BONES

April, 1999 Volume 4, Issue 2

In This Issue
 
Allosaurus on Display For Your Notebook...
Paleooceanography class College for Kids
Diplodocid feet research project Tyrannosaurid excavation
Dinosaurs of Warm Springs Ranch, pt 2 Kid's Corner
Calendar of Events

 

Allosaurus Now on Display

Allosaurus was a fierce meat-eating dinosaur that roamed Wyoming during the late Jurassic period about 145 million years ago. A thirty-foot reconstruction of this fierce predator is now on display at the Wyoming Dinosaur Center (WDC), in Thermopolis, Wyoming.

The Allosaurus is the newest addition to the Center’s growing dinosaur display. With the addition of Allosaurus the Center now displays two fierce predators that inhabited Wyoming at different periods during the rein of dinosaurs.

The skeletal model, based on the casting of original bone, has been constructed in a feedingpose. The model was designed by Big Horn Basin Foundation and Timescale Adventures paleontologist, Dave Trexler.
Remains of Allosaurus have been found at the Warm Springs Ranch Dinosaur Quarries where the Big Horn Basin Foundation is conducting research on the possible presence of an Allosaurus lair site. A lair is a site where adult Allosaurs brought the remains of prey , or scavenged animals, to feed juveniles. Numerous remains of prey species, such as Apatosaurus, Diplodocus, Camarasaurus and Stegosaurus have been found. Numerous teeth of juvenile Allosaurus and tracks have also been found at the prposed lair site. The new Allosaurus can be viewed seven days a week at the WDC. Summer hours, 8am to 8pm, beginning May 15th. Depending on weather, tours are already being led to the dig sites.

Allosaurus fragilis is the Center’s newest dinosaur 


 

For Your Notebook

The Morrison Formation is a deposit of sediments from the final years of the Jurassic period . It has extensive exposures of dinosaur bone bearing deposits spread throughout Wyoming, Colorado, Utah and parts of Montana and New Mexico. The formation was deposited as a great low plain following the retreat of the Sundance Seas. It is famous for dinosaurs such as Apatosaurus, Allosaurus and Stegosaurus. A large diversity of dinosaurs occurred at the time that Morrison deposits were being formed. Good sites in Wyoming to observe the Morrison Formation include the Warm Springs Ranch Dinosaur Quarries, and Commo Bluffs near Rock River, and the Howe Quarry near Shell. 

College For Kids Begins This July

Florida Atlantic University (FAU), of Fort Lauderdale, Florida will bring a pilot program, "College for Kids", to the Wyoming Dinosaur Center,(WDC), July 22 through August 1, 1999.The program is a colaboration between FAU, WDC and the Big Horn Basin Foundation. 

The 5-day program includes three days of dinosaur activities including, digging, casting, molding and preparation skills. They will spend time hunting invertebrate fossils and a day on a geology and wildlife tour of Yellowstone National Park. Dr. Ed Petuch, paleoecology professor from FAU, will lead the activities. 

Paleooceanography Taught This Summer

Invertebrate Paleoecology will be taught this summer by Dr. Edward Petuch, of Florida Atlantic University (FAU), on the Warm Springs Ranch sites. The course is featured as a pilot program that is part of a new cooperative relationship between FAU, Big Horn Basin Foundation, the Wyoming Dinosaur Center, Timescale Adventures and the Graves Museum in Florida.

The course will feature the paleooceonography of the Sundance Sea, a prehistoric sea that innundated Wyoming during the middle of the Jurassic period. Petuch is one of the world’s leading authorities in Invertebrate Paleontology and he has helped innovate the field of paleooceanography. His book, Coastal Paleooceanography of Eastern North America, is already a classic in the field. Not much is known about the paleoecology of Wyoming’s Sundance Sea and Petuch hopes to change that as he begins his latest efforts in Wyoming. 


 

Diplodocid Feet; A Research Priority

The Warm Springs Ranch Dinosaur Quarries have produced more articulated (as it would be on the animal) Dipodocid feet than anywhere in the world. The Diplodocids are a Sauropod family that includes Diplodocus and Apatosaurus. The foot finds are important to the science of paleontology and the description of these bones has become a research priority of the Big Horn Basin Foundation (BHBF).

Paleotechnician, Malcolm Bedell, is working closely with BHBF Paleontologist, Dave Trexler, to describe the feet. Consultations have been made with ranking Sauropod expert, Dr. Jack McIntosh, of Wesleyan University in Connecticut. 

The first step is to prepare the feet by removing them from the concreted sediments, which encase them. According to Bedell, this is a time consuming process that has to be accomplished carefully. 

The feet will be measured, bone by bone, then described. An abstract has been prepared by Bedell which will be used as a submittal in a science forum. Castings of the feet in concreted sediments have already been prepared. At least three articulated and one associated foot of a Diplodocid have been discovered at the Quarries to date. What appears to be a potentially complete Diplodocid was found with the feet. That dinosaur will be dug in the 1999 digging season.

Diplodocid foot in concretion

Tyrannosaurid Being Prepared Some Digging Remains

Dave and Laurie Trexler have spent two seasons digging a large Tyrannosaurid in Two Medicine Formation of the later Cretaceous. It is apparently a Daspletosaurus, but Trexler is unwilling to say for sure until he has all of the animal prepared, and all of the information that will allow him to identify the giant. Some digging remains to complete the removal.

