Surfing The Wierd

Tuesday, November 24, 2009

Five Species of Crocs Once in Sahara, Some Stood Upright

Five Crocodile Species That Once Lived in Sahara/ BoarCroc

Prehistoric Crocodile In a newly published paper, scientists have described five crocodile species who once lived in present-day Niger and Morocco. The scientists gave their discoveries names that evoke each species' unique physical attributes. The meat-eating "BoarCroc," above, measured 20 feet, with an armored snout and three sets of dagger-shaped fangs.

Lead Scientist The expedition was guided by Professor Paul Sereno, from the University of Chicago, who stands with models of some of the team's discoveries in this photo.



RatCroc Discovered in Morocco, this three foot long croc could walk upright. Many of the specimens were found at one location, lying on the surface of a remote stretch of dunes, which in prehistoric times, had been covered by lush plains and broad rivers.

PancakeCroc PancakeCroc-2

PancakeCroc Named for its flat head, this 20-footer lived in Niger and Morocco.

DogCroc DogCroc Like several of the newly described species, the DogCroc was able to walk upright.

Croc Fangs Fangs Scientist Sereno theorizes that crocodiles as a species survived the dinosaur era because of their agility on land and in the water.


DuckCroc The crocs will be featured in a documentary "When Crocs Ate Dinosaurs" to be shown on the National Geographic Channel. A story about them also appears in the November issue of National Geographic Magazine.


Dinosaur-Era Crocodiles are Discovered in the Sahara

Prehistoric Super-Crocodiles May Have Dined on Dinosaurs

BoarCroc Odd new species of ancient crocodiles stood on two legs, lived alongside dinosaurs and sometimes even hunted them

The Age of Dinosaurs may have been dominated by dinosaurs, but they certainly weren't the only fearsome creatures around. A series of remarkable discoveries by a team led by Paul Sereno, a paleontologist at the University of Chicago and a National Geographic Explorer-in-Residence, has made it clear that another, less celebrated group of animals lived alongside the dinos, and sometimes even dined on those better-known cousins.

The animals in question were crocodiles, which thrived in abundance in the wetlands of the ancient Sahara 100 million years ago. Sereno found his first specimens of these prehistoric monsters about a decade ago, a species called Sarcosuchus, nicknamed SuperCroc: it was some 40 ft. long, and weight eight tons. (See a photoessay on the discovery of prehistoric crocodile fossils in the Sahara Desert) (post above)

Now, reporting in the journal ZooKeys, Sereno's team has announced the discovery of fossils from three brand-new species and new fossils from two known species. Along with SuperCroc, they add up to a virtual menagerie of ancient crocodiles that inhabited a range of ecological niches — species nicknamed BoarCroc, RatCroc, PancakeCroc, DuckCroc and DogCroc. See the top 10 scientific discoveries of 2008.

The strangest thing about these animals isn't their names, though: it's the fact that many of them weren't flat to the ground, like modern crocs, but stood upright and walked on their legs, like modern mammals. "We have an idea of what a crocodile should be and what a mammal should be," says Sereno, "but you have to break down these categories to see what was going on in Africa back then." BoarCroc, for example, was 20 ft. long and had three rows of fangs, like a boar from Hell, which made it what Sereno calls "a dinosaur slicer." With its agile legs, he says, "that thing probably came out of the water and charged up the bank to attack dinosaurs." Photos: Where Did the Hobbit Come From?.

DocCroc, by contrast — dog-sized and with a doglike nose — mostly ate plants and grubs. It could run too, but, Sereno suspects, "it probably ran down the bank to escape from dinosaurs." Bucktoothed RatCroc was also small and ate a similar diet. DuckCroc, about 3 ft. long, had a broad snout for rooting in shallow water and onshore, duck-like, for fish and frogs. And PancakeCroc was named for its wide, flat head, which it kept on the bottom, jaws open, waiting for an unsuspecting dinosaur to step in. "Modern crocs can take prey three times their size, if necessary," says Sereno — which means that the 20-ft.-long PancakeCroc could have taken down some reasonably large dinosaurs, like a multiton, long-necked sauropod, for instance. And SuperCroc, which was probably too heavy to run, and which probably lurked at the water's edge, could have taken even bigger ones.

