The Amazing Ostrich Egg

August 27, 2009

KenByrneby: Ken Byrne

The ostrich is a member of the Ratite family, which also includes emu, rhea, cassowary, and kiwi. Ratites are distinguished as flightless and keel-less (having no breast bone) birds. Ostrich skeletons and fossils date back over 120 million years.

The ostrich, native to Africa, is the largest of living birds. Some males reach a height of 8 ft (244 cm) and weigh from 200 to 300 lb (90 – 135 kg), while females will range between 5.5 and 6.5 (170 cm – 200 cm) feet tall at maturity.

In the wild, a mature female will lay between 12 and 15 eggs after mating (at the rate of one every other day for several weeks). Ostrich farmers quickly remove the eggs from the nest to extend the laying season. In some cases, a domesticated hen can lay up to 80 eggs, although 40 to 50 is more typical. Ostrich eggs are the largest of all bird eggs and weigh about 2.75 pounds (1.2 kg). The contents of one ostrich egg can be equivalent to as much as two dozen chicken eggs. Both male and female ostriches share sitting responsibilities, usually the male at night and the female during the day. Fertile eggs begin to hatch on the 42nd day.

Ostrich eggs are as beautiful as they are fascinating, and they areost100 surprisingly durable. Artists paint them, cut them and even decorate them with intricate carving. The Bush Men of the Kalahari Desert use them as sturdy canteens that can hold about 1.25 liters of water.

Educational Innovations has ostrich eggs that have been emptied through a hole in one end and thoroughly cleaned. The somewhat mottled, glossy surface is natural.

Ostrich Egg Activities:

How big a breakfast?
Fill your ostrich egg with water and measure the contents. Now measure the fluid that comes from a regular chicken egg. Comparing the two, can your students determine how many omelets could be made from your ostrich egg? Can they estimate the mass of the egg before it was emptied?

Discussion Topics:
Is it accurate to say that an ostrich egg is the largest single cell in the world today?
Why is the shell of an ostrich egg so thick?
Eggs shells are made of calcium. Where do ostriches, and other birds, get the calcium to produce hard shells?

Super! Neat! Wow! Ostrich Facts!

• Ostriches cannot fly.
• Ostriches produce extremely strong leather.
• Ostriches are not an endangered species – there are at least 2 million worldwide.
• Ostriches are one of the fastest animals in the world. They can sustain a speed of 40 miles per hour (64 kph) for 30 minutes!
• Ostriches do not bury their head in the sand. They lie down and extend their neck along the ground when threatened.
• The ostrich egg is the largest bird egg in the world today, but not the largest ever. That distinction goes to the elephant bird. Its eggs were up to 90 cm in circumference, and could hold 9 liters! They’re extinct now but may have walked the earth as recently as the mid 17th century.


Real Amber

August 24, 2009

tamiby: Tami O’Connor

What is Amber?
Millions of years ago large forests in some parts of the world began to seep globs of sticky, aromatic resin down the sides of the trees. Unlike sap, resin is produced to protect the tree from disease and injury and is extruded through the barkamb100 of the tree during rapid periods of growth.

As it continued to ooze, this resin would trap such things as insects, seeds, leaves and other light debris. As geologic time progressed, these forests were buried under sediment and the resin hardened and formed the soft, warm golden gem we know today as amber. Most of the amber in the world ranges from 30 to 90 million years old and is found in sedimentary clay, shale and sandstones associated with layers of lignite.

Amber is found in the far-corners of the world and is mined from the ground. It can be found from the shores of the Baltic Sea (Poland, Russia, Germany, Denmark, Lithuania), to mountain ranges in the Dominican Republic and Columbia. There is also Romanian, Burmese and Canadian Amber. Amber can be found in the United States and is most abundant in Alaska and New Jersey. This amber dates back to the Cretaceous Period, the age of the Dinosaurs! The size of amber found varies tremendously. The biggest piece of Dominican amber ever found was 18 pounds!

Amber can be hand or machine polished. Professionals use machinery such as sanding wheels to polish amber. They first start with coarser grit levels of sandpaper and as material is removed and they get closer to the surface, they switch to less coarse grit levels to add final touches. Final polishing can be done with a cotton buffing wheel and dental polishing compound. For amber jewelry, holes are drilled with a very fine drill bit. Experts must be aware that amber is sensitive to extreme heat.

Amber actually has the ability to develop a static charge when rubbed with a cloth. In fact, the source of the word electricity is from the Greek name for amber elektron.

