Sunday, July 31, 2011


Acanthostega (uh-canth-oh-STAY-guh) was a genus of tetrapod from the late Devonian Period. Its name means "spiny roof."

Although Acanthostega had legs, they were probably not used for walking because its feet could not support it.

When scientists first discovered Acanthostega, they only found parts of a skull. Very recently, they found a more complete skeleton.

Acanthostega had a leaf-shaped tail, which could have helped it swim. It was about 2 feet long and was probably a descendant of the Sarcopterygii (lobe-finned) fishes Tiktaalik and Panderichthys, and an ancestor of the land-dwelling tetrapod Ichthyostega.

Acanthostega probably lived in swamps full of plants and debris. It was one of the first animals to catch prey by actually biting it, unlike fish, which simply had to suck food in. Acanthostega probably fed by swimming close to shore and grabbing prey with its mouth, or catching things with its head above the water. It had eight digits on the front feet, and maybe even on the hind feet. 

Saturday, July 30, 2011


Furcacauda is a genus of thelodont from the Silurian to Devonian Periods. It had a large caudal fin which made it look very odd. Furcacauda was closely related to the Silurian thelodont Lanarkia.

Since the largest thelodont, Thelodus, was 30 cm, Furcacauda was smaller than that. Furcacauda and other thelodonts were jawless. Scientists have found a fossilized part of Furcacauda that looks like a stomach. So Furcacauda could have had the first stomach of any vertebrate.

This image shows a fossil of Furcacauda on the bottom, and the top fossil is Lanarkia. Although Furcacauda didn't look anything like Lanarkia, they were still both thelodonts. Thelodonts were covered in tooth-like scales rather than having armor on their head like most jawless fish did.

Friday, July 29, 2011


Marrella is a genus of arthropod from the Cambrian Period. It is the most common fossil in the Burgess Shale. Since Marrella had a diffraction grating pattern, it was probably very colorful. Marrella grew up up to 2 centimeters long.

Marrella had four spines running down its back. It had two pairs of antennae, two long ones and two short ones. Marrella had 24 to 26 segments. At the end of the thorax Marrella had a tiny telson.

Marrella's legs had two parts, the gills on top, and on the bottom it had walking legs. Marrella was a marrellamorph related to the Devonian Mimetaster. Monster predators like Anomalocaris, Amplectobelua, and Hurdia probably didn't bother to eat it, because it was much too small. One specimen of Marrella shows it molting. Scientists have discovered over 25,000 specimens of Marrella in the Burgess Shale. It was the first fossil that Walcott found there.

Thursday, July 28, 2011


Canadaspis is a bizarre genus of crustacean from the Cambrian Period. Its name means "Shield of Canada." It had a large shield that covered its head.

Canadaspis probably used its legs to crawl along the sea floor. When Canadaspis crawled, its legs made a rippling motion that could have stirred up food or helped it with respiration by stirring up the water.

Canadaspis are commonly found in the Burgess Shale. But Canadaspis is also found in Utah, Nevada, and China.

This image shows Anomalocaris grabbing a Canadaspis with its claws.

The type species of Canadaspis is C. perfecta.

Wednesday, July 27, 2011


Waptia is a shrimp-like genus of arthropod from the Cambrian Period. It has been classified as a crustacean, but they haven't been able to link it to other crustaceans of its time.

Waptia could swim using its book gills and steer with its tail, but since it had weak jaws, it probably spent most of its time crawling around on the bottom of the ocean eating detritus.
This image shows two Waptia swimming with one Canadaspis. Waptia looked sort of like Canadaspis and they were both crustaceans. 

Tuesday, July 26, 2011

Asaphus kowalewskii.

Asaphus kowalewskii was a peculiar genus of trilobite from the Ordovician period. It is sometimes classified as its own genus, Neoasaphus.

Asaphus kowalewskii had eyes on stalks, which probably helped it avoid turbid water (turbid water is murky water), which would cloud its vision. If it didn't evolve the eyes on stalks, it would have been devoured by predators because it would not be able to see right in the turbid water at the bottom.