Oddly enough, it was a modern crocodile — an Australian freshwater croc known as a "freshy," that helped Sereno figure out how some of his ancient crocs behaved. "It's able to get up and gallop, unlike the saltwater crocodiles that live nearby," he says. Since many of the ancient crocodiles have legs like the freshies but tails like the salties, he figures they were both good swimmers and good runners — a lethal combination that may explain something intriguing about the dinosaurs.

"[Dinosaurs] never went into the water in a serious way," he says, "never radiated into the oceans the way mammals did after the asteroid hit." Maybe that's because dinos were simply afraid of what lurked in the waters waiting for them.

(Read "Maybe an Asteroid Didn't Kill the Dinosaurs.")

See pictures of the effects of global warming.


Wednesday, November 11, 2009

Fossil finds slideshow. Click on arrows to view all 34 pictures in slideshow. (photo not available. See slideshow ) All the better to eat you with? Paleontologist Richard Forrest measures the jawbone of a fossilized pliosaur that was discovered off the coast of England. The massive sea monster trawled the ocean 150 million years ago. The skull alone stretched 8 feet -- the entire creature, 52 feet. The discovery was announced Tuesday.


Sunday, November 8, 2009

Weird Toothed Dino Oddly Angled Teeth Make Masiakasaurus Stick Out

It had a long neck and tail, walked on two feet, and weighed about as much as a German shepherd. But the most unique feature of the newly discovered Masiakasaurus knopfleri is its teeth, some of which protruded from its jaw almost horizontally.

Reconstruction of the head of Masiakasaurus knopfleri based on fossils recently discovered in Madagascar. Copyright Bill Parsons

Saturday, November 7, 2009

"SuperCroc" Fossil Found in Sahara

Scientists have unearthed the remains of an ancient crocodile that was as long ... SuperCroc Photo Gallery: Go>> Hey, Crocodile Dundee, try this on for size. ... -- Photobucket Photobucket

From the blistering sands of the Sahara, paleontologist Paul Sereno has pulled an incredible find: the nearly complete remains of Sarcosuchus imperator, one of the largest crocodilians to ever walk the Earth.

As long as a city bus, and weighing in at about ten tons, “SuperCroc” lives up to its nickname.

Sarcosuchus imperator, or “flesh crocodile emperor,” lived roughly 110 million years ago, when rivers coursed over what is now sub-Saharan Africa. Sarcosuchus prowled the rivers’ banks, crushing fish—and other creatures—in its massive jaws.

Paleontologists first gave Sarcosuchus imperator a name in the 1960s. Four decades later, in 2000, National Geographic Explorer-in-Residence Sereno and his team of fossil hunters found Sarcosuchus remains so enormous they dubbed the creature SuperCroc.

Sereno and his team, funded in part by the National Geographic Society, pored through the hot sands of a fossil graveyard called Gadoufaoua in Niger, unearthing scores of Sarcosuchus remains, including vertebrae, limb bones, armor plates, jaws, and a nearly complete 6-foot (1.8-meter) skull.

From their find, Sereno believes SuperCroc weighed as much as ten tons and measured as long as 40 feet (12 meters).

Now Sereno has teamed with National Geographic’s resident herpetologist, Brady Barr. They’re studying today’s tiny-by-comparison crocodilians—alligators, crocodiles, caimans, and gavials—to learn more about the giant SuperCroc, which is undoubtedly one of the largest crocs that ever lived.

" SuperCroc" Fossil Found in Sahara (October 2001)

"SuperCroc" Fossil Found in Sahara

D.L. Parsell National Geographic News
October 25, 2001

SuperCroc Photo Gallery: Go>> Scientists have unearthed the remains of an ancient crocodile that was as long as a city bus and as heavy as a small whale.

The giant creature, which lived 110 million years ago, during the Middle Cretaceous, grew as long as 40 feet (12 meters) and weighed as much as eight metric tons (17,500 pounds).

Its jaws alone were nearly six feet (1.8 meters) long and its more than 100 teeth so powerful that the colossal creature probably consumed small dinosaurs as well as fish, the researchers say.

