How to look at dinosaur tracksApril 30, 2007
A new study appearing in the May issue of The Journal of Geology provides fascinating insight into the factors geologists must account for when examining dinosaur tracks. The authors studied a range of larger tracks from the family of dinosaurs that includes the T. Rex and the tridactyl, and provide a guide for interpreting the effects of many different types of erosion on these invaluable impressions.
"Well-preserved vertebrate tracks in the rock record can be an invaluable source of information about foot morphology, soft tissue distribution, and skin texture," write Jesper Milàn (Geological Institute, University of Copenhagen) and David B. Loope (Department of Geosciences, University of Nebraska, Lincoln). "However, in most instances, the tracks are less than perfectly preserved, and sometimes they can be barely recognizable as tracks at all."
With this in mind, Milàn and Loope sought to describe and categorize different levels of preservation. For example, dinosaur tracks may still exist as true tracks, that is, the original prints left in the ground by the dinosaur. True tracks preserve many of the anatomical details of the foot, such as number of digits and impressions of claws.
However, the true tracks may be filled with sediment or the original tracked surface may have eroded away. In the latter case, erosion may expose prominent layers of concentric circles extending from the former location of the true track. These "undertracks" reveal the squishing and displacement of sand when the heavy dinosaur took a step.
"The tracks and undertracks of large theropods found in the [Middle Jurassic] Entrada Sandstone at the studied locality come in a wide range of morphologies, mainly as a result of present-day erosion that has exposed the track-bearing surfaces at different depths," the researchers explain. "[They] demonstrate that great care should be taken when describing fossil footprints that have been exposed to subaerial erosion, because the shape, dimensions, and general appearance of the footprint become seriously altered by erosion."
Geologists also must account for whether the step was taken on a sloped surface or on a horizontal surface, and whether it was taken during dry season or wet season.
For example, estimating foot length from tracks can be inaccurate without these considerations - the more erosion that has occurred, the larger the apparent dimensions of the track. Applications of this apparently larger foot size derived from an undertrack may lead to calculations of higher estimated hip length, and, as the authors point out, may also lead to slower speed estimates.
Jesper Milàn and David B. Loope, "Preservation and Erosion of Theropod Tracks in Eolian Deposits: Examples from the Middle Jurassic Entrada Sandstone, Utah, U.S.A." The Journal of Geology: 115, p. 375-386.
University of Chicago Press Journals
Related Dinosaur Articles:
The complete skeleton of an eight-meter-long dinosaur has been unearthed from marine deposits dating back 72 million years at Japan's northern island of Hokkaido, making it the largest dinosaur skeleton ever found in Japan, according to researchers.
First baby of a gigantic Oviraptor-like dinosaur belongs to a new species.
One of the last dinosaurs living in Africa before their extinction 66 million years ago has been discovered in a phosphate mine in northern Morocco.
Researchers at the University of Alberta have matched the headless skeleton to a Corythosaurus skull from the university's Paleontology Museum that had been collected in 1920 by George Sternberg to the headless dinosaur.
Researchers recently confirmed it is possible to extract proteins from 80-million-year-old dinosaur bones.
Utilizing the most rigorous testing methods to date, researchers from North Carolina State University have isolated additional collagen peptides from an 80-million-year-old Brachylophosaurus.
Our ancestors evolved three times faster in the 10 million years after the extinction of the dinosaurs than in the previous 80 million years, according to UCL researchers.
A chance fossil discovery in Montana a decade ago has led to the identification of an audacious new species of horned dinosaur, Spiclypeus shipporum, according to a study published May 18, 2016, in the open-access journal PLOS ONE by Jordan Mallon, from the Canadian Museum of Nature, Canada, and colleagues.
EARTH Magazine travels through time to meet the major players of the Triassic, Jurassic and Cretaceous -- from sauropods and theropods to protomammals -- that created the rich tapestry of life in this region millions of years ago.
A 'dinosaur' fossil originally discovered on Prince Edward Island has been shown to have steak knife-like teeth, and researchers from U of T Mississauga, Carleton University and the Royal Ontario Museum have changed its name to Dimetrodon borealis -- marking the first occurrence of a Dimetrodon fossil in Canada.
Related Dinosaur Reading:
How Do Dinosaurs Say Happy Birthday?
by Jane Yolen (Author), Mark Teague (Illustrator)
Surprise! Our bestselling little dinosaurs are back for a BIG birthday celebration!
Everyone has a birthday, and from riotous birthday parties to the excitement of being one year older, having a birthday is the highlight of a young child's year.
All little dinosaurs love to get presents, and this new board book will be an immediate favorite. From birthday hats to Ceratosaurus-sized cakes, America's young readers will laugh out loud as the celebration moves from "bad" birthday behavior to just the right amount of silliness and sharing. Bestselling duo Jane Yolen and Mark Teague have... View Details
Discovery Kids Dinosaurs Rumble Sound Book (Discovery 10 Button)
by Parragon Books (Author)
With 10 cool sound buttons, fun facts, full-color pictures and much more, this Discovery Kids sound-and-reference book is a unique way for kids to learn about life on the farm! Kids ages 2 and up will love matching the sounds to the animals in this vibrant and interactive book.
