Archive for June, 2011

Fossil Gap Partially Bridged by Buck Toothed Dinosaur

By: The Scribe on June, 2011

One of the problems with studying dinosaurs is that there are large gaps in the fossil record. This makes it difficult to tell where some of This creature was first discovered in New Mexicothe dinosaurs evolved from. Scientists make guesses based on factors such as bone shape and tooth shape. They may find out later that two dinosaurs may be totally unrelated even though they may look the same in many ways. Or, as in the case of the brontosaurus, they may have ended up renaming a dinosaur that already had a name.

Now, scientists may need to do a little rethinking as one of the fossil gaps has been closed a little. It is now possible to connect a dinosaur such as Tyrannosaurus rex with some of the earliest predators. When you think about how ornery the T-rex was, it is no surprise that early predators would have been similarly nasty. The T-rex was quite an evolved predator for the time (between 67 to 65.5 million years ago) so when you think that these creatures were related to an extremely advanced predator it is no wonder that they were so effective at hunting and bringing down their prey.

Paleontologists who were working at the Ghost Ranch fossil site in New Mexico found the fossils and named the creature Daemonosaurus chauliodus which, appropriately enough, is Greek for “buck-toothed evil spirit”. It was named this for the buck teeth that the creature sported. Daemonosaurus was about the size of a large dog in height. The shape of the skull and the kind of teeth that filled it were quite unusual. The front teeth were extremely large, giving rise to the “buck-toothed” nickname. The snout was quite deep and short which scientists have said is unusual for a predator living at the time.

It is not the only buck-toothed dinosaur to have been discovered. A second species of dinosaur was found in China. Called Incisivosaurus gauthieri because of its beaver-like front teeth, this dinosaur was small and extremely quick. It was found to be one of the first oviraptorosaur species and shows that this species of dinosaur was once herbivorous. Although they belong to a group of dinosaurs called theropods (which are carnivorous), it was apparent that Incisivosaurus was actually a plant eater. The skeleton, which was discovered in Liaoning Province in northeastern China has been found to be approximately 128 million years old.

Scientists are still trying to piece together the fossils that have been found into oneThe skull of this dinosaur was first found in China continuous fossil record. There are many large gaps and it can be difficult to see how changes came about over time. Sometimes the gaps are caused by a total lack of fossils or because earlier testing techniques may have failed to show a connection. Many times scientists are working with only a partial set of fossils from prehistoric creatures, making it difficult to check areas such as skull and tooth shape.

Scientists are also trying to definitively prove where dinosaurs first lived. The best records show that they likely began life in South America. Fossils in that area have been found from as early as the late Triassic period, which was about 230 million years ago.

Ancient Predatory Shrimp Fossil found in Morocco

By: The Scribe on June, 2011

These predators grew up to three feet in lengthWhen someone thinks about shrimp they usually think about cocktails and skewers made up of small pink bodies. Now, a fossil belonging to a prehistoric ancestor of modern crustaceans has been found in southeastern Morocco. At just over three feet in length, it is a full foot longer than previous specimens. Experts believe that this creature was edible and that it would have produced enough meat to feed a large group of individuals for a month. This is certainly not a creature that could be hung on the side of a glass and then dipped in sauce.

The massive prehistoric creature is called an anomalocaridid. The name actually means “strange shrimp” due to the fact that they look much like a shrimp or a cuttlefish. Their remains are usually found with fossils that date from the Cambrian period (542 million to 488.3 million years BCE) and these specimens usually max out at around two feet in length. This new specimen, which was discovered in rock from the Ordovician period (488 million to 443 million years BCE), is not only younger than previous specimens it is also a full foot longer.

It was believed that this massive creature was actually a predator and that it likely dominated the waters where it lived. The creatures had many of the features that modern shrimp do, including a similar body shape and two appendages that extended out from the mouth area. They were able to swim freely thanks to swimming lobes located along each side of the body. This made them extremely agile swimmers.

