idaho Museum of Natural History

National Geographic Article

Researcher's Webpage

Helicoprion

Copyright Ray Troll

Scimitar Cat

In addition to Saber Toothed cats like Smilodon fatalis, Idaho was home to Scimitar Toothed cats classified in the genus Homotherium.   Much rarer than Saber Toothed Cats and the North American Lion, Scimitar Toothed cats are thought to have been especially adept at chasing prey out in open spaces.  Their skulls suggest that they were adapted to be able to breathe efficiently during long chases after prey.  Their oddly shaped bodies, long forelimbs and short hind limbs, suggest that they were also good jumpers.

Further Exploration

3D Homotherium Fossil from Idaho 

Homotherium Article 

Homotherium Picture

Allosaurus spp.

Allosaurus was a genus of large therapods that lived during the late Jurassic.  The Utah state fossil, Allosaurus fragilis, grew to lengths of 35 ft, thought babies have been identified that were no more than 3 ft long.  Unlike T-rex, Allosaurus had large claws on its forelimbs that could have been used for hunting prey.  Analysis of Allosaurus' legs indicate that it was likely very fast compared to its prey.

Further Exploration

3-D Allosaurus Fossil from Utah 

Allosaurus Article

National Geographic Allosaurus Article 

Allosaurus

Projectile Point

Projectile points are tools left by humans, generally, in the Holocene.  Often, projectiles can inform scientists about the behavior of people thousands of years ago.  In Idaho, archaeologists have found evidence of projectile points from spears, atl atl darts, and bows and arrows. In particular, The Wasden excavation, located in southeast Idaho, is a site unlike any other in the region. While used sporadically throughout the Holocene, its significant archaeological and natural deposits have much to teach us about prehistoric hunter-gatherer activities as well as climate change over the last 12,000 years.

Further Exploration

3D Model of Replica Clovis Point Created by Allen Denoyer

The Wasden Site

Projectile Points in Idaho 

 
Projectile Point

Trilobite

Trilobites are animals that lived in the ocean during the Paleozoic era.  They are some of the first arthropods identified by science, meaning that they are related to modern animals like crabs, insects, and arachnids.  Trilobite behavior is thought to have varied considerably, with some species scavenging on the bottom of the sea bed while others ate plankton.  In Idaho, trilobites can be found in a  number of Cambrian rock deposits.

Further Exploration

3D Trilobite Fossils by 3Digify

Trilobite Collection at the American Museum of Natural History 

Trilobite Informational Website 

trilobites eating

Another Trilobite

Trilobites are animals that lived in the ocean during the Paleozoic era.  They are some of the first arthropods identified by science, meaning that they are related to modern animals like crabs, insects, and arachnids.  Trilobite behavior is thought to have varied considerably, with some species scavenging on the bottom of the sea bed while others ate plankton.  In Idaho, trilobites can be found in a  number of Cambrian rock deposits.

Further Exploration

3D Trilobite Fossils by 3Digify

Trilobite Collection at the American Museum of Natural History 

Trilobite Informational Website 

trilobites eating

Clam

Clams arose millions of years ago in the Paleozoic era.  Like brachiopods, clams are classified as bivalves.  They open their shells and filter feed on tiny organisms floating through the water.  Clams used to be second class bivalves until a major extinction event at the end of the Permian killed off many brachiopods.  After that, biodiversity of clams exploded and they are now one of the most common bivalves around.

Further Exploration

3D Giant Clam by KW3D

Clam Mass Extinction Survival Article

Maxima Clam

 

Dog

A favored companion of field scientists, the domestic dog goes by the species name Canis framiliaris.  While hotly debated, dogs likely arose in the late Pleistocene.   Early hypothesis speculated that dogs evolved after humans "stole" wolf pups from the wild and raised them as their own.  However, scientists now think that certain wolves started following bands of humans and eating their garbage.   Over time, the "friendlier" of these of wolves gained access to more and more human food, giving them a competitive edge.  Their decedents are the dogs we know and love today.

Further Exploration

National Geographic Article on Dog Domestication 

Breeds from Around the World Game

Dog Research 

doubletrouble

 

Sea Scorpion

Eurypterids, or Sea scorpions, are extinct arthropods that ruled the ancient sea with an iron claw.  These are the largest arthropods that have ever lived on plant earth, with some species measuring 6-8 ft long.  Their smaller cousins, horseshoe crabs, are still alive today.  Sea scorpions called Idaho home during the Ordovician period, and were likely the first large animal predator of their day.