The Copal vs. Amber Debate
Copal is a younger form of amber. Much of it from Columbia is said to be up to 10 million years old. Over the past several years, it has become available in great supply. Dealers who sell other types of older and more rare amber, such as Baltic or Dominican, due to their commercial interest, have been trying to convince others to not classify copal as a type of amber. Many scientists disagree, stating that anything made from resin IS technically amber, despite its age.

amb200In the movie Jurassic Park, the storyline was that dinosaur DNA had been retrieved from insect remains found in amber, allowing them to regenerate dinosaur life for the park. Though there are actual insects found embedded inside some amber, this is just a story. Scientists have never been able, in real life, to do this.

Beware! There are actually counterfeit producers of amber who make fake amber using living insects and synthetic resins. Experts have tests to confirm what is real or fake. At Educational Innovations, our amber is real. We only purchase our amber from reputable miners who guarantee authenticity.

Educational Innovations has a terrific hands-on lesson to use with your students as a culminating activity for your geology unit or unit on dinosaurs. This class kit comes complete with everything your students will need to clean and polish actual pieces of amber. Your students will all leave your classroom with a small sample piece as each kit includes 8 one-inch pieces of amber for polishing and 17 smaller amber samples The kit also includes 25 plastic bags to secure samples, 8 polishing brushes, amber polish (aka: gel toothpaste), sandpaper and a complete teacher’s guide. This activity is perfect for the elementary and middle school classroom.

Kit Contents

• 8 large pieces of rough amber to use for class activity
• 17 small pieces of rough amber
• 25 plastic bags for students to secure their amber samples
• 8 polishing brushes
• Tube of amber polish
• 2 Sheets of sandpaper (9×11)


Sink Your Teeth Into Some Shark Facts

August 19, 2009

LaurieNby: Laurie Neilsen

In honor of The Discovery Channel’s Shark Week, here are some common questions asked about shark teeth, and some meaty facts to sink your teeth into.

Q. Why are some shark teeth black and others are tan?

A. The color of a fossil shark tooth is dependent upon the sediment in which it settled. As minerals slowly replace the calcium in the tooth, it changes to the color of the minerals. Color does not necessarily indicate age in a shark tooth fossil. It usually indicates the region from which the tooth was collected. Our rm-11fossilized shark teeth are collected from Morocco.

Q. Then how old are these fossil shark teeth?

A..It’s hard to say. A shark tooth takes approximately 10,000 years to become a true fossil. These teeth could be as much as a few million years old!

Q. Why are there only fossils of shark teeth and vertebrae, but not their other bones?

A. A shark’s skeleton is made of cartilage. This makes the shark flexible and fast, and provides buoyancy, precluding the need for a swim bladder like other fish have. Only the teeth and vertebrae of a shark are calcified enough to turn into fossils. Without calcium, the cartilage eventually disappears, and does not become a fossil.

Q. Do sharks have molars?

ps-300A. No, sharks do not have molars, incisors, or bicuspids like humans have. Shark’s teeth are all the same shape, but vary in size throughout the mouth. Each species of shark has a different tooth shape, making it easier to identify and sort the fossil shark teeth by species.

Q. Are sharks hunted for these teeth?

A. No, the shark teeth we sell were collected from beaches, not from live sharks. A shark will lose thousands of teeth throughout its lifetime. While the teeth are calcified for strength, they are not as firmly attached in the mouth as our teeth are. Sharks have rows of teeth to provide added grip when they bite their prey, and so they always have replacement teeth ready to take the place of the ones that fall out.

Most sharks live and hunt in coastal waters, though some have been tracked going far out to sea and traveling many miles throughout the course of a year. When the sharks lose teeth while hunting near the shore, these teeth settle in the sediment, fossilize, and sometimes eventually wash up on the beach. Many teeth are also collected by divers close to the shore.

Shark populations are declining because not only are they over hunted, but there have been many man-made changes in their environment. Many shark species are becoming endangered. Sharks are hunted out of fear and misunderstanding, but they are also hunted for trophies, and for their fins. The practice of shark finning – catching sharks just to collect their fins for shark fin soup, and throwing the injured sharks back into the water to drown – is one of the leading causes of the decline in population. For more information on sharks and shark week, visit the discovery channel website at: http://dsc.discovery.com/convergence/sharkweek/sharkweek.html.


Follow

Get every new post delivered to your Inbox.