This Fossil Friday is a Florida native!

Metaxytherium floridanum is a 12-million-year-old sea cow. The earliest known fossils of sea cows are found in 50-million-year-old marine sediments, yet even at that early stage, two groups of sea cows had already evolved—the dugongs and the manatees. Metaxytherium is an extinct dugong. Unlike manatees, dugongs lack nails on their flippers, and have a deeply notched tail fin with two pointed lobes. Throughout most of the evolutionary history of sea cows, their habitat has corresponded to the places where sea grass grows. These are primarily in tropical and subtropical coastal shoreline environments and estuaries. This fossil was collected in 1929 in Gadsden County, Florida. 

Another immense dugong species, the Stellar sea cow, survived until around the year 1800 in the waters of the North Pacific. Reaching a length of almost 25 feet (7.5 meters) and weighing about 9,000 lbs (4,000 kg), it was hunted to extinction by humans. 

See this fossil in the Museum’s Hall of Advanced Mammals

AMNH/C.Chesek

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The Mesozoic Park: Pteranodon

Common name: Pteranodon (ter-AN-oh-DON)
Size: Wingspan: 7.8-10m (25-33ft); Standing height: 1.8m (6ft)
Age: Late Cretaceous Period (85-75 million years ago)
Geographic range: North America and Europe
Liked: being huge and eating fish
Disliked: being mistaken for a “dinosaur”
Taxonomy: Animalia > Chordata > Archosauria > Pterosauria (flying reptiles) > Pteranodontidae > Pteranodon

Pteranodon was a flying reptile. Now, do not mistake this for a dinosaur. Flying reptiles and marine reptiles are not technically considered dinosaurs. Dinosaurs are classified as diapsid (skull classification meaning two holes behind the eye hole) reptiles with an upright stance. By this definition, the semi-upright stance of the Pteranodon makes it just a reptile.

Pteranodon was a 1.8m (6ft) tall reptile with a massive 7.8-10m (25-33ft) wingspan. The Pteranodontidae family is considered to be the first vertebrate to take flight. It had hollow bones and likely had a variation of fur called “pycnofibres.” Its entire body was covered by a thin, though skin that stretched from the knees to the finger tips, creating the wing structure. They were a carnivorous species that likely ate fish. The name “Pteranodon” means “winged and toothless.” They are also likely to have been warm-blooded.

In Jurassic Park, the Pteranodon was incorrectly portrayed as being a toothed dinosaur. This is incorrect. The beak of the Pteranodon was similar to that of common birds; long, slender, and toothless. The Pteranodon in the movie also lacked the pycnofibres.

Jurassic Park introduces three variations of the Pteranodon: one that is bird-like, with tan/brown colouration and a green head. The second is more reptile-like with teeth and a quadruped terrestrial gait and a tan/brown colour with black on the wings and beak. The third variation is not an available clone, but was an actual species.

~Rosie

Images:
http://bit.ly/1HvRgcN
Movie screenshot belongs to Universal Pictures/Jurassic Park.
References:
http://bit.ly/1FDgwgT
http://bit.ly/1F33809
http://bit.ly/1R5yR8t

This article is a part of our “Mesozoic Park” series that is leading up to the release of Jurassic World. For more information, please see our introductory post at: http://on.fb.me/1ELwHW5 or if you already know about the series but missed a few articles you can find links to the first 10 posts at “Update #1,” here: http://on.fb.me/1ED1tOH

Fossil Friday, Fossil dig. 

Check out the amazing landscape.

© The Field Museum, CSGEO44836.

L to R: C. Harold Riggs, John B. Abbott, expedition members excavating the skeleton of Krytosaurus. Landscape and mountains.

Marshall Field Paleontological Expedition Geology Paleontological North America Canada Alberta Belly River Formation.

5x7 album print 

6/1/1922 

Happy #fossilfriday, friends! Here’s a lovely Parasaurolophus sculpture at the Grand Staircase Escalante National Monument visitor’s center. #grandstaircaseescalante #grandstaircaseescalantenationalmonument #utah #science #geology #science #bone #biology #fossil #dinosaur #dinosaurs #museum #nhmu #paleo #paleontology #prehistoric

Large #fossil #ceratitic #chambered #goniatite exceptional quality specimen with a unique occurrence of the smaller specimen #goniatite naturally sedimented into the last living chamber of the #cephalopod, #evolution in action, a barometer of time, we see here the processes of fossilisation, a window into the larger picture. Amazing stuff under our noses. #Devonian period around 480 million years old.

Get ready Toronto - the Prehistora Natural History Centre and SkullStore Oddity Shop is getting closer to opening! You can already schedule an early visit by emailing BuySkulls@gmail.com! This is a fossil cave bear skull and a 1902 tiger skin rug! They are just two of literally thousands of specimens at our location (and both happen to be for sale)!

