Earth's Earliest Gigantic and Bizarre Creatures


Anomalocaris, an odd creature

Much has been written about dinosaurs and the fury of T-Rex in popular culture; but are you aware there were giant creatures dominating Earth's oceans long, long before the dino-era ending 65 million years ago (mya)? Enjoy the following journey of giants and strange creatures through the time scales beginning far back as the Cambrian Period.

The Cambrian Period began 542 million years ago (mya) and lasted till about 488 mya. Cambrian is the first period on the time scale respresenting the arrival of complex organisms.

Anomalocaris dominated the Cambrian seas for tens of millions of years. It grew to only two feet long which doesn’t seem very big in today’s terms, but in relation to anything else during the Cambrian, it was huge.

Interesting history of its stalled scientific discovery: A segment fossil of Anomalocaris, canadensis was first discovered in the Canadian Rockies in 1892, but it wasn't until 1981 that a major breakthrough about its identity occurred; and that was further refined in 1996. The one hundred year history of inaccurate theories is but one example of the difficulty identifying fossil remains of Cambrian animals having no apparent living descendants. Anomalocaris and other genera have since been discovered at various Cambrian fossil locations around the world; including the famous Burgess Shale site in Canada, Rocky Mountains USA, China, and Australia.

Anomalocaris with its large eyes, impaling front spines and strong swimming lobes probably could pursue any prey during its time period, including trilobites. Although, some scientists argue that its pineapple-ring mouth did not have hard parts necessary to crush the tough outer shells of trilobites. Much still remains to be clarified about their anatomy and habits. Scientists believe it swam with an "S" method of locomotion, undulating up and down the length of its body. Watch the video to observe its unique movement in the water, I think it's kinda soothing.

The Giant Orthocone

The second period on the time scale falls under the Ordovician Period (448 to about 443 mya).

The T-Rex of the Ordovician was a cephalopod nautiloid creature related to squids and octopuses known as the Giant Orthocone. The massive creature's living tissue was at one end of a very long conical shell which could reach eleven meters in length. Its inner shell contained chambers that could be filled with water and likewise emptied in order to jet propel itself; or to descend up and down through the ocean waters. The inner chambers also contained gases for buoyancy. It seized its prey using meter long muscular tentacles and a beak-like mouth to rip them apart. It fed upon fish and its arch enemy, large sea scorpions.

Did you know fossils of Orthocones and other straight-shelled nautiloids have been quarried by Europeans for many years and adorn floors, stairs, jewelry, gravestones and art pieces with their durable and desirable beauty?


The Eurypterids

Eurypterids were sea scorpions, the largest known arthropods that ever lived. Their fossils are found all over the world and within the US, the state of New York has unearthed a large number of them. Eurypterids survived a long history beginning with the Ordovician Period extending into the Permian from about 460 to 248 million years ago.That's over a 200 million year history!

Megalograptus was one of the earlier large species reaching 4 feet long, not including its front pincher claws. Most common species were only 8 inches long. Sea scorpions walked on six legs, the back two of which were flattened like paddles. They were normally sea-floor dwellers, but could also live in freshwater. Sea scorpions preyed upon fish, trilobites and other animals living near the seabed. They had strong defenses with spines, crushing claws and armor plating. Their has been disagreement among scientists whether some of their species possessed stingers.The giant straight-shelled nautiloids were their worst enemy.

Jaekelopterus was a later species emerging during the Devonian Period around 390mya, reaching over two meters (8 feet) or more in length. Try to imagine a scorpion about the size of a kayak! Their arch enemies, the cephalopod nautiloids, declined in size during the Devonian time slot from their Ordovicain predecessors. Now the tables were turned and eurypterids like Jaekelopterus could gain the upper hand using their powerful claws to clamp down and crush the linear shells of nautiloids.


