SERENO’S AFRICAN ADVENTURE
Paul Sereno from the University of Chicago and his expedition left for Niger Africa August 7 and will be on the road until early December. On this trip you can follow his progress on the web at www.projectexploration.com. In addition to a lot of information about past trips and the dinosaurs of Africa, they will have a webcam sending back pictures from the dig as it happens. It should be an exciting adventure. Three months in the desert at about 110 degrees sounds like a real adventure in and of itself.
FLORIDA FOSSILS
If you get to Florida and are looking for something fun and interesting to do, I can highly recommend a fossil tour with Fossil Expeditions (near Fort Meyers, Florida). It is run by a friend of our member Rob Sula named Mark Renz. He also has written a very good book about his adventures in Florida called "Fossiling in Florida". Last week Irene Broede and I took a trip to the Peace River with Mark and panned for fossils. Although there weren’t any big spectacular finds that day, we did enjoy being up to our armpits in the lovely river (reminded us of The African Queen, without the leeches). We did find a lot of small shark teeth from several types of sharks. Also some manatee rib bones, turtle shell fragments and alligator teeth. There were parts of other teeth that we still need to get identified. All in all it was a great day and a fun adventure and we are both anxious to return in hopes of finding the big stuff (megaladon teeth which are rare now)!! If you want to see more of what Mark does, his website is www.fossilexpeditions.com.
KILLER SAND
An article in the July/August issue of Natural History talks about a possible therory to explain the good preservation of many of the fossils from Mongolia (authors are Lowell Dingus and David Loope). Fossils from the late Cretaceous number in the hundreds from 12 foot ankylosaurs to tiny mammals. Some have been found sitting atop their nests. One theory that the animals were caught in sandstorms may not be a good explanantion because there are no modern examples of that kind of event. In general, healthy animals do not die that way. Some of the sandstones found there are solidified sand dunes with distinct layers called cross beds. The bones are not found there, but tracks are found. The bones are found in another kind of sandstone that is not layered. To understand how these kinds of dunes formed, they studied the dunes in Nebraska’s Sand Hills. When there are heavy rains during the summer, they see sudden avalanches of wet sand that they call debris flows. The Nebraska events have been too small to cause loss of life, but the storms in the Gobi may have been much greater. Their finding of layers called caliche helped explain the slides. The caliche layers form below the surface of the sand and are layers cemented with calcium carbonate. This makes it easier for the rain to cause a slide above them instead of letting the water seep down to a lower level. This type of activity is also seen in some of the big mudslides in California when the upper layers of mud are loosened by a lot of rain and slide off the layers of bedrock underneath. The Gobi slides would have caused good preservation with very fast and complete burial.
DINO-BIRD AGAIN
Another article on this still hot issue is in the August 10 issue of Nature and is titled "Fine structure of bone in dinosaurs, birds and mammals" by Rensberger and Watabe. In this study they looked even more closely at the detailed structure of bones of representatives of dinos, birds and mammals. Previous studies have concentrated on the vascular canals, but here they look at the micro sized channels (canaliculi) that interconnect those, and at the differences in the organization of the collagen bundles in the bones. They concluded that the ornithomimid dinosaurs are more like birds than mammals and that ornithiscian dinos are more like mammals. Mammals tend to have parallel canaliculi, while those of birds are randomperhaps derived because of the high rate of growth of the bones. Under electron microscopes it was found that the collagen fiber bundles were also well defined and long, while those of birds are irregular and change over distances. More work needs to be done with studies of an age series when samples are available. It will be interesting to see the reaction to this report.
BITS & PIECES
Did you see the August 2000 issue of National Geographic? There is a great story about discoveries in that fascinating island country of Madagascar called Monsters of Madagascar.. It includes the story of the finds of the Field Museum including the oldest dinosaurs ever discovered and the plant eating crocodile discussed by John Flynn ( a two time visitor to ESCONI). It also includes a section by David Krause and all the photos are terrific.
Word on the street is that the new Museum of Natural History (New York) exhibit is a great one. It includes the famous fighting dinosaur exhibit as its certerpiece. Other Gobi specimens include small mammals, lizards, and other dinosaurs, dromeosaurs, protoceratopsians, and oviraptors. The September 2000 issue of Discover magazine has an article called "What Did Dinosaurs Really Look Like…And Will We Ever Know?" by William Weed. He uses the New York Museum exhibit to ask the question. An example is the velociraptor in the death struggle model which shows it with feathers. It was Mark Norell’s idea to show it that way and not all agree with it.
Kansas has ousted the creationists on their Board of Education. This means that there probably will be changes to allow the teaching of evolution again.
Another important fossil may be up for auction. The gliding reptile is called Icarosaurus siefkeri. It was dug up in 1961 and was at the Museum of Natural History in New York for many years. The discoverer Siefker reclaimed it to auction it for $5 million. There were no bidders. Butterfield’s is now set to auction it at the end of August, hopefully for $300,000. This flying reptile preceded pterosaurs and birds by 50 MYA. The fear in the scientific community is that it will end up in private hands and be lost to science.
A new fossil track from Korea may indicate that web footed birds evolved earlier than previously thought. The tracks are dated at 110 MYA, which is about 50 MY before previously thought. The toes were not fully webbed so they may have been occasional swimmers. They may also have had an opposable hallux or first toe, indicating that they could also perch.
Karen Nordquist, ESCONI Paleontology Study Group
Featured Web Sites
Field Museum of Natural History
SVP Society for Vertebrate Paleontology