Czaszka z czterema k??ami

Dyskusje na temat ssaków kopalnych.
Awatar użytkownika
Dino
Administrator
Administrator
Posty: 4000
Rejestracja: 13 marca 2006, o 20:45
Imię i nazwisko: Łukasz Czepiński
Lokalizacja: Warszawa
Kontakt:

Czaszka z czterema k??ami

Post autor: Dino »

http://tinyurl.com/2h888y
Mesa is on the verge of getting a big head.

That may seem an odd thing to say about a city mired in a perpetual identity crisis, but it's true.

The head, or what's left of it, is currently encased in plaster and sitting on the hood of a junked car in the wilderness outside of Safford. If all goes well, it could be in the lab of the Mesa Southwest Museum in the next few days.

And if things go really well after that, in a couple of years museum visitors could be looking at the skeleton of a weird, four-tusked elephant-like critter that roamed Arizona an estimated 2.4 million years ago.

That would make the museum, if not the only, one of the few places in the world displaying a complete Rhynchotherium.

"It's among the most complete animals I've ever found - at least bigger animals," said Bob McCord, the museum's curator of paleontology.

Actually, McCord credits Larry Thrasher, a geologist for the federal Bureau of Land Management, who is an expert on the fossils in an area called 111 Ranch, in the San Simon River valley south of Safford.

McCord said Thrasher was "poking around" the area in late 2005 when he found a large leg bone and tusks sticking out of a hillside.

Thrasher called the museum, which partners with BLM on digs around the state, and before long Rhynchotherium bones began making their way to Mesa. Some, still encased in the plaster-and-burlap "jacket" used for safe transport, are already on display.

But the skull was another matter.

McCord said the old cranium is covered with "conglomerate" of rock and dirt that prevents full assessment of its condition but probably has helped preserve it.

The skull was further buffered in plaster and burlap, creating a final package McCord estimates at about 1,200 pounds.

Enter the car hood.

McCord finagled one from the city's fleet services departments, then helped lug it to the site.

That was a trick in itself.

"It's about a mile off road," McCord said. "And that's a mile off extremely rough four-wheel-drive road. So it's tough to get into, it's tough to get supplies back to. It's in general a nuisance."

After the skull was wrestled onto and fastened to the hood, "We used a BLM fire crew, an ATV and a lot of screaming, grunting and terror-filled moments," McCord said. "We got it out about 100-plus yards from the site" to a place where he hopes it can be picked up by heavy equipment for transport to Mesa.

McCord thinks it's probably the best Rhynchotherium skull in captivity. A Las Vegas museum had a better one, McCord said, but it fell on the floor and now it's not so good.

The find speaks to the museum's mission as one of the Southwest's premier natural history museums, McCord said. A proposal to change its name to the Arizona Museum of Natural History is beginning to percolate through the city bureaucracy.

It also speaks to Arizona's rich biological past. Rhynchotherium was part of a bizarre menagerie that included two or three kinds of camels, a couple types of horses, huge armadillo-like glyptoheriums, hyenas, cheetahs, giant otters and raccoons, saber-toothed cats and bone-crushing dogs.

Scientists believe that diversity was enhanced when lowering sea levels exposed the Panama isthmus and created a land bridge between North and South America, allowing animals to swap continents.

"This site's one of the earliest sites in the country where you see that," McCord said.

And it suggests that some things never change.

"It's kind of amusing to me," McCord said, "that Arizona, 2.4 million years ago, was a place of a lot of movement in populations from south to north. Almost seems relevant, doesn't it?"
.

ODPOWIEDZ