During the Devonian Period (416 till about 360mya) vertebrates had greatly arisen on the scene. A highly evolved class of fish called "placoderms", possessing advanced characteristics stemming from their predecessor "ostracoderms", dominated the ancient seas. For protection, both classes of fish possessed armored plates covering their head and upper torso regions. They looked very unusual compared to modern fish species. The main advancement with placoderms was the development of a jawbone and paired fins. Those two significant adaptations provided them the necessary speed and power to become fearsome predators, aggressively chasing prey rather than waiting for the perfect opportunity. Ostracoderms were eventually overrun into extinction unable to compete with their cousin placoderms.

The Dunkleosteus placoderm was the T-Rex of the Devonian terrorizing the ancient seas. He measured 10 meters (33 feet) and weighed almost 4 tons. Instead of teeth, Dunkleosteus possessed two pairs of impaling sharp boney blades. Dunkleosteus could open its mouth 1/50th of a second, which would have caused a powerful suction that pulled the prey into its mouth, a food-capturing ability reinvented by many of the most advanced fishes today. Then it could bite down with a pressure of up to 8,000 pounds per square inch (55mph), placing it in the league of T-Rex and modern crocodiles! There wasn’t anything the great placoderm didn’t or couldn’t eat, including its own kind.

In recent decades, Dunkleosteus has finally achieved the recognition it deserves as a super predator. There are a large number of its fossil specimens on display which have been found in North America, Poland, Belgium and Morocco.

Largest of the Trilobites during the Devonian Period

Terataspis, grandis whose name means “great monster shield” was a large spiny trilobite. Trilobites had to evolve some serious defenses to survive predators of the Devonian. Like most trilobites,Terataspis, grandis was a bottom feeder, scavenging anything it could find, but it also was an opportunistic predator preying on burrowing animals such as mollusks, worms and smaller arthropods. It reached about two feet in length which in relation to most trilobites was enormous. Having the distinction of a segmented body, multiple jointed limbs and an armored outer shell, places it in the category of arthropods related to insects and crustaceans.

Going back in the time scale, the largest trilobite ever found is Isotelus, rex from the Ordovician Period. It reached 28 inches in length. Many of Isotelus, rex fossils have been discovered in the great state of Ohio where it is the proud state fossil.


Bizarre Sharks

Beginning in the late Devonian into the early Carboniferous Period (360 to 300mya) sharks were diversifying so much that scientists have labeled it the “Golden Age of Sharks”. The placoderms were dying out, only lasting a 50 million year history compared to sharks 400 million year history. With the decline of placoderms, environmental niches allowed sharks to fill in and as a result they assumed a wide variety of bizarre shapes. From this stage of evolution they had become the top predators of the oceans.

Stethacanthus grew 11feet long (sources differ). One thing undisputed is the strange anvil growth protruding from its back. This was completely topped with sharp spikes which also covered the top of its head. There’s much speculation about its use, one theory proposes it may have played a role in courtship. In truth, it may have just made the creature look more frightening.

Another strange shark emerging during the period was Helicoprion. Not much is truly known about this shark, but the pattern of its teeth is instantly recognizable. They formed a whorl semi-circle arrangement protruding out of its mouth. Unlike modern sharks,the teeth did not fall away at the front resulting in the rotated bizarre spiral which mystifies modern science.

The largest genus of sharks in the bizarre top predator category would be Edestus, giganteus which lived during the latter part of the Carboniferous. He probably grew 20ft long weighing in up to 2 tons. Like its relative Helicoprion, its teeth formed a strange curved shape, and it also did not shed its teeth. It must have been very intimidating for other creatures at the time looking as if it possessed saw blades for a mouth.


Gigantic Ammonites

Ammonites were closely related to the straight-shelled cephalopod nautiloids. Their main difference would be the coiling of the shell which allowed them more freedom of mobility. They even used the same jet propulsion mode of movement. Their numbers greatly grew, beginning as early as the Devonian and peaking some 300 million years later during the Cretaceous Period (145 - 65 mya). Consecutively, the straight-shell forms greatly declined, unable to compete with the more mobile ammonite nautiloids. The ammonites were so successful and numerous that their remains are now excellent index fossils for scientists to date rock layers. The biggest forms are found in later rocks of the upper Jurassic Period (200mya-145mya) such as Titanites. Another huge form, Parquzosia from the Cretaceous Period, was found in Germany reaching 2 meters (6.5 foot diameter).

