devonian

A spiny Comura trilobite from Morocco.  This 350 million year old trilobite shows amazing detail including over 40 free standing spines and eye facets thanks to being encased in hard limestone.  It was found when the limestone was broken and a cross section of the trilobite could be seen.  It then had to be meticulously prepared from the surrounding rock under microscope.  Truly a stunning specimen.

Trilobites are an extinct type of marine arthropod that had a hard exoskeleton.  They were one of the dominant life forms in our oceans for 270 million years before going extinct along with 90% of all life during the Permian mass extinction.  Owing to their hard shell they are often exquisitely preserved in limestones and shale.

Photo from Fossil Era

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The last 600 million years of Earth’s continental evolution in 10 images:

  1. 600 Ma: Ediacaran
  2. 500 Ma: Cambrian
  3. 400 Ma: Devonian
  4. 300 Ma: Carboniferous
  5. 220 Ma: Triassic
  6. 150 Ma: Jurassic
  7. 90 Ma: Cretaceous
  8. 50 Ma: Palaeogene
  9. 20 Ma: Neogene
  10. Present: Quaternary

Source + more

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Mat Brown
Deep History, Illustrated  
[images on Flickr]
Artist’s website / store  |  Artist’s work in other series

Hadean
The first geologic eon began with the formation of the Earth about 4,600 million years ago and ended 4,000 million years ago.

Thermal Genesis   
More broadly: abiogenesis - the natural process by which life arises from simple organic compounds. The earliest life on Earth existed at least 3,500 million years ago, at the beginning of the Archean Eon when sufficient crust had solidified following the molten Hadean Eon

Cambrian
First geologic period of the Paleozoic Era, lasting from 541 to 485 million years ago.   Although complex, multicellular organisms gradually became more common in the millions of years immediately preceding the Cambrian, it was during the Cambrian that life exploded, rapidly diversifying and producing the first representatives of many modern phyla,  However, while diverse life forms prospered in the oceans, the land was comparatively barren.

Devonian
A geologic period of the Paleozoic Era that occurred from 419 to 358 million years ago. This was the first significant adaptive radiation of terrestrial life.

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The Ancient King of the Sea

Dunkleosteus could concentrate a force of up to 8,000 pounds (3,628 kg) per square inch at the tip of its mouth, effectively placing Dunkleosteus in the league of Tyrannosaurus rex and modern crocodiles as having the most powerful known bite. It was one of the earliest jawed fishes. Instead of actual teeth, Dunkleosteus possessed two long, bony blades that could slice through flesh and snap and crush bones.

Dunkleosteus was a large Placoderm that lived in the late Devonian period, about 380–360 million years ago. It grew up to 10 meters (33 feet) and was possibly the the size of a great white shark, making it most likely the top predator of its time.

The only remains of Dunkleosteus are it’s head armor pictured above.

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Wood sculptures by Taburin

"This Japanese sculptor carved his niche by carving out an army of clearly accurate dinosaur skeletons entirely out of wood. (…) Extraordinarily detailed, his work is not for sale, sometimes taking several months to complete one species." paleoartistry

Extinct Animals of the Cambrian to the Cretaceous!

This will be a limited edition 11x17 print exclusively for sale at spx​ this year!

I love extinct animals, especially lesser-known and non-dinosaur ones. So here are some critters from the Paleozoic through the Mesozoic. Don’t take the period designations too literally, it’s more of a “pretty much around this time” thing, since I couldn’t fit all of them exactly where they should be, scientifically. I’d love to do a sister-image to this with the Cenozoic era!

Here’s a list of the creatures featured!
Cambrian Period
Hallucigenia
Opabinia
Trilobite

Ordovician
Orthoceras

Silurian
Eurypterus
Nektaspida

Devonian
Tiktaalik
Dunkleosteus

Carboniferous
Akmonistion
Pederpes
Arthropleura

Permian
Dimetrodon
Saroctonus

Early Triassic
Erythrosuchus

Middle Triassic
Batrachotomus
Ceresiosaurus

Late Triassic
Oligokyphus

Early Jurassic
Temnodontosaurus

Late Jurassic
Rhamphorhynchus
Pterodactylus
Brachiosaurus
Liopleurodon

Early Cretaceous
Microraptor
Deinonychus
Gobiconodon

Late Cretaceous
Protoceratops
Hesperornis
Corythosaurus

Class Sarcopterygi, Infraclass Tetrapodomorpha, Superorder Osteolepidida, Order Osteolepiformes, Family Osteolepidae

Geological Time: Middle Devonian (385 Million Years Old)

Size (25.4 mm = 1 inch): Fossil fish is 151 mm in length (tip of nose to tip of tail along backbone) on 145 mm by 120 mm matrix

Fossil Site: Caithness Flagstones, Cruaday Quarry, Caithness, Orkney, Scotland

Also see: Paleozoic Fish Fossils

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Stethacanthus - The Ironing Board Shark

When: Late Devonian to Early Carboniferous (385 - 320 million years ago)

Where: The seas that covered what is now North America and Europe 

What: Stethacanthus is an extinct shark. Over all this ancient shark is an excellent example of the amount of conservation the simple shark body plan has seen throughout the eons. It is relatively small, 2.3ft/70 cm long, and has a general form very much like an extant shark. The one major exception to this is the shape of its dorsal fin. It was flattened and covered with enlarged denticles (the particles in shark skin that give it it’s sandpaper texture). The head of Stethacanthus was also topped with enlarged denticles. Though some sort of courtship role has been suggested for the structures, detailed studies have determined that the dorsal fin could be flexed forward, to start to come into occlusion with the patch of denticles on the top of the head. This would give the illusion of a much bigger mouth than Stethacanthus actually possessed, allowing this little pre-historic shark to hopefully scare off potential predators. 

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Sea scorpions, or eurypterids, were the largest arthropods the world has ever seen.

Jaekelopterus rhenaniae

8.2 feet (2.5 meters) long

18-inch (46-centimeter) spiked claw

They had a pair of pincers, and in some species these too could become very large. Sea scorpions were predators that were in their heyday in the Silurian and Devonian, though they survived into the Permian.


it’s fine.  This is normal.

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Here is a killer Zlichovaspis rugosa trilobite that has been expertly prepared in a “flying” pose. The prep work on this piece is FANTASTIC with all the microscopic surface details on the exoskeleton present. All of the dozens facets in the segmented eyes can easily be seen. The trilobite is slightly arched which causes the genal spines which have been prepared free of the matrix to stick upwards at a 45 degree angle. A very beautiful and impressive specimen.  Just added for sale at FossilEra.com