QUETZACOATLUS :THE KING OF HEAVEN

Quetzalcoatlus was a pterodactyloid pterosaur known from the Late Cretaceous of North America (Maastrichtian stage, about 68–65.5 million years ago), and one of the largest known flying animals of all time. 

It was a member of the Azhdarchidae, a family of advanced toothless pterosaurs with unusually long, stiffened necks. Its name comes from the Mesoamerican feathered serpent godQuetzalcoatl.During the 19th century, in England many fragmentary pterosaur fossils were found in the Cambridge Greensand, a layer from the early Cretaceous, that had originated as a sandy seabed. Decomposing pterosaur cadavers, floating on the sea surface, had gradually lost individual bones that sank to the bottom of the sea. Water currents then moved the bones around, eroding and polishing them, until they were at last covered by more sand and fossilised. Even the largest of these remains were damaged and difficult to interpret. They had been assigned to the genus Pterodactylus, as was common for any pterosaur species described in the early and middle 19th century.Young researcher Harry Govier Seeley was commissioned to bring order to the pterosaur collection of the Sedgwick Museum in Cambridge. He soon concluded that it was best to create a new genus for the Cambridge Greensand material that he named Ornithocheirus, "bird hand", as he in this period still considered pterosaurs to be the direct ancestors of birds, and assumed the hand of the genus to represent a transitional stage in the evolution towards the bird hand. To distinguish the best pieces in the collection, and partly because they had already been described as species by other scientists, he in 1869 and 1870 each gave them a separate species name: O. simus, O. woodwardi, O. oxyrhinus, O. carteri, O. platyrhinus, O. sedgwickii, O. crassidens, O. capito, O. eurygnathus, O. reedi, O. cuvieri, O. scaphorhynchus, O. brachyrhinus, O. colorhinus, O. dentatus, O. denticulatus, O. enchorhynchus, O. 

xyphorhynchus, O. fittoni, O. nasutus, O. polyodon, O. compressirostris, O. tenuirostris, O. machaerorhynchus, O. platystomus, O. microdon, O. oweni and O. huxleyi, thus 28 in total. As yet Seeley did not designate atype species.When Seeley published his conclusions in his 1870 book The Ornithosauria, this provoked a reaction by the leading British paleontologist of his day, Richard Owen. Owen was not an evolutionist and he therefore considered the name Ornithocheirus to be inappropriate; he also thought it was possible to distinguish two main types within the material, based on differences in snout form and tooth position — the best fossils consisted of jaw fragments. He in 1874 created two new genera: Coloborhynchus and Criorhynchus. Coloborhynchus, "maimed beak", comprised a new species, Coloborhynchus clavirostris, the type species, and two species reassigned fromOrnithocheirus: C. sedgwickii and C. cuvieri. Criorhynchus, "ram beak", consisted entirely of former Ornithocheirus species: the type species Criorhynchus simus and furthermore C. eurygnathus, C. capito, C. platystomus, C. crassidens and C. reedi.In 1914 Reginald Walter Hooley made a new attempt to structure the large number of species. Keeping the name Ornithocheirus, he added to it Owen's Criorhynchus, in which however Coloborhynchus was sunk, and to allow for a greater differentiation created two new genera, again based on jaw form: Lonchodectes and Amblydectes. Lonchodectes, "lance biter", comprised L. compressirostris, L. giganteus and L. daviesii. Amblydectes, "blunt biter", consisted of A. platystomus, A. crassidens and A. eurygnathus. However, Hooley's classification was rarely applied later in the century, when it became common to subsume all the poorly preserved and confusing material under the name Ornithocheirus. In 1978 Peter Wellnhofer, assuming no type species had been designated, made Ornithocheirus compressirostris the type.Seeley did not accept Owen's position. In 1881 he designated O. simus the type species of Ornithocheirus and named a new species O. bunzeli. In 1888 Edward Newton renamed several existing species names into: Ornithocheirus clavirostris, O. daviesii, O. sagittirostris, O. validus and O. giganteus; as new species he created: O. clifti, O. diomedeus, O. nobilis and O. curtus. Others had already named an O. umbrosus, O. harpyia, O. macrorhinus and O. hilsensis and would create an O. hlavaci,O. wiedenrothi and O. mesembrinus.From the seventies onwards many new pterosaur fossils were found in Brazil, from formations about the same age as the Cambridge Greensand, 110 million years old. Contrary to the English material, these new finds included some of the best preserved large pterosaur skeletons and several new genera names were given to them, such as Anhanguera. This situation caused a renewed interest in the Ornithocheirusmaterial and the validity of the several names based on it, for it might be possible that it could by more detailed studies be established that the Brazilian pterosaurs were actually junior synonyms of the European types. Several European researchers concluded that this was indeed the case. Unwin revived Coloborhynchus and Michael Fastnacht Criorhynchus, each author ascribing Brazilian species to these genera. However, in 2000 Unwin stated that Criorhynchus could not be valid. Referring to Seeley's designation of 1881 he considered Ornithocheirus simus, holotype CAMSM B.54428, to be the type species. This also made it possible to revive Lonchodectes, using as type the former O. compressirostris, which then became L. compressirostris. This position has not universally been accepted. Brazilian workers also typically reject the identification of their genera with European types. Unwin, and this caused no controversy, reaffirmed that most Ornithocheirus species are nomina dubia, names that are invalid because the fossils they refer to lack sufficient diagnostic features.As a result, though over forty species have been named in the genus Ornithocheirus over the years, not a single one of them, not even O. simus, is currently recognized as valid by all pterosaur researchers. Often, there is a total lack of consensus; e.g.Tropeognathus mesembrinus named by Peter Wellnhofer in 1987 has afterwards been considered Ornithocheirus mesembrinus by David Unwin in 2003 (making Tropeognathus a junior synonym) , but as Anhanguera mesembrinus by Alexander Kellner in 1989, Coloborhynchus mesembrinus by André Veldmeijer in 1998 and Criorhynchus mesembrinus by Michael Fastnacht in 2001. Even earlier, in 2001, Unwin had referred the "Tropeognathus" material to O. simus in which he was followed by Veldmeijer; however the latter, denying that O. simus is the type species instead of O. compressirostris, now uses the name Criorhynchus simus. Kellner in 2000 again recognized Tropeognathus as a valid genus.