The species on the side of the mountain was discovered 60 years ago in British Columbia. It is not scientifically recognized until it can be collected and turned over to an authoritative institution. It is assumed to be a Titanites genera and is being evaluated by a company to collect it. The fossil measures 2 meters (6.7 foot diameter).

The super successful ammonites experienced the same fate 65 million years ago along with the dinosaurs. The nautilus, their close relative often referred to as a living fossil, is the lone survivor of nautiloids.

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Comments 57 comments

damian0000 profile image

damian0000 5 years ago from Belfast

Hey Fossillady --- i asked for nice hub about some millipedes and you gone and frightened the life out of me with some pre-historic monsters! No doubt i will have nightmares about sea-scorpions and dunkleosteouses tonight... great hub and the pictures and videos are very vivid and informative :-)

Fossillady profile image

Fossillady 5 years ago from Saugatuck Michigan Author

If you have a nightmare you'll have to write about it with your famous flare for creating a vision! Thanks for stopping by!

Mentalist acer profile image

Mentalist acer 5 years ago from A Voice in your Mind!

The creatures of the water-world Earth are greatly facinating and even neater is the fact that man can develop such great knowledge of a time so long ago!;)

Eaglebomber profile image

Eaglebomber 5 years ago from Texas

I've got to give it to you, this was an incredibly interesting article.

Kudos to you!

Minnetonka Twin profile image

Minnetonka Twin 5 years ago from Minnesota

I loved this fascinating hub. Cool videos and cool pictures.

Nell Rose profile image

Nell Rose 5 years ago from England

Hi, I really loved this! I grew up studying fossils and have had great times digging for fossils in the jurassic coast in England, a couple of years ago I found an ammonite in the stones on the beach! the locals find them, clean them up and sell them at the shops, but they missed this one! I have also collected quite a few ammonites too, they sit in residence on my cabinet in the front room! loved it, even if some of these frightened the life out of me! lol cheers nell

Fossillady profile image

Fossillady 5 years ago from Saugatuck Michigan Author

acer, yes, that always mystified me how scientists could gather so much information about extinct species. They study in depth is an understatement. I know they do use similar living species and base some knowledge in combination to the time period along with the fossils.

Eaglebomber, nice to meet you, thank you for stopping by, appreciate the compliment! Smiles

Minn Twin, good to see you again. Thank you for the compliment, so glad you liked it!

Nell, What I would give to find an ammonite! Oh, my heart flutters. Thanks for following me! Your hubs are right up my ally. I love the unexplained phenomenon that you write about!

A.A. Zavala profile image

A.A. Zavala 5 years ago from Texas

This was absolutely facinating. I think it's interesting that Dunkleoteus resembles the modern day wolf fish. Thank you for sharing.

Fossillady profile image

Fossillady 5 years ago from Saugatuck Michigan Author

Thanks for stopping by AA, I have to admit I'm not familiar with the wolf fish, but I'm glad you found Dunkleoteus fascinating. Take Care

b. Malin profile image

b. Malin 5 years ago

Wow, what great photos and videos, this Hub has been a wonderful learning experience, as well as a History Lesson. You put a lot of work into giving this one to us. Thank you Fossillady!

epigramman profile image

epigramman 5 years ago

...well Kathi you have left quite an indelible fossil impression on my life since we've met with your support and comments and friendship. I really do think this is an essential and definitive hub once again from you - and you are quite the authority on this subject and it shows in this labor of love. You not only make this subject enlightening but also entertaining with an interesting mix of text and images ......I am also so happy for you that you are getting the recognition you deserve from your followers, fans and colleagues here at the Hub!

Fossillady profile image

Fossillady 5 years ago from Saugatuck Michigan Author

b. I appreciate your complimentary comments! Glad you enjoyed the learning experience!

Colin, It is my labor of love, like gardening and writing, I'm compelled to pursue it. I feel blessed to enjoy my labors of love and share them with kind people like you! Your support is always my inspiration!