Much of the skull was recovered, including diagnostic parts, according to Trexler. The prepation work began this past winter. Laurie Trexler, of Timescale Adventures, will lead this effort. The Wyoming Dinosaur Center will display Daspletosaurus in the year 2,000. 

Dave Trexler At Tyrannosaurid Dig Site

The Dinosaurs Of The Warm Springs Ranch Quarries, Part II
(This is a continuation of a story that appeared in Volume 4, Issue 1)

Theropods: 
   The meat-eating dinosaurs were called the Theropods which means "beast foot". They first appeared in the Triassic about 230 million years ago, living for 160 million years. They are found at most dinosaur localities but they tend to be rare . 
    During the Jurassic there was a diverse group of theropods especially during the time when the Morrison Formation was deposited. There were Ceratosauroids, a primitive, medium to large, meat eating dinosaur. There was the small Compsognathus and Ornitholestes. And giants like the Megalosauroids and the allosaurs.

    Theropods were slender, long-legged, bipedal animals that preyed on the larger, slower herbivores. 
    Allosauroids: This is a family of large Carnosaurs that comprised the most dominant meat-eater found in the late Jurassic. These were powerful hunters with skulls that were up to one meter (about 3 feet) in length teeth. 

    They grew to lengths of eight meters (over 25 feet) and had three sharp claws on their hands. They probably used their fore-arms to catch and hold prey.
    Allosaurus fragilis: The most frequent species of Allosaurus found in Wyoming is fragilis. Their hind legs were large and powerfully muscled They could probably move at speeds of up to 20 miles per hour. The skull had small horns located on the nasal above the eyes.
    They preyed on herbivore dinosaurs such as Sauropods, Stegosaurs and Camptosaurs. They probably were not able to kill adult Sauropods unless they hunted in groups. They were probably able to take Sauropod calfs. Stegosaurus would have been formidable prey with its tail spikes, but was invariably sought by Allosaurus.
    An Allosaurus lair site is being studied at the Warm Springs Ranch Dinosaur Quarries. Allosaurus seemed to keep their juveniles in these lairs and bring them food, usually parts of prey. Numerous scattered remains of several species of dinosaur are found associated with teeth of primarily juvenile allosaurs. Many of the bones have teeth marks on them or are chewed. Some are trampled and others are fossilized in the sediments in a manner that indicates they were picked up and moved from their original death location. The Big Horn Basin Foundation has made the study of this potential lair site a priority.
    Remains of Allosaurus have been found at another site and will be excavated during the 1999 digging season to determine if a more complete dinosaur is present. 
    During the past four years the two most complete Allosaurus were discovered by Swiss Scientist, Kirby Siber, near the historic Howe Quarry near Shell, Wyoming. Recently he excavated the most complete of the two. (More dinos next issue ).

KIDS CORNER
Bart Says Dinosaurs Are For The Birds!

Bart recently visited Solnhofen,Bavaria to look at the site where one of the earliest and most famous bird fossils was found, Archaeopteryx. The first one to be discovered may have been swept out to sea then washed back into a lagoon where it was fossilized.

The Archaeopteryx lived toward the end of the Jurassic period about 150 to 140 million years ago. Bart reports that the Archaeopteryx looks very similar to the small Jurassic meat eater the Compsognathus. The difference, Bart learned, is that Archaeopteryx had feathers and wings and probably could fly. It was a bird. Compsognathus was a dinosaur. 

The Solnhofen Archaeopteryx, or "ancient wing," was preserved beautifully and it prompted Bart to look into the theory that is being hotly debated today. Are birds actually dinosaurs? The theory basically states that birds came from a common thecodont ancestor with dinosaurs and evolved from either a small tree climbing dinosaur or a small two legged running dinosaur that eventually glided and flew as Archaeopteryx probably did.

Bart found that researcher’s have shown that Archaeopteryx closely resembles small meat eating dinosaurs in the way that it was built. He also found that new evidence shows that Archaeopteryx was also closely related to a group of birds that appeared in the early Cretaceous identified as the Ornithurine birds.


The ancient bird, Archaeopteryx, Frichinger Photo

The Ornithurine birds include Ambiortus from Mongolia and Chaoyangia and Ganus from China. Many credible paleontologists are leaning towards the theory that birds are an extension of the dinosaurs, suggested Bart. There are still some very good paleontologists who remain skeptical. Bart believes that the evidence shows that birds and dinosaurs are probably related. Archaeopteryx seems to be one of those birds that could be called a link, and Bart says that he is not a missing link. If you have questions you can Email Bart at bhbf@thermopwy.net.

BHBF On Your Computer!
BHBF Website:
http://www.thermopwy.net/bhbf

 

Calendar Of Events

April -Museum hours, 10am-5pm 
        Dig-site Tours, weather permitting

May -Summer hours begin, May 15 8am-8pm

June -Kids’ Dig, June15-16

Natural Science Workshop for Elementary Teachers, June 21-25

July -Kids’ Dig, July 6-7

Teens’ Dig, July 8-9

KIDS’ DIG and TEENS’ DIG
Enrollment Available!
An Educational Adventure
Call: (307) 864-2259 or 2997

Don’t Forget
Dig-For-A-Day!
Wyoming Dinosaur Center
Call: (307)864-2997