Paleontologist Paul Sereno and his colleagues pieced together a portrait of the monster—which they've dubbed SuperCroc—based on fossils they've collected at Gadoufaoua in Niger, a remote site in the Sahara Desert where Tuareg nomads roam.

The fossils are from an extinct species that first came to light more than 30 years ago. French paleontologists reported several skulls and other parts of the creature and named it Sarcosuchus imperator, meaning "flesh crocodile emperor."

Much about the giant croc remained a mystery, however, until Sereno's team began excavating at Gadoufaoua in 1997. "People hadn't gone back with any expedition capacity since then, so not much else was collected," said team member Hans Larsson.

The 1997 dig had barely begun when the team discovered the fossilized jaws, each as long as some members of the team. The group had traveled to the site—one of the richest fossil beds in Africa—to search for dinosaurs. But it was immediately clear that the giant jawbones had not come from a dinosaur, Sereno said.

"We had never seen anything like it," he said. "The snout and teeth were designed for grabbing prey—fish, turtles, and dinosaurs that strayed too close."

Other massive crocodiles have been reported, but Sarcosuchus imperator is the most complete specimen found so far and among the largest crocodilians that ever lived.

During expeditions in 1997 and 2000, Sereno's team found skulls, vertebrae, limb bones, and foot-long (30-centimeter) bony armor plates called scutes. From this trove of bones, the scientists were able to assemble about half of the giant croc's skeleton, providing a good picture of Sarcosuchus.

"The new material gives us a good look at hyper-giant crocodiles," said Sereno, an Explorer-in-Residence at the National Geographic Society and a professor at the University of Chicago. "There's been rampant speculation about what they looked like and where they fit in the croc family tree."

David Schwimmer, a paleontologist at Columbus State University in Georgia, said he was familiar with Sereno's discovery and was "thrilled with it" because it helps fill in the picture of giant crocs, which appeared repeatedly in evolutionary history. Schwimmer is an expert on a giant croc genus named Deinosuchus, which was prevalent in North America.

Sereno and his colleagues announced their discovery October 25 at National Geographic headquarters in Washington, D.C. The research expedition to Niger last year was funded in part by the National Geographic Society.

The announcement was made in conjunction with the publication of a scientific report on Sarcosuchus by the journal Science, which posted the paper on its Science Express Web site.

The co-authors of the Science paper are Sereno; Larsson, who is a postdoctoral fellow at Yale University and the University of Toronto; Christian Sidor of the New York College of Osteopathic Medicine in Old Westbury, New York; and Boubé Gado of the Institut de Recherches en Sciences Humaines in Naimey, Niger Republic.

Not a "Modern" Croc

SuperCroc lived in Africa during the Middle Cretaceous period, when broad rivers stretched across lush plains.

Larsson said Sarcosuchus was not from the same branch of the reptile family tree that gave rise to modern crocodilians, which consist of about 23 species that include alligators, crocodiles, caimans, and gharials. "It's not a modern croc, but they share an early common ancestor," he said.

The oldest precursors of crocodiles may have spent more time on land, but Sarcosuchus was a river dweller that appeared after early crocodilians had already split into two separate land-based and marine groups.

Sereno said Sarcosuchus probably spent most of its time underwater, "living an ambush lifestyle." Like the gharial, a large long-nosed crocodilian in India, the ancient croc had eye sockets that tilted upward, which helped it conceal its huge body underwater while scanning the river's edge.

Another distinctive feature that Sarcosuchus had in common with the gharial was a round bony protrusion at the tip of its snout that housed a large bowl-shaped inflatable nasal cavity, called a bulla. The function of the bulla isn't clear, but the researchers think it may have heightened the croc's sense of smell or enabled it to emit striking calls. Larsson said gharials are known to use the muscles around the bulla to make different kinds of sounds, especially for mating.

Sereno said some people have an erroneous image of crocodiles "as dumb, clumsy, silent creatures." But crocodiles "are anything but clumsy, and they communicate extensively by calling, even roaring and splashing," he said. "It looks as if Sarcosuchus did some of that too."

The narrow jaws of an adult Sarcosuchus housed more than 100 teeth, which Larsson likened to "railroad spikes." While the giant croc shared the water with large fish, its hearty teeth—which included bone-crushing incisors—suggest that Sarcosuchus "didn't seem limited to eating fish," Larsson said. Other prey may have been small dinosaurs and other terrestrial animals, such as turtles.

