HAPPY NEW YEAR

Another year begins and who knows what it will bring. It seems like things are developing fast in the world of Paleontology and I am looking forward to trying to keep up with at least some of it.

"FEATHERS" DISPUTED

Back in the July/August issue of 2000, I mentioned a reptile specimen called longisquama that was said to have long feathers sprouting from its back. Since it lived in the Triassic (225 MYA) it would predate the first bird, Archaeopteryx (145 MYA), as the first feathered tetrapod. And now a response by R. Reisz and H.-D. Sues disputes the feather theory and says that the dorsal appendages are elongated scales that were anchored in the skin or muscles. They appear to be more substantial than feathers which have convex and concave counterparts.This specimen has two concave counterparts indicating three dimensional structures. Upon close inspection they appear to have a membrane like structure instead of the pinnae of feathers. The tubular membrane structure was infilled with fine sediment after death. This seems to agree with the reaction of most other paleontologists who questioned the feather theory from the beginning. However, the original author John Rubens continues to support the feather interpretation and claims that the specimen studied for the scale theory is a poor one. Other specimens show the concave/convex counterparts and the feather features.

DINO UPDATE

Emily Rayfield has carefully studied the skull of Allosaurus fragilis and has concluded that it had a weak bite force because of its flexible lower jaw. The T rex lower jaw by contrast was not flexible and was one of the strongest bite forces in any animal. The Allosaurus did have a strong skull that could resist a very high level of stress. So if the lower jaw could only take the force of chewing, it would mean that the animal would have to have used a high impact attack to drive its upper jaw and teeth into the prey and then use its strong neck muscles and teeth to rip out the flesh.

Another Madagascar find by Scott Sampson includes some very strange dentition. Although most of the serrated teeth of this theropod curve slightly backwards (as is typical) the four teeth in the front of both lower jaws begin to point forward with the middle one almost completely horizontal. These cone shaped teeth may have been used to grasp and puncture small prey. They have about 40% of the skeleton of the slightly built bipedal theropod that was about 6 feet long. It is simlar to dinosaurs found in India and South America except for the strange teeth.

Brazil is on the trail of a large Spinosaurus dinosaur. This is a sail backed long crocodile-like snouted fish eater. These animals have been found in North Africa, which is believed to have been attached to South America around Brazil before Gondwana split. They have found the skull and some teeth and jaw fragments in northeasteren Brazil. They believe that this animal was very big, measuring about 43 feet long and about 11 feet tall. The expedition is to begin this month.

John Bird reported on two new dinosaur finds from near Price Utah. One is a new brachiosaur that lived about 100 MYA (Lower Cretaceous) and the other is a new species of ankylosaur. Both of these plant eating species are known from the Jurassic and the late Cretaceous. These provide information about a link between those times. They have found about 400 bones of about five brachiasaurs, both juvenile and adult.

Denmark is claiming its first dinosaur find. It is a single tooth of a velociraptor or deinonychus that lived about 125 MYA. It was found by a group of unemployed people working in a government program. The area where it was found was the only part of Denmark that was not covered by water during the Mesozoic.

EARLY BIPEDAL REPTILE

A German fossil of Eudibamus cursoris has been dated at 290 MYA (Permian) and may be the earliest example of bipedal locomotion. It was reported in the November 3 issue of Science which showed the very complete specimen in situ. This 10 inch long animal was able to reach high speeds because of its long rear legs and its long toes. Its short forelimbs indicated that it was a tetrapod that could be bipedal when it wanted to. It probably used the speed to elude predators rather than to hunt prey. Its teeth indicate that it was a vegetarian. The specimen was found in a terrestrial environment (no fish or scales were found) along with insects, ferns, and other small plant eating vertebrates. The top predator of the time was probably Dimetrodon. The fossil site in Germany is an excellent one with very good preservation. The specimens found are very similar to those found in the western US supporting the supercontinent concept. Eudibamus is not believed to be the first in the line of bipeds and is probably a dead end. Bipedal locomotion probably evolved several times.