“LAURA THE JUVENILE DUCK-BILLED DINOSAUR”

 

l    Laura is a juvenile Hypacrosaurus stebingeri, a crested duck-billed dinosaur, and she lived during the Late Cretaceous Period, about 75 million years ago.

 

l       Laura’s fossilized bones were discovered in July 2004 on private land north of Dupuyer, Montana in the Two Medicine Formation.  David Wolf and crew of Two Girls Fossils in Houston excavated her bones during the 2004 and 2005 dig seasons.

 

l       The recovered skeleton is over 90% complete, with a skull that is about 50% complete.  This makes Laura’s fossil skeleton one of the most complete of all dinosaur skeletons!

 

l       Laura’s fossil skeleton was brought to Eastern Iowa by the EIPP sponsors.  Laura may have been a male or female dinosaur.  She is named after EIPP President Don Johnson’s daughter.

 

l       Laura will be 11’ long and 5’ high at the hips when mounted, would have been about 4 years old and weighed about 750 lbs. when alive, and had only a hint of the plate-shaped head crest of the adults.

 

l       Laura’s species is only one of a handful of dinosaur species that are known from eggs, nests, embryos, hatchlings, and all stages of development to adulthood.

 

ANSWERS TO MANY OF YOUR “LAURA” QUESTIONS:

 

How was Laura's fossil skeleton discovered?

 

In July 2004, David Wolf, owner of Two Girls Fossils in Houston, Texas, was fossil hunting in the badlands of northwestern Montana on private land north of Dupuyer.  One day he discovered a few duck-billed dinosaur vertebrae eroding out of a hillside.  After doing some exploratory digging and finding a number of additional vertebrae, he thought there was a good chance that the rest of the dinosaur skeleton was buried beneath the surface.  He began making plans to excavate the hillside in partnership with the private landowner.

 

How do you dig the dinosaur bones?

 

David Wolf and his crew used a small backhoe to first construct a primitive road to the dig site.  The backhoe was then used to remove 6 to 10 feet of overburden (the hillside above the fossil bones) to within a foot of the bone layer.  During this process, a jackhammer was needed to break through a 6-inch layer of extremely hard sandstone about 3 feet above the bone layer.  Crew members then carefully removed the remaining siltstone, mudstone, and sandstone using hand tools until the fossil bones were uncovered.  A high-strength adhesive was used to stabilize the bones before they were removed from the ground.  Each bone was labeled and packaged separately, and a bone map was completed of the dig site.  The dig was completed in three phases during July 2004, April 2005, and June 2005 as excavation continued deeper and deeper into the hillside.

 

How do you prepare the dinosaur bones?

 

The late Dave Brissey (former EIPP Sponsor) can be seen to the right using a dental tool to remove matrix (the surrounding rock) from the surface of one of Laura's fossil thigh bones.  Air-powered scribes are also used to remove harder matrix from Laura’s bones.  The fossil bones were fractured into many pieces due to pressure exerted by natural processes after fossilization and before excavation.  After the matrix is removed, a high-strength adhesive is used to glue the pieces back together.  Later, a hardening epoxy will be used to fill in any missing portions of each bone.  Replicas will be used to stand in for the few missing bones.  Finally, a welded steel frame armature will be built to mount the skeleton in a natural pose.

 

How complete is Laura's skeleton?

 

Laura's fossil skeleton is over 90% complete, with a skull that is about 50% complete by bone mass.  Her skeleton is missing a number of vertebrae, ribs, toe and finger bones, and portions of the skull including the braincase.  Laura will be 11' long and 5' high at the hips when mounted.  She was about 4 years old, and weighed about 750 lbs when she died.  An adult of her species would have been 23’ long and weighed 3-4 tons, with a lifespan of about 15 years.

 

What's so special about Laura's species?