Further Exploration

National Geographic Article

Research on Sea Scorpion Eyes

Fossil Specimens and Anatomy

Sea Scorpion Fossil

Falcatus Shark

Falcatus is an extinct genus of shark that roamed the oceans above North America during the Paleozoic era.  The male and female Falcatus shark were mistakenly identified as different species by scientists because the males sport a large fin spine on top of their heads and females do not.  A specimen researched in Montana solved the mystery and now Falcatus male and females are classified as the same type of animal.

Further Exploration

Falcatus Anatomy and Evolution 

General Falcatus Information 

Mountain View

Cephalaspis Fish

Cephalaspis was a heavily armored genus of jawless fish that lived in freshwater during the Devonian period.  Their armor helped them fend of predators such as sea scorpions and other fish.  Their mouths are located on the bottom of their heads, suggesting that their prey lived on the bottom of the stream or lake where they lived.

Further Exploration

General Information and Morphology

More Devonian Fossils 

Other Devonian Fish 

Devonian Fish

Ammonite

Ammonites are extinct relatives of living cephalopods like squid, nautiloids, and octopus. They evolved about 240 millions years ago and were predatory in nature. Like their modern relatives they had a beak used to crunch up their prey. Some ammonite fossils are over 3ft across!

Further Exploration

3D Model 

National Geographic Article 

BBC Ammonite Page

Ammonite

Lycopod

Lycopods are the earliest vascular plants.   These plants evolved over 400 millions years ago and include clubmosses, quillworts, and scale trees.  During the Carboniferous period, Lycopods were the most common plants on the landscape creating great forests.  Most large Lycopods became extinct by the end of the Permian because of climate change.

Further Exploration

Go Botany Page with Digital Specimens

Plant Evolution 

Lycopod Forest

Horsetail Plants

Horsetails are plants in the class Equisetopsida and only a few species are left today.  These vascular plants evolved over 100 million years ago and could grow to over 30 meters tall.  These large horsetails made up the forests of the Paleozoic.  While Horsetails are not biodiverse today, they are quite common around ponds and streams often going by the common name Scouring Rush or Snake Grass.

Further Exploration

Plant Evolution by New Scientist 

Horsetail Activities

Horsetail fossil

Permian Extinction

The Permian (P-Tr) extinction happened around 250 million years ago and is often referred to as "The Great Dying."  While not as well known as the extinction of the dinosaurs, the The Great Dying wiped out approximately 96% of all ocean going species and about 70% of all species living on land.

Further Exploration

National Geographic Article

BBC Resources and Videos

Clues to the Great Dying

The Great Dying

Fern

Ferns evolved in the Devonian period around 360 millions years ago.   They reproduce via spores rather than making seeds.   While many ferns look similar, genetics has revealed that ferns are more divers than previously thought.  Also, they have way more chromosomes than you. 

Further Exploration

3D Fern Fossil 

American Fern Society 

Fossil Ferns and Evolution 

Fern Fossil

Parasaurolophus

Parasaurolophus is a genus of dinosaur lived around 75 millions years ago in North America.   In particular, they are a genus of hadrosaurid, large herbivores that sported crazy looking head crests.  It is possible that two of the described Parasaurolophus species are actually just the male and female versions of a single species, but scientists are not sure.

Further Exploration

Joe the Baby Dinosaur

Mating Calls

Parasaurolophus

Knightia spp.

Knightia spp. are the most common fossilized fish that paleontologists find in the Green River Formation.  Knightia resembled Herring in appearance, and they lived in a freshwater lake in Wyoming around 50 millions years ago.  Knightia fossils are some of most common vertebrate fossils bought and sold in the United States.

Further Exploration

3D Fossil

Green River Formation 

Knightia

Uintatherium

Going extinct around 40 million years ago Uinatherium spp. browser on vegetation and weighed in at around 2 tonnes.  While it looks like a Rhino or Hippo, scientists have not been able to agree on which modern animals Uintatherium spp. is related to.   Fossil specimens have been located in Wyoming and Utah.