A. kowalewskii probably crawled around beneath the mud and sand at the bottom of the ocean, with its two eyestalks poking out to watch for danger. A. kowalewskii had eyestalks that were sometimes as tall as one inch.

A. kowalewskii is a popular fossil because of its odd eyestalks. It has only been found in Russia. A. kowalewskii probably lived alongside animals such as Cothurnocystis.

Monday, July 25, 2011


Sigillaria (sidge-ill-AIR-ee-uh) is a genus of lycopod that lived from the Carboniferous to early Permian Period. It had a forked top with a club of pine needle-like leaves on both branches. Although Sigillaria and other lycopods resembled trees, they are their own group. They are actually very different from true trees. Sigillaria was not made of wood and its trunk was covered in photosynthetic tissue, so its trunk may have been green.

Sigillaria was very similar to Lepidosigillaria, which didn't have a forked top. Instead, it only had one club of leaves.

Sigillaria had a short life cycle and only lived for a few years. Some people believe that Sigillaria may have died after reproduction, but no one has found any proof of this.
Sigillaria reproduced with spores like other lycopods. It probably lived alongside other lycopods, such as Lepidodendron, and may have grown to 130 feet.

Sunday, July 24, 2011


Lituites is a peculiar genus of nautiloid cephalopod from the Ordovician Period. Its shell had a coiled tip. Juvenile Lituites did not have a conical part of the shell, they only had the coiled part of the shell. Then they later grew the conical part of the shell as they got older. Lituites was about seven inches long.

Lituites probably had to avoid predators such as Cameroceras and Anomalocaris. Lituites has been found in the United States (New York), China, Europe, and South America.


Some fossils of Lituites are similar to those of Orthoceras, because the fossils are the same color and preserved in the same way. But Orthoceras did not have the coil at the tip of the shell.

Saturday, July 23, 2011

And the winner is...

Thanks to everybody who entered the t-shirt giveaway. All names were entered into Randomizer and we awarded shirts to the first and second place winners.

The prizes will go to:

First place: Noodlefish

Second place: William

Winners, please send your mailing address and shirt size to The shirts are printed on Hanes Beefy Ts, and a sizing chart can be found here. We have adult and youth sizes.

Thanks again to everybody who reads the blog and who entered the contest. Congratulations to our winners! We just might have more shirts to give away in the near future, so if you didn't win this time, don't despair!


Eldonia is an odd genus of animal that lived from the Cambrian to the Ordovician. When Charles Doolittle Walcott first found Eldonia in the Burgess Shale, he classified it as a holothurian (a sea cucumber), but other scientists didn't agree. They classified it as a medusoid (a jellyfish). Others classified it as a siphonophore. But no one knows for sure what it was.

There are three species of Eldonia: Eldonia ludwigii, Eldonia eumorpha, and Eldonia berbera. Although many people believe that Eldonia was a pelagic animal, some now believe that it was benthic and lived on the bottom of the ocean.

Some fossils of Eldonia show the lobopod Microdictyon feeding on them. Eldonia could grow up to 4 inches, but most specimens of Eldonia are smaller than this.

The part of the Burgess Shale where Walcott found so many Eldonia is called "The Great Eldonia Layer." Eldonia has also been found in China and in Morocco.

Friday, July 22, 2011


Parapeytoia (para-puh-TOY-uh) was a weird genus of anomalocarid from the Cambrian Period. It probably ate animals such as trilobites, priapulid worms, and annelid worms. Its fossils have been found in China and are not well preserved.

Since Parapeytoia had legs, it probably spent most of its time crawling around on the bottom in search of prey. Scientists don't know if Parapeytoia was either related to anomalicarids like Anomalocaris and Amplectobelua, or if it was related to anomalocarids like Yohoia and Haikoucaris. But what is clear is that it was an anomalocarid because it had claws for grabbing prey, a "pineapple ring" mouth, and swimming lobes along the side.

