Jurassic Crocodile Unearthed in Oregon

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Mar 30, 2006
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By Jeanna Bryner

The fossil of an ancient amphibious reptile with a crocodile's body and a fish's tail has been unearthed in Oregon. Scientists believe the creature's remains were transported by geologic processes nearly 5,000 miles away from where it originally died more than 100 million years ago.

The new fossil is the oldest crocodilian ever unearthed in Oregon and one of the few to be unearthed on this side of the Pacific. The “hybrid” animal is thought to be a new species within the genus Thalattosuchia, a group of crocodilians living during the age of dinosaurs.

The reptile roamed a tropical environment in Asia about 142 to 208 million years ago. Called a Thalattosuchian, the amphibious creature represents an early milestone in evolutionary history, marking a transition during which these reptiles moved from being semi-aquatic to wholly ocean species.

Rocky ride

Scientists uncovered the remains of the six- to eight-foot-long reptile in Jurassic rock on private property in the Snowshoe Formation of the Izee Terrane, a rock formation in Oregon. They knew the croc came from Asia due to distinct anatomical features, such as the way its ribs were connected to the rest of its body.

The rock-entombed animal migrated eastward from perhaps Japan via continental drift, a theory of land movement in geological time, suggests William Orr, part of the fossil-discovery team and director of the Thomas Condon State Museum of Fossils at the University of Oregon.

During ancient times, the Pacific Ocean was much wider than it is today, and Orr suggests the rocky ride could have taken as long as 100 million years before reaching North America.

“This idea is kind of profound, that you can move pieces of the Earth’s real estate about the globe,” Orr told LiveScience.

Into the ocean

Like modern-day crocodilians, the creature sported both land-lubbing and ocean-faring equipment. It had short, stubby legs, which the scientists say would have allowed it to creep easily along the ground and lay eggs.

But the amphibious Thalattosuchia was also at home in the water. With webbed feet and a fish’s tail, the reptile was likely a swift swimmer that could pulse through the water in search of aquatic prey.

“The thing that makes this creature unique is its tail,” Orr said. Unlike today’s reptiles, the creature had a shark-like tail, an indication of its ability to maintain itself in a marine environment.

“[The animal] was awfully close to being purely aquatic,” Orr said.



 

ThaG

Sicc OG
Jun 30, 2005
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HERESY said:
Thats the fossil?
part of it

they have 50% of the bones which is pretty good for a jurassic fossil


An ancient sea-going crocodile has surfaced from the rocks of Crook County in eastern Oregon. Really.

Its discovery by the North American Research Group (NARG), whose members were digging for Jurassic-age mollusks known as ammonites, is another confirmation that the Blue Mountains consist of rocks that traveled from somewhere in the Far East, says retired University of Oregon geologist William Orr, who was called in to examine the find for the state.

The remains – about 50 percent of a 6- to 8-foot reptile, including long, needlepoint teeth – were found imbedded in Jurassic rock on private property in the Snowshoe Formation of the Izee Terrane south of Dayville, Ore. Rocks containing the fossils were slowly cut out of the rock, after NARG members realized that the linear appearance of the fossils in the region's hard rocks suggested that a whole creature had been found, Orr said.

"This taxon was a crocodile-like creature but had a fish tail," said Orr, a NARG adviser and director of the Thomas Condon State Museum of Fossils at the University of Oregon. "This creature lived in Jurassic times, so it's 150 to 180 million years old. It probably lived in an area from Japan to East Timor, somewhere in the western Pacific in a tropical estuarine environment."

The remains of the crocodile, believed to be from the species Thalattosuchia and member of the Metriorhynchids group, now belong to the state, Orr said. The remains will be displayed on loan to the Rice Northwest Museum of Rocks and Minerals in Hillsboro, Ore., after undergoing an expected two-year analysis at the University of Iowa. The Hillsboro museum is operated by NARG, whose members are private researchers with experience and interests in paleontology, paleonbotany and geology who study the Pacific Northwest. NARG is based in Beaverton, Ore.