Further Exploration

Prehistoric Wildlife Article

Smithsonian

Uintatherium

Creodont

An extinct order of mammals, Creodonts were predatory placental mammals.  They could be as small as a ferret or as large as a wolf depending on the species.   They went extinct about 8 million years ago, and modern carnivorous mammals took their place in the world.

Further Exploration

Wikipedia

Taxonomy and Teeth

Creodont

Brontothere

Animals in the extinct mammal family Brontotheriidae looked like modern rhinos but were likely more closely related to horses.  No one knows for sure.  These creatures were herbivorous and likely very social.

Further Exploration

San Diego Natural History Museum

Fossils of the White River Badlands

Prehistoric Wildlife 

Brontothere

Archaeotherium

"Hell Pigs", Archaeotherium spp. were more closely related to modern whales than pigs!  Fossil evidence tells us that these animals lived in North America and the size of their nasal cavities suggested that they hunted using their sense of smell.

Further Exploration

Prehistoric Wildlife

Giant Killer Pigs from Hell 

National Geographic Documentary

Hell Pig by Ray Troll

Copyright Ray Troll

Cretaceous Extinction

The Cretaceous extinction, also knows as the K-T extinction, occurred approximately 66 millions years ago and is responsible for killing most dinosaur species.  Many scientists believe that this extinction event occurred after a large comet or asteroid smashed into the surface of Earth.

Further Exploration

BBC Nature

LiveScience Asteroid Hypothesis Article

Feathered Dinosaurs Escape Extinction 

Impact

Gomphotherium

Gomphotheres are an extinct family of animals related to elephants.  Unlike elephants, they sported "buck-teeth" on their lower jaws.  Scientists this that they used these modified tusks to scoop of water plants to eat.  They are a common fossil to find in Idaho.

Further Exploration

3D Fossil

UC Berkeley Information 

Prehistoric Wildlife

Gomphothere

Mammoth

Animals in the genus Mammuthus are closely related to modern elephants that includes many different species.  In Idaho, remains of Columbian Mammoths and Mastodons have been uncovered.   These giants were herbivorous and Columbian Mammoths went through six sets of adult teeth!  There is evidence that humans hunted Mammoths using a throwing spear called an Atl Atl.

Further Exploration

BBC Nature Page 

In Idaho

Hybrid Mammoths

Mammoth

Mammoth

Old Blue

The Ford F250 is an F series Ford pickup truck.  The first f-series truck was built in 1948.  On of the most popular vehicles in US history the Ford f-series truck is great for paleo field work.

Pteranodon

Pteranodons are an extinct family of flying reptiles from the Cretaceous period.  Often confused as a kind of dinosaur, Pteranodons are actually in their own order.  With wingspans of over 20ft in some species these large predators ruled the skies.  Fossil evidence suggests that these fierce predators had a diet that consisted of mainly fish.

Further Exploration

Livescience Article

American Museum of Natural History

Oceans of Kansas

Pteranodon

Jackalope

The Jackalope is a fictitious creature invented by taxidermists and is not featured anywhere in the fossil record.  Specimens are often taxidermy jackrabbits with deer antlers.

Further Exploration

Wired Magazine Article

Jackalope

Ray Troll

In his studio on a hill above Tongass Narrows in rainy Ketchikan, Alaska, Ray Troll creates fishy images that swim into museums, books and magazines, and onto t-shirts worn around the world. He draws his inspiration from extensive field work and the latest scientific discoveries, bringing a street-smart sensibility to the worlds of ichthyology and paleontology.

Further Exploration

Ray Troll's Page

The Ratfish Wranglers

Cruisin' the Fossil Freeway

Ray Troll Painting

Dr. Kirk Johnson

Johnson is a paleontologist who has led expeditions in 11 countries and 19 states that resulted in the discovery of more than 1,400 fossil sites. His research focuses on fossil plants and the extinction of the dinosaurs. He is known for his scientific books and articles, popular books, museum exhibits, presentations, and collaborations with artists. -Smithsonian Bio

Further Exploration

Smithsonian Page

Trollart Page

Kirk Johnson

Need help remembering the Ages of Rock?  Try this song by Ray Troll, Russell Wodehouse & the Ratfish Wranglers.  Musically talented? Download the Chords.