My Science School

The Cambrian period extended from 541 to 485.4 million years ago. It was a time when the Earth was still cold but gradually getting warmer. All pre-Cambrian life was aquatic and soft-bodied. But because Cambrian creatures had hard body parts, many of the earliest known fossils are from this period.

The Cambrian Period marks an important point in the history of life on Earth; it is the time when many kinds of invertebrates and the first vertebrates—fishes—appeared in the fossil record. The Burgess Shale contains the best record of Cambrian animal fossils including soft-bodied forms. This locality reveals the presence of creatures originating from the “Cambrian explosion”—an evolutionary burst of animal origins dating from 545 to 525 million years ago. The “explosion” describes the very rapid proliferation of a truly amazing diversity of living things on Earth. Most of these creatures are now extinct and are known only from their fossils.

During Cambrian time, life was only common in the water. The land was barren and subject to erosion; these geologic conditions led to mudslides, where sediment periodically rolled into the seas and buried marine organisms. At the Burgess Shale locality in the Canadian Rocky Mountains, sediment was deposited in a deep-water basin adjacent to an enormous algal reef with a vertical escarpment several hundred feet high.

Credit: National Park Service

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When a plant or animal is buried quickly, it gets enclosed in sediment before it decomposes. As pressure transforms this sediment into rock, a hollow mould of the organism is formed. Gradually minerals seep into this hollow and harden over time to form a detailed, three-dimensional cast. Soft tissue organisms are preserved as impressions between layers of sediment. Perfectly preserved fossils of insects and other small forms of life have also been found trapped inside hardened tree sap.

The most common way an animal such as a dinosaur fossilises is called petrification. These are the key steps:

1. The animal dies.

2. Soft parts of the animal's body, including skin and muscles, start to rot away. Scavengers may come and eat some of the remains.

3. Before the body disappears completely, it is buried by sediment - usually mud, sand or silt. Often at this point only the bones and teeth remain.

4. Many more layers of sediment build up on top. This puts a lot of weight and pressure onto the layers below, squashing them. Eventually, they turn into sedimentary rock.

5. While this is happening, water seeps into the bones and teeth, turning them to stone as it leave behind minerals.

This process can take thousands or even millions of years.

Credit: Natural History Museum

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Fossils, both plant and animal, are a valuable source of information on how life has evolved on Earth - they are a window into the past. They also provide insight on ecological, climatic and environmental changes that have taken place over the ages.

1. Beginnings of life. Apart from the sheer wonder they see the morphology of giant creatures millions of years ago from studying their fossil remains, fossils teach us about the beginnings and transformations of life itself.

2. Ecosystems. Fossils help us understand the environment where extinct life forms once existed.

3. Human origin. Paleo-anthropologists study the beginnings of human life, from the tools our ancestors used, the food they ate, their physical adjustments, to their social behaviour and migration.

4. Age of the country. All living organisms inhabited the Earth only at certain intervals and are reflected in the fossil record in sequence by each layer of rocky sediment.

5. Our past and future. The study of fossils also leads to discoveries and understandings of processes on Earth that may be of benefit to mankind.

It is wonderful for everyone to find stones that sometimes have figures of animals inside and out. People learn from fossils – Whether fossils are from humans or dinosaurs, they may not learn much about the species and cultures that existed in the past. Fossils give us educated guesses about the evolution of different species and what the climate looked like in the past.

Credit: Teach with Europeana

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The word archipelago refers to an island chain. An archipelago is a type of landform that consists of a group of islands, often including similar formations like atolls or islets. The islands that make up an archipelago are clustered or form a chain within a body of water, such as an ocean, gulf, sea, or lake.

The Hawaiian Islands, the Aleutian Islands, the Florida Keys, Bermuda, The Bahamas, the Philippines, the Canary Islands, Indonesia, and islands in the Aegean Sea are all examples of archipelagos.

Archipelagos have been formed by seafloor volcanism, sea level rise or fall, coral reefs, and occasionally by the actions of people.

• Most archipelagos include a combination of inhabited and uninhabited islands, including ones that can only be accessed by sea.
• They can be made up of volcanic islands or continental fragments, or be formed via processes like erosion, sedimentary deposits or rising sea levels.
• Some are large, spreading out over thousands of miles, while others extend over much smaller areas of less than 100 miles

.Credit: yourdictionary.com

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Praia do Cassino (Portuguese for Casino Beach) is the longest sea beach in the world and is located in the southernmost of the Brazilian coast, on the South Atlantic Ocean, in the state of Rio Grande do Sul. It is the longest uninterrupted sandy seashore in the world, with various sources measuring it from 212 kilometres (132 mi) to 254 kilometres (158 mi), stretching from the Molhes (breakwaters) at the entrance of the Rio Grande seaport in the north to the mouth of the Chuí Stream, on the border with Uruguay, in the south. Praia do Cassino in Brazil stretches for 241.40 km.

Cassino Beach is known as the oldest spa in Brazil, dating back to 1890. The beach was developed by the Suburban Mangueira Company as a tourist destination. The director of the company, Antonio Condido Sequeira, and the investors of the company acquired the land in the beach area with the help of the state government and built a tourist complex on January 26, 1890. Later this tourist center became very popular and big companies started investing here. At the time, Brazilians of German, English, Portuguese, and Italian descent often came to the beach to enjoy the sea in expensive hotels. The persecution of Italians and Germans during World War II and the ban on roulette in 1948 had a devastating effect on the region’s economy.

The Praia do Casino was recognized as the longest beach in the world by Guinness World Records in 1994.

Around 150,000 tourists visits Praia do Cassino every year. During the summer season, especially from December to January, the number of tourists visiting this place increases. Tourists can be seen participating in various activities including swimming and surfing. This beach is home to the largest number of seals in the world. Many tourists visit these seals by boat.

Credit: Wikipedia

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