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Invertebrate Notes

The appearance of trilobites in the fossil record is recorded in the sedimentary layers of the Cambrian period some five hundred and forty million years ago, that is quite a...

The appearance of trilobites in the fossil record is recorded in the sedimentary layers of the Cambrian period some five hundred and forty million years ago, that is quite a thought, especially if your not used to palaeontological timescales, so to put this into perspective the age of the earth at the time of the trilobites was around ten times that. Trilobites became the most complex form of life in that period and an apex predator.

These hard segmented bodies and jointed appendages that also include modern insects and crustaceans. through the next two hundred and fifty million years post the emergence of the trilobites in the Cambrian, became a reign of supremacy on the ocean floor and above it. Some types may even have evolved into pelagic free-swimming varieties accounting for the trilobites global range and diversity.

Spiny trilobites

The range of Moroccan trilobites at the fossil store is intriguing as we update new varieties continually from expeditions into continental Africa our preferred area of collecting. This area boasts some of the best-preserved and diverse fossil trilobites of the world today, industrious diggers who are permanently searching for new fossil beds containing the fossil invertebrates occasionally find new types hidden in the limestone hamada, mountains and rocks which outcrop in the vast Saharan ténéré.

The anatomy of the trilobites is a greater part of the fun of studying the group, identifying new types is the ultimate goal of the fossil diggers of this region. Here we describe a brief explanation of that anatomical terminology.


The naming of all species on the planet was introduced by Carl Linnaeus around 1753 with the publication of; Species Plantarum. Linnaeus's work was the binomial nomenclature or Latin name which consists of two parts, the first, names the genus to which the species belongs, the second part identifying the species within that genus. To illustrate, humans belong to genus Homo and within this genus to the species Homo-sapiens. So all creatures are known by their binomial name.

Phacops trilobites for sale

The trilobites are no exception to these rules and hopefully, you will find this helpful in our descriptions of trilobites within our web pages. Quite often trilobites are the subject of an error anatomically speaking. From Latin the name trilobite is broken down thus, tri - meaning three and - lobite from the Greek lobos, translates to lobe, so we get our three main constituent parts of the arthropod, the longitudinal lobes which name it and is the name of this species of prehistoric arthropod. The hard carapace body of the trilobite being an exoskeleton, this exoskeleton is scientifically termed the carapace, the carapace is the hard exterior, the exoskeleton is made up of silica-rich minerals calcium carbonate and calcite, these minerals are woven into a lattice framework of chitin, chitin is the substance of the exoskeletons of lobsters, crabs, insects etc. This hard exoskeleton protected the soft body parts of the trilobite.

The exoskeleton or carapace is essentially made up of three lobes these lobes run the full length of the carapace through the head to the tail. The head is the cephalon and the tail the pygidium, the midsection is the thorax, containing the thoracic segments. That's basically the main bits! The error comes in occasionally when the name trilobite is referenced to the three parts of the cephalon, thorax and pygidium, when in fact the three naming genus parts are the three lobes running longitudinally through the invertebrates body length, head, body and tail. These lobes have names too, the central lobe is the axial lobe, the lobes each side are the pleural lobes. That completes the major parts of the trilobite, of course, there are dozens of other parts to a trilobite each with Latin anatomical terms which we will go through in later narratives at some point. 

Trilobite Fossils

We go into the field collecting specimen trilobites, expeditions into North Africa (read our other blog posts), to locate trilobite fossil sites, dig for trilobites and work alongside the fossil diggers, discuss the latest trilobite finds, trade with merchants and generally mess about with fossil trilobite bugs, which is our business and also our passion, we have established many fruitful associations with our Moroccan colleagues whom not only find trilobites, also work in the preparation laboratories.

We work with our preparations on the ground in the regions of North Africa and so have important find information on the historical trail of each specimen we offer for sale, these pertinent facts, in this land of finite resources, is crucial in authenticating the genuineness of each fossil as an end product, offering for sale to you our customer the original, authentically retrieved fossil which has been treated carefully on removal from the fossil layers with the minimum amount of disturbance, cleaned and prepared sympathetically.

Trilobite Collecting History; In North Africa really took off in the nineteen seventies when French geologists encouraged indigenous nomad Berbers of the desert to collect fossils on an annual basis. Year on year the geologists returned for a few weeks and more and more information and specimens were gleaned from the desert regions. These beginnings started with a clan of Berbers and grew into a national and international fossil industry. We sojourn to the desert in the company of the next generation of that localised clan and listen to the story of how it all began, the trials and tribulations of the families involved and the desert scene and what is to yet come. The oldest member of the family still owns a herd of about fifty camels which he watches through binoculars at long range from a rocky outcrop in the northern Sahara. His eldest son M'Bark has taken a back seat as his other sons Mohamed and Brahim came into the family business, their work evolving as did the trilobites aeons ago. 

The international trilobite fossil business has grown exponentially over the last four decades, relaxing of restraints on the free exchange of scientific information along with the opening up of international borders and trade, particularly with Russia and China has meant many new species are now being discovered. This has also encouraged fossil diggers in North Africa, particularly Morocco to dig deeper, longer and further into the vastness of the wilderness of the Sahara to unearth more rarities, this seems to be working, new species are found each year, adding to the known seventeen thousand species types already discovered worldwide and scientifically named. That sounds an incredible amount of trilobite types, however, when one considers trilobites existed as a group for around two hundred and fifty million years, they had time to develop, range and evolve into some of the weirdest animals on the planet.

The fossil Store recently launched a new web site catalogue and we are in the process of loading hundreds of new fossils to this, do keep visiting our collection and watch it grow over the next few months we are sure you will find the voyage of discovery most rewarding. So are you ready to now take a peek at what The Fossil Store has to offer? Review our trilobite section from our menu or click any image above and be intrigued by the world of trilobite fossils! 


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