Andrew Bland, one of nine NARG members seeking fossils, first located the crocodile bones during a weekend trip in October 2005. "I followed the bone fragments I was finding up hill a few feet to the area they were weathering out of," Bland wrote in a group newsletter. "I started to dig and found more bone material. It was hard for me to stop digging, as I wanted to uncover more."

Thalattosuchia, a predator believed to have been common around much of the world during the Jurassic Period (142 million to 208 million years ago) was named in 1901 by German researcher Eberhard Fraas. Based on locations where fossils have been found, scientists have theorized that Thalattosuchians may have moved from semi-aquatic freshwater reptiles into fully ocean forms.

Fossils similar to the Oregon crocodile appear today in many areas around South China, Orr said.

Orr theorizes that the remains in Oregon migrated eastward in rock by continental drift, a theory of land movement in geological time now encompassed under plate tectonics. Terrane formations, such as those where these fossils were found, are believed to be portions of the earth’s crust riding apart of a plate that is pushed upward at contact with another plate.

The reptiles' short stubby legs would have allowed them to move about land, where they may have laid eggs. But also, the creatures may have had webbed feet, which, in combination with the fish-like tail, would have made them rapid swimmers, allowing them to hunt along the surface of aquatic environments, scientists have theorized.

Fossils from other crocodile families and other reptiles, especially ichthyosoaurs, from the Mesozoic Era (65 million to 248 million years ago) have been found previously in Oregon, but none have been as old as the newly found crocodile, Orr said.

"While fossil marine crocodiles frequently occur in Jurassic rocks of Europe and Africa, they are scarce in North America," Orr and his wife Elizabeth L. Orr, a courtesy research assistant in the department of geological sciences, noted in their book "Oregon Fossils." And while these reptiles lived during the age of dinosaurs, only a single fragmentary dinosaur bone, from the Cretaceous Period (65 million to 144 million years ago), has been discovered in the state.

The new discovery, Orr said, suggests that dinosaur fossils "must be out there somewhere, but we just haven't looked hard enough."
 

ThaG

Sicc OG
Jun 30, 2005
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#8
of course

and he burried them 5000 miles away from the other bones of the same species for us to think continental drift is real
 
Aug 6, 2006
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I bet heresy was gonna ask how in the hell do they illustrate these elaborate ass pictures of some ancient species' based on the inference of what's usually no more than a jaw bone? Do these drawings have more so to do with imagination or a real firm visual grasp on what the creatures actually looked like?
 

ThaG

Sicc OG
Jun 30, 2005
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#14
ParkBoyz said:
I bet heresy was gonna ask how in the hell do they illustrate these elaborate ass pictures of some ancient species' based on the inference of what's usually no more than a jaw bone? Do these drawings have more so to do with imagination or a real firm visual grasp on what the creatures actually looked like?
2-0-Sixx partially answered your question

many fossils like that have been previously found, some of them much more complete so they can reconstruct the whole animal with a great confidence

it is ture that there are many artificial taxons based on partial fossils, but very often that's all we have

but, if you're smart enough and you know how to deal with bones, you can get an amazing amount of information even from just a few bones

A great example are the superbig dinosaurs from the Titanosauridae family, most of them are known just from a single vertebrae and/or a broken rib, tibia, etc.

But based just on the size of the few bones they have, scientists can extrapolate the size of the whole animal based on the proportions found in similar taxons which are much more well-preserved

And, because I know you are going to ask - yes, as I already said, if you know how to "read" bones, you can unamibsuously indentify what animal a single vertebrae belonged to

BTW it is unrealistic to expect a 40-45 meter dinosaur to be entirely preserved in the fossil record. I have talked a lot about how rare fossilization is. I will just add that fossilization is much harder for big animals, because they can't be buried so easily, their bones get carried away by other animals, and last, but not least - their big size means that tectonical movements are much more likely to destroy or deform the remains
 
Apr 7, 2006
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#16
HERESY said:
I need to say this, but I actually don't want to say it because it will probably lead into a long drawn out debate, and thats something I don't want to partake in right now.

Forget it. I just typed it and wiped it out.
Y'feel