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April 2, 2005
Science Activity 1 - Leapin' Lizards
Crocodiles are survivors from the dinosaur age. A crocodile then looked very much like it does now. Crocodiles belong to a reptile family that did not become extinct like most dinosaurs 65 million years ago.
The features of the crocodile today are very similar to what they were 15 million years ago. A crocodile's armor-plated skin is made up of tough scales called scutes. These are reinforced from bony plates just below the surface.
Prehistoric crocodiles were giants, some up to 40 feet (13 meters) long! They preyed on other reptiles, including small dinosaurs. Other prehistoric crocodiles were as small as lizards.
Crocodiles have been honored throughout history. Egyptians in the town of Crocodilopolis had a crocodile god. The ancient Egyptian god of water, Sobek, was in the shape of a crocodile. Alligators, from the same reptilian family as crocodiles, got their name from 'el lagarto,' the Spanish word for lizard!
The estuarine (saltwater) crocodile from Australia, Indonesia, and Southeast Asia is the biggest of all crocs! This massive croc is the only one to swim in the sea. They live in estuaries along the coast and can grow BIGGGGG! The largest saltwater crocodile on record was 27 feet (9 meters) in length and weighed two tons!
With the coming of the European colonists, crocodile habitats became crowded with humans. Both enjoyed the living conditions along the Australian coastal areas. Unfortunately, they couldn't cohabitate as both were creating a problem for the other! No only did crocodiles hunt their prey from the rivers as animals came to drink, they also have the ability to leap as much as 9 feet (3 meters) out of the water after a meal! Crocs began feeding on livestock and then humans nearly hunted the crocs out of existence.
In 1972, crocodile hunting was banned in Australia. It is believed that around 270,000 saltwater crocodile skins and between 200,000 and 300,000 freshwater crocodile skins were exported from Australia before the ban. To meet consumer needs for their meat and their skins, crocodile farms now raise crocs. Poaching of these reptiles has become less of a problem. The croc farms have also become a major tourist attraction, especially at feeding time!
Here's the first scientific challenge for the research assistants...
Use these links to help you research:
Crocodiles.com>
Aborginal Crocs
Marine Bio
Species List
Alligators & Crocs
Posted by april at April 2, 2005 4:51 PM
Comments
Crocodiles and alligators are different in many ways but I will only name a few. Alligators are only found in the USA and crocodiles are found in all parts of the world. Alligators have longer snouts than the crocodile’s short snout. Also the alligators have wide snouts and the crocodile has a skinny snout. Crocodiles have lower teeth that you can see unlike the alligators unseen lower teeth. Crocodiles are an olive brown color while the alligator is more blackish. Nesting is another difference. The alligators nest is a mound of vegetation and the crocodiles nest is mud or sand. Both reptiles have glands in there tongue. The crocodile still use this gland to excrete excess salt and alligators have seemed to have lost this ability. All in all crocodiles and alligators are very different reptiles.
Posted by: Lance, Nick H , Ashley, Robbie at May 11, 2005 9:09 PM
View are power point about crocks and alligators.
Posted by: Matt D Tiffant A Tony V adam H at April 28, 2005 9:31 PM
View are Download filepower point about crocks and alligators.
Posted by: Matt D Tiffant A Tony V adam H at April 28, 2005 9:30 PM
The differences between the alligator and the crocodile are:
• The Jaw- The alligator’s jaw is U shaped, with a rounded snout, while the croc’s are long and V shaped.
• Teeth- The 4th tooth on the bottom jaw of a crocodile sticks up over the top lip, so you can see it while its mouth is shut. The gator’s 4th tooth is covered.
• How they look- A croc when it is a fully grown adult, has a grayish green back, with lighter undersides. The young crocs have dark brown crosses on their small tails. Alligators have green and brown on their backs and have lightish yellow undersides. Both babies and adults have dark crosses on their backs and tails.
• Habitat- The crocodile has a special gland inside of their tongues that reduce the amount of salt inside their mouths when they dive. Alligators have this gland too, but it is not working well, so the crocodiles live in more saltwater areas, and alligators live in freshwater.
• Nests- Crocs build dirt nests that look like holes or mounds. Alligators make nests made of withered leaves and dry plants. Both of the reptiles lay eggs and they hatch in these nests.
• Diet- The reptiles eat birds, snakes, mammals, crabs, and sometimes, but very rarely, humans. Crocs and gators are great hunters with acute hearing. But it is illegal to capture, hurt, feed, harass or kill alligators or crocodiles.
Members of Project: Nick, Dustin, Conner, James, Nicole, Ranae, Bryanna
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Posted by: Nick M. at April 19, 2005 8:17 PM
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