DzyMsLizzy profile image

DzyMsLizzy 5 years ago from Oakley, CA

Very interesting. I often wonder what still lurks in the ocean depths, lingering from earlier eras. After all, wasn't the Coelocanth once thought exinct, and then they caught one?

I remember, as a child, staring awestruck at its ugly magnificence. It was on display "forever" in a display case in the aquarium at the California Academy of Sciences in Golden Gate Park, in San Francisco, where I grew up.

It also amuses me when the scientists change their minds, frequently, about what they've found, and the name the creature should have.

Wasn't there just such a change-up between "Brontosaurus" and "Brachiosaurus?" (Or am I thinking of two different things...aghh..a mind is a terrible thing to lose...) ;-)

Fossillady profile image

Fossillady 5 years ago from Saugatuck Michigan Author

Yes, they changed the Brontosaurus name to Apatosaurus for some strange reason. I would have loved to see that Coelocanth on display, they thrived during the Devonian Period about 400 million years ago. That means they survived several mass extinctions. I wish they could discover more of them without killing them of course. Good to see you! Smiles!

always exploring profile image

always exploring 5 years ago from Southern Illinois

Well, I must say, " I am amazed at your expertise in this area " This was so interesting. Geez, I don't think i want to go boat riding or swimming Hee. Watching the videos were like watching the National Geographic. I enjoyed it immensely. Thank you.


Fossillady profile image

Fossillady 5 years ago from Saugatuck Michigan Author

Thank you Ruby, It's a bit of an obsession with fossils ever since my husband gave me one he found and then his friend hand me over about twenty fossils. Had to know what everything was and how it lived. It's turned into a fun, fun hobby.Glad you enjoyed it. That's what its all about!

DzyMsLizzy profile image

DzyMsLizzy 5 years ago from Oakley, CA

Just take a trip to San Francisco--it's probably still there...

And check out my Apatosaur poem...I wrote it "way many" years back, even before the name change, I suspect...for some reason, that name hopped into my head, and I thought "there's a poem there someplace." ... ;-)

Fossillady profile image

Fossillady 5 years ago from Saugatuck Michigan Author

Great poem here MsLizzy!


Doug Turner Jr. 5 years ago

Seeing these creatures and reading about them seriously makes my skin crawl. Just the raw, survival-of-the-fittest power of these animals is truly terrifying.

Very original and fun hub. I love finding hubs like this, especially after spending time reading serious or commercial topics. It's a refreshing break, like a cold lemonade.


fibo777 profile image

fibo777 5 years ago

Wow! Wow! Wow! The hub is useful, beautiful and awesome. One of the best I have seen on hubpages. I have not expected that you could write about the creatures. Awesome analysis. Thanks a lot.

Fossillady profile image

Fossillady 5 years ago from Saugatuck Michigan Author

Doug, if I made your skin crawl, then I did my job! LOL Appreciate the refreshing comment!

Fibo, Hi, That's why I'm the fossillady!! You're comment gave me a big smile! much thanks

daydreamer13 profile image

daydreamer13 5 years ago

This is so cool! I absolutely love this planet we live on! Excellent hub!

Fossillady profile image

Fossillady 5 years ago from Saugatuck Michigan Author

Thank you sweet lady, I agree, it is an amazing place!

prasetio30 profile image

prasetio30 5 years ago from malang-indonesia

Wow.... you have done a great job. I learn much from you and I never knew about this before. I'll show this to my student, they'll like this very much. Thanks for writing this. Vote up. Take care!


Fossillady profile image

Fossillady 5 years ago from Saugatuck Michigan Author

Good idea Pras! I think your students will like it. You could do a lesson plan around it! Kids go for this kind of stuff, specially the boys! lol

GusTheRedneck profile image

GusTheRedneck 5 years ago from USA

Fossillady - Brought back some memories... that dunkleosteous of yours reminded me of my sixth grade teacher. Only difference was that her teeth were shorter and that she carried a heavy wooden ruler in her right hand.

