The Cambrian Critter Project
     550 million years ago, when the Earth was still young, the prehistoric ocean was teeming with life.  Living organisms had not yet ventured out onto land and the skies were absent of any birds, insects or winged dinosaurs.They would not appear for another 100 million years.  It was during this period that an "explosion" of life took place featuring the arrival of over 10,000 new animal species most of which had never been seen before.  These creatures were truly something out of a science fiction novel but they represented all of the known body types or structures we know today.  This was a remarkable time in the history of life but there is still so much that we do not know about it.  In fact, the Cambrian and Pre Cambrian periods are seldom  mentioned in textbooks or middle school classroom's even today.  Until now...

Project Objective:To explore evolutionary adaptations during the Cambrian Period 550 mya.  Students will examine how some of the first complex organisms adapted to changes in the environment such as predation, food availabililty, ocean chemistry and others.     Students can identify how some of the organisms adapted new behavioral strategies and physical features that enabled them to survive in a changing landscape.  In addition, some of our very first ancestors emerged during this fascinating time featuring a notochord or the first backbone.

Students will be asked to construct a Cambrian Critter using a variety of suggested materials outlined on the following pages.  Students will also examine how their critter responded to changes in the environment while learning more about its behavior, physical specifications, diet, natural enemies as well as the Cambrian ocean ecosystem.  This project should encompass approximately two weeks with much of the construction taking place at home.

Outlined below is a list of some of those creatures or Cambrian Critters that were featured in David Attenborough's First Life video (BBC/Youtube).  This guide will prove useful to you as you learn more about this strange and exciting time in our planet’s history.  The spelling and physical description will help you as you research your creature and before engaging in the Cambrian Critter Project.


  The Trilobite (right) is a familiar Cambrian creature but scientists do not know a great deal about its habits.  The name 'TRILOBITE' means 'three lobed" and is derived from the fact these animals had bodies featuring three longitudinal lobes, not lateral (head, body, tail) as is often thought.  Trilobites are hard-shelled, segmented creatures that lived hundreds of millions of years ago in the Earth's ancient seas.  They are considered to be one of our planet's earliest complex life-forms and are one of the key signature creatures of the Paleozoic Era.  Trilobites went extinct before dinosaurs even existed.

  Wiwaxia is an interesting little fellow pictured on the left.  It is often described as a prehistoric “pin cushion”.  Longer spines project in two rows along the back, and evidently provided some protections against predators.  Since there are no spines on the bottom of its ventral surface, the animal partly resembles the slug, a member of the mollusk family.

     Nectocaris pictured right means ‘swimming shrimp” and was probably related to the cephalopod family which include cuttlefish.  It must have been a predator and used its tentacles to capture prey and position it towards its mouth.  It was a free swimmer and capable of moving quickly through the water column in search of its next meal.  Its long dorsal fin provided it with tremendous manueverability and speed which helped to escape close calls with a predator.

    Anomalocaris is the “bad boy” of the Cambrian epoch and is pictured on the left.  Measuring 2-3 meters long with two long spiked appendages used for grasping its prey.  A circular mouth underneath its head facilitated the chewing of its food.  Its tail features two pairs of long spines while its flattened body undulates like a sting- ray to make it an efficient swimmer and hunter.  The creature featured two large eyes on stalks were apparently all anomalocaris needed to spot its next meal.

    The emergence of Anomalocaris is particularly significant because it was the first true predator in the Cambrian ocean.  Its arrival forced creatures to adapt to this dramatic and deadly change in their environment or else they would be eaten.  Creatures adapted in many unique ways and the arrivale of Anomalocaris is considered to be one of the greatest evolutionary events during this period.
Hallucigenia  (right) is appropriately named.  This unusual creature has confounded scientists for years.  It possesses spines along its back with several pairs of segmented legs to help maneuver along the Cambrian ocean floor.  Early fossils made identification of this creature difficult since it was hard to tell the top or bottom of this bizarre fellow.  The creature's name suggests that it might have been the product of a wild imagination or hallucination.  Initially scientists believed that its spines were a response to the arrival of Anomalocaris and were used as an effective defensive weapon.
     Pikaia (left) is a very important creature in our study of early life forms and body structures.  Although at first glance it appears to closely resemble a sea snake with a flattened tail, elongated body and small head.  However, Pikaia has a notochord which is a long, ribbon like organ made from cartilage.  It represents the first backbone and possibly the first creature with a backbone.  This would mean that Pikaia could easily be our earliest ancestor- a vertebrate.

