Not Your Typical Pterosaur
by Janet Raloff
For a decade, scientists largely ignored a fossil of a juvenile, late-Jurassic flying reptile that’s just 14 centimeters long. It appeared to be just another of some 120 specimens of the genus Rhamphorhynchus excavated at Germany’s famed Solnhofen limestone beds.
Closer inspection now shows it’s something new, David Hone of the University of Bristol in England and his colleagues report July 5 in PLoS ONE. They’re creating a genus dubbed Bellubrunnus, or Brunn beauty, to honor the German quarry where it was unearthed.
The tiny flyer has fewer teeth and a more flexible tail than other Rhamphorhynchus-like pterosaurs. And the outermost bone of each wing curves outward, distinguishing it from any known flying vertebrate alive or extinct. This would have made flying somewhat harder, Hone explains, but afforded somewhat improved maneuverability to this animal, which had a perhaps meter-wide wingspan at maturity.
(Source: ScienceNews)
(via rhamphotheca)
Kaprosuchus (“Boar Crocodile”)
… is an extinct genus of mahajangasuchid crocodyliform. It is known from a single nearly complete skull collected from the Upper Cretaceous Echkar Formation of Niger. Kaprosuchus is estimated to have been around 6 m (20 ft) in length. It possesses three sets of tusk-like caniniform teeth that project above and below the skull, one of which in the lower jaw fits into notches in upper jaw. This type of dentition is not seen in any other known crocodyliform. Kaprosuchus is thought to have been a primarily if not exclusively terrestrial predator…
(read more: Wikipedia)
____________________________
(top image: Nobu Tamura)
(bttm image: Sereno PC, Larsson HCE (2009) Cretaceous Crocodyliforms from the Sahara. ZooKeys 28: 1–143. doi:10.3897/zookeys.28.325)
BAMF!
(via gogoatz)
harryallard:dailyfossil: Diprotodon - The Giant Wombat
When: Pleistocene (1.6 million to 46,000 years ago)
Where: Australia
What: Diprotodon is the biggest marsupial to have ever lived. The largest specimens found were roughly the size of an extant hippopotomus; 10 feet (3 meters) long, 6.5 feet (2 meters) tall at the shoulder, and with a weight estimate of over 6,000 lbs (over 2,500 kgs). They inhabited forests and grasslands in Australia, and were herbivores that had an extremely varied diet. There was not much that their large grinding cheek teeth could not process. There are multiple ‘bone-bed’ deposits containing almost nothing but Diprotodon skeletons, offering strong support that they also traveled in herds. Many of these deposits are reconstructed as deaths due to droughts; it took a lot of plant material to sustain a Diprotodon. They occupied simular niches as large ungulate herds today on other continents.
The closest living relatives of Diprotodon are koalas and wombats. This was the largest member of the apt named Australian mega-fauna. This giant animal and many other Australian mega-fauna went extinct shortly after the arrival of humans on the continent, in a mirror of the extinction of the North American mega-fauna 10,000 years ago. In both extinction events this colonization was accompanied by climate changes, leading to much debate as to how influential human habitation was on the loss of these forms. It is thought that Diprotodon and its close relatives may be the basis for the bunyip of aboriginal folklore.
Tulip-shaped Creature Found in Canadian Rockies
by Karen A. Frenkel
If you could tiptoe through the Middle Cambrian Burgess Shale in the Canadian Rockies 500 million years ago, you’d come across a tulip-shaped sea creature that defies classification. The 20-cm-long animal, given name Siphusauctum gregarium (Latin for “cup-shaped, gregarious herd member”),was first discovered in 1983. A detailed description was not attempted until now, however, until a Canadian graduate student took interest in it. Siphusauctum’s unusual shape and structure has no direct counterparts with any other organisms (fossil, left; artist’s impression, right).
It sported a long stem and bulbous cup-like structure, or calyx, near its top, which enclosed a unique filter feeding system and gut, according to an analysis of more than 1000 fossils reported this month in PLoS ONE. A small disc at the base of the stem anchored the animal to the sea floor, as the animal ate algae or pieces of detritus in the water. Siphusauctum lived in large clusters, so researchers nicknamed the region of the shale in which it was found Tulip Beds. It is not the only peculiar organism in phylogenetic limbo found in the Burgess Shale, however. Twenty other so-called “problematica” have eluded classification.
(via: Science NOW) (image: (L) Royal Ontario Museum; (R) M. Collins)
discoverynews: Was First Winged Dinosaur Jet Black?
by Jennifer Vieges
The winged dinosaur Archaeopteryx, which may represent the missing link in birds’ evolution to powered flight, had at least some jet-black feathers, according to new research published today in Nature Communications.
Aside from creating more of a cool visual for this raven-sized animal, the discovery suggests that Archaeopteryx could fly, since the color and parts of cells that would have supplied the black pigment are evidence that the wing feathers were rigid and durable. These are traits that probably would have permitted flight…
Dunkleosteus
When: Late Devonian (380-360 million years ago)
Where: Worldwide.