TERATORNIS: THE DEATH BIRD

Teratornis merriami (Merriam's Teratorn) was a huge North American teratorn, with a wingspan of around 3.5 to 3.8 meters (11 to 12 feet) and a wing area of 17.5 square meters, standing an estimated 75 cm tall and weighing about 15 kg. It was somewhat larger than the extant Andean Condor and nearly two times as heavy as the California Condor. A closely related genus, Aiolornis, was about 40% larger and lived at an earlier time; it was formerly known 

as Teratornis incredibilis, but is distinct enough to be placed in its own genus.T. merriami is the best-known of the teratorns. A large number of fossil and subfossil bones, representing more than 100 individuals, have been found in locations in California, southern Nevada, Arizona, and Florida, though most are from the Californian La Brea Tar Pits. All remains but one Early Pleistocenepartial skeleton from the Leisey Shell Pit near Charlotte Harbor, Florida (which may represent a different species or a subspecies) date from the Late Pleistocene, with the youngest remains dating from the Pleistocene-Holocene boundary.The finger bones are fused as in all modern birds; however, part of the index finger forms a shelf which aided in bearing the load of long and stout primaries, which enabled the bird to utilize strong upcurrents. The legs were similar to an Andean Condor's, but stouter, and the feet were able to hold prey items for tearing off pieces, but not able to exert a very forceful grip such as in birds of prey. Its wing loading was not much larger than a Californian Condor's, and Merriam's Teratorn should have been able to take off by simply jumping and beating its wings under most circumstances. (Campbell & Tonni, 1983). Indeed, it seems to have been better adapted for that than for utilizing a short run into the wind from an elevated location as condors do, as its legs are proportionally smaller and its stride less than in condors (Fisher, 1945).T. merriami generally lived in a manner similar to condors, although its larger bill suggests that it was a more active predator. Prey up to the size of a small rabbit would probably have been swallowed more or less whole, while carrion would have been fed on in a manner similar to that of condors or vultures. The large number of finds in the La Brea Tar Pits were usually considered to be from teratorns which were attracted by Pleistocene megafauna that became stuck in the viscous asphalt trying to drink from pools of water that gathered on the surface and died, with the teratorns subsequently falling victim to the sticky deposits too. Merriam's Teratorn probably played an important role in opening up the body cavities of carcasses for smaller birds like eagles and ravens which are also known to have frequented the locality, as mammalian predators, being unable to fly, could hardly reach most carcasses without getting mired in the asphalt themselves.

TITANOBOA: THE SNAKE KING

The world's biggest snake was a massive anaconda-like beast that slithered through steamy tropical rain forests about 60 million years ago, says a new study that describes the ancient giant.

Fossils found in northeastern Colombia's Cerrejon coal mine indicate the reptile, dubbed Titanoboa cerrejonesis, was at least 42 feet (13 meters) long and weighed 2,500 pounds (1,135 kilograms).

"That's longer than a city bus and … heavier than a car," said lead study author Jason Head, a

 fossil-snake expert at the University of Toronto Mississauga in Canada and a research associate with the Smithsonian Institution.Previously the biggest snake known was Gigantophis garstini, which was 36 to 38 feet (11 to 11.6 meters) long. That snake lived in North Africa about 40 million years ago.

Hans-Dieter Sues, associate director for research and collections at the Smithsonian's National Museum of Natural History, was not involved with  the study but has seen the snake fossils.

