Agriculture
Keeping Bugs Away from Food
Making the most of a meal
Where Have All the Bees Gone?
Amphibians
Toads
Poison Dart Frogs
Tree Frogs
Animals
Odor-Chasing Penguins
Polly Shouldn't Get a Cracker
Mating Slows Down Prairie Dogs
Behavior
Wake Up, Sleepy Gene
World’s largest lizard is venomous too
Girls are cool for school
Birds
Chicken
Parrots
Eagles
Chemistry and Materials
Butterfly Wings and Waterproof Coats
The newest superheavy in town
Silk’s superpowers
Computers
Look into My Eyes
The science of disappearing
The solar system's biggest junkyard
Dinosaurs and Fossils
Three strikes wiped out woolly mammoths
Message in a dinosaur's teeth
A Big, Weird Dino
E Learning Jamaica
Results of GSAT are in schools this week
2014 GSAT Results for Jamaican Kids
E Learning in Jamaica WIN PRIZES and try our Fun Animated Games
Earth
Riding to Earth's Core
On the Trail of America's Next Top Scientists
Less Mixing Can Affect Lake's Ecosystem
Environment
City Trees Beat Country Trees
Forests as a Tsunami Shield
The Birds are Falling
Finding the Past
Unearthing Ancient Astronomy
Ancient Art on the Rocks
A Human Migration Fueled by Dung?
Fish
Basking Sharks
Tiger Sharks
Pygmy Sharks
Food and Nutrition
Symbols from the Stone Age
In Search of the Perfect French Fry
Sponges' secret weapon
GSAT English Rules
Pronouns
Whoever vs. Whomever
Order of Adjectives
GSAT Exam Preparation Jamaica
Scotiabank Jamaica Foundation Grade Six Achievement Test (GSAT) Scholarships
Results of GSAT are in schools this week
GSAT stars reap scholarship glory
GSAT Exams Jamaica Scholarships
GSAT Practice Papers | GSAT Mathematics | Maths
2014 GSAT Results for Jamaican Kids
GSAT Scholarship
GSAT Mathematics
Detecting True Art
Deep-space dancers
Math and our number sense: PassGSAT.com
Human Body
Heavy Sleep
Smiles Turn Away Colds
Workouts: Does Stretching Help?
Invertebrates
Octopuses
Giant Clam
Daddy Long Legs
Mammals
Cocker Spaniels
Sea Lions
Black Bear
Parents
Expert report highlights the importance to parents of reading to children!
Choosing a Preschool: What to Consider
The Surprising Meaning and Benefits of Nursery Rhymes
Physics
Dreams of Floating in Space
Gaining a Swift Lift
The Mirror Universe of Antimatter
Plants
Fast-flying fungal spores
Plants Travel Wind Highways
Sweet, Sticky Science
Reptiles
Snapping Turtles
Reptiles
Chameleons
Space and Astronomy
A Star's Belt of Dust and Rocks
A Dead Star's Dusty Ring
Sounds of Titan
Technology and Engineering
Are Propellers Fin-ished?
A Light Delay
Dancing with Robots
The Parts of Speech
Adjectives and Adverbs
Pronouns
What is a Noun
Transportation
Seen on the Science Fair Scene
Where rivers run uphill
Robots on the Road, Again
Weather
A Change in Climate
The Best Defense Is a Good Snow Fence
Watering the Air
Add your Article

Have shell, will travel

Many modern animals, like crabs, live in shells and carry their homes around with them. Picture one of these animals in your mind, and you may have some idea of what the first land-dwelling animals looked like. After studying strange marks that accompany some sets of ancient fossil footprints, scientists recently suggested that the oldest creatures to crawl out of the ocean probably wore shells. Scientists have long known that life on Earth began in the sea. The first vertebrates — animals with backbones — came crawling out of the water between 385 million and 376 million years ago. But those animals weren’t the first creatures to come ashore, says paleontologist James W. Hagadorn of Amherst College in Massachussetts. Hagadorn and Yale University paleontologist Adolf Seilacher say that a different group of animals, called arthropods, probably beat the first land vertebrates by more than 100 million years. Arthropods are animals that lack a backbone and have a hard exoskeleton. Examples include modern-day scorpions and insects. These ancient arthropods may have dragged themselves out of the ocean 500 million years ago. These ancient arthropods had the right kind of bodies to survive out of the water, says Hagadorn. Their hard exoskeletons would have kept them from drying out too quickly. And though these creatures breathed through gills, which require water, a shell would have trapped humid air. This handy gear would allow the animals to keep their gills moist. The paleontologists found evidence for the shells by studying fossilized, or preserved, tracks discovered in central Wisconsin. The tracks were left by the ancient arthropods as they walked around on soft ground. Over time, this soft ground hardened, and the tracks remained as etchings in stone. When the scientists looked at the fossilized tracks, they found something strange. Some of the tracks included an extra mark alongside the footprints. Whenever the tracks turned, to the right or to the left, the extra mark swung out a little wider, always to the left. The scientists realized this mark could not have been made by a tail, because a tail would swing out wider on both sides. If the animal turned left, a tail would have swung right; if the animal turned right, a tail would have swung left. Because the mark swung out on one side only, the scientists believe it was made by a shell that dragged on the ground. Furthermore, they suspect the shell was coiled, probably in a right-hand spiral. “This is an exciting find,” says Sally E. Walker, a paleobiologist at the University of Georgia in Athens . Now, she says, scientists can approach these ancient arthropods from a different direction. They can study ancient shells to look for scratch marks on the outside that might have been made as the shells were dragged through the sand. Or, she says, researchers can look for scratch marks on the inside — which may suggest that another animal took over a shell, after the original animal that lived there died. Power words: (from the Yahoo! Online Kids dictionary) Paleontology: The study of the forms of life existing in prehistoric or geologic times, as represented by the fossils of plants, animals and other organisms. Fossil: A remnant or trace of an organism of a past geologic age, such as a skeleton or leaf imprint, embedded and preserved in the earth's crust. Arthropod: Any of numerous invertebrate animals of the phylum Arthropoda, including the insects, crustaceans, arachnids and myriapods, that are characterized by an exoskeleton made of a hard material called chitin and a segmented body to which jointed appendages are attached in pairs. Gills: The respiratory organ of most aquatic animals that breathe water to obtain oxygen.

Have shell, will travel
Have shell, will travel








Designed and Powered by HBJamaica.com™