Parapeytoia was probably one of the top predators, like other anomalocarids, but it still wasn't the top predator because it would have been good prey for bigger anomalocarids, like Anomalocaris.

Unlike other anomalocarids, Parapeytoia's claws were more like hands. Parapeytoia probably did not need to keep crunching its prey with its claws before eating. It would only have to tear it apart with its pinchers and then eat it.

Thursday, July 21, 2011


Diplocaulus was an usual genus of boomerang-headed amphibian from the Permian Period. The use for its boomerang-shaped head is a mystery. Maybe it used it to glide through the water like a hydrofoil, or maybe it used it to dig up food, maybe for fighting for a mate, or maybe something else. Very young Diplocaulus did not have the boomerang-shaped head, but older Diplocaulus eventually grew it.

Many fossils of Diplocaulus show that a predator must have been eating it, because they were torn apart and have fossilized teeth in them. The teeth belonged to Dimetrodon. It's not obvious how any predator would have been able to eat Diplocaulus without being choked by swallowing its head. But if something could eat it piece by piece, it would be able to avoid swallowing the head. So synapsids like Dimetrodon would not have trouble eating it.

Diplocaulus was about three feet long. Its closest relative was Diploceraspis, which also had a boomerang-shaped head and resembled Diplocaulus in many ways.

Wednesday, July 20, 2011

Cothurnocystis Has a Brain at the End of Its Tail.


Spriggina (sprig-EE-nuh) is an odd genus of animal from the Ediacaran Period (about 600 million years ago). No one really knows what kind of animal Spriggina really was--if it was an annelid, arthropod, sea pen, or maybe even something else. Spriggina had a horseshoe-shaped head and many tapering segments that formed a body that looked like a flattened worm.

Spriggina could have had eyes and antennae on the head, but no one really knows if it did have these. On top, Spriggina had overlapping plates of cuticle (cuticle is a hard layer that is not quite a shell), and possibly a mouth in the middle of the head.

Spriggina was probably not an arthropod if it didn't have eyes, antennae, or legs. And also probably not an annelid because it didn't have chaeta, which are bristles.

Spriggina was found in Australia and is 3 cm long.

Only three days left to enter to win a Life Before the Dinosaurs t-shirt featuring my drawing of Eldonia!

Tuesday, July 19, 2011


Tiktaalik was an unusual genus of lobe-finned fish from the late Devonian period. This image shows how tetrapods (four-legged animals) evolved from lobe-finned fish. First, there were lobe-finned fish like Eusthenopteron, then Panderichthys, then Tiktaalik, then Acanthostega, then Icthyostega.

Tiktaalik had lungs, a moveable neck, and a ribcage like a tetrapod, but it also had gills, fins, and scales like a fish. So this makes it a transitional fossil between lobe-finned fish and tetrapods.

Tiktaalik probably crawled along the bottoms of shallow freshwater habitats, like ponds and swamps, then waited for prey to come by. But it may have occasionally even crawled up onto land using its leg-like fins to walk.

Tiktaalik was about 3 to 9 feet long, and most likely a predator eating fish, and maybe some small terrestrial arthropods. Tiktaalik could have been related to Panderichthys, which is a similar transitional fossil between the lobe-finned fish and the tetrapods. 

Monday, July 18, 2011


Meganeura was a genus of huge griffinfly (a griffinfly is similar to a dragonfly, but much bigger), which lived during the Carboniferous Period. It had a wingspan of about 2-1/2 feet and probably ate animals such as other flying insects and probably some small amphibians and reptiles.

Fossils of Meganeura have been found in North America, France, and Great Britain. Meganeura means "big nerves," referring to the veins in its wings.

Meganeura was probably not very fast because of its huge size. But it probably was a successful predator because it had very large and sharp mandibles for killing its prey, and long spiny legs to grab prey and also prevent it from escaping.

Meganeura probably was able to grow so big because there were so many plants around in the Carboniferous Period that insects like Meganeura would be able to absorb enough oxygen to grow huge. The whole earth was either sea or a thick swamp forest during the Carboniferous Period, so the oxygen level would be immensely high.