It’s Fossil Friday! Paracolobus chemeroni lived during the Pliocene, about 3 million years ago, and is one of the largest colobine (leaf-eating) monkeys ever known. The fossil skeleton (of which this is a cast) was found nearly complete; only the hands, part of the feet, and rear of the skull were lacking. Like the living proboscis monkey, Paracolobus was probably mainly tree-dwelling. The fossil was collected in 1966 in the Chemeron Formation, Baringo Basin, in Kenya. Find this cast in the Museum’s Hall of Advanced Mammals

AMNH/D.Finnin

Some scientists have speculated that snakes first evolved in water and that their long, slithery bodies were streamlined for swimming. But a new analysis suggests that the most recent common ancestor of all snakes actually lived on land.

This ancestral protosnake probably was a nocturnal hunter that slithered across the forest floor about 120 million years ago. And it likely had tiny hind limbs, left over from an even earlier ancestor, says Allison Hsiang, a researcher at Yale University.

“They probably weren’t using them in locomotion in any way, but they did probably still have vestigial hind limbs stuck on the back of their bodies,” Hsiang says.

The evolutionary origin of snakes has been a bit of a mystery for scientists, because the fossil record has an unfortunate dearth of snakes. “For a long time there weren’t very good snake fossils,” says Hsiang, who explains that researchers had not found “things that sort of told us what snakes looked like early on, or transitional fossils between snakes and their closest ancestors.”

Earth’s First Snake Likely Evolved On Land, Not In Water

Illustration: Julius Csotonyi/BMC Evolutionary Biology

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An absolutely gorgeous Comura trilobite with exceptionally preserved eye detail.  It takes on the order of 40-50 hours of work under high magnification to prepare one of these trilobites to this level of quality.  Low-pressure air abrasives are used to slowly remove the hard limestone surrounding the spines one layer at a time.  Unlike many specimens out there, the spines on this one are real and not simply reconstructed.

Just added for sale at: https://www.fossilera.com/fossils/large-spiny-comura-trilobite-3-1

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The Mesozoic Park: Velociraptor

Scientific Name: Velociraptor Mongoliensis Size: about 2m long and 0.5m high Age: 85-70 Million Years Ago, during the Late Cretaceous Geographic Range: Mongolia Liked: Running and trying to fly Disliked: Being wrongly portrayed in movies Taxonomy: Animalia > Chordata > Dinosauria > Theropoda > Dromaeosauridae > Eudromaeusaria > Velociraptorinae > Velociraptor

Velociraptor was a small and agile dinosaur that lived in present day Mongolia around 85-70 million years ago, during the late Cretaceous period. Its first fossils were discovered in the 1923 by Peter Kaisen during an expedition to the Gobi desert and named in 1928 by Henry Fairfield Osborn, the then president of the American Museum of Natural History. Only one species was described since its discovery, Velociraptor Mongoliensis, until in 2008 a second species also found in Mongolia, Velociraptor Osmolskae, was described. Its name means, in latin, “velox” (swift) and “raptor” (robber).

Keep reading

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Oldest broken bone reveals our ancestors’ switch to life on land

by Colin Barras

It was one small fall for a tetrapod, but it signals one giant leap for tetrapod kind. A broken leg bone pushes back the emergence of our four-legged ancestors from water on to land by at least 2 million years.

A gap in the tetrapod fossil record means we know little about what happened between the time when limbs evolved from fish fins some 360 million years ago and the first land-adapted tetrapods appeared 330 million years ago.

To find out, Peter Bishop at the Queensland Museum in Hendra, Australia, and his colleagues analysed a rare tetrapod fossil from that gap, a 1.5-metre-long Ossinodus which lived some 333 million years ago in what is now Australia. They found that Ossinodus’s forearm bones were strong enough to support the animal’s body on land.

It also has what Bishop believes is the world’s oldest known broken tetrapod bone. When the team used computer software to reconstruct the forces required to cause the break, they found the magnitude of the force was so large relative to the size of the animal that the accident must have occurred on land…

(read more: New Scientist)

illustrations: Bishop et al./2015, NSF/Science Photo Library

Get your Trilobite Tuesday fix! Trilobites were certainly not solitary creatures. Indeed, mass mortality plates featuring dozens of complete specimens have been found everywhere from the Cambrian strata of Morocco to the Ordovician rocks of Oklahoma. 

This example of Eldredgeops milleri (named in recognition of Dr. Niles Eldredge, Curator Emeritus, AMNH Division of Paleontology) from the Middle Devonian and collected in Michigan features 11 trilobites that lived approximately 400 million years ago. 

More trilobites this way!