Well preserved rare fossil of mammoth skull discovered in US

New York, Sep 20 (IANS) A team of paleontologists has unearthed an exceptionally well preserved fossil of a complete mammoth skull in the US, which according to them exhibits features unlike any of its kind.

The unique mammoth skull was recovered from an eroding stream bank on Santa Rosa Island within Channel Islands National Park in California.

"This mammoth is extremely rare and thus of particular scientific importance. It appears to have been on the Channel Islands at nearly the same time as humans," said Justin Wilkins, paleontologist at Mammoth Site in South Dakota.

"I have seen a lot of mammoth skulls and this is one of the best preserved I have ever seen," Wilkins added.

The scientists hypothesised that the specimen could be a young Columbian mammoth -- which appeared on the continent of North America approximately a million years ago -- or possibly an intermediate-sized mammoth.

The size of this specimen is unusual. It is not large enough to be readily identified as a Columbian mammoth nor small enough to definitively qualify as a pygmy mammoth, they said.

The Columbian mammoths who were believed to have migrated to the Channel Islands during the past two ice ages were downsized from approximately 14 feet to a six feet tall pygmy form, becoming an endemic species known as Mammuthus exilis.

"The discovery of this mammoth skull increases the probability that there were at least two migrations of Columbian mammoths to the island," said Dan Muhs, geologist at the US Geological Survey (USGS).

"One, during the most recent ice age 10,000-30,000 years ago, and the other during the previous glacial period that occurred about 150,000 years ago," explained Muhs.

The newly-discovered mammoth's tusks have also aroused curiosity.

While the right tusk protrudes 1.4 meters in a coil characteristic of an older mammal, the shorter sloped left tusk is more typical of a juvenile.

The team hopes to estimate the animal's age at its death by measuring the size, spacing and the thickness of the enamel of the mammoth's teeth.

In addition, it will also clarify whether it is a pygmy or Columbian mammoth or, less likely, a transitional species, the researchers noted.

The mammoth will be kept at the Santa Barbara Museum of Natural History for public display.