 

Laura is a juvenile Hypacrosaurus stebingeri, a crested duck-billed dinosaur.  The duckbills were a diverse group of plant-eating dinosaurs that lived during the Late Cretaceous Period (85 - 65 million years ago).  The duckbills had a large "tooth battery" in each jaw composed of hundreds of teeth in compacted rows.  New teeth grew into the tooth battery deep in each jaw as others were worn down during chewing.  Laura would have had only a hint of the plate-shaped head crest of an adult HypacrosaurusHypacrosaurus stebingeri is special in that it is only one of a handful of dinosaur species that are known from eggs, nests, embryos, hatchlings, and all stages of development to adulthood.

 

What's in a name?

 

"Laura" is the name of "Fossil Guy" Don Johnson's daughter.  She's still not sure how she feels about having a dinosaur named after her!  We're not sure if Laura the dinosaur was a boy or a girl, but we refer to Laura as a "her" because of her name.  Hypacrosaurus means "near-topmost lizard" — when Barnum Brown named the genus in 1913 he noted that this dinosaur was nearly as large as the “tyrant king” Tyrannosaurus.  The species name stebingeri is in honor of Eugene Stebinger who first described the Two Medicine Formation where Laura's bones were found.  The species Hypacrosaurus stebingeri was first described by Dr. Jack Horner and Dr. Phil Currie in 1994.

 

What was Laura's world like?

 

Laura comes from the Upper Two Medicine Formation, and her fossil bones date to about 75 million years ago.  She lived in what is now northwestern Montana in the upper coastal region of the vast inland sea that covered much of the Midwest at that time including what is now Iowa.  The environment was subtropical at that time, and it supported a wide variety of plants and animals.  Other dinosaurs that lived with Hypacrosaurus include the horned-faced dinosaur Einiosaurus, the tyrannosaur Daspletosaurus, the raptor dinosaur Bambiraptor, the armored dinosaur Euoplocephalus, and the non-crested duckbill Prosaurolophus.  Many other smaller dinosaurs from hypsilophodonts to ornithomimids and pachycephalosaurs lived alongside Laura at this time.  Fossils of fish, amphibians, turtles, lizards, crocodilians, Champsosaurus, pterosaurs, and even small mammals have also been found in this formation.  Leaf impressions and fossilized wood hint at the types of subtropical plants that Laura might have fed upon.

 

How can I learn more?

 

Dr. Jack Horner's book, "Dinosaurs under the Big Sky" (Mountain Press Pub. Co., 2001) is an excellent resource to learn more about Hypacrosaurus and the world of the Late Cretaceous Period in Montana.  This book is a thorough introduction to the science of paleontology for general readers.  To see mounted Hypacrosaurus specimens and other dinosaurs, visit the world-famous Children's Museum in Indianapolis or click here to visit their web site.

A portion of the fossil skeleton of “Laura” is laid out for public display at the UI Museum of Natural History in October 2005.

 

Don Johnson’s daughter Laura with a portion of the skeleton of “Laura the Kid Dinosaur” in December 2005.

The complete fossil skeleton of “Laura the Kid Dinosaur” is laid out at the special “Laura” showing for the EIPP sponsors  at the UI Museum of Natural History in October 2005.

 

The late Dave Brissey (former EIPP Sponsor) uses a dental tool to clean a fossil femur of  “Laura the Kid Dinosaur.”

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Click on pictures & graphics to see larger versions!

Young EIPP Sponsor meets Dr. Phil Currie (co-discoverer of Hypacro- saurus stebingeri) during Paleofest ‘05 at the Burpee Museum of Natural History in Rockford, IL.

EIPP Sponsors meet Dr. Jack Horner (co-discoverer of Hypacro-saurus stebingeri) during Paleofest ‘06 at the Burpee Museum of Natural History in Rockford, IL.

“Dawn at the Rookery” (1990) by paleoartist Mark Hallett shows a mother tending to her nestlings at a Hypacrosaurus stebingeri nesting ground.  To learn more about Mark Hallett’s artwork, visit his web site

at www.hallettpaleoart.com.  Copy-righted image used with permission.

Click here to learn more about Roby Braun’s 1:4 scale life restoration of “Laura the Kid Dinosaur”!