Scientific Illustration

astronomy-to-zoology:

Genus Prionosuchus

was a genus of large Temnspondyl amphibians from Permian Brazil. Prinosuchus is the largest described species of amphibian ever found, with individuals growing up to 30 ft long! Prinosuchus while an amphibian looks and acts very similar to extant crocodiles like the gharial, as it had a long snout and body and short legs. They presumably had a similar lifestyle as well as they probably were ambush hunters and fed primarily on fish and aquatic animals.

Phylogeny

Animalia-Chordata-Tetrapoda-Amphibia-Temnspondylia-Archegosauridae-Prionosuchus

Source,Source

rhamphotheca:

Fossil Fish With “Limbs” Is Missing Link, Study Says

by James Owen, Apr., 2006

Fossil hunters may have discovered the fish that made humans possible.

Found in the Canadian Arctic, the new fossil boasts leglike fins, scientists say. The creature is being hailed as a crucial missing link between fish and land animals—including the prehistoric ancestors of humans.

Researchers say the fish shows how fins on freshwater species first began transforming into limbs some 380 million years ago. The change was a huge evolutionary step that opened the way for vertebrates—animals with backbones—to emerge from the water.

“This animal represents the transition from water to land—the part of history that includes ourselves,” said paleontologist Neil Shubin of the University of Chicago.

Shubin was co-leader of a team that uncovered three nearly complete fossils measuring up to nine feet (3 m) long on Ellesmere Island in 2004. The new species, Tiktaalik roseae, had a flattened, crocodile-like head and strong, bony fins…

(read more: National Geo)                  

(image: T - Shawn Gould, Nat. Geo.; BL - Univ of Chicago; BR - Graham Roberts, NY Times)

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read more:

http://en.wikipedia.org/wiki/Tiktaalik

http://tiktaalik.uchicago.edu/index.html

http://evolution.berkeley.edu/evolibrary/news/060501_tiktaalik

nemertea:

Oenosaurus muehlheimensis

From a new study published in PLOS One, this is the skull of a new fossil rhynchocephalian (tuatara and their fossil relatives) from the Jurassic of Germany. This is a really incredible find because instead of having separate, distinct teeth like … basically all other tetrapods, it has large, continuously-growing tooth plates that actually look a lot like what you find in lungfish.

This is exciting because it suggests a lot of developmental flexibility within the tuatara lineage (even though these are classically considered a pretty conservative group), and also because it suggests that these animals are crushing very hard foods, which is not something that’s previously been recorded in the fossil record of these animals, and isn’t seen in living tuatara.

(The tooth plates are the white structures on the skull, coded as ‘tp’ in the diagram.)

(via dendroica)

paleoillustration:

Pictures from Tiffany Turrill’s book Dinosaurs Before Bedtime. And I just found out that Tiffany Turrill is on Tumblr!

paleoillustration:

Tungsenia by Gogosardina:

“The whole tetrapod dynasty, from finches to frogs, cats to chasmosaurs, not to mention Homo sapiens, can trace their lineage to a little fishy like this.” Full comment here

lostbeasts:

Ventastega

A Devonian tetrapod, and one of the largest animals of the period, being around 1 metre long. Its discovery aided in the understanding of the evolution of limbed animals from finned ones.

(via dendroica)

rhamphotheca:

Shift to shore: New model shows extinct tetrapod Ichthyostega couldn’t walk

by Kate Trinajstic, Assoc. Prof., Dept. of Chem. at Curtin Univ.

Palaeontology has gone high-tech: no more wax and plaster-cast models. Instead, 3D data from computed tomography (CT) scans is overturning long-held views of how the earliest land animals moved.

Research published today (May 23, 2012) in Nature reveals how a famous extinct animal, the early four-legged vertebrate (tetrapod) called Ichthyostega, moved on land 360m years ago.

One major problem in putting together fossil skeletons is actually getting the fossil out of the rock, but now palaeontologists don’t have to! Instead, the CT scans allow the virtual preparation of the fossil so delicate bones can be fully isolated and then fitted together so the anatomy can be better understood.

It was this process that has allowed scientists (Stephanie E. Pierce and Professor John R. Hutchinson from the UK’s Royal Veterinary College and Professor Jennifer A. Clack from the University of Cambridge) to overturn long held assumptions on how one of the earliest tetrapods moved from the water on to land…

(read more: PhysOrg)       (image: T - Julia Molnar, B - Stephanie Pierce)

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Journal reference: Nature

Source: The Conversation - This story is published courtesy of the The Conversation (under Creative Commons-Attribution/No derivatives).

paleoillustration:

Postosuchus illustration by Christian Jegou | And I must add this surprisingly good Postosuchus rubber toy (I look forward for Stella’s critique).

From BBC Nature:

A cousin of modern crocodiles, Postosuchus was an archosaur - the lineage of reptiles that include the crocodiles, dinosaurs and birds. Reaching lengths of five metres, Postosuchus was the top predator during the Late Triassic in what’s now the southern USA. Since its front limbs were shorter than its hind limbs, there is debate as to whether it walked on two legs or four, but most palaeontologists favour the latter. Its stance, with the legs under the body, would have made it a faster and more efficient runner than a modern crocodile. Most Postosuchus fossils have been found in Texas’ Post quarry, hence the name.

paleoillustration:

Tetrapod fauna of the upper Triassic Chinle Formation of Petrified Forest National Park, Northern Arizona.

paleoillustration:

“Tiktaalik roseae is an intermediate between fish that lived in water and animals that evolved to walk on land. Its fin is like that of fish, but it was capable of propping the body of the animal up, much like a limb”.

Full article and video. It’s old news (April 5, 2006) but it’s still interesting.