Overlapping rows of scutes covered the crocodile's body from head to tail, forming a tough protective armor. The scutes, like trees, have annual growth rings. By counting these rings in the fossilized scutes, the researchers estimated the giant croc's full life span as 50 to 60 years.

Unusual Diversity

The fossils unearthed at Gadoufaoua included bones from four other croc species of varying sizes that lived at the same time as Sarcosuchus. One specimen was the three-inch (eight-centimeter) skull of a new species of dwarf croc.

The discovery of five ancient species existing side by side was especially interesting, Larsson said, because such diversity at a single site is seldom seen today. "Most modern crocs are relatively similar," he explained. "Perhaps for that reason, you rarely get more than one species at a particular location."

"The reason why we can get five [ancient] species at the same time," he added, "is because of differences in size and antomy. They were not eating the same thing or competing for the same resources."

Early forms of crocodiles first appeared about 230 million years ago, during the late Triassic, and diverged into "an amazing number of forms," said Larsson.

The few existing fossils show that these earliest crocs didn't much resemble the crocodiles we know today. "They were more dog- or cat-size, with elongated limbs like those of a gazelle or antelope," Larsson said. "The skull also was not crocodilian at all, but more 'dog-faced.'"

These earliest forms of crocodiles were succeeded in the late Triassic by a diverse group of terrestrials with squat bodies and more croc-like skulls (Crocodyliformes). In the early Jurassic, crocodilians split into two distinct groups—one group living in water (even sporting tail fins), the other on land. Crocs most like modern ones, with amphibian bodies and distinctive skulls, began emerging in the Early Cretaceous.

Behemoth Rivals?

Although it's still uncertain, Sarcosuchus may have had some rivals throughout history that matched or exceeded it in size and weight.

As with dinosaurs, many branches of crocodilians spawned giants. "There are actually quite a few giant crocodilians," said Schwimmer. "The idea of really big crocs is a repeat theme in evolution."

Deinosuchus, the subject of much of Schwimmer's research, lived in the Late Cretaceous, which means it's younger than Sarcosuchus. The two species "were not closely related," Schwimmer noted.

The range of Deinosuchus was much of North America. It dwelled from New Jersey to Montana, and was especially common in Texas and Alabama. The first report of the species came in 1858, based on ancient teeth that were discovered in North Carolina, said Schwimmer, who has received research grants from the National Geographic Society.

A number of fairly complete skulls of Deinosuchus have been found, but "we haven't yet put together a full body reconstruction," said Schwimmer. Once that happens, he added, the analysis might show that Deinosuchus was similar in body size or even bigger than Sarcosuchus.

That conjecture is based in part on differences in the snouts of the two species. "Sarcosuchus had a long, narrow snout, so a lot of its length is in the snout," Schwimmer explained. "But Deinosuchus was broad-snouted, built more like an alligator, so a skull of the same length [as Sarcosuchus] would, based on proportional size, be an even bigger animal."

Why have giant crocs recurred throughout evolutionary history?

One reason, Schwimmer said, is because crocodilians have been primarily aquatic. Massive bodies, like those of whales, are especially suited to an aquatic environment because they can float, thereby diminishing the physical burden of size that would be more taxing on land.

Another advantage is that crocodiles have osteoderms, or skin armor, across their backs. These armor plates are embedded in the creatures' back tissue, helping to support the back "like an external flying buttress," Schwimmer said. Crocodiles also have very strong skulls, he added, "so they can bite hard and feed on big prey."

Research Supported by the National Geographic Society:

Paul Sereno is one of a distinguished group of scientists from around the globe, in fields ranging from astronomy to zoology, who have been awarded grants from the National Geographic Society. Here are some recent news stories about the work of other NGS grantees:

Legged Sea Cow Fossil Found in Jamaica Africa's Rock Art in Peril After Thousands of Years Meerkats Become Fat Cats in Large Cooperatives Ancient Walking Whales Shed Light on Ancestry of Ocean Giants DNA Tests Show African Elephants Are Two Species Study Calls Into Question Global Quotas on Bluefin Tuna Skeleton of New Dinosaur Species Found in Madagascar Russian Tombs Hold Clues to Obscure Life of Asian Huns Egyptian Archaeologist Named National Geographic Explorer-in-Residence Total Eclipse May Help Solve Mystery of Sun's "Halo" Expedition Reveals Black Coral's Bleak State Ancient Reptile Was First To Chew Plants