What: Dunkleosteus is one of the biggest placoderms to ever swim in the paleozoic oceans. Placoderms were some of the first jawed vertebrates, and rapidly put these jaws to use, becoming the top predators of the devonian seas. Dunkleosteus was the apex predator of its days, with nothing to fear but other Dunkleosteus (some specimens show evidence of cannibalism). It reached lengths of up to 33 feet (~10 meters) and is estimated to have weighed 8,000 lbs (~3,600 kg). Studies have shown that these giant fish could open their mouths extremely fast, creating massive suction that would draw prey into their mouths. Larger prey would then be captured and crushed by the giant ‘teeth’ of Dunkleosteus. These animals did not have true teeth, but instead what served as their teeth were sharped and exposed projections of bone.
Placoderms were an early off shoot of jawed vertebrates, and have no living descendants. Modern fish are more closely related to land animals than they are to Dunkleosteus. This giant placoderm, along with the rest of it’s clade, went extinct at the end of the Devonian. Their disappearance is primarily attribute to large anoxic (a lack of oxygen) events on the ocean floor, which dramatically disrupted the food chain - leading to one of the largest extinction events in Earth’s history.
(via gogoatz)
Helicoprion - the Sprial Saw shark
When: Late Permian (~290-270 million years ago)
Where: Fairly globally distributed
What: Helicoprion is a fossil shark. Though it has been known to science for over 100 years, it is still poorly understood. Teeth are the part of it that has ever been found. This not that strange for a fossil shark, as sharks do not ossify their skeletons - they are cartilaginous all of their lives. Thus it is extremely rare to find a fossilized shark skull or skeleton. What makes Helicoprion such a scientific puzzle is the arrangement of these teeth. They are in a spiral, with the smallest teeth in the center. Modern sharks go though dozens upon dozens of teeth in their lifetimes, and fossil sharks were no different. What was very different however, is these extinct sharks retained their older teeth, instead of shedding them as we see in all modern forms. There are well preserved fossil sharks from the Devonian which incorporated their older teeth into bumps and ridges on their heads, but they did not develop an elaborate spiral as seen in Helicoprion.
The biggest problem with reconstructing Helicoprion is determining the location of the spiral. Some of the first studies of this shark located the spiral on the upper jaw (the first small image above), but closely related fossil finds have shown unarguably this structure was located on the lower jaw. However, even with the position on the lower jaw certain, there are other debates and various reconstructions, two more of which are shown above. A recent study conducted by researchers at the Smithsonian concluded that these placements outside of the body were not realistic, as this would create too much drag when the shark swam, not only slowing it down but alerting it’s prey as it approached. They have interpreted the spiral to be located in the throat region of Helicoprion - their reconstruction is the large one shown above.
(via gogoatz)
Eurypterus
- Sea Scorpion
When: Late Silurian ~ 430-420 million years ago
Where: In ancient relatively shallow seas, swimming over what is today North America and Europe. They are very common in the eastern US, and are the state fossil of New York.
What: Eurypterus is the most well known member of the Eurypterida. Okay that probably didn’t help much! These animals are arthropods (insects, spiders, crustaceans, etc) and in the group that incudes the horseshoe crabs, spiders, and scorpions. They are not actually scorpions, though they are closely related to them. Like a lot of living arthropods, they grow by successive molting and can become very large, in fact the largest arthropods known were eurypterids! Most fossil are small, just a few centimeters, but the largest one is over 4 feet (120cm) long from head to tail tip! They moved both by swimming though the water with their large paddles arms and walking on the substrate with their smaller legs. They were carnivorous and most likely at the top of the food chain in their day - jawed fishes were just starting to appear. Its possible the evolution and migration of these fishes is what lead to the extinction of the sea scorpions.
(via gogoatz)
Megalonyx- Jefferson’s ground sloth
When: Late Miocene to end Pleistocene (~10 million years to 10,000 years ago)
Where: Throughout North America
What: Megalonyx is a giant ground sloth, that grew to roughly 8-10 feet (~2.5 to 3.0 meters) long. They are the genus of giant ground sloth mostly closely related to the living two-toed sloth Choloepus. Sloths originated, and most of them diversified in South America, moving northward during the great American interchange, but Megalonyx is a major exception. Its ancestors reached North America millions of years prior to the massive migrations of other South America taxa; via island hopping. This relatively early arrival allowed it to spread throughout the northern continent. Megalonyx is the only species of sloth to have reached as far north as Alaska and the Yukon. It was common in many of the lower 48 states. Like many ground sloths, Megalonyx went extinct at the end of the last glacial period.
A more recent historical note about Megalonyx; this genus was the first fossil from the Americas to be described, and the person who did so was none other than Thomas Jefferson. He proposed the name Megalonyx for the genus, based on first material recovered - the gigantic claws. Later this genus name was formalized and a species named in his honor: Megalonyx jeffersoni (this species is the state fossil of West Virginia). Jefferson was very hopeful that living Megalonyx would be found in the uncharted west, he told Lewis and Clark to be sure to be on the look out for this beast and report back when it was discovered.
(via gogoatz)