Sunday, July 17, 2011


Cooperoceras was an odd genus of nautiloid cephalopod from the Permian Period. It looked like a spiny ammonite. Cooperoceras was about 4 inches long and 3 inches high. It probably had to avoid edestids, like Helicoprion, Parahelicoprion, and Sarcoprion, because their saw-like jaws could easily smash any kind of shell.

Since all Cooperoceras's living relatives, like squid, cuttlefish, octopus, and nautilus, are carnivores, scientists believe that Cooperoceras was also a carnivore which ate small animals such as echinoderms, bivalves, gastropods, and trilobites. Its spines were probably either for defense, telling each other apart, or attracting a mate.

Cooperoceras had a siphuncle and septa like Orthoceras. But unlike Orthoceras, it had a coiled shell which would have allowed it to live deeper in the ocean than an orthocone's shell would. Even though Cooperoceras had a coiled shell, it was not an ammonoid, because ammonoids do not have the operculum and Cooperoceras did. An operculum is part of the shell that can open and close to give the animal better protection from predators.

Don't forget to enter for a chance to win a Life Before the Dinosaurs t-shirt!

Saturday, July 16, 2011

Life Before the Dinosaurs t-shirt giveaway!

Certain extremely cool people already have a Life Before the Dinosaurs t-shirt, and now you (yes, you!) can join this exclusive club. The t-shirt is currently not available anywhere else. This is your big chance!

This white shirt features Art's own drawing of Eldonia above the words Just leave a comment on this post about your favorite creature featured on the blog so far, or about what you like about the blog in general. Only one entry per reader. I'll use randomizer to select a winner next Saturday, July 23rd. We'll ship to anywhere in the world!


Vetulicola is a bizarre genus of vetulicolian from the Cambrian Period. Vetulicola was probably either a planktivore or a detritivore. Like all other vetulicolians, Vetulicola is thought to be a swimmer, occasionally going down to the bottom to eat detritus.

Vetulicola means "ancient inhabitant." Vetulicola could have been related to Xidazoon, Didazoon, Skeemella, Ooedigera, and Banffia. It had a tail made up of seven segments. At the end of its tail, Vetulicola had a paddle to propel it though the water. One specimen shows a carpoid called Cotyledion tyloides on the last segment of Vetulicola's tail.

Vetulicola had a beak-shaped mouth with no jaws, which it would use to suck in food. It had a row of holes along both left and right sides, which may have been gills. It also had no eyes, and flaps that looked like skate fins on both top and bottom. This may have helped to stabilize Vetulicola when it was swimming.

Friday, July 15, 2011

Cambrian Explosion Song.

Deep Sea News posted this really good song about the Cambrian Explosion!


Drepanaspis is a genus of heterostracan (which is a jawless placoderm with two plates of armor on its head) from the Devonian Period. Drepanaspis means "sickle shield." It probably swam along the bottom in search of food, but its mouth pointed up. The main mystery about Drepanaspis is that, if its mouth pointed up, how could it be a bottom feeder? It may have eaten bits of dead animals and plants that drift down to the bottom called "marine snow." Or maybe it could have stirred the sand up so much that the food came flying up, and then Drepanaspis would be able to suck it in. But those are just my hypotheses.

This image shows Hemicyclaspis in the lower right-hand corner, which is the one with the headshield that looks like half an oval. Astraspis is in the lower left-hand corner, and is the one that only has a caudal fin and a shield that looks like half of a medicine capsule. Anglaspis is similar to Astraspis, because it has two plates of armor, and the only fin it has is a caudal fin. Anglaspis is the one in the upper right-hand corner. The other two fish in this image are Pterapis, the one in the upper left-hand corner with the long, lower lobe on the caudal find and the beak-like rostrum, and Drepanaspis, which is the one with one of its pectoral fins scraping the bottom.

Drepanaspis was usually about six inches long, but it could grow up to one foot long. Drepanaspis had a flattened, ray-like body with two wide pectoral fins.