325-Million-Year-Old Fossil Found in Ark.
FAYETTEVILLE, Ark. (AP) _ University of Arkansas students unearthed the world’s largest fossil of the squid-like, straight-shelled cephalopod at a city intersection as cars and trucks zipped by them.
Freshman Sarah Kee and senior Kevin Morgan made the discovery while digging along a drainage ditch for ammonoid fossils, a spiral-shelled subclass of cephalopods. A cephalopod is a marine mollusk that has a distinct head with suckers attached to it, highly developed eyes and varying numbers of arms.
After Kee noticed a bulge in the shale, the students dug farther and found a calcite shell fossil almost 9-feet long and nearly 325 million years old. The students had found another subclass of cephalopod, the straight-shelled, called a nautiloid.
Walt Manger, a university geology professor who has written several publications on cephalopods, said the fossil is the world’s largest of its kind.
``I really have to admit, when they called me up I was a little skeptical,″ Manger said Wednesday. ``They said, ‘We’ve got one over eight feet long.’ And I said, ‘Maybe.’ But when I came out on Tuesday, I said, ’Yeah, you got it. That’s exactly what it is.‴
Manger said the nautiloid lived in a water column during a time when most of the southern United States was under water. The creature lived in the lower, larger part of the straight shell and used the narrower part of the shell to maintain buoyancy.
Cephalopods reproduced when they were young, then died, Manger said, which explains the typically small size of their fossils. The professor said the cephalopod found by the students is a pathological giant, which possibly suffered from parasitic castration. In other words, parasitic algae destroyed the reproductive organs of the creature and the creature continued to grow.
Kee called a friend to help them remove the fossil, and the students carefully chiseled away shale for almost 24 hours before the fragmented fossil could be seen.
Manger and the students said they will move the fossil from its black shale bed and transport it to the university, where they can examine the shell and theorize why the creature was so large. The fossil will then be moved to the University Museum for public display.