Monday, 27 April 2009

Fossil Snippets...

Nine fossil teeth have been found in desert scrubland near Addis Ababa, Ethiopia, which have been dated as 10 million years old, bearing big similarities with modern gorillas. This means the difference between gorillas and chimpanzees and humans must have happened before 10 million years ago. Once again this points to Africa being the place of origin of humans.

For a couple of million years after the permian extinction, around 251 million years ago, which wiped out 95% of living species at the time, piggy like animals ruled the world. They were called Lystrasaurs, they reached up to 3 metres in length, and they probably survived through the turbulence of volcanic action and climate and atmospheric change of their times by their ability to burrow and hibernate,

A tedious American academic has had our very own and famous Isle of Wight Iguanodon renamed Mantellisaurus as he says it differs too much from the most complete Iguanodons found, those from Bernissart, Belgium. Gideon Mantel, an obsessive and rather tragic Victorian dinosaur enthusiast certainly deserves more recognition – he was royally shafted in his lifetime by smug, wealthy and well connected Richard Owen, first head of the British Natural History Museum, who scorned amateur academics with a vengeance.
The first dinosaur to be named was Megalosaurus in 1824 from remains found in Oxfordshire, Gideon Mantel named Iguanodon one year later from remains found in Sussex.

In 2004 Dr Nudds and Dr Seldon, both from Manchester University, compiled ‘Evolution of Fossil Ecosystems’, a description of 14 of the most famous global lagerstatten – sites of extraordinary fine fossil preservation where as well as the hard bony parts of animals, also skin and soft parts are preserved.
They have now concentrated their energies on North America and published ‘Fossil Ecosystems of North America’. Good stuff. Check it out.

A new soft body fossil site has been found in Newfoundland. Dating from the Precambrian – actually called Ediacaran which is 630 – 542 million years old –fossils resemble nothing we would identify with living creatures. These exotic looking creatures are shaped like candelabras, rope ladders, spindles and discs with radiating tentacles.

A new site in Central Manitoba, Canada from the late Ordovician (450 million years ago) has yielded the earliest known specimen of horseshoe crab.

Whip spiders live today in tropical and subtropical areas. A recent study has shown that its relatives go back to the late Carboniferous period (325 million years) and have been found in coal deposits in Europe and North America. The fossils used in the study were from the collection at London’s Natural History Museum and were found in ironstone nodules from collieries in Staffordshire. The spiders were 11 – 15mm long.

George Poinar, the most prominent expert on Dominican amber which is 28 million years old, has turned his attention to the rare and usually badly preserved deposits of cretaceous amber from Canada, Lebanon and Burma for his new publication ‘What bugged the dinosaurs’ – insects, disease and death in the cretaceous.
He finds evidence of mosquitoes, biting flies, worms, lice, beetles, fleas living off dinosaurs and passing on all manner of diseases to them.

At the same time a French team based at Paris Natural History Museum have identified a carnivorous fungus found trapped in cretaceous amber deposits from South West France. It seems these fungi, which fed on nematodes or mud worms, had already developed to a point of complexity that matches that of modern species. To understand its roots a much older find will be required.

A team from the University of Oslo have found the largest known pliosaur in the world in the remote and inhospitable island of Spitzbergen. The 150 million year old monster, largest marine predator of the Jurassic, was 50 foot long. The team has to fly everything in by helicopter including shotguns to protect themselves from polar bears.

Two new species of bat have recently been described from Wyoming’s Green River Formation famous mostly for its prolific fish fauna. On rare occasions birds, crocodiles, a number of mammals and plant and tree remains have been found. Three years ago a small horse was found by commercial diggers (Current price $2 million, as yet unsold) and last year a stunningly well preserved snake was found by commercial diggers (also priced around $2 million and as yet unsold)

A skull and fragmentary body parts from the upper Devonian period (365 million years) of Latvia are from an animal half-way between an amphibian and a fish. Ventastega’s skull resembled a crocodile, and it had 4 primitive flippers, but otherwise its body was fish-like. Sediments suggest it lived in shallow waters but, while adapting to a land habitat, it found locomotion easier by swimming. While following as an evolutionary trend towards dwelling on land Ventastega itself was an evolutionary dead end which died out without further evolution,

Robert Makin, an amateur palaeontologist and professional reptile breeder has raised interesting questions about sauropod dinosaurs diets that have not yet been answered by academic experts. In the American publication ‘Fossil News’ he asks what infant sauropod dinosaurs ate in order to attain the massive size of their parents in a short time. The vegetation that was their parent’s diet was low in protein and particularly low in calcium required to form bones.
Today large herbivore reptiles eat food exclusively provided by their mothers until they have reached at least a quarter of adult size.

Modern herbivorous reptiles are insectivorous until they have reached adult size. For a dinosaur to do the same thing would be impractical. A large sauropod eating its own weight in plant matter daily would take 700 years to incorporate enough calcium to form bones. A calculation of the growth rate of Argentinasaurus, which reached an adult weight of 100 tons, is 1500kgs per month.

Some frogs make high protein food eggs for their young. As their stomachs were so far from their mouths it is unlikely (but not impossible) that adult sauropods regurgitated processed food. Perhaps they added a ‘milk’ of calcium and extra protein to their babies diet but how did they deliver it? As soft body preservation (of skin and organs) is so rare, there is little, if any, evidence to support any theory – but plenty of room for conjecture.

Any ideas?

An outstanding well preserved 50 million year old goose skull was found on the Isle of Sheppey recently and described by academics from Senkenberg Museum, Frankfurt. Dasornis had sharp teeth, a 16 foot wingspan and no doubt a voice like a foghorn!