Gus :-)))

Fossillady profile image

Fossillady 5 years ago from Saugatuck Michigan Author

You make me laugh out loud! Oh my gosh!

DaNoblest profile image

DaNoblest 5 years ago from California

Wow this was a fascinating read. You had me transported back 100s of millions of years. It is amazing to see what creatures our ocean had long ago. Great hub!

Fossillady profile image

Fossillady 5 years ago from Saugatuck Michigan Author

Hi DaNovlest, nice to meet you! Very nice compliment, Thank you! It's always good to escape into another world from time to time! tee hee

toknowinfo profile image

toknowinfo 5 years ago

Wow, some of those creatures, actually most of them were scary to me. But ohhh so fascinating. Thanks for creating this very interesting hub. Your expertise is showing and I love it. voted up and awesome.

Fossillady profile image

Fossillady 5 years ago from Saugatuck Michigan Author

Thank you my friend, We live in a milder day and age as far as ferocious beasts go, but it's fun to imagine life on our planet before us!

amymarie_5 profile image

amymarie_5 5 years ago from Chicago IL

Very cool hub. I never knew about any of these ancient animals. Thanks for sharing!

Fossillady profile image

Fossillady 5 years ago from Saugatuck Michigan Author

Thank you Amy, not many people do! Thanks for checking it out!

dablufox profile image

dablufox 5 years ago from Australia

This is one jewel of a hub! I love natural history and wildlife documentaries from national geographic and PBS and I found this Hub extremely interesting and entertaining. I'm sure you would make a great documentary presenter/commentator.

Congratulations on one of the best hubs I have seen!

Thank you dearly.

Fossillady profile image

Fossillady 5 years ago from Saugatuck Michigan Author

Wow, Thank you Dablufox, great compliment! I'm glad you enjoyed it and really appreciate you stopping by! It was fun putting it together too!

katiem2 profile image

katiem2 5 years ago from I'm outta here

WOW now that's a lot of paleozoic giants and weird creatures indeed. It's amazing what nature can do. Thank you for the interesting education on weird creatures. :) Katie

Fossillady profile image

Fossillady 5 years ago from Saugatuck Michigan Author

Your welcome Katie, I'm glad you liked it, they are pretty cool!

Granny's House profile image

Granny's House 5 years ago from Older and Hopefully Wiser Time

Loved this. I always like to learn something new and the photos made it even better.


Fossillady profile image

Fossillady 5 years ago from Saugatuck Michigan Author

Hello Granny's House, I like what you said on your profile page about family's and they are your friends now so spend time with them and cook teach them manners! I thank you for you nice compliment!

tritrain profile image

tritrain 5 years ago from United States

Boy, that would have been a scary time to live. But fascinating!

Fossillady profile image

Fossillady 5 years ago from Saugatuck Michigan Author

Thank you Tritrain, Scary indeed! I like your profile photo, is that your dog? Perfect timing whoever shot

Micky Dee profile image

Micky Dee 5 years ago

Nicely done. There are so many creatures we can't see - so many too small to see. It's a wild world! Great job!

Fossillady profile image

Fossillady 5 years ago from Saugatuck Michigan Author

Hello Micky! Thank you so much dear! It truly is a wild world, both today and yesteryear!

Eiddwen profile image

Eiddwen 5 years ago from Wales

Wow how interesting was this one !!!!

I have a great interest in this subject and all my children had a teacher who taught them so much on projects about Dinosaurs. I used to love helping them and thank you for sharing this one.

Take care


carolinemoon profile image

carolinemoon 5 years ago

Wow! I am so much amazed with these gigantic creatures. They are all gorgeous and magnificent. Thanks for sharing this great article, Fossillady.

Didge profile image

Didge 4 years ago from Southern England

Excellent hub, Fossillady!

Greensleeves Hubs profile image

Greensleeves Hubs 4 years ago from Essex, UK

Nice to see this page Fossillady. So few hubs seem to cover life before the dinosaurs and this one gives the best overview of the many extraordinary creatures from this era. The photos and drawings are good and illustrate well all the species covered. All this and videos too. Voted up accordingly.

