September 2003
Thomas the T. Rex Goes to Los Angeles
Luis Chiappe of the Natural History Museum of Los Angeles County is welcoming a new exhibit – a T. rex named Thomas after its discoverer schoolteacher Bob Curry who named it after his brother Thomas. It was found on BLM land in Carter County Montana and will be the best preserved and most complete specimen (about 50%) in any collection on the West Coast. It is 40 feet long and is estimated to have weighed about 6 tons. Two of its teeth (longest one is 13 in long) will be on display now while the rest of the skeleton is prepared for display in a year. They hope to go back and find the rest of the specimen next year. Last year they brought back a well-preserved skeleton of a Triceratops. This museum is among the top 3 US museums known for its T rex collections – the other two are the American Museum in New York and the Museum of the Rockies in Bozeman.
Still Trying to Clone a Mammoth
Japanese scientists are attempting to use frozen DNA to clone wooly mammoths. They are using samples of bone marrow, muscle and skin from the Siberian tundra from 20,000 year old frozen mammoth fossils. They are studying the DNA to be sure that it is from mammoths and that it is complete enough to use. They had hoped to find sperm cells to use to inseminate into modern elephants, but have not found any yet. Good luck to them – I think they will need it.
K/T Caused by Climate Change in New Zealand Study
Yet another study of the K/T (Cretaceous/Tertiary) extinction is now coming from New Zealand. They studied fossils and sediments at 6 sites there where they found a layer of meteorite dust about a centimeter thick at the 65 MY mark. There was also an abrupt change in microscopic plants and animal fossils in marine sediments. This strengthens the asteroid impact and dust cloud theory. However, they feel that the climate was already changing from the unusually warmer weather before the K/T. The cooling after the impact was really just a return to more normal temperatures. There were more species that survived in New Zealand than in most other parts of the world that might have been a result of the fact that its normal climate was cooler and darker. It was closer to the Antarctic then. They feel that the asteroid impact was mainly felt in North America. They have concluded that many species were already in decline before the K/T and the impact winter only finished them off.
Hydrostatic Skeleton Supports Newly Molted Crab
Are crabs that have just molted vulnerable without their hard exteriors? Of course, but they are able to move around because they inflate their stomachs with water and use hydrostatic pressure. Their outer cuticle then thickens into a new shell to protect them. Researchers from the University of North Carolina reported on pressure measurements on newly molted crabs before and after molting. The pressure from added water builds up and cracks the old shell allowing the new soft cuticle to expand and thicken in about 3 days. It was interesting that one of their experiments involved cutting a hole in the new soft cuticle of a newly molted crab to drain the extra fluid. This did not work because the crab has a rapid wound repair mechanism. They then drained it from one of the joints and the crab completely collapsed without the hydrostatic pressure. Other tests showed that within 12 hours the crab’s hardening cuticle is completely formed and starting to harden although hydrostatic pressure is still needed. This is the only animal so far found to regularly alternate between two support systems during life.
Chin Finds Muscle Tissue in Tyrannosaurid Coprolite
Karen Chin, Jack Horner et al report in Palaios on this remarkable specimen. The coprolite was found near Onefour, Alberta, Canada in Campanian (Late Cretaceous) rocks and measures 64 cm by 17 cm (25 in by 7 in) with a volume of about 6 liters. It has high concentrations of phosphorus (32.9%) and calcium (47.7%) compared to 0.96% and 2.09% in the surrounding sediment. It includes bone fragments that suggest it is from a large carnivore. Daspletosaurus, Gorgosaurus and Aublysodon are the candidates that lived at that time. It includes what appear to be fossilized soft tissues with two surface patterns. Some are fluted and formed by multiple layers of long, parallel fibers, suggesting muscle tissue. Others have a reticulated configuration with a web of ridges and resemble views of red blood cells in capillaries. The bone fragments (possibly from a pachycephalosaurid) throughout the coprolite are the same and indicate they are from the same prey animal. This specimen implies that there were short gut residence times for the large masses of flesh that were ingested by this eater. The bones found within the mass are small and would have been digested with a longer residence time. The specimen was found on a sandstone unit with a shale layer over it indicating that it may have been deposited in sandy soil among rooted plants and was buried during a flood. This fossil gives a fascinating look into the life of one of our favorite animals.