The creatures were thought to live on hard-shelled creatures such as trilobites and that These creatures were often eaten by anomalocarididsthey had developed a ring shaped mouth full of sharp, hard teeth in order to do so. They also had large eyes which enabled them to see their prey.

This discovery raises a lot of questions and issues for scientists who are studying the Cambrian and the Ordovician eras. They want to know whether other animals also grew larger than the fossil records would indicate. The fact that the anomalocaridid was a full foot longer than previous specimens suggested that other animals from the same time might also have been somewhat larger as well.

The discovery of the fossil in the Ordovician period is causing scientists to also rethink when these creatures might have lived. Originally, it was believed that these creatures were not present in rock dating from before about 510 million years CE although there are many examples that have been found in Cambrian-era rocks.

The problem with finding anomalocaridid fossils is that they had soft bodies. This means that there was little remaining to become fossilized the way the bones and exoskeletons of other creatures could be. It took a sediment cloud to protect and preserve these fossils to preserve these anomalocaridids enough that they could be studied.

Anomalocaridids did eventually become extinct although not as soon as scientists had first thought. Although they look like modern shrimp there is no relationship between shrimp and anomalocaridids.

Ancient Africans also plagued by Parasitic Worms

By: The Scribe on June, 2011

A parasite which plagues hundreds of millions of people today has also been found in some ancient Nubian mummies. Eggs had been discovered on some Nubian mummies as early as the 1920’s but scientists were still searching for proof of exactly which parasite affected them. Now there has been conclusive proof that the mummies were affected by Schsitosoma mansoni, a parasite that lives in water.

This body was preserved by dry air instead of deliberate mummificationThe parasite causes a disease called schsitosomiasis. It does not usually kill people however it does cause many different health issues. Some problems that are caused by schistosomiasis include anema, impaired growth, impaired cognitive development in children, and anemia. The parasite uses aquatic snails as a host. The eggs are excreted from the body in urine and feces. If this contaminates the water supply, the eggs hatch and live in snails until they can infect a human host. The parasite that causes this disease can lead to higher rates of bladder cancer.

What is interesting about the discovery of S. mansoni in humans is the fact that the snails generally inhabit irrigation channels. Infection rates are highest among people who use irrigation channels because the snails tend to prefer water that is clean, moving, well-oxygenated to water that is stagnant or heavily polluted. In the past, scientists thought that a similar parasite, S. haematobium was actually the one that was infecting the mummies.

The group of Nubians that had the highest rates of infection was the Wadi Halfa. These individuals settled along the banks of the Nile and were farming there as early as 1,500 years ago. It has now been discovered that as much as 25 % of the Wadi Halfa population was infected by this particular parasite. The fact that it is S. mansoni infecting these individuals is yet more proof that the Wadi Halfa were using irrigation channels to allow their crops to flourish. Archaeologists had not thought that these ancient Nubians had been sophisticated enough to make irrigation channels. This parasite infects millions of people around the world

The mummies that showed infection were actually mummified naturally rather than by the methods utilized by ancient Egyptians. The dry air mummified the bodies and preserved them. The skin and some of the internal organs were usually dried out and preserved and are still able to be studied today. Hundreds of naturally mummified bodies were studied before the findings were announced.

Today, a modern city stands among ruins of the ancient Wadi Halfa population. Archaeologists have been searching for Nubian antiquities in the area because flooding from construction of the Aswan Dam. The Noba were a nomadic people who settled in the area around the fourth century CE. The words Nubia and Nubian are derived from the name Noba. They settled in northern Sudan as well as in southern Egypt. Ancient Egyptians imported luxury goods along trade routes that travelled through Nubia as early as 2300 BCE. This is when Nubia was first mentioned in records from Egypt’s Old Kingdom. They also traded directly with Nubia as well. The Egyptians also expanded into Nubia by building garrison forts along the Nile so that they could protect trade routes.

We’re back on Monday!

By: The Scribe on June, 2011

Regular posts will be resuming on Monday, thanks for reading!

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