Godzilla - Real Life Sea Monster

Photobucket Fossils from a real-life sea monstera massive crocodile-like specieshave been unearthed in Patagonia, Argentina. The animal likely measured 13 feet (4 meters) long from nose to tail. The researchers who made the discovery say the marine reptile, nicknamed Godzilla, lived about 135 million years ago. They describe their find in the November 11, 2005, issue of the journal Science. Details about the ancient predator will also appear in the December 2005 issue of National Geographic magazine. The article will feature exclusive images, like this illustration, of what the reptile might have looked like. The fossilized skull of a newfound species of ancient marine reptile, pictured above, measures about two and a half feet (one meter) long. The creature's large jaws and jagged teeth prompted researchers to nickname the animal Godzilla after the sci-fi legend that first emerged from the ocean to terrorize Japan in the 1954 cult classic Gojira. "Other marine crocodiles that were around at the same time had very delicate featureslong, skinny snouts and needle-like teeth for catching small fish and mollusks," Diego Pol said in a press statement. The Ohio State University researcher helped identify the Paleontologist Zulma Gasparini, a professor at Argentina's Universidad Nacional de La Plata, examines the skull of the newly discovered species of ancient marine reptile. Gasparini and colleague Luis Spalletti recently unearthed the skull and other fossils in Patagonia. The scientists, along with Ohio State University researcher Diego Pol, describe their find in the November 11, 2005, issue of the journal Science and the December 2005 issue of National Geographic magazine. Computer images of the skull of a newfound species of crocodile-like marine reptile show how the massive predator might have looked. Diego Pol, a researcher at Ohio State University, used sophisticated software to map the features of the skull and other fossils discovered in Argentina. Using these images, Pol was able to place the unusual creature on the crocodile family tree.


TRex of Ocean Found in Arctic February 27, 2008Dubbed the "the Monster," this newly identified fossil predator is one of the largest marine reptiles ever found, scientists announced today. (Read full story.) The 50-foot-long (15-meter-long) "sea monster" was excavated last summer on Norway's Arctic island of Spitsbergen (see map). The Monster likely represents the biggest species of pliosaur known to science, said Jxrn Hurum, of the Natural History Museum in Oslo, Norway, who led the dig teamand who called the reptile "the T. rex of the ocean." Pliosaurs were the top marine predators during the Jurassic period (200 to 145 million years ago), but their fossils are rarely found. The Monster is portrayed here leaping after a pterosaur, but the creature's main prey was likely other large sea reptiles. (See 3-D animations of other sea monsters in our interactive time line.) ................................................................. A newly excavated pliosaur from the Arctic island of Spitsbergen is illustrated in the company of a blue whale, a killer whale, and a human. The prehistoric "sea monster" is one of the largest marine reptiles known to science. Its head alone measures some ten feet (three meters) long, the Norwegian-led team that found the fossil skeleton announced on February 27, 2008. While blue whales are considered the planet's biggest ever animals, pliosaurs probably had the biggest bite, according to sea-reptile fossil expert Richard Forrest. "Inside their enormous skulls they had huge areas of muscle available for biting force," said Forrest, who is affiliated with the New Walk Museum in Leicester, England. "One of these animals would have been big and strong enough to pick up a small car and bite it in half." ........................................................................ A 150-million-year-old pliosaur with teeth the size of cucumbers, was excavated by fossil hunters last year among the desolate mountains of Spitsbergen, part of Norway's Svalbard archipelago in the Arctic Ocean. The recently discovered fossil site is described as a graveyard of dinosaur-era marine reptiles, including dolphin-shaped ichthyosaurs and previously unknown forms of long-necked plesiosaurs. (See related pictures: "'Sea Monster' Graveyard Found in the Arctic".) Some 40 skeletons have been located at the site as of February 27, 2008, when the new "sea monster" was announced. A second pliosaur fossil was also located in the barren landscape in the summer of 2007. The team plans to excavate the newfound skeleton during a return visit later in 2008. ............................................................................................ The remains of a massive pliosaur excavated on the Arctic island of Spitsbergen include sections of dinner-plate-size vertebrae and an almost complete forelimb "paddle." "Although we didn't get the entire skeleton, we found many of the most important parts," said team member Patrick Druckenmiller. "Amazingly, the paddle alone is nearly ten feet [three meters] long." The ocean predator likely used its giant flippers to launch sudden, ferocious attacks on other marine reptiles, according to fossil expert Richard Forrest. "We don't think they were particularly good at cruising but were very good at accelerating, so they'd lurk in the depths and shoot up to catch things," he said on February 26, 2008, the day before these images were released.

