08 October 2010

Ancient critters

Utahceratops gettyi. Kosmoceratops richardsoni. Concavenator corcovatus. Sarahsaurus aurifontanalis. Prorotodactylus. Inkayacu paracasensis. All sorts of fossils have been in the news lately.

To begin with, ZUI this article (dated 23 Sep) from Laboratory Equipment:
Two remarkable new species of horned dinosaurs have been found in Grand Staircase-Escalante National Monument, southern Utah. The giant plant-eaters were inhabitants of the "lost continent" of Laramidia, formed when a shallow sea flooded the central region of North America, isolating the eastern and western portions of the continent for millions of years during the Late Cretaceous Period.

The newly discovered dinosaurs, close relatives of the famous Triceratops, were announced yesterday in PLoS ONE, the online open-access journal produced by the Public Library of Science.


The bigger of the two new dinosaurs, with a skull about 7 feet long, is Utahceratops gettyi (U-tah-SARA-tops get-EE-i). The first part of the name combines the state of origin with ceratops, Greek for "horned face." The second part of the name honors Mike Getty, paleontology collections manager at the Utah Museum of Natural History and the discoverer of this animal.

In addition to a large horn over the nose, Utahceratops has short and blunt eye horns that project strongly to the side rather than upward, much more like the horns of modern bison than those of Triceratops or other ceratopsians. Mark Loewen, one of the authors on the paper, likened Utahceratops to "a giant rhino with a ridiculously supersized head."

Second of the new species is Kosmoceratops richardsoni (KOZ-mo-SARA-tops RICH-ard-SON-i). Here, the first part of the name refers to kosmos, Latin for "ornate," and ceratops, once again meaning "horned face." The latter part of the name honors Scott Richardson, the volunteer who discovered two skulls of this animal. Kosmoceratops also has sideways oriented eye horns, although much longer and more pointed than in Utahceratops.

In all, Kosmoceratops possesses a total of 15 horns-one over the nose, one atop each eye, one at the tip of each cheek bone, and ten across the rear margin of the bony frill-making it the most ornate-headed dinosaur known. Sampson, the paper's lead author, claimed that, "Kosmoceratops is one of the most amazing animals known, with a huge skull decorated with an assortment of bony bells and whistles."


The dinosaurs were discovered in Grand Staircase-Escalante National Monument (GSENM), which encompasses 1.9 million acres of high desert terrain in south-central Utah. This vast and rugged region, part of the National Landscape Conservation System administered by the Bureau of Land Management, was the last major area in the lower 48 states to be formally mapped by cartographers.

Today GSENM is the largest national monument in the United States. Sampson added that, "Grand Staircase-Escalante National Monument is now one of the country's last great, largely unexplored dinosaur boneyards."

For most of the Late Cretaceous, exceptionally high sea levels flooded the low-lying portions of several continents around the world. In North America, a warm, shallow sea called the Western Interior Seaway extended from the Arctic Ocean to the Gulf of Mexico, subdividing the continent into eastern and western landmasses, known as Appalachia and Laramidia, respectively.

Whereas little is known of the plants and animals that lived on Appalachia, the rocks of Laramidia exposed in the Western Interior of North America have generated a plethora of dinosaur remains. Laramidia was less than one-third the size of present day North America, approximating the area of Australia.

Next, ZUI this article (dated 13 Sep) from the New York Times:
Researchers have discovered the most complete fossil of a meat-eating dinosaur from Europe in Las Hoyas, Spain. Curiously, it is humpbacked. The study appears in the journal Nature.

Named Concavenator corcovatus, the dinosaur belongs to the theropod family. In most ways, the dinosaur is not unusual, and it shares many characteristics with other medium-size theropods.

But the humplike structure on the 20-foot creature has previously never been seen in a dinosaur.


The fossil also suggests that the dinosaur had bony bumps on its limbs, possibly structures from which feathers protruded. The dinosaur lived during the Early Cretaceous period, about 130 million years ago. Earlier dinosaur fossils have shown evidence of feathers, and birds are now generally considered to be dinosaur descendants.

And this article (dated 6 Oct) from National Geographic:
The discovery of Sarahsaurus aurifontanalis, which roamed North America about 190 million years ago, also boosts the idea that at least some dinosaurs became masters of their domain less by dominance than by opportunistic behavior and a bit of good luck.

A remarkably complete Sarahsaurus skeleton, found in Arizona, shows that the early Jurassic herbivore was, at 14 feet (4.3 meters) long and 250 pounds (113 kilograms), smaller than its enormous sauropod cousins such as Apatosaurus, which arose later. (See a sauropod picture.)

Like the sauropods — the largest animals to walk Earth — Sarahsaurus featured a long neck and small head. But the newly identified creature also boasted strong teeth and an unusual clawed hand, that, while only human size, was clearly built for enormous power and leverage, according to paleontologists.

And this article (dated 6 Oct) from Fox News:
The oldest footprints of the dinosaur lineage have been found, dating back about a quarter-billion years.

The age of these prints reveals they were made in the immediate aftermath of the worst mass extinction in history -- the devastating Permian-Triassic event, which eliminated as much as 95 percent of the planet's species. As such, these findings suggest the roughly 160-million-year-long Age of Dinosaurs not only ended in disaster, but might have begun because of one as well.

"The Permian-Triassic was a time of global devastation, but also a time of great opportunity, because new groups had the space and freedom to evolve in the post-apocalyptic world," said researcher Stephen Brusatte, a paleontologist at the American Museum of Natural History in New York.

Scientists uncovered the roughly 250-million-year-old footprints in the Holy Cross Mountains of central Poland. They came from a housecat-sized creature [named Prorotodactylus] with feet only about three-quarters of an inch (2 cm) long. The animal walked on all four legs, and possessed much longer hindlimbs than forelimbs, given how its footprints apparently overstep the handprints.

The different lengths of the creature's toes and the way they were angled suggest it was an ancestor of the dinosaur lineage known as a dinosauromorph.

And finally, ZUI this article (dated 5 Oct) from ABC News:
The preserved feathers and scales of a giant fossilized penguin discovered on Peru's central coast provide a glimpse of Peru's Eocene period, and how the species evolved to its modern state, paleontologists say.

The ancient version of the marine bird was about 1.5 meters (5 feet) tall and weighed almost 60 kg (132 lb), dwarfing today's Emperor Penguin, the largest of the modern-day species."By looking at this fossil, we were prompted to ask new questions about living penguins and the world we live in today," said Julia Clarke, an expert in avian anatomy at the University of Texas at Austin.

The paleontologists date the remains to 36 million years ago. They dubbed the ancient penguin "Inkayacu paracasensis," which means "emperor of the water" in the indigenous language of Quechua.

(Links appear in original articles.)

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