    Pterygotus on the right means “winged animal” or “finned one” was one of the largest member of the arthropod family.  It is directly related to the sea scorpion which are the ancestors to modern day scorpions.  This creature was a swimmer but had a segmented body with jointed pincers or claws. It had two large compound eyes with two smaller eyes in the center of its head.

    Pterygotus may have reached a length of over seven feet which made it one of the largest inhabitants of the Cambrian period.  Scientists believe that this creature may have appeared during the Silurian period and died off in the Devonian.  It was clearly a fierce predator and an effective hunter to say the least.

     Naraoia pictured left is an interesting relative of the trilobite genus that appeared during the Cambrian.  Its body was composed of two body parts or shells which were soft and non calcified which means they did not contain calcium.  This creature was probably blind and did not possess eyes of any kind.  It used a pair of tentacles or feelers as a means of sensing the presence of food or the approach of a predator.  Tiny legs propelled this creature along the ocean bottom.

    More than likely this peaceful little creature was a detritus feeder and fed off of decaying plant and animal matter.  Without any defence mechanisms its only hope for survival was to sense the presence of a predator before it was detected.
   Sanctacaris is an unusual creature found in the Burgess Shale and is pictured to the right. The head bears five pairs of grasping appendages and a sixth pair of large separate appendages. The grasping appendages each bear a short antenna. There are 11 body segments, each with a pair of walking legs and gills. There is a broad, flat paddle-like telson or tail very similar to that of a lobster.

Originally Sanctacaris was called informally 'Santa Claws' however, its Latin name translates as "saintly crab".

   The Nautiloid (left) is truly one of my favorite creatures of the Cambrian/Devonian periods.  It is a member of the group of animals known as “cephalopods” which includes octopus, squid and cuttlefish.  Nautiloids flourished during the late Cambrian period and continued on into the Paleozoic era.  They are the ancestors of the modern Nautilus which is alive and well living in the Southwest Pacific Ocean.  These were very effective predators with the ability to capture and consume large prey items with their lightening fast tentacles.  There are a number of different shell shapes associated with the Nautiloid but they often fell into two general shapes- straight or curved.  Fossilized shells have been found measuring up to 13 feet long!  Keen eyesight also enabled this bottom dweller to spot its next meal with deadly accuracy.

    The Chambered Nautilus is pictured below.  Its shell has taken on a curved shape  over the last few hundred million years.  It is a lethal predator and has survived extinction by living in the deep ocean realm.

    Opabinia (left) is a strange one indeed.  It possessed five eyes, a long segmented body, a spiked tail and a long appendage probably used for grasping its prey. As with many of the Cambrian critters, Opabinia does not have any living relatives today.
How to Construct a Cambrian Critter without making it really mad....
This page was last updated: December 11, 2014
    Pictured to the left is Kimberella which represents an important evolutionary jump before the Cambrian Explosion took place.  These fascinating soft bodied creatures resembled water balloons that were capable of locomotion.

    Pictured to the right is another version of the Nautiloid.  The shell closely resembles an ammonite but the creature living inside is the earliest ancestor of the cephalopod.  These creatures were fierce predators and grew quite large.
   Here on the left is another good picture of our friend the Pikaia.  An evolutionary marvel.
    The Trilobite on the right is one of the more bizarre creatures to have emerged from the Cambrian Period.  These early ancestors of the horseshoe crab appeared in a variety of shapes and sizes from several inches to several feet in length.  The fossil on the right is beautifully preserved.  Note the segmented body parts which are typical of early arthropods whose modern day relatives are insects, crustaceans and spiders.
    This interesting creature is called Diania Cactiformis also known as the "Walking Cactus".  What is significant about this simple creature is that scientists believe that it is the first of the group of animals known as "lobopods" or creatures with segmented legs.  This is really important because the lobopods actually came before arthropods and may have a modern relative in the velvet worm.  They have hooked claws at the end of their stubby legs and spines all along each appendage which were probably used for defense against predators. 

    This particular creature was found in China and there is not a lot known about its feeding or social behavior.

               Click on the creepy creature above to learn how