—Illustration by Tor Sponga/BT (top); Drawing by Espen M. Knutsen/ Natural History Museum/University of Oslo/Norway
.................................................. Fossil hunters removed a hundred tons of rock by hand last summer to extract the skeleton of a huge pliosaur in Norway's Svalbard archipelago. Revealed to the public on February 27, 2008, the "sea monster" is one of the biggest marine reptiles ever found. It was discovered at the site of 40 other large Jurassic-era sea creatures some 800 miles (1,300 kilometers) from the North Pole. The reptiles swam in temperate seas and sank to the ocean floor after they died, where their bodies were preserved in soft mud, according to expedition leader Hurum. The pliosaur's fossil bones have been softened by freezing Arctic conditions, Hurum noted. "They are almost like gravelthey have been frozen and thawed many, many times." So far, 6.5 gallons (25 liters) of glue have been used to stabilize the skeleton, he said
—Photograph by Natural History Museum/University o >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> A 33-foot-long (10-meter-long) marine reptile dubbed the Monster leaps from the water to snare a smaller reptile known as a plesiosaur in this artist's interpretation. The Monster is a member of a group of dino-era sea creatures called pliosaurs. Its fossil was among 28 specimens of predatory sea reptiles recently found on the Arctic island of Spitsbergen in Norway's Svalbard archipelago. The 150-million-year-old graveyard was unearthed by a team from the University of Oslo's Natural History Museum, along with a paleontologist from Montana State University in Bozeman. The remains of the Monster may represent the largest complete pliosaur ever found. So far the team has uncovered a skull measuring 6.9 feet (2.1 meters) in length, dinner plate-size neck vertebrae, and portions of the lower jaw with huge teeth that the scientists say are as thick as cucumbers. Cliffs rise along the Inner Isfjorden, the second longest fjord in the Svalbard archipelago. The Norwegian islands lie about 600 miles (966 kilometers) from the North Pole. Experts say the recent discovery of a huge "sea monster" graveyard ranks the Arctic islandalready noted for its large polar bear populationas one of the best marine reptile fossil sites in the world. An outline of small rocks traces the final resting place of the fossil known as the Monster on the island of Spitsbergen. The labels show where different parts of the massive pliosaur have been revealed in the shale. Pliosaurs were the top marine predators of the Jurassic (200 million to 145 million years ago), a time when the oceans were teeming with large, meat-eating reptiles, says Jxrn Hurum of the Natural History Museum in Oslo. It was the T. rex of the ocean, Hurum added. It would have eaten everything. And the reptile's powerful jaws, scientists say, would have been capable of lifting a car and biting it in half.
Photograph courtesy Natural History Museum, University of Oslo, Norway
The skull of an ichthyosaur, a marine reptile that resembles a dolphin, is prepared for study after it was found in the Arctic island chain of Svalbard. Ichthyosaurs, likely once a common prey for larger sea beasts such as pliosaurs, used an upright tail fin to propel themselves through the water. Most ichthyosaurs averaged 13 to 20 feet (4 to 6 meters) in length, but some reached 75 feet (23 meters). The Monster hunts a pair of ichthyosaurs in this artist's interpretation. The bed of fossils where the large pliosaur has been discovered also yielded six ichthyosaurs, including specimens that may be species new to science


Ancient Sea Life In Utah .......................................... .............................................................. T.Rex of Inland Sea