Other great titles in this series include:
* Oink on the Farm! 9781472361073
* Growl with the Animals 9781472361080 View Details
Oh Say Can You Say Di-no-saur?: All About Dinosaurs (Cat in the Hat's Learning Library)
by Bonnie Worth (Author)
The Cat in the Hat makes another surprise appearance at Dick and Sally's house--only this time he makes his entrance riding atop a brachiosaurus! Soon, he's off, along with Dick and Sally, millions of years back in time to see how fossils were created. Then it's on to a tour through the Cat's own Super Dino Museum--a fabulous place where the correct pronunciation of a dinosaur's name wins you a peek at the real living thing! Beginning readers will love exploring the prehistoric world of dinosaurs with the Cat in the Hat as their guide! View Details
Encyclopedia Prehistorica Dinosaurs : The Definitive Pop-Up
by Robert Sabuda (Author), Matthew Reinhart (Author), Robert Sabuda (Illustrator), Matthew Reinhart (Illustrator)
From renowned pop-up masters Robert Sabuda and Matthew Reinhart comes an awe-inspiring tribute to the world's most beloved extinct animals and their 180-million-year reign on our planet.
Open this book and a massive T. REX springs out, flashing a startling jawful of jagged teeth. Turn the next spread and a ravishing raptor unfurls and appears to fly off the edge of the page. Inside the amazing ENCYCLOPEDIA PREHISTORICA: DINOSAURS are "shield bearers" in full-body armor, creatures with frilly headgear, and weighty, long-necked giants. There are even amusing tidbits on the history... View Details
The Berenstain Bears' Dinosaur Dig
by Jan Berenstain (Author), Mike Berenstain (Author), Jan Berenstain (Illustrator), Mike Berenstain (Illustrator)
When Brother and Sister visit the Bearsonian Museum, they luck out. A real dinosaur dig is taking place! What sort of fossils will they find? A Stegosaurus? A Spinosaurus? The mighty Tyrannosaurus rex? Dig in with the Berenstain Bears and find out! View Details
National Geographic Little Kids First Big Book of Dinosaurs (National Geographic Little Kids First Big Books)
by Catherine D. Hughes (Author), Franco Tempesta (Illustrator)
The third title in National Geographic Little Kids First Big Book series, this book is for kids 4- to 8-years-old who LOVE dinos! The prehistoric world comes alive with dinosaurs small, big, giant, and gigantic, with stunning illustrations by Franco Tempesta—who illustrated National Geographic Kids The Ultimate Dinopedia. Bursting with fun facts and age appropriate information, each spread features a different dinosaur, along with simple text in big type that is perfect for little kids. Young dino fans will love the interactivity included in every chapter, and parents will... View Details
Dinosaur A-Z: For kids who really love dinosaurs!
by Roger Priddy (Author)
-Ideal for children aged 3 years and up.
-Features 26 one-of-a-find dinosaur models from Allosaurus to Zephyrosaurus specially commissioned from experts in the field.View Details
The Rise and Fall of the Dinosaurs: A New History of a Lost World
by Steve Brusatte (Author)
"THE ULTIMATE DINOSAUR BIOGRAPHY," hails Scientific American: A sweeping and revelatory new history of the age of dinosaurs, from one of our finest young scientists.
"This is scientific storytelling at its most visceral, striding with the beasts through their Triassic dawn, Jurassic dominance, and abrupt demise in the Cretaceous." — Nature
The dinosaurs. Sixty-six million years ago, the Earth’s most fearsome creatures vanished. Today they remain one of our planet’s great mysteries. Now The Rise and Fall of the... View Details
The Dinosaur That Pooped a Planet!
by Tom Fletcher (Author), Dougie Poynter (Author), Garry Parsons (Illustrator)
From Tom Fletcher and Dougie Poynter of McFly comes a supersonic space adventure filled with planets, poop, and pandemonium!
One boy, one space rocket, one very hungry dinosaur: the ingredients for an explosive space adventure of epic poop-portions! But when Danny realizes he’s forgotten Dino’s lunch box, the very hungry dinosaur eats everything in sight, including their only way home: the rocket! How will Dino get them back home?
Meet Danny and his pet Dinosaur, Dino. No matter what this ravenous reptile ingests, he never keeps it down for long. View Details
by Kathleen Weidner Zoehfeld (Author)
There's nothing more fascinating than dinosaurs. In this Level 1 reader, youngsters learn all about the terrifying giants that once roamed the Earth—maybe even as close as their own backyard! They'll be wowed by new information and eye-popping illustrations from National Geographic, a trusted source of children's nonfiction content. National Geographic supports K-12 educators with ELA Common Core Resources.
Visit www.natgeoed.org/commoncore for more information. View Details