Because the hub provides a much needed coverage of little known creatures, I would like to review and promote this as one of ten 'prehistoric creatures' hubs which I will be publishing very shortly. I will want to incorporate just one image from the hub to effectively show what the hub is all about. Hope this is OK?

An example of one of my already published reviews is at


Fossillady profile image

Fossillady 4 years ago from Saugatuck Michigan Author

Hello Greensleeves, Nice of you to include my hub on you top list. It's also nice to have someone appreciate the prehistoric creatures before dinosaurs. I'm glad I checked into my hub today as I have been too busy lately. Looking forward to the day I can come back more often. Will check out one of your hubs. Fossillady p.s. okay with me to include one of my photos in your hub

Greensleeves Hubs profile image

Greensleeves Hubs 4 years ago from Essex, UK

My pleasure Fossillady. Dinosaurs have always had the lion's share (or T rex's share?) of the publicity, and yet so many extraordinary creatures existed before and since the dinosaurs. So it was an easy decision to include your hub in my review because it's undoubtably the best hub I have seen on the subject of the earliest life forms. Best wishes. Alun.

Pamela Kinnaird W profile image

Pamela Kinnaird W 3 years ago from Maui and Arizona

WOW! I can hardly believe the amount of information you have put together here on this huge topic. You researched it so well. Or maybe you have retained a goodly portion of this information from years of studying it. I am of the open-minded opinion that all of these creatures once lived and yet I also believe the scriptures in Genesis. Science and truth go hand in hand. It's just that we humans have very limited information. We don't know the whole picture yet. But when we study the book of Genesis we find that the earth was placed in this solar system. Where God created it and how it evolved through the eons of time before we learned of it in this solar system -- and what fantastic creatures walked upon it before it was placed in this solar system -- are not known by us. I certainly didn't come up with this theory myself. Greater minds have mulled it and written upon the subject.

Great hub, Fossillady. Voting up and awesome.

Fossillady profile image

Fossillady 3 years ago from Saugatuck Michigan Author

Hello Pamela, I do believe there's a difference between following an ideology exactly according to some authority and spirituality where it's okay to have original thoughts. Seems that you have found a way to reconcile the Genesis theory and your own theories and that is what spirituality can offer us for our own sense of peace in this life! Right on! Thank you so much for sharing your thoughts and for your support! Kathi :O)

pstraubie48 profile image

pstraubie48 3 years ago from sunny Florida

Wow, this was amazing. I know for sure that an orthocone would have been the one I found most startling. What an interesting creature.

I learned so much here. Thanks for sharing. Sending Angels your way this morning :) ps

Fossillady profile image

Fossillady 3 years ago from Saugatuck Michigan Author

Hi p. sorry so late to respond as I'm trying to balance a new job and all. So glad you found the information here amazing which it truly is. I feel the angels you're sending and will try to catch up soon, their help will be needed, tee hee!

newenglandsun 3 years ago

My favorite is Ambolocetus. Early whale ancestor.

Were the sea scorpions ancestors of lobsters, modern scorpions, or both?

Are you a paleontologist?

Fossillady profile image

Fossillady 3 years ago from Saugatuck Michigan Author

Hello Newenglandsun . . . (btw, love that name) To answer your question the sea scorpions were not true scorpions and are more closely related to arachnids than lobsters and belong to the family of arthropods for their jointed limbs and segmented bodies. No, I am not a paleontologist . . . just have a fascination I guess! Thanks for stopping by, Kathi

newenglandsun 3 years ago

I remember in elementary school, I would always watch dinosaur shows and read dinosaur books. I loved dinosaurs. Of course, being raised in a Christian family, all I knew at that point was YECism and dinosaurs and wasn't sure how God got along with them.

Well, no longer a YECist now and actually would say I have a stronger fascination with both God and dinosaurs and evolution equally now. Even though my actual specialties are history and religion.

Fossillady profile image

Fossillady 3 years ago from Saugatuck Michigan Author

A great perspective you have gained now that you are older! Thank you for your wonderful comment! Kathi :O)

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