Chinese Dino Cemetery Yields Over 1,000 Fossils
Sometimes it seems as though China is just sitting on a huge pile of fossils! So much is coming out of that country that this story is no surprise. It appears to be a very rich site with bones of thousands of animals in a relatively small area. It may represent the final resting place of animals drowned in a flood nearby. They are dated to 160 MYA when it was an alluvial plain covered with lush vegetation near a large delta area. The site is located in southwestern Sichuan province and is about 300,000 square meters. In the less than 1 % they have worked so far, there are 100 fossils of sauropods and other dinosaurs. In addition they have found turtles, crocs, fish and reptiles in the mix. Sounds like it will be very long term project with a lot of potential.
Two New Dinosaurs Going to Carnegie Museum
Two specimens found on private land in South Dakota and acquired by the Carnegie Museum from a private company will be displayed in their new expanded dino hall in 2007. One is Pachycephalosaurus wyomingensis that is about 5 feet tall. The second is an unnamed oviraptorid which they describe as “a chicken from hell”. The Museum says that they may be open to naming it for a donor like they did when naming Diplodocus carnegii many years ago (anyone interested?). The cost may have been several hundred thousand dollars). I’m sure we will hear more about them as they are studied. These are their first dino additions since the early 1980s and they will be on display in a new three story atrium that will begin construction next year. The expansion will cost $37 million and the state has just given them $15 million (the rest will be from donations). Because of the high cost the new research and collection facility has been scrapped but there will be a new third floor gallery for botany, insects and birds. At the same time they will be restructuring their T. rex to be more scientifically correct. As we are all well aware, Museum additions are expensive and hard to fund in these difficult times. Good luck to them with their expansion!
Dinos Invade Pittsburgh
Not to be outdone by Chicago’s cows, Pittsburgh is having Dinos on Parade this summer in honor of the new construction to be done at the Carnegie Museum there. Check out their website for examples of some of the beasts (www.dinomitedays.org). Of course, the T. rexes are all modeled in the old upright pose.
Did Diving Plesiosaurs Get the Bends?
It has been known that mososaurs did show susceptibility to “the bends” or decompression syndrome which implies that they made deep and repetitive dives. This causes avascular necrosis or bone death from lack of blood flow to parts of the bones. Earlier research indicated that plesiosaur vertebrae showed no signs of the disease indicating that perhaps they had adapted to avoid it or that they did not dive as often or deeply as mososaurs. The susceptible parts are the vertebrae and the heads of the femur and humerus that can show collapse of damaged bone. Other animals besides diving humans to show results of this disease are certain turtles, snakes, birds and pinnipeds. Shorter dives or spacing out dives can alleviate its development, with many short deep dives causing the greatest problems. This study reported in the Journal of Vertebrate Paleontology by Bruce Rothschild and Glenn Storrs looked at many museum specimens (including FMNH). They found the disease in 32 of 576 humeri (5.6%) and in 10 of 479 femora (2.1%) but in none of the vertebrae. The vertebrae were probably protected by an extensive wealth of blood vessels supplying them and may have evolved to protect them during dives. The report shows that some families of plesiosaurs were more susceptible to the disease and this may indicate that some lived in shallow waters than others. It appears as though several of the groups did more deep diving than the Crytoclididae that showed almost no disease (although this is still a mystery). Another interesting factor is the gastroliths or stomach stones used by some of the plesiosaurs. They may have been used as a buoyancy compensation mechanism and are found more often within the larger rather than the faster shorter necked animals. It is interesting to see pathology used as a tool to try to determine the behavior of fossil animals.
Karen Nordquist, ESCONI Paleontology Study Group
Featured Web Sites
Field Museum of Natural History
SVP Society for Vertebrate Paleontology
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