Sues noted that humans would stand no chance against one of these giants, which killed their prey by slow suffocation."Given the sheer size—the sheer cross-section of that snake—it would be probably like one of those devices they use to crush old cars in a junkyard," Sues said.In addition, the snake's heft indicates that it lived when the tropics were much warmer than they are today, a find that holds potential implications for theories of once and future climate change.Biggest Snake Needed the HeatScientists know there's a link between a snake's body size, how fast it uses and produces energy, and climate.(Related: "World's Smallest Snake Discovered, Study Says" [August 3, 20008].)"We were able to use the snake, if you will, as a giant fossil thermometer," study author Head said.His team found that, for Titanoboa to reach its epic proportions,  mean year-round temperatures would have been about 90 degrees Fahrenheit (32 degrees Celsius)—significantly hotter than today's tropics.This supports the idea that tropical temperatures spike as the rest of the world heats up due to global warming, the study authors say.The competing theory is that, during bouts of warming, the tropics stay about the same average temperatures as they are today while areas north and south of the Equator heat up.James Zachos, an expert on ancient climates at the University of California, Santa Cruz, who was not involved in the study, agreed.As the biggest known snake, Titanoboa supports the idea of "much hotter tropics during extreme greenhouse periods," Zachos said.Big Reptiles on the Horizon?Study co-author Jonathan Bloch is a vertebrate paleontologist at the University of Florida's Museum of Natural History in Gainesville.The same Colombian coal mine that contained the biggest snake also yielded massive turtles and crocodiles, he said."You can think about it as an ecosystem dominated by giants, I think, and these are probably giants that got large because of the warmer mean annual temperature," he said.The findings, detailed in this week's issue of the journal Nature, paint a picture of what the future might hold if supercharged global warming takes place.According to some models, global temperatures could approach the same levels that gave rise to the biggest snake by the end of this century.If current greenhouse gas emissions continue apace, there's a chance snakes the size of Titanoboa could return, Bloch said."Or maybe snakes would go extinct in the tropics," he said. "In other words, the warming could happen so rapidly that they wouldn't have time to adapt.

PERMIAN EXTICION: THE GREAT DYING

The Permian extinction event, informally known as the Great Dying, was an extinction event that occurred 251.4 Ma (million years ago), forming the boundary between the Permian and Triassic geologic periods. It was the Earth's most severe extinction event, with up to 96% of all marine speciesand 70% of terrestrial vertebrate species becoming extinct  It is the only known 

mass extinction of insects.Some 57% of all families and 83% of all genera were killed. Because so much biodiversity was lost, the recovery of life on Earth took significantly longer than after other extinction events.This event has been described as the "mother of all mass extinctions."Researchers have variously suggested that there were from one to three distinct pulses, or phases, of extinction.There are several proposed mechanisms for the extinctions; the earlier phase was likely due to gradual environmental change, while the latter phase has been argued to be due to a catastrophic event. Suggested mechanisms for the latter include large or multiple bolide impact events, increased volcanism, and sudden release of methane clathrate from the sea floor; gradual changes include sea-level change, anoxia, increasing aridity, and a shift in ocean circulation driven by climate change.There are several proposed mechanisms for the extinction event, including both catastrophic and gradualistic processes (similar to those theorized for the Cretaceous–Tertiary extinction event). The former include large or multiple bolide impact events, increased volcanism, or sudden release of methane hydrates from the sea floor. The latter include sea-level change,anoxia, and increasing aridity. Any hypothesis about the cause must explain the selectivity of the event, which primarily affected organisms with calcium carbonate skeletons; the long (4–6 million year) period before recovery started; and the minimal extent of biological mineralization (despite inorganic carbonates being deposited) once the recovery began.

KAPROSUCHUS

Kaprosuchus is an extinct genus of mahajangasuchid crocodyliform. It is known from a single nearly complete skull collected from theUpper Cretaceous Echkar Formation of Niger. The name means "boar crocodile" from the Greek kapros ("boar") and souchos ("crocodile") in reference to its unusually large caniniform teeth which resemble those of 

a boar.It has been nicknamed "BoarCroc" by Paul Serenoand Hans Larsson, who first described the genus in a monograph published in ZooKeys in 2009 along with other Saharan crocodyliformes such as Anatosuchus and Laganosuchus. The type species is K. saharicus.Kaprosuchus is estimated to have been around 6 metres (20 feet) 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. Another unique characteristic of Kaprosuchus is the presence of large, rugose horns formed from the squamosal and parietal bones that project posteriorly from the skull. Smaller projections are also seen in the closely related Mahajangasuchus.The snout of Kaprosuchus shows generalized proportions and the naris is positioned dorsally. In Kaprosuchus many teeth are hypertrophied and labiolingually (laterally) compressed, unlike those of crocodyliforms with similarly shallow snouts, which are usually subconical and of moderate length. Another difference between the skull of Kaprosuchus and those of crocodyliforms that also possess dorsoventrally compressed snouts is the great depth of the posterior portion of the skull.In Kaprosuchus, the orbits (i.e., eye sockets) open laterally and are angled slightly forward rather than upward. The orbits turned forward suggest that there was somewhat stereoscopic vision, i.e., an overlap in the visual field of the animal.The surfaces of the premaxillae are rugose with the edges elevated above the body of the bone, suggesting that a keratinous shield would have been supported by the rugosities at the tip of the snout. Along the interpremaxillary suture, the area where the two premaxillae meet, the surface is smooth, giving the paired rugosity of the premaxillae the resemblance of a moustache in anterior view.