More comprehensive article about Pterosauria at: ............................................................................................................................................... Pterosaur Introduction to the Pterosauria The flying reptiles Rhamphorhynchus A fossil of Rhamphorhynchus, an early pterosaur. Ranging from the size of a sparrow to the size of an airplane, the pterosaurs (Greek for "wing lizards") ruled the skies in the Jurassic and Cretaceous, and included the largest vertebrate ever known to fly: the late Cretaceous Quetzalcoatlus. The appearance of flight in pterosaurs was separate from the evolution of flight in birds and bats; pterosaurs are not closely related to either birds or bats, and thus provide a classic example of convergent evolution. It was once thought that pterosaurs were not well adapted for active flight and relied largely on gliding and on the wind to stay in the air. However, based on analyses of pterosaur skeletal features (including work done by Berkeley's own Kevin Padian), it is now thought that all but the largest pterosaurs could sustain powered flight. Pterosaurs had hollow bones, large brains with well-developed optic lobes, and several crests on their bones to which flight muscles attached. All of this is consistent with powered flapping flight. Various pterosaurs The largest pterosaur (Quetzalcoatlus, wonderfully named for the Aztec winged serpent god) had a wing span from eleven to twelve meters long (about forty feet). The wing's main support was an amazingly elongated fourth digit in the hand. Fibers in the wing membrane added structural support and stiffness. At least some pterosaurs may have had some sort of hair-like body covering, which could very well mean that they were endothermic. Pterosaurs had a diverse range of head types, as you can tell from the pictures below. Their ability to fly probably allowed them to evolve into many niches, taking advantage of many different food sources, which would explain the range of skull morphology seen. Pterosaurs consist of two main types (they do form a single (monophyletic) group, though): the "rhamphorhynchoids," more properly termed the basal Pterosauria, which had long tails, and their descendants the "pterodactyloids," which had shorter tails. Why is the term "rhamphorhynchoid" an invalid one? Since the later Pterosauria (the"pterodactyloids") are the descendants of the basal Pterosauria, "rhamphorhynchoid" is a paraphyletic term, which phylogenetic researchers shy away from using. The basal Pterosauria (including Rhamphorhynchus, pictured at the top of this page) first appeared in the Late Triassic and all went extinct at the end of the Jurassic. The more derived pterosaurs (including Pteranodon, below) that were the descendants of this group appear first in Late Jurassic rocks, and the last of them died out at the end of the Cretaceous. Below is a mounted skeleton of Pteranodon ingens on display at the UCMP. Click on the picture to view an enlargement. What was Pteranodon like? Pteranodon skeleton Pteranodon. Photo by Dave Smith, © 2005 UCMP. The genus Pteranodon includes several species of large pterosaurs from the Cretaceous period in North America. As you can tell from this photo, it had a large crested head, a huge wingspan (some 20-25 feet; the UCMP specimen is about 22 feet), and a comparatively small body. This is deceiving; it looks like the head and wing bones were too bulky, and the hindlimbs appear small and weak. Not so; the bones of Pteranodon are actually completely hollow (about 1 millimeter thick!), and were quite light. The whole animal probably weighed about 25 pounds, only slightly heavier than the largest flying birds. The hindlimbs are actually perfectly sized for the body; Pteranodon would have been capable of bipedal terrestrial movement (but was no rapid runner, unlike its ancestors, some of whom seem to have been fast bipedal runners). The wing bones look thick because a large bone diameter is more vital for resisting the bending stresses involved in flight (as opposed to large bone thickness, which is important for resisting compressive forces, such as those imposed by the weight of a large body), so actually the wings of Pteranodon were more than adequate for flight. Pteranodon was almost certainly a soaring animal; it used rising warm air to maintain altitude; a common strategy among large winged animals (among birds, albatrosses and vultures are adept at soaring). Its scooplike beak was used for snapping up fish as it soared over the oceans that it nested by. A good modern analog for Pteranodon would be the pelican. The UCMP's mounted specimen of Pteranodon ingens is actually a composite specimen, pieced together from a few different specimens to form a complete one.i

Find out more about Pterosauria by searching our Vertebrate Type Catalog or visit the Pterosaur Database.


UCMP Special Exhibit: Vertebrate Flight For more information on pterosaur flight, see the pterosaurian flight portion of our series of pages